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UNITED STATES DEPARTMENT OF T&E INTERIOR
MOLLUSCA FROM THE MIOCENE AND LOWER PLIOCENE OF VIRGINIA AND NORTH CAROLINA i PART 1. PELECYPODA
GEOLOGICAL SURVEY PROFESSIONAL PAPER 199-A
UNITED STATES DEPARTMENT OF THE INTERIOR Harold L. Ickes, Secretary GEOLOGICAL SURVEY W. C. Mendenhall, Director
Professional Paper 199-A
MOLLUSCA FROM THE MIOCENE AND LOWER PLIOCENE OF VIRGINIA AND NORTH CAROLINA
PART 1. PELECYPODA
BY JULIA GARDNER
WITH A SUMMARY OF THE STRATIGRAPHY By W. G. MANSFIELD
UNITED STATES GOVERNMENT PRINTING OFFICE WASHINGTON : 1943
For sale by the Superintendent of Documents, Washington, D. C. ------Price 55 cents
CONTENTS
Pag« Page. Abstract-.______-______i______---_-__-_-_-___ 1 Systematic descriptions, by Julia Gardner—Continued. Introduction ______1 Order Prionodesmacea—Continued. Stratigraphy of the Miocene of Virginia and the Miocene Superfamily Ostracea______-___-_-_-_-___ 41 and Pliocene of North Carolina, by W. C. Mansfield __ Family Ostreidae______41 Summary- ______Order Anomalodesmacea______-_-___-___ 41 Maryland______Superfamily Anatinacea____..______-____ 42 Miocene (Chesapeake group)______Family Periplomatidae______42 Pliocene ______Family Thraciidae______42 Virginia.______Family Pandoridae______44 Miocene (Chesapeake group)______Superfamily Poromyacea.______50 Pliocene-______Family Verticordiidae______50 North Carolina-______Order Teleodesmacea______51 Miocene ______Superfamily Astartacea______51 Pliocene._ __-___----_____-___-______-_ Family Astartidae_____-______-_---_____ 51 Other States of the Atlantic coast-______Family Crassatellitidae______61 Miocene strata of Virginia.______Superfamily Cyrenacea.^______64 Nomenclature. ______Family Cyrenidae--_-_-_------__--_-_-__ 64 Calvert- formation ______Superfamily Cyprinacea______65 Choptank formation ______Family Euloxidae______65 St. Marys formation.______Family Pleurophoridae.______66 Stratum A______Superfamily Isocardiacea______67 Zone 1, or Bulliopsis quadrata zone______Family Isocardiidae______67 Zone 2, or Crassatellites meridionalis zone_ _ Superfamily Carditacea______68 Stratigraphic sections.______Family Carditidae______68 Yorkto wn formation ______Family Condylocardiidae______73 Zone 1, or Pecten clintonius zone______Superfamily Lucinacea______74 Zone 2, or Turritella alticostata zone. ______Family Lucinidae_-_-______74 Bed at Biggs farm.______Family Diplodontidae______79 Sections in the Yorktown formation______Superfamily Leptonacea______81 Miocene strata of North Carolina...______Family Leptonidae_____-_-______81 Yorktown formation.______Family Sportellidae______83 Groups A and B______Family Montaoutidae______85 Group C______Superfamily Chamacea______-_---___-_-_-__ S§> Group D______Family Chamidae______._-__-_-______88 Group E______Superfamily Cardiacea______-______89 Group F, bed at Mount Gould Landing. _ _ Family Cardiidae______89 Duplin marL______Superfamily Tellinacea.______-----______-_ 94 Family Tellinidae______94 Pliocene strata of North Carolina.__-______---____ Family Semelidae______100 Geologic ranges of certain species ______Family Donacidae______105 Localities in Virginia and North Carolina..______Family Gariidae_-___-___-----__-_-_____ 107 Systematic descriptions, by Julia Gardner-____-_-____ Superfamily Solenacea______108 Order Prionodesmacea______Family Solenidae______108 Superfamily Nuculacea______Superfamily Mactracea______-______109 Family Nuculidae______Family Mactridae______109 Family Nuculanidae______Family Mesodesmatidae______115 Superfamily Veneracea______116 Superfamily Arcacea______Family Petricolidae.______116 Family Arcidae.______Family Cooperellidae______-_____ 119 Family Glycymeridae______Family Veneridae______120 Superfamily Mytilacea______Superfamily Myacea______138 Family Mytilidae______Family Myacidae______138 Superfamily Pectinacea______Family Corbulidae______139 Family Pectinidae______Superfamily Adesmacea______141 Family Spondylidae-_-___-______-- Family Pholadidae______-______141 Superfamily Anomiacea______Family Teredinidae______143 Family Anomiidae______Index. ______169 in IV CONTENTS ILLUSTRATIONS
Page PLATES 1-23. Miocene and Pliocene pelecypoda of Virginia and North Carolina._-____-______-______--_---_-__--_- 145 FIGURE 1. Columnar sections of Horsehead, Stratford, and Nomini Cliffs, Va______j______--__-__--__-.._ 5 2. Section on shore of the James River, east of old Kings Mill Wharf, Va___-.___-______-______-___-___-__ 9 3. Diagrammatic representation of the beds of zone 2 of the Yorktown formation within 2 miles southeast of York- town, Va____-______-____i_____---___-_-_--_---___--_-_-_-_------_ 10 4. Index map showing Miocene and lower Pliocene localities in Virginia and North Carolina...______18
TABLES
TABLE 1. Correlation of the Atlantic and Gulf Coastal Plain deposits ranging in age from the upper part of the middle Miocene to the Pleistocene______•______-______-_-_------3 2. Geologic range of species.______- t --____ 14 MOLLUSCA FROM THE MIOCENE AND LOWER PLIOCENE OF VIRGINIA AND NORTH CAROLINA PART 1. PELECYPODA
By JULIA GARDNER
ABSTRACT companying chapter on the stratigraphy, by Dr. A brief sketch of the stratigraphy of the Miocene of Virginia Mansfield, is based upon work done by him alone. and the Miocene and Pliocene of North Carolina was prepared I am greatly indebted both to Miss Frances Wieser, by Dr. W. C. Mansfield before his death in July 1939. His who has so skillfully retouched the photographs, and purpose was "to provide a background of formational nomen to Miss N. L. Bowen, who has sustained the drudgery of clature" for the taxonomic treatment of the molluscan faunas. The physical nature and distribution of the upper Tertiary reworking an old manuscript with a cheerful patience formations within those States are discussed, characteristic and an ever alert mind and eye. sections given, and diagnostic molluscan species listed. Part 1 of the systematic report covers the Pelecypoda. A STRATIGRAPHY OF THE MIOCENE OF VIR monographic treatment is not attempted, but 132 previously GINIA AND THE MIOCENE AND PLIOCENE known species are considered, and 62 new species and subspecies OF NORTH CAROLINA are described and figured. By W. C. MANSFIELD INTRODUCTION This summary of the stratigraphy of the Miocene of Some 20 years ago I studied collections made in the Virginia and the Miocene and Pliocene of North Caro course of investigations upon the later Tertiary forma lina is intended to provide a background of forma tions by the State Surveys of Virginia and North Caro tional nomenclature for Dr. Julia Gardner's systematic lina. The taxonomic work was completed, and illus descriptions of Miocene and Pliocene Mollusca from trations were made for all the new and most of the those States. Though the literature pertaining to the previously described species. This first report was not region is extensive, a bibliography has been omitted. published. However, this omission is not a serious lack, for a bib The present report covers the same general field. It liography of publications on the Miocene and Pliocene includes descriptions and illustrations of the new of Virginia to 1912 was compiled by Clark and Miller 2 species, of several previously described species that and a similar bibliography for North Carolina by were figured in publications not widely distributed or Miller and Stephenson.3 Most of the important later easily accessible, and of forms for which some biologic publications have been noted in several papers by me.4 or stratigraphic information has been added. The This chapter is based in part on information that has report makes no claim to consistency of treatment or been published from time to time during recent years to completeness. and on unpublished field and laboratory observations The greater number of the collections on which my made by the writer. early work was based were assembled before the de SUMMARY tails of the stratigraphy and the interrelationship to MARYLAND the faunas were understood. The late Dr. W. C. Mans Miocene (Chesapeake group).—TfreMiocene deposits field, who was responsible for practically all the refine of Maryland (the Chesapeake group) were admirably ments of the stratigraphic sections that have been made during recent years and for the careful correlation of 2 Clark, W. B., and Miller, B. L., Physiography and geology of the the faunas contained in these sections, was good enough Coastal Plain province of Virginia: Virginia Geol. Survey Bull. 4, pp. 19-45, 1912. to check the distribution of the species represented in 3 Clark, W. B., Miller, B. L., and Stephenson, L. W., The physiography my old collections and thus to give to them any strati- and geology of the Coastal Plain of North Carolina: North Carolina Geol. and Econ. Survey, vol. 3, pp. 44-73, 1912. graphic significance that they may possess.1 The ac- 4 Mansfield, W. C., New fossil mollusks from the Miocene of Virginia and North Carolina, with a brief outline of the divisions of the Chesa 1 The important "Stratigraphic study of the mollusks of the Calvert peake group: U. S. Nat. Mus. Proc., vol. 74, art. 14, pp. 1-11, 1929; and Choptank formations of southern Maryland," by Lois Schoonover, in The Chesapeake Miocene basin of sedimentation as expressed in the new Bull. Am. Paleontology, vol. 25, No. 94 B, pp. 1-135, 1941, unfortunately geologic map of Virginia: Washington Acad. Sci. Jour., vol. 19, p. 266, was received too late for Miss Schoonover's results to be given adequate fig. 2, 1929; Stratigraphic significance of Miocene, Pliocene, and Pleis consideration in this paper. Her zonal studies, particularly of the tocene Pectinidae in the southwestern United States: Jour. Paleontol Pectan and Astarte groups, are essential alike to the stratigrapher and ogy, vol. 10, No. 3 1936; Additional notes on the molluscan fauna of the paleontologist concerned with the molluscan faunas of the Middle the Pliocene Croatan sand of North Carolina: Idem, No. 7, pp. 665-668, Atlantic seaboard. 1936. 1 MOLLUSCA FROM MIOCENE AND LOWER PLIOCENE OF VIRGINIA AND NORTH CAROLINA
described in 1904 by Clark, Shattuck, and Ball,5 and The Calvert formation, 200 feet thick, consists of this brief characterization is based largely upon their dark-gray or olive sandy clay, usually diatomaceous. report. The Choptank formation, 50 feet or more thick, con The deposits of the Chesapeake group lie wholly sists of dark-brown, rather soft sand and greenish-gray within the tidewater region, on the Eastern Shore, clayey sand alternating with indurated sandstone between Chesapeake Bay and the Delaware River, in layers. It is not recognized widely. a broad belt between the Chester River on the north and The St. Marys formation } 180 feet thick, contains Fishing Bay on the south; on the Western Shore, a lower part, "stratum A," that consists of nearly un~ between Chesapeake Bay and the Potomac River, ex- fossiliferous dark sandy plastic clay; and an over ten'ding inland as far as the District of Columbia. lying fossiliferous part, of bluish clay and light-colored On both sides of Chesapeake Bay the strike of the sand, that is divided into two faunal zones. beds is northeast. The Yorktown formation, 145 feet thick, consists In Maryland the Chesapeake group has been sepa dominantly of gray to buff sands. It is divided into rated into three formations, all of middle Miocene age— two faunal zones, and the upper zone is subdivided into in ascending order, the Calvert formation, the Chop- three minor parts. tank formation, and the St. Marys formation. The The divisions of the Chesapeake group, as recognized Yorktown, the uppermost formation of the Chesa by me,8 are as follows: peake group in Virginia, has not been recognized in Maryland. Upper Miocene: Yorktown formation: The Calvert formation, 200 feet thick, is divided by Zone 2, or Turritella alticostata zone: Shattuck 5a into the Fairhaven diatomaceous • earth Upper part (beds at Suffolk). member, which is subdivided into three zones (zones Middle part (beds at Yorktown). 1-3); and the Plum Point marl member, which is sub Lower part (including C7i«ma-bearing bed). divided into twelve zones (zones 4-15). The Fair- Zone 1, or Pecten clintonious zone. Middle Miocene: haven member is especially characterized by diatomite. St. Marys formation: The Plum Point member consists of a series of sandy Zone 2, or Crassatellites meridionalis zone. clays and clayey sands ranging in color from bluish- Zone 1, or Bulliopsis quadrata zone. green to buff and containing a large assemblage of Stratum A (unfossiliferous dark clay). vertebrate and invertebrate remains. Choptank formation. The Choptank formation, 80 feet thick, consists1 of Calvert formation. reddish, yellowish, or greenish sand and sandy clay. Pliocene.—No certain Pliocene deposits have been Locally the materials are consolidated into hard rock. recognized in Virginia. The formation is divided by Shattuck 6 into five zones (zones 16-20). Zones 17 and 19 contain well-preserved NORTH CAROLINA fossils in great abundance. Miocene.—The lower formations of the Chesapeake The St. Marys formation, 74 feet thick, consists of group are not exposed in North Carolina. The upper clay, sand, and clayey sand. The clay is usually of a most part of the St. Marys formation may be present dark color. The formation is divided by Shattuck ' in the lowest part of some exposures, but the entire into four zones (zones 21-24). The basal zone (zone 21) Yorktown formation is represented, though not all ex consists mainly of drab clay and appears to be devoid posures may be accurately placed in the formation. of fossils. The three other zones are fossiliferous, some The Yorktown (late Miocene) in the northern part of parts being almost entirely composed of shells. North Carolina contains a fauna suggestive of deposi Pliocene.—No certain Pliocene deposits have been tion in colder water than that forming the environment recognized in Maryland. of the fauna of the Miocene beds in the southern part of the State.9 The deposits in the southern part of the VIRGINIA State, the Duplin marl, represent the uppermost Mio cene and are equivalent to the uppermost Yorktown, Miocene (Chesapeake group).—The Chesapeake though constituting a warm-water facies. At no place group of Virginia, 575 feet thick, is divided into four are the Miocene deposits, as now exposed, more than formations, in ascending order, the Calvert, Choptank, 50 feet thick. St. Marys, and Yorktown. Pliocene.—The Croatan sand, in the northeastern
5 Clark, W. B., Shattuck, G. B., and Ball, W. H., The Miocene deposits of Maryland: Maryland Geol. Survey, Miocene, pp. xxi-clv, pis. 1-9, 8 Mansfield, W. C., New fossil mollusks from the Miocene of Virginia 1904. and North Carolina, with a brief outline of the divisions of the Chesa 5a Shattuck, G. B., Maryland Geol. Survey, Miocene, pp. Ixxii-lxxvii, peake group : U. S. Nat. Mus. Proc., vol. 74, art. 14, pp. 1-2, 1929. 1904. 9 Mansfield, W. C., The Chesapeake Miocene basin of sedimentation as 6 Idem, pp. Ixxxi-lxxxii. expressed in the new geologic map of Virginia: Washington Acad. Sci. T Idem, p. Ixxxv. Jour., vol. 19, p. 266, fig. 2, 1929. PART 1. PELECYPODA part of the State,10 and the Waccamaw formation, in 1835. Conrad, T. A.: the southern part,11 represent the Pliocene epoch. Older Pliocene (in part). Both are thin superficial deposits. 1835. Conrad, T. A.: Medial Pliocene (in part). OTHER STATES ON THE ATLANTIC COAST 1835. Rogers, W. B.: Middle Tertiary=Miocene of Lyell. In listing the distribution of species in the system 1836. Rogers, W. B.: Miocene. atic part of this work, various other formations of 1836 or 1837. Conrad, T. A.: Tertiary and Quaternary age in States north of Mary Medial Tertiary or older Pliocene. land and in South Carolina, Georgia, and Florida are 1837. Rogers, W. B.: cited. Most of these formations are shown in table 1, Miocene. and also the commonly accepted correlations with 1838. Conrad, T. A.: Medial Tertiary or older Pliocene. European divisions of the later Tertiary. 1838. Rogers, W. B.: Miocene. MIOCENE STRATA OF VIRGINIA 1839. Rogers, H. D., and W. B.: Meiocene (Miocene). NOMENCLATURE 1840. Conrad, T. A.: Medial Tertiary. As indicated in the summary on page 2, all the 1840. Rogers, W. B.: formations of the Chesapeake group are present in Miocene—Horizontal beds (?). Virginia. The existence of these deposits was recog Yellow marl. nized in early geologic work in the region, and though Blue marl. for long only a very simple nomenclature was applied 1841. Rogers, W. B.: Meiocene (Miocene). to them, the terminology now in use eventually ap 1842. Conrad, T. A.: peared. As it may be of interest to record in compact Medial Tertiary or Miocene. form the usage of the various authors who have dealt 1842. Lyell, Charles: with the Miocene strata, the appended list is presented. Miocene [less] excluded infusorial beds. The list gives the name of the author, the year of 1843. Tuomey, Michael: his publication, and the name or names used by him for Miocene (includes infusorial beds). 1843. Conrad, T. A.: the Miocene deposits or a brief statement of his results. Miocene. The name cited may include more deposits than are 1843. Rogers, W. B.: now referred to the Miocene epoch. If the item cited Miocene (includes infusorial beds). refers to a State other than Virginia, this is indicated. 1844. Rogers, H. D.: Miocene (includes infusorial beds). 1809. Maclure, William: 1845. Conrad, T. A.: Alluvial (in part). Medial Tertiary or Miocene. 1820. Hayden, H. H.: 1845. Lonsdale, William: Alluvial (in part). Miocene. 1822. Cleveland, Parker: 1845. Lyell, C.: Alluvial (in part). Miocene=Crag of England and faluns of Loire. 1824. Finch, John: 1846. Lea, H. C.: Tertiary (in part). Miocene. 1825. Van Renssellaer, Jeremiah: 1850. Wyrnan, J.: Tertiary, Virginia (in part). Miocene (includes infusorial beds). Upper Marine and London clay (?), Maryland. 1853. Hitchcock, B.: 1828. Vanuxem, Lardner, and Morton, S. G.: Miocene (includes infusorial beds). Tertiary (in part). 1853. Marcou, Jules: 1829. Morton, S. G.: Miocene. Upper Marine in Maryland and probably southward. 1861. Conrad, T. A.: 1830. Conrad, T. A.: Medial Tertiary or Miocene. Upper Marine in Maryland. 1861. Rogers, W. B.: 1832. Conrad, T. A.: Meiocene (Miocene) (infusorial beds). Upper Marine or upper Tertiary. 1862. Conrad, T. A.: 1833. Lea, Isaac: Miocene or Upper Tertiary. Older Pliocene. 1863. Dana, J. D.: 1834. Conrad, T. A.: Yorktown or Miocene. Pliocene. 1864. Meek, F. B: Miocene. 10 Mansfield, W. C., Notes on Pleistocene faunas from Maryland and 1866,1868, 1869. Conrad, T. A.: Virginia and Pliocene and Pleistocene faunaus from North Carolina: Miocene. U. S. Geol. Survey Prof. Paper 150, pp. 129-133, 1928; Additional notes 1877. Stodder, C.: on the molluscan fauna of the Pliocene Croatan sand of North Carolina : Miocene (for Richmond, infusorial deposit). Jour. Paleontology, vol. 10, no. 7, pp. 665-668, 1936. 11 Miller, B. L., Tertiary formations : North Carolina Geol. and Econ. 1880. Dana, J. D.: Survey, vol. 3, pp. 256-258, 1912. Miocene, Yorktown period (in part). MOLLUSCA FROM MIOCENE AND LOWER PLIOCENE OF VIRGINIA AND NORTH CAROLINA
1882. Heilprin, A.: 1911. Berry, E. W.: Miocene: Richmond; fossil plants assigned to Calvert=middle Marylandian (uncertain for lower bed). Miocene. Virginian. 1912. Clark, W. B., and Miller, B. L.: 1884. Heilprin, A.: Chesapeake group: Miocene: Yorktown. Virginian. St. Marys. Oarolinian (not unlikely). Calvert. 1888. Heilprin, A.: 1913. Sanford, S.: Metagene (used instead of Miocene). Chesapeake group: 1891. Barton, N. H.: Yorktown. Miocene, Chesapeake group. (Separates it into three St. Marys. beds.) Choptank (?) 1892. Ball, W. H., and Harris, G. D.: Calvert. Miocene, Chesapeake group. 1914. Olsson, A.: 1893. Harris, G. D.: Suggests placing Petersburg fauna with St. Marys or In Maryland: younger. St. Marys fauna. 1916. Watson T. L.: Jones Wharf fauna. Yorktown. Plum Point fauna. St. Marys. 1893. Dall, W. H., and Harris, G. D.: Calvert. In Maryland: St. Marys, Jones Wharf, and Plum Point. 1916. Berry, E. W.: Virginia: Yorktown considered younger. Places Calvert in middle Miocene or equivalent to 1895. Dana, J. D.: Tortonian. Miocene period (Yorktown epoch). 1917. Olsson, Axel: L896. Darton, N. H.: Miocene: Miocene, Chesapeake group. Upper: 1898. Dall, W. H.: Yorktown stage. Miocene, Chesapeake group=Helvetian of Europe. Murfreesboro stage. 1902. Shattuck, G. B.: Middle: For Maryland: St. Marys stage. St. Marys formation. Lower: Choptank formation. Choptank stage. Calvert formation. Calvert stage. 1904. Clark, W. B., and others: 1921. Cooke, C. Wythe: Duplin and Yorktown (North Carolina, Virginia) = For Maryland: Chesapeake group: upper Miocene. Calvert, Choptank, and St. Marys=middle Miocene. St. Marys, 4 zones. Choptank, 5 zones. 1922. Olsson, Axel: Calvert, 15 zones. Miocene: 1904. Dall, W. H.: Upper: For Atlantic and Gulf: Yorktown stage. Duplin (North Carolina). Murfreesboro stage. Suffolk (Virginia). Middle: Yorktown (Virginia). St. Marys stage. Alum Bluff (Florida). Choptank stage. St. Marys (Maryland). Calvert stage. Choptank (Maryland). 1929, 1936. Mansfield, W. C.: James River (Virginia). Miocene: Calvert (Maryland). Upper: Petersburg (Virginia). Yorktown formation: 1909. Berry, E. W.: zone 2 (Turritella alticostata). Places Richmond diatomaceous deposits in Calvert zone 1 (Pecten clintonius). formation. Middle: 1910 (read in 1908). Miller, B. L.: St. Marys formation: Yorktown. zone 2 (Crassatellites meridionalis) . St. Marys. zone 1 (Bulliopsis quadrata). Calvert. stratum A. 1910 (Read in 1908). Miller, B. L.: Choptank formation. Yorktown. Calvert formation. St. Marys. CALVERT FORMATION Choptank. Calvert. Lithologic character and thickness.—The material 1911. Watson, T. L.: composing the Calvert formation consists largely of Yorktown. St. Marys. dark-gray or olive sandy, usually diatomaceous clay, Calvert. which changes to a lighter color when weathered. It is TABLE 1.—Correlation of the Atlantic and Gulf Coastal Plain deposits ranging in age from the upper part of the middle Miocene to the Pleistocene
European equivalent New Jersey Maryland Virginia North Carolina South Carolina Oeorgia Florida
.S3i QJa Deposits at Wailes Deposits on Yonges Is Marl on North Creek.1 ^3-Sg Bluff.1 land.1
Upper. Sicilian (Arnian). (?) (?) Deposits on Myakka River.2 Pliocene. Middle. Astian. (?) (?) (?) Waccamaw forma Limestones of Tamiami Trail.4 Lower. Plaisancian. Croatan sand to north. tion to south. Waccamaw formation.3 Caloosahatchee marl. Beds at Suffolk, with bed at Uppermost Yorktown, Duplin marl at )rktownformation. with bed at Mt. Gould Duplin marl. Duplin marl. Porters Land Cancellaria zone (upper part) . Biggs Farm at at top. ing. ** top. Sahelian. Pontian. 0>a Choctawhatcheeformation. Upper. ® Beds at Yorktown. Equivalent to the beds at Yorktown, Va. Cancellaria zone (lower part).
Miocene. C/iama-bearing C/zawa-bearing bed. "Aluminous clay." bed. Sarmatian. x z PART 1. PELECYPODA believed to attain a maximum thickness of 200 feet. lected by me: Area staminea Say, Pecten marylandicus The formation is exposed in the Horsehead, Stratford, Wagner, Astarte obruta Conrad. It is believed that and Nomini Cliffs (see p. 5) and forms the lower Shattuck's zones 16 to 20 of the Maryland sequence 13 40 feet of the section at Carter Wharf, on the Rappa- may be recognized in Virginia. hannock River. Diatomaceous deposits at Richmond The Horsehead, Stratford, and Nomini Cliffs 14 form and Petersburg have usually been referred to the a series of northward-facing bluffs about 6 miles long, Calvert. extending from a point a mile east of the mouth of Stratigraphic relations.—The Calvert formation Popes Creek eastward nearly to Currioman Bay. These rests unconformably upon either the Eocene or older cliffs afford exposures of the upper part of the Calvert deposits and is overlain, apparently unconformably, formation, all of the Choptank formation, and the either by the Choptank formation or by a later deposit. lower part of the St. Marys formation. In general the Paleontologic character.—The molluscan fauna is formations are less fossiliferous here than in the Calvert sparse and poorly preserved. The following species Cliffs, on Chesapeake Bay in Calvert County, Md., were collected by me and appear to be the more though at one place in the lower part of the Nomini abundant forms: Ecphora tricostata Martin, PedaHton Cliffs fossils are abundant in the Choptank formation. maxillatum (Deshayes), and Pecten madisonius Say. The stratigraphic and structural relationships of the Certain deposits have yielded vertebrate remains and formations exposed in the cliffs are shown in figure 1. fossil plants. A separation of the deposits into faunal The Calvert formation in these sections consists Nomini Cliffs, Late Miocene or St Marys formation Choptank formation Cafvert formation Pliocene andEm Pleistocene Undifferentiated Zone 2 I Zone 2O Zone 19 Probably zonesI6to16 FIGURE 1.—Columnar sections of Horsehead, Stratford, and Nomini Cliffs, Va. zones corresponding to those recognized by Shattuck 12 mainly of a rather compact greenish-gray diatoma- in the Calvert of Maryland is impracticable because of ceous sandy clay and contains a few poorly preserved the lack of faunal data. invertebrate fossils. The upper limit of the formation has been drawn at^a plane about 5 feet above a thin CHOPTANK FORMATION bed containing many Isocardia, which may represent Lithologio character and thickness.—The material the Isocardia bed referred to zone 14 of Shattuck in composing the Choptank formation consists of dark- the Calvert formation of Maryland. brown, rather soft fossiliferous sand alteranting with The lowest bed of the Choptank formation, believed indurated sandstone layers. Its thickness is not defi to represent Shattuck's zones 16 to 18, consists of nitely determined in Virginia but may exceed 50 feet. greenish-gray clayey sand and at a locality 1% miles Distribution.—The areal distribution of the Chop- west of the east end of the Nomini Cliffs contains two tank in Virginia is not precisely known. It is believed, zones of fossils, one within 3 feet above the beach however, that this formation underlies the St. Marys and the other 10 to 12 feet higher. In the lower layer formation in part of the area between the Potomac and are Grassatellites turgidulus (Conrad), Phacoides Rappahannock Rivers. It appears that this formation crenulatus (Conrad), Diplodonta subvexa (Conrad)?, thins southward and finally disappears, and where it is a large variety of Isocardia fraterna (Say), Cardium absent the younger St. Marys formation rests upon the sp., and Venus plena (Conrad) ?. In Maryland Gras Calvert instead of the Choptank. At only two localities satellites turgidulus occurs only in zone 17 of the Chop- were fossil remains found that established the presence of this formation in VirginiX—one in the Nomini Cliffs, tank formation. about 1% miles west of the east end of the cliffs, and The middle part of the Choptank formation, assigned the other near Carter Wharf, on the Rappahannock to zone 19, consists of dark-brown soft fossiliferous River. The section in the Nomini Cliffs is described sand, with a sandstone layer about 2 feet thick at the top containing many individuals of Pecten madisonius below. Paleontologic characters.—The molluscan fauna is Say. In this sand are also Area staminea Say, Pecten poorly preserved. The following characteristic spe marylandicus Wagner, Astarte ol>ruta Conrad, Crassa- cies, in addition to others of longer range, were col- 18 Shattuck, G. B., Maryland Geol. Survey, Miocene, pp. Ixxxi-lxxxii, 1904. 12 Shattuck, G. B., Maryland Geol. Survey, Miocene, pp. Ixxii-lxxvii, M Stephenson, L. W., Cooke, C. W., and Mansfield, W. C., 16th Inter- 1904. nat. Geol. Cong. Guidebook 5, pp. 25-28, 1932. 6 MOLLUSCA FROM MIOCENE AND LOWER PLIOCENE OF VIRGINIA AND NORTH CAROLINA tellites marylandicus (Conrad), Thracia sp., Dosinia the James River no surface outcrops or exposures sp., and Corbula idonea. Conrad. In the Choptank were found in the stream channels. It is apparently formation of Maryland Crassatellites marylandicus has unconformable with the overlying Yorktown. This been found only in zone 19. apparent unconformity is indicated not only by an The upper part of the Choptank formation consists abrupt faunal change but also by the fragmental nature of sandy clay that contains a few vertebrate fossils of the upper part of the St. Marys formation. but no invertebrates. It is believed to correspond to The fauna of zone 2 is closely allied to that of zone 1, zone 20. differing mainly in containing slightly more modern The next higher bed, which represents the lower part types. Prominent species are Turritella plebeia Say, of the St. Marys formation and is assigned to zone 21, Glycymeris tumulus (Conrad) (or1 a closely related consists of very plastic clay. At the west end of the form), Pedalion maxillatum (Deshayes), Pecten santa- Stratford Cliffs this clay, though only a few feet thick, marla. middlesewensis Mansfield, P. eboreus urban- contains Turritella plebela Say, Turritella variabilis ndensis Mansfield, Crassatellites meridionalis surryensis Conrad, Glycymeris subovata (Say) var., Area sp. Mansfield, and C. undulatus url)annaensis Mansfield. (young individual), Ostrea disparilis Conrad, Astarte Stratigraphic sections.—The following sections show aff. A. obruta Conrad, Euloxa Idtisulcata (Conrad), the relations of the strata at two localities on the James Chione cf. C. athleta Conrad, Spisula confraga (Con River and one locality near Lanexa, on the Chicka- rad), and Corbula sp. hominy River. ST. MARYS FORMATION Section of right bank of James River at Schmidts Bluff, 8^ miles The St. Marys formation in Virginia may profitably below Claremont Wharf, Surry County, Va. be subdivided. The lower, nearly unfossiliferous part Feet is designated "stratum A." The overlying fossiliferous Pleistocene: Reddish gravelly clay and sand————__—— 20-25 part is subdivided into two faunal zones—zone 1, or Unconformity. Bulliopsis quadrat® zone, below, and zone 2, or Crassa Miocene: Yorktown formation, probably zone 2: tellites meridional-is zone, above. It attains a thickness Gray indurated fossiliferous marl bed resembling of 180 feet. one at Marlboro, Va___———___————— 4-5 Stratum A.—Stratum A consists of dark-gray sandy Unfossiliferous reddish sand______——__—— 3-4 clay, soft when wet and stiff when dry. It is the Yorktown formation, zone 1: Grayish to buff sand con highest bed in the Miocene sequence in the Nomini taining Turritella variabilis pilsbryi Gardner, Oly- Cliffs. Near Ethel and Garlands Mill, between the cymeris subovata (Say), Pecten clintonius Say, Pec Potomac and Rappahannock Eivers, it is the lowest bed ten jeffersonius Say, Pecten eboreus watsonensis Mansfield, Astarte eovaltata Conrad, Astarte undu- exposed. It is believed to represent Shattuck's zone 21 lata deltoidea Gardner, Astarte uttdulata vaginulata and perhaps zone 22. 15 Dall, Crassatellites undulatus cyclopterus Dall, Pha- Zone 1, or Bulliopsis quadrata zone.—Zone 1 con coides (Pseudomiltha) anodonta Say, Venericardia sists predominantly of blue to greenish sandy clay. granulata Say, Venus rileyi Conrad, Spisula con- It crops out at an altitude of 75 to 80 feet at Garlands fraga Conrad, and Kuphus calamus H. C. Lea. Pedalion maxillatum does not occur in this bed. - Mill and near Warsaw, Richmond County; below Contact with underlying bed is evident but not very Bowlers Wharf, on the Rappahannock River, and at irregular______<_ 8 Essex Mill, about 5 miles south of Tappahannock, St. Marys formation, zone 2: Material in the upper Essex County. It is believed to correspond to zones 23 part similar to the overlying bed but containing a and 24 of Shattuck, and it carries a well-preserved different fauna. The following species were col and characteristic molluscan fauna. Conspicuous lected here: Glycymeris cf. O. tumulus (Conrad), Area (Barbatia) centenaria Say, Area idonea Say, species are Terebra simplex Conrad, Conus diluvianus Pecten santamaria middleseseensis Mansfield, Peda Green, Bulliopsis quadrata Conrad, Turritella plebeia lion maxillatum (Deshayes). Pedalion maxillatum Say, Glycymeris tumulus (Conrad), Area idonea Say, and Pecten madisonius are abundant. The lower and Pecten santamaria Tucker. part contains more clay______—— 25 Zone 2, or Crassatellites meridionalis zone.—Zone 2 consists of bluish sandy clay overlain by loose light- Section of right banJc of James Kiver just above Sunken Marsh colored beachlike sands. It crops out along the Rappa CreeJc, 2 miles below Claremont Wharf, Surry County, Va. hannock Hiver from Jones Point southward to a point Pleistocene: Feet just below Burhans Wharf; along the James River Yellowish to red sandy loam with gravel at the base__ 10-12 from Cobham Bay, where it dips below water level, Band of large pebbles and cobbles as much as 1 foot in to a point a little above Claremont Wharf. South of diameter______1 Cross-bedded reddish gravel with 1-foot band of clay 16 Shattuck, G. B., Maryland Geol. Survey, Miocene, p. Ixsxv, 1904. at base_——_,__„__„______6 PART 1. PELECYPODA Section of right bank of James River just above Sunken Marsh Section in Chesapeake & Ohio Railway cut one-third of a mile Creek, 2 miles below Claremont Wharf, Surry County, Va.— below Lanexa, near left bank of the Chickahominy River, New Continued Kent County, Va.—Continued Unconformity. M iocene— Continued. Miocene: Unconformity. Torktown formation, zone 1: Feet Brown to gray medium-grained sands with fossil St. Marys formation, zone 2: Feet impressions______9 Loose unfossiliferous fine-grained buff sand—— 4 Highly fossiliferous fine gray to buff sands, with a Sand similar to above but containing Pecten few black grains intermixed, containing Turri- eboreus urbannaensis Mansfield in great abun tella variabttis pilsbryi Gardner, Fissuridea re- dance, as well as Pedalion maxillatum (Des- dimicula Say, Pecten jeffersonius Saj% Crassa- hayes) ______.______—__———————— 11 tellites unditlatus Say, Isocarclia fraterna Say, Concealed to railroad tracks.———————————— 10-12 Astarte undulata vaginulata Dall, Astarte undu- The base of the Pecten je-ffersonius bed is about 50 lata deltoidea Gardner, Astarte exaltata Conrad, and Dentalium attenuatum Say______15 feet above sea level. Covered______2 YORKTOWN FORMATION St. Marys formation, zone 2: Blue medium- to fine-grained clayey sand with The Yorktown formation has been conveniently di Turritella plebeia carinata Gardner, Dentalium vided into two faunal zones—zone 1, or Pecten clin- attenuatum Say, Area idonea Conrad, Pecten santamaria middlesexen sis Mansfield, Crassa- tonius zone, below and zone 2, or Turritella alticostata tellites meridionalis surryensis Mansfield, As zone, above. Zone 2 may in turn, be subdivided into tarte perplana Conrad, Pleiorytis centenaria three minor divisions, to which for reference have been Conrad______8 applied the terms, in ascending order, "6Viam#.-bearing Blue clayey sand with many fossils, especially bed," "beds at Yorktown," and "beds at Suffolk." The Area, Peclen, and Pedalion______10 Blue clayey sand with Turritella, Scapharca, and Yorktown formation attains a thickness of 145 feet. Pedalion maxillatum. The following species Zone 1, or Pecten clintonius zone.—Zone 1 consists were collected 8 to 20 feet above water level: largely of medium-grained gray to buff sands. It con Turritella plebeia carinata Gardner, Fissuridea stitutes the earliest deposit referred to the Yorktown near F. nassula Conrad, Dentalium attenuatum formation and apparently rests uncomformably on the Conrad, Glycymeris subovata (heavy form), Area idonea Conrad, Area virginiae Wagner, St. Marys formation. Its upper limit is less distinctly Pecten santamaria middle sexensis Mansfield, marked, though the overlying deposits are usually Crassatellites meridionalis surryensis Mansfield, glauconitic and in many places contain coarse sediments. Venericardia aranulata Say, Phacoides contrac- Its contact with the St. Marys formation dips to the tus Say, Dosinia acetabulum Conrad, Chione southeast at a rate of 3 to 5 feet to the mile. The thick dalli Olsson, Corbula inaequalisi Say______10 Blue fine-grained clayey sand, slightly fos- ness of this zone probably does not exceed 25 feet. •siliferous_,__,______4 This zone is exposed at Bellefield, on the York Eiver, Blue fine-grained clayey sand containing Turritella where for a short distance the bed rises 2 to 3 feet above plebeia carinata Gardner, Area idonea Con the beach; and at several localities between the York rad, Pecten santamaria middleseivensis Mans and Eappahannock Eivers. Along the James River field, Ostrea disparilis Conrad, Pleiorytis cen tenaria (Conrad)—______4 it is exposed at many places between old Kings Mill (The series of blue clays forming zone 2 do not Wharf and a point 2 miles below City Point. (See contain the black grains observed in other beds.) fig. 2, bed v.) From Cobham Bay, on the right bank Section in Chesapeake & Ohio Railitxty cut one-third of a mile of the James Eiver, to Claremont Wharf, zone 1 rests below Lanexa, near left bank of the Chickahominy River, New on the St. Marys formation, rising to an altitude of 30 Kent County, Va. to 35 feet at Claremont Wharf. Pleistocene: Feet The fauna of this zone is characterized not only by Reddish sandy clay, forming a nearly vertical cliff_ 8-10 the presence of certain peculiar species but also by Thinly laminated pink to mottled clays separated by the initiation of ^several species that are represented narrower bands of sand______8-10 Laminated, slightly cross-bedded mottled clays, pink by many individuals in later' deposits. Some of the re- predominating ______27-30 .stricted species are Fusinus propeparilis Mansfield, Gly~ Greenish-gray coarse sandy clay with a 2- to 3-inch cymeris subovata plagia Dall, Pecten clintonius Say, ferruginous band at the base______3 Astarte undulata vaginulata Dall, and Astarte undulata Clayey sand______3% deltoidea Gardner. Some of the species that appear Unconformity. here first are Conus marylandicus Green, "Drillia" Miocene: lunata (H. C. Lea), Pecten je-ffersonius Say, Phacoides Yorktown formation, zone 1: Indurated shell bed in cribrarius (Say), Divavicella quadrisulcata (D'Or- a matrix of gray to buff glauconitic sand contain ing many Pecten jeffersonius Say and Ostrea dis- bigny), and .Cardium virginiammi Conrad. Other parilis Conrad_____—______3 fossils are listed on page 9. -;" 8 MOLLUSCA FROM MIOCENE AND LOWER PLIOCENE OF VIRGINIA AND NORTH CAROLINA Zone 1 includes in part the Murfreesboro stage of colored oyster were noted near water level 1% miles Olsson.16 The term "Murfreesboro" is preoccupied, below Indian Field Creek and in the bluffs on both sides having been used by Safford and Killebrew 17 to desig of this stream. Upon the blue clayey sand rests a buff nate the lowest limestone of the Central Basin of Ten to gray fine-grained sand, which can be observed from nessee. As the fauna of this zone is more closely re half a mile to 1 mile above Yorktown. It is the Toldia lated to the fauna of the Yorktown formation than to bed of Harris. Fossils from the beds above Yorktown that of the St. Marys formation, I have placed it in the are listed on page 10. Yorktown. Bed at Biggs farm.—Fossils collected by me in 1922 Zone 2, or Turritetta alticostata Bone.—Zone 2 is di on the Biggs farm, 3 miles west of Franklin, Southamp visible into three minor parts. ton County, and about 21 miles nearly west of Suffolk, Va., are of special interest because they appear to be The lowest part consists of coarse sand containing more closely related to those of the Duplin marl at the many specimens of Chama and other fossils; it is ex Natural Well, North Carolina, than any others so far cellently exposed in a bluff on the north shore of the collected from Virginia. This fauna may have lived James Eiver east of the old Kings Mill Wharf. In a near or at the end of the last Miocene marine invasion section of the bluff given by Stephenson, Cooke, and in Virginia and apparently at a time a little later than Mansfield 18 (see fig. 2), the 6^A«ma-bearing bed is indi the fauna in the neighborhood of Suffolk, Va., but not cated by "bed 10" and is underlain by zone 1 of the much later. The cooler-water fauna at Suffolk is formation. Higher beds in the lower part of zone 2, usually regarded as largely contemporaneous with the exposed in the same bluff above the C^ama-bearing bed, warmer-water fauna of the Duplin marl to the south. are indicated by "beds a?, y, 0" and consist of gray to I place the exposure at the Biggs farm in the upper buff sands and laminated clay. Equivalent beds are most part of zone 2 of the Yorktown formation. present on the York Eiver southeast of Yorktown and are indicated 19 in figure 3 by "beds a, 5, oysters, Ostrea Petaloconchus sculpuratus (H. C. Lea) 1 sculpturata. Similar sediments containing the dark- Crepidula fornicata cymbaeformis Conrad. Crepidula aculeata costata Morton. M Olsson, Axel, The Murfreesboro stage of our east coast Miocene: Bull. Am. Paleontology, vol. 5, No. 28, pp. 153-164, 1917. 20 Mansfield, W. C., The Chesapeake Miocene basin of sedimentation 11 Safford, J. M., and Killebrew, J. B., The elements of the geology of as expressed in the new geologic map of Virginia: Washington Acad. Tennessee, p. 125, 1900. Sci. Jour., vol. 19, No. 13, p. 266, fig. 2, 1929. M Stephenson, L. W., Cooke, C. W., and Mansfield, W. C., 16th Inter- 21 Mansfield, W. C., Miocene gastropods and scaphopods of the Choc- nat. Geol. Cong. Guidebook 5, p. 35, 1932. tawhatchee formation of Florida: Florida Geol. Survey BulL 3, pp. 32, »Idem. p. 32. v 63, 1930. PART 1. PELECYPODA 9 Polinices duplicatus Say. northwest of the old Grove Wharf), is represented in Calliostoma mitchelli (Conrad). figure 2. Bed v is the upper part of zone 1; bed w Fissuridea sp. cf. specimen from Darlington, S. C. is the lowest part of zone 2; beds a?, y, and 0 the re Cadulus thallus (Conrad). Nuculana acuta (Conrad). mainder of the lower part of zone 2. A list of the Glycymeris subovata tuomeyi Dall? more common fossils found here and of the less Eontia trigintinarea (Conrad) MacNeil (identified by common ones that are useful in zonal differentiation MacNeil). is given below: Ostrea sculpturata Conrad. Pecten cf. P. eboreus eboreus Conrad (fragments). Zone 1 (bed v) : Plicatula marginata Say. Mollusks: Crassinella galvestonensis Harris. Conns marylandicus Green (rare). Venericardia granulata Say var. Scaphella (Aurinia) mutabilis (Conrad) (rare). Venericardia perplana abbreviata Conrad. Fusinus propeparilis Mansfield (rare). Cardita arata verdevilla Gardner. Turritella pilsbryi Gardner. Phacoides crenulatus Conrad. Crucibulum grande (Say) (rare). *Phacoides trisulcatus multistriatus Conrad. Glycymeris subovata plagia Dall. Semele subovata (Say) var. Ostrea disparilis Conrad (rare?) *Gemma magna Dall. Pecten jeffersonius Say. Corbula inaequalis Say. Pecten clintonius Say (occurs in the lower part of the Mulinia congesta Conrad (a large form). bed). Modiolus pulchellus Olsson. Fossils that appear to be at the same horizon as those Astarte undulata vaginulata Dall. of the Biggs bed occur in North Carolina in Greene Astarte undulata deltoidea Gardner. Astarte exaltata Conrad (common). Feet Crassatellites undulatus cyclopterus Dall. 60- Venericardia granulata Say. 55- stocene Phacoides anodonta (Say). Cardium virginianum Conrad (rare). 50- Isocardia Carolina Dall (rare). 45- 0) Chione cortinaria (Rogers) (rare). Q. Kuphus calamus H. C. Lea. 40- Bed Z Coral: " 35- Septastrea marylandica (Conrad). Bed Y 30- Zone 2 (beds w to z): BedX 25- .Zone 2 Molluslrs: 15 Fissuridea redimicula (Say) (rare). Area (Noe'tia) incile Say. IO Area (Striarca) centenaria Say. Bed V 1 Zone 1 5 Ostrea sculpturata Conrad (rare). V J Pecten decemnarius Conrad (rare). Pecten virginianus Conrad (rare). FIGURE 2.—Section on shore of the James River, east of >old Kings Mill Wharf, Va. Pecten jeffersonius edgecombensis Conrad. Astarte coheni Conrad (rare)? Astarte undulata Say. County, 8 miles northwest of LaGrange (U. S. G. S. Astarte arata Conrad (rare). sta. 11822); in Wayne County, 1% miles east of Crassatellites undulatus (Say), Fremont (sta. 11836); and in Craven County, at Eock Chama congregata Conrad. Landing, on the right bank of the Neuse Eiver 16a/2 Cardita arata (Conrad) (rare). miles above Newbern (sta. 10898). The localities in Venericardia granulata Say. Mulinia congesta (Conrad) (occurs near the top of Greene and Wayne Counties indicate that the upper zone 2). Yorktown, with a cooler-water fauna, transgressed a Corals: considerable distance inland.22 Astrangia lineata (Conrad). Sections in the Yorktown formation.—A line of Septastrea marylandica (Conrad) (occurs in the lower bluffs on the north shore of the James River 6% to 7 part of zone 2). miles southeast of Williamsburg exposes the upper part The type section of the Yorktown formation is ex of zone 1 and the lower part of zone 2 of the Yorktown posed in a series of bluffs along the south shore of the formation. The best section, in a bluff about half a York River within 2 miles southeast of the ferry land mile east of the old Kings Mill Wharf (1% miles ing. (See fig. 3.) Only the beds of zone 2 are ex posed in these bluffs. A notable structural feature is 22 Mansfield, W. C., The Chesapeake Miocene basin of sedimentation the northwestward dip, contrasting with the normal as expressed in the new geologic map of Virginia: Washington Acad. Sci. Jour., vol. 19, p. 266, fig. 2, 1929. regional dip to the east or southeast. Beds a to d are 10 MOLLITSCA FROM MIOCENE AND LOWER PLIOCENE OF VIRGINIA AND NORTH CAROLINA part of the lowest unit of zone 2, and beds e and / are Semele subovata (Say). the middle unit. Farther upstream (west), beyond Mulinia congesta (Conrad). Panope reflexa (Say). the section shown in the diagram, are exposures assigned Bed f: to the upper unit of zone 2. Caecum stevensoni Meyer. The following lists indicate the more common and Glycymeris amerieana (De France). more significant species of fossil organisms found in Ostrea disparilis Conrad. the beds of the Yorktown formation shown in figure 3. Pecten jeffersonius edgecombensis Conrad. Plicatula marginata Say. Beds a and 6: Crassatellites undulatus (Say). "Drillia" lunata (H. C. Lea). Venericardia granulata Say. Oliva sayana Ravenel. Astarte coneentrica Conrad. Lirosorna sulcosa (Conrad). Venus tridacnoides Lamarck. Fusinus exilis (Conrad). About 2y2 miles above Yorktown an exposure reveals Ptychosalpinx altilis (Conrad). Ptychosalpinx laqueata (Conrad). alternating beds of clay and marl carrying entire and Scalaspira strumosa Conrad. broken shells. These beds lie stratigraphically above YORKTOWN j NW Pleistocene (Penholoway) terrace deposit Pleistocene(TaIbot) terrace deposit- Bed f Bed e i Mile FIGURE 3.—Diagrammatic representation of the beds of zone 2 of the Yorktown formation within 2 miles southeast of Yorktown, Va. Turritella alticostata Conrad (abundant). the Yoldia bed of Harris, and the fauna is closely re Crepidula aculeata costata Morton. lated to that in the beds at Suffolk, the uppermost unit Calliostoma philanthropum (Conrad). of zone 2. The species collected here are as follows: Calliostoma virginicum (Conrad). Fissuridea rediniicula (Say). Conus marylandicus Green. Yoldia laevis (Say). Turritella alticostata Conrad. Area (Noe'tia) incile Say. Crepidula fornicata (Linnaeus). Ostrea sculpturata Conrad. Polynices heros (Say)? Pecten jeffersonius edgecombensis Conrad. Glycymeris subovata (Say). Pecten virginianus Conrad. Glycymeris amerieana (DeFrance). Pecten decemnarius Conrad. Area incile Say. Phacoides (Lucinoma) contractus (Say). Pecten eboreus yorkensis Ball. Cardium virginianum Conrad. Pecten jeffersonius edgecombensis Conrad. Dosinia acetabulum Conrad. Plicatula marginata Say. Callocardia sayana (Conrad). Astarte symmetrica Conrad. Kuphus calamus (H. C. Lea). Astarte undulata Say. Bed c: Cardita arata (Conrad). "Drillia" pyrenoides Conrad. Venericardia granulata Say. Turritella alticostata Conrad. Rangia clathrodon (Conrad). Crepidula aculeata costata Morton. Venus rileyi Conrad. Crepidula plana Say. Fissuridea redimicula (Say). The stratum at water level between Indian Field Area (Striarca) centenaria Say. Creek and Felgates Creek is the same stratum that Area (Noe'tia) incile Say. crops out at the foot of the bluff along the James Kiver Ostrea sculpturata Conrad. between old Kings Mill Wharf and old Grove Wharf Pecten jeffersonius edgecombensis Conrad. Crassatellites undulatus (Say). and is stratigraphically lower than the basal bed below Crassinella galvestonensis Harris. Yorktown. This stratum (part of zone 1) was ob Venericardia granulata Say. served for a short distance only, at one place, between Venus plena (Conrad). the mouths of the two streams. Here it arches 2 or 3 Pleiorytis centenaria (Conrad). feet above the shore. Bed e: Glycymeris subovata (Say). Near Felgates Creek the beds stratigraphically above Pecten jeffersonius edgecombensis Conrad. the basal bed assume the regional dip to the east. The Astarte symmetrica Conrad. material consists of coarse-grained glauconitic sand Crassatellites undulatus (Say). and contains well-preserved and fragmentary shells. Crassinella galvestonensis Harris. This fauna is heterogeneous, including St. Marys, Venericardia granulata Say. Cardium acutilaqueatum Conrad. Yorktown, and perhaps later species, and indicates re- PART 1. PELECYPODA 11 deposition of an earlier fauna in later sediments. The Section of right bank of Meherrin River one-eighth mile above species have, therefore, little value for correlation. highway bridge and extending up ravine to Murfreesboro, These observations of the bluffs were made before Hertford County, N. C.—Continued the new Yorktown-Williamsburg road (which parallels Unconformity. these bluffs) was constructed. On my last visit there Miocene: (1936) I was unable to find the former bluff at Belle- Yorktown formation, zone 2: Feet Bluish to gray sands with shell impressions——— 4 field and assumed that it had been leveled down in Bluish to gray clayey sands containing many the process of landscaping. Along a creek that the Mulinia congesla, especially near the base and new road crosses about iy2 miles east of Williamsburg top. The following species were collected near I observed zone 1 of the Yorktown formation in the the top of this 12-15 foot bed: Fissuridea cf. stream bed and above it the <7A«m«-bearing bed, these specimens from Suffolk, Va., Glycymeris subo- vata tuomeyi Dall, Pecten jeffersonius Say, units exhibiting the same relationships as in the bluffs Pecten eboreus eboreus Conrad, Crassatellites below old Kings Mill Wharf. undulutas Say, Phacoides crenulatus Conrad, Venus tridacnoides (Lamarck), Mulinia con- MIOCENE STRATA OF NORTH CAROLINA gesta Conrad______——__———————— 12-15 The St. Marys formation is doubtfully recognized in Brownish coarse sands containing dark particles the northern part of North Carolina. It is probably and a few pebbles 1 inch or less in diameter. Ostrea is the most common fossil———————— 3 exposed at very low stages of some of the streams, Clayey sands, sparsely fossiliferous. The follow though certain identification has not been made. ing species were collected above zone 1: Urosal- The Yorktown formation, on the other hand, is pinse trossulus Conrad, Lirosoma sulcosa Con widely exposed in the northern part of the State. . Ap rad, *Turritella alticostata Conrad (like form parently the whole formation is represented, though it from C7wMna-bearing bed below old Kings Mill Wharf, James River, Va.), Crepidula aculeata is not easy to place all the exposures exactly within the costata Morton, Fissuridea redimicula Say, formation. It contains a fauna suggestive of deposi Solarium nupcrum Conrad, Dentalium atten- tion in colder water than that of the Miocene beds in uatum Say, Mytilus conradinus D'Orbigny? the southern part of the State.23 The cold-water fauna *Astarte arata Conrad, Venericardia granulata apparently lived in an embayment whose waters trans Say, Chama congregata Conrad, Phacoides con- gressed the older rocks of the Piedmont Plateau; the tractus Say, *Venus tridacnoides Lamarck, Mulinia oongesta Conrad. Those with an as fauna, especially that near the inner shore line, was terisk (*) came from that part of the bed consequently somewhat protected from the influence of directly above zone 1______—__ 3 the warmer oceanic waters that lay east of the Yorktown formation, zone 1: Soft medium-grained embayment. greenish-gray sand, oxidizing to light yellow, con In the southern part of the Coastal Plain the Duplin taining many black particles; contains Pecten clin- tonius in great numbers, also Isocardia, but no marl, uppermost Miocene, equivalent to the uppermost Mulinia congesta. The following species were col part of the Yorktown formation, occurs in patches,- as lected from the basal bed (zone 1): Glycymeris at Natural Well. The formation contains a fauna sug subovata tuomeyi Dall, Pecten jeffersonius Say, gestive of deposition in warmer water than that of cor Pecten clintonius Say, Ostrea disparilis Conrad, responding deposits farther north in North Carolina Phacoides contractus murfreesboroensis Mansfield, Astarte hertfordensis Gardner, Astarte undulata and Virginia. deltoidea Gardner, Venericardia granulata Say, The Miocene rocks, as exposed, probably do not any Isocardia Carolina Dall______4 where exceed 50 feet in thickness. Groups A and B.—At . Murf reesboro (see strati- YORKTOWN FORMATION graphic section), on the Meherrin Eiver, zone 1 of the The beds assigned to the Yorktown formation are Yorktown formation forms the lower bed (group for convenience grouped into units lettered A to F, A A) and is directly overlain by a bed (group B) corre being the lowest and F the highest. Groups A to C sponding to the bed in the lowest part of zone 2 that are well shown in the section on the Meherrin River contains many Chama in the cliffs below old Kings near Murfreesboro, Hertford County, which follows: Mill Wharf on the James Eiver, Va. A similar fauna occurs around Halifax, at Bell's old bridge over the Section of right bank of Meherrin River one-eighth mile above Tar Eiver, Edgecombe County; and at several other highway bridge and extending up ravine to Murfreesboro, Hertford County, N. C. places in North Carolina. Group 0.—The highest beds (group C) in the sec Pleistocene: Blue fine-grained sandy laminated clay bed containing mica flakes, with pebbles at the base 2 inches tion at Murfreesboro contain the latest identifiable in diameter (thickness estimated)______20 fauna (U. S. G. S. sta. 10225) in the bluff. Beds that carry a similar fauna, although all may not be exactly te Mansfield, W. C., The Chesapeake Miocene basin of sedimentation at the same horizon, are found at the following localities: as expressed in the new geologic map of Virginia: Washington Acad. Sci. Jour., vol. 19, No. 13, p. 266, fig. 2, 1929. 6.8 miles below Murfreesboro (sta. 11225) ; in Edge- 12 MOLLUSCA FROM MIOCENE AND LOWER PLIOCENE OF VIRGINIA AND NORTH CAROLINA combe County, at Shiloh Mills, on the Tar Eiver above ably overlain by about 25 of cross-bedded sand Tarboro (sta. 10911); in Pitt County, at Greenville (sta. and clay. 10918) and 1% miles west of Greenville (sta. 11232). The species collected from the type locality (U. S. The fauna at most of the above-named localities includes G. S. sta. 11999) are as follows: Pecten jeffersonius, Pecten eboreus eboreus, Astarte un~ Acteocina canaliculata Say. dulata (like the form occurring in the Cl^ima-bearing Mangilia aff. M. magnoliana Olsson. bed), and many individuals of Mulinia congesta. No Marginella limatula Conrad. specimens of Astarte arata or A. Toanokensis were noted Marginella bella Conrad. Olivella mutica Say. in these faunas. The position of the fauna as a whole at Oliva nitidula (Dillwyn). these localities ranges from the (7Aama-bearing bed up Scaphella mutabilis Conrad. to the fragmental series as exposed in the bluffs at Busyeon canaliculatum canaliferum Conrad. Yorktown—that is, the lower and middle parts of Uzita chowanensis Gardner. zone 2 of the Yorktown formation of Virginia. Ilyanassa granifera sexdentata Conrad. Anachis milleri Gardner. Group D.—The faunas at the following localities are Seila adamsi (H. C. Lea). very similar in character and appear to represent Turritella variabilis Conrad (stout variety). about the same horizon: Lower bed at Colerain Land Crepidula fornicata cymbaeformis Conrad. ing, Chowan Eiver; bed along Tar Eiver about 6 miles Nueula proxima Say. Nuculana acuta (Say). below Greenville (sta. 10916); bed about 1 mile north Glyeymeris subovata Say. of Grimesland, Pitt County (sta. 11835), and beds in Eontia carolinensis (Conrad).2* the vicinity of Chocowinity, Beaufort County (sta. Area improeera Conrad. 11837). / In these faunas Turritella variabilis var. is Ostrea sculpturata Conrad. common; Pecten eboreus eboreus is also very common; Pecten eboreus bertiensis Mansfield. Modiolus ducatellii Conrad. P. jeffersonius edgecombensis is rare; Astarte berryi is Astarte concentrica Conrad. present at two or three localities. Crassatellites undulatus Say. The horizon of the faunas is believed to be about the Venericardia granulata Say (a low form). same as that of the becls at Suffolk, Va., or at a some Phacoides multistriatus Conrad. what lower horizon—that is, essentially the upper part Callocardia sayana Dall. Tellina declivis Say. of zone 2 of the Yorktown formation of Virginia. Cumingia medialis Conrad. Group E.—The fossils collected at Eock Landing Spisula delumbis Conrad? and at other localities in North Carolina are regarded Corbula inaequalis Conrad. ^ as a little younger than those in the beds of group D. Panope goldfussii Wagner, var. The localities are mentioned under the discussion of The most characteristic species in this bed are Eontid the bed at the Biggs farm in Virginia (p. 8). carolinensis (Conrad) and Pecten eboreus bertiensis Group F, bed at Mount Gould Landing.—In east Mansfield.25 ern North Carolina, along the Chowan Eiver in Bertie No specimens of Mulinia congesta Conrad were col and Hertford Counties and in Martin County, a marl lected at Mount Gould Landing. This species is rare bed crops out that is believed to have been deposited at this horizon, as only about half a dozen specimens during the time of the last invasion of the Miocene sea are in the National Museum collection from Tar Ferry into this part of the State. Its deposition appears to (sta. 11230). The specimens of the genus Spisula are have succeeded closely that of the bed at the Biggs more common. No specimens of Dentalium carolmense farm in Virginia, and it is therefore a little higher Conrad were collected in deposits referred to this hori stratigraphically than the highest part of the York- zon in Bertie, Hertford, and Martin Counties. Other town in Virginia. The bed at Mount Gould Landing localities at which the fauna of group F occurs are contains a cooler-water fauna than that of the Duplin station 13814, upper bed at Colerain Landing (not the marl to the south but in age is nearly contemporaneous lower 3-foot bed in the bluff), Bertie County; station with some part of the Duplin, perhaps with that part 11230, Tar Ferry, Wiccacon Creek, Hertford County; deposited south of the Cape Fear Eiver in Eobeson station 13798, upper bed at Beaver Dam, Martin and Bladen Counties, which appears to represent County; station 12004, Poplar Landing, Martin rather late Duplin time. Stratigraphically group F is County; station 11833, near Shelmerdine and station placed in the uppermost part of zone 2 of the Yorktown 11827, Hanrahan, Pitt County. Most of the species formation. near Shelmerdine and Hanrahan are poorly preserved. The type exposure is in the right bank of the The fauna in Pitt County includes, besides other forms, Chowan Eiver about three-quarters of a mile below 2* Identified by F. S. MacNeil. Mound Gould Landing, Bertie County, where the bed 25 Mansfield, W. C., A new species of Pecten from the upper Miocene of North Carolina: Washington Acad. Sci. Jour., vol. 27, No. 1, pp. rises about 10 feet above the beach and is unconform- 10-12, 1937. PART 1. PELECYPODA 13 many individuals of Spisula and one fragment of into lower, middle, and 'upper parts; consequently Dentalium, carolindnse Conrad. zone 2 in Virginia includes the species that range through deposits "from the 6"Aam#-bearing bed (lower DUPLIN MARL part of zone 2) to the beds at and in the vicinity of The Duplin marl includes deposits that occur in thin Suffolk (upper part of zone 2). patches in Duplin, Sampson, Bladen, a^id Robeson For North Carolina, zone 2 includes species ranging Counties, in the southern part of North Carolina. The from the ^Aama-bearing bed to the top of the York- fauna is suggestive of deposition in warmer water than town formation. The geographic separation of the that of the Yorktown formation, though it is fairly Yorktown formation, carrying a colder-water fauna, sure that the beds containing Duplin fauna were con from the Duplin marl, carrying a warmer-water fauna, temporaneous with the upper part of zone 2 of the is shown by line c-c on the map included in my paper Yorktown of Virginia. of 1929.28 PLIOCENE STRATA OF NORTH CAROLINA The faunas at Neills Eddy Landing and Walkers Bluff on the Cape Fear River 29 are placed in the Plio In the eastern part of North Carolina the Croatan cene Waccamaw formation. Certain beds at Wilming- sand is exposed in the right bank of the Neuse Kiver ton are now considered of Pliocene age.30 2 to 15 miles below Newbern and in Onslow'County The observed geologic ranges of a few important and contains well-preserved fossils.26 species that are not included in table 2 are shown in In the southern part of the State abundantly fossilif- the following list: erous strata of the Waccamaw formation overlie Cre taceous beds at Neills Eddy Landing, at Walkers Bluff Terebra (Hastula) simplex Conrad— St. Marys. Conus diluvianus Green______Do. on the Cape Fear River,27 and elsewhere. Conus marylandicus Green_—___. Yorktown, zone 1 and higher beds. GEOLOGIC RANGES OF CERTAIN SPECIES Oliva eboreus Conrad__—______St. Marys. Table 2 shows, so far as known, the geologic ranges Busycon coronatum Conrad______Do. of species of mollusks in deposits in Virginia and Busycon coronatum rugosum Conrad. Calvert, Choptank, and St. Marys. North Carolina extending in age from the medial Mio Busycon maximum fllosum Conrad_- Yorktown and higher beds. cene (Calvert formation) to the Pliocene (Waccamaw Fusinus parilis Conr.ad_—_—_____ St. Marys. formation). Fusinus propeparilis Mansfield-—___ Yorktown, zone 1. In preparing this table I have had before me a table Alectrion peralta Conrad___—_____ St. Marys. prepared by Miss Julia Gardner with a list of the Turritella plebeia Say______Calvert, Choptank, and St. Marys. species and the locality or localities at which they Turritella plebeia carinata Gardner- St. Marys. occur. The localities given in Miss Gardner's table Turritella pilsbryi Gardner———__. Yorktown, zone 1. do not indicate, at localities where there is more than Turritella terstriata Rogers______Do. one horizon, the positions in the sections at wjiich the Galliostoma humile Conrad______. St. Marys. species were taken, as at the time the collections were Glycymeris tumulus (Conrad)—__. Not above the St. Marys. Glycymeris americana Defrance___. Yorktown, zone 2 and made, either the different stratigraphic units as now higher beds. interpreted were not recognized, or stratigraphic in Area incile Say—————_—————. Yorktown, Chamd^bearing formation concerning the material was not recorded.' bed and higher beds. During my field work in Virginia and North Caro Area idonea Conrad-—__—_—____ St. Marys. lina I collected fossils from each bed or fauna! unit Area virginiae Wagner______Do. Pedalion maxillatum (Deshayes)___ Calvert, Choptank, St. in the sections, and relying in part upon the informa Marys, mechanically tion thus obtained I have endeavored to interpret the mixed with zone 1 of range of the species in Miss Gardner's table. How Yorktown. ever, I have relied mainly upon her identification of Astarte perplana Conrad—_ St. Marys. species and record of localities at which they are Astarte symmetrica Conrad. Yorktown, zone 2, middlf and upper parts. •reported to occur. Cardium taeniopleura Dall_ Yorktown, zone 2. Under these circumstances it is impracticable to di Chione dalli Olsson_—_____ St. Marys. vide in the table zone 2 of the Yorktown formation 28 Mansfield, W. C., The Chesapeake Miocene basin of sedimentation 26 Mansfield, W. C., Notes on Pleistocene faunas from Maryland and as expressed in the new geologic map of Virginia: Washington Acad. Virginia and Pliocene and Pleistocene faunas from North Carolina: Sci. Jour., vol. 19, p. 266, fig. 2, 1929. U. S. Geol. Survey Prof. Paper 150, pp. 129-133, 1928; Additional notes 29 Miller, B. L., Tertiary formations ; North Carolina Geol. and Econ. on the molluscan fauna of the Pliocene Croatan sand of North Carolina : Survey Kept., vol. 3, pp. 256-25.8, 1912. Jour. Paleontology, vol. 10, No. 7, pp. 665-668, 193G. 30 Mansfield, W. C., Additional notes on the molluscan fauna of the 27 Miller, B. L., Tertiary formations: North Carolina Geol. and Econ. Pliocene Croatan sand of North Carolina : Jour. Paleontology, vol. 10, Survey, vol. 3, pp. 256-258, 1912. pp. 665-668, 1936. 401033—43- TABLE 2.—Geologic ranges of species Virginia North Carolina St. Marys Yorktown Yorktown Plio Chop- cene, Calvert Duplin Wacca- tank Undiffer- Undiffer- Undiffer- Zone 1 Zone 2 entiated Zone 1 Zone 2 entiated Zone 1 Zone 2 entiated maw (?) (?) X X X X X X X X Yoldia laevis (Say) .______- X X X X X X X X X X X X X A T*l"*f} f Slf^QY^ll Q Tf*Q "^ SPftloT1 ! S fV^TlTfl H X X x • X X X ' X X X X X X X X X X X X (?) X X X - X (?) X X X X X X X X Pecten (Amusium) mortoni RaveneL- _- _, X X X X X X X X X X •x X X X , X X Thracia transversa H. C. Lea _ _ __- _ -- - ___ X X (?) X X X X X X X X X X X X (?) X X X X X (?) X •x X X X X X X X ^ X X X X X X X X X X X "X X X X Astarte (Ashtarotha) concentrica bella Conrad ______(?) X X 1 X X X X (1) X X X X - X X Crassinella lunulata harrisi Gardner, n. subsp ______X (?) X X X (?) X X X (?) X (?) X v X X X X X X X X X X • X X X X X X X X X X X X X X X X X X X X X 2 X X X X _ X X (?) X X X X X X (?) X X X X X X X X Erycina carolinensis Dall _ _ _ _ _ X X X X X X X X X 1 X X X X X X X X X X X X X X X X X Cardium (Cerastoderma) virgimanum Conrad _ _ _ X (?) X Cardium (Laevicardium) sublineatum Conrad _ _ X X X X Isocardia fraterna Say_ N X X v X (?) X X Petricola (Rupfillaria) grinnelli Olsson X X (?) Cooperella carpenter! Dall _ X X v X • X X X X X X X X X Callocardia (Agriopoma) chioneformis Gardner, n. sp _ - X X X (?) • X X Chione (Timoclea) grus (Holmes) ______>____ ~ X X X X v Venus (Mercenaria) plena inflata Dall X (?) X (?) X X X / Gemma magna insulcata Gardner, n. subsp X X Gemma magna maiorina Gardner, n-. subso _ _ _ _ X X Fide Gardner. * Collected near Franklin by Mansfield. 16 MOLLUSCA FROM MIOCENE AND LOWER PLIOCENE OF VIRGINIA AND NORTH CAROLINA Ss|a X XXX xxxxxx XX X X XX XX "S X ' 3 X XX XX X X XX X ft 03 "o.a 1 . trt-O oS iS-2 1- 1 a PH N a0 X N . il X t> oS X X N || 03 '3-S o 5 5 1 ?• .1? *"* >> a IN S 1 X X X X X S N X X X X X iN O rt rfl c3 J-i •a o • ft ft s • OQ ^ H c^ *" o: 3 X OQ pO PH OQ _4 3 - * (^ CO F-H (H~a d OQ . ® c3 w '^ L^ ^ ft CD OQ P3 OQ T3 C £S OQ' p . 03 i S b i? " M d (Conrad). GO B s- a, G,ecursor Gardalta -% CD^ OQ Gardneis ,v)______lockensis CD B o3 e£ ft B B o3 'O *" OQ 3 e -IT3 OQ !H B OQ s— •" SH 05 V. t-( 3 o3 O 3 T: o3 "^O O t- 03 B 03 B P CD OQ C5 o ^ M _ ^ — ' 2: aMOQ03,^"__°5gs^piii fl- Q CQ O^^Q :l|.sJ|-i«J ^ o d T3 '*~! r^ -£J "^ C^ Donaxemmonsipreaequilibrata< Sc'S r3 -3 "T3 ft'-v CD g *-"O a GemmavirginianaDall_.magna S ^ " ^ eS ^ Tagelus(Spengler)gibbus____. DonaxchuckatuckensisGardner, (Moerella?)GardnTellinacalpix AbraaequalisdeltoideaGardner, Tagelusgibbus(Concarolinensis *-«2.Sc3ao3o3'a03 g g o o ft'O a (Moerella)Tellina(Deshayesayi 2 g ^ 03 § g «*nX! 5 g g M (LH g §§B^|§ B oS O oT3 o3^,O °O IO 3 3 3-3 ra . _, _, M •+-= LOCALITIES IN VIRGINIA AND NORTH CAROLINA Virginia—Continued. Nansemond County—Continued. The numbers assigned to the key localities in the list 31. Exit. that follows correspond to those on the index map, 32. Reids Ferry, 1% miles southeast of. figure 4. On the index map the numbers are arranged 33. Suffolk, 5% miles northwest of, 2% miles north west of, 1% miles northwest of, 1% miles north serially, beginning with the northernmost localities in of, 1% miles north of, 1 mile west of, half a Virginia and progressing southward. The numbers mile below the Suffolk waterworks dam, 1 mile within each county are likewise arranged from north'to northeast of Suffolk, 1% miles northeast of south. Suffolk, 1% miles southeast of Suffolk. 34. Drainage ditch of Norfolk & Western Railway Virginia: just east of Jericho ditch. Westmoreland County: North Carolina: 1. Horsehead, Stratford, and Nomini Cliffs. Halifax County: Northumberland County: 35. Halifax, Durham's farm, near Halifax. 2. 8184, east bank of Hull Creek. 36. Palmyra Bluff, 3y2 miles below. , Richmond County: „ Northampton County: 3. Carter Wharf, 1% miles west of. 37. Branches Bridge, 1% miles above, 1 mile above 4. Farnham, 2% miles south of. and 1% to 2 miles below. 5. Union Mill. Hertford County: Essex County: 38. Murfreesboro, near Murfreesboro, 1 mile above. 6. Bowlers Wharf, 1 to 2 miles below and 2% miles 1% miles above, and 2% miles northwest of. below. 39. Tar Ferry, above Tar Ferry, l1^ miles below and 7. Jones Point, a quarter of a mile above. 3 to 4 miles below. Middlesex County: Bertie County: 8. Urbanna. 40. Colerain Landing. 9. Burhans Wharf. 41. Mount Gould Landing. King and Queen County: 42. Edenhouse Point, half to three-quarters of a mile 10. Walkerton, 3 miles northeast of. above. New Kent County: Edgecombe County: 11. Lanexa. 43. Rocky Mount, 2 miles west of, S1/^ miles northwest James City County: of, and 6 to 7 miles below. 12. Kings Mill Wharf. 44. Bells Bridge, half a mile above, 15% miles above, York County: an eighth of a mile below, and 1 to 1% miles 13. Yorktown, three-quarters of a mile above. below; New Bridge, two-thirds of a mile north 14. Bellefield. of, 6% miles below, and 5 miles below. Gloucester County: 45. Shiloh Mills. 15. Ware River. 46. Tarboro. Prince George County: Martin County: 16. Near mouth of Baileys Creek. 47. Williamston, 3 miles west of, 4 miles northwest of, Surry County: 2% miles northwest of, and 1 mile northwest of. 17. Claremont, old Claremont Wharf, Claremont 48. Hamilton Landing, a third of a mile below and Wharf, 6% miles below Claremont, Sunken 2 miles southeast of. i Marsh Creek 2 miles below Claremont, and S1^ Wilson County: miles below Claremont Wharf (probably 49. Wilson, Hominy Swamp, 1 mile west of, 3 miles Schmidts Bluff). east-southeast of, 5 miles south of. 18. Schmidts Bluff. 50. Stantonsburg, 1 mile northwest of. 19. Scotland Wharf. Pitt County: 20. Cobham Wharf. 51. Tugwell, 2 miles southeast of, and Toddy Station Dinwiddie County: near Tugwell. 21. Petersburg. 52. Standard, 2% miles north of. 53. Farmville, 1% miles northeast of and 3 mileb Isle of Wight County: south of. ' 22. Smithfield, 2 miles northwest of, 1% miles west of, 54. Greenville, south of county bridge, 8 or 9_ miles three-quarters of a mile northeast of, 1% miles west of Greenville, 3 miles west of Greenville, northeast of, and 5 miles northeast of. 2 miles west of Greenville, 1% miles west of 23. Benns Church. Greenville, l1/^ miles northwest of Greenville, 1% 24. Zuni, 1% miles above, 2% to 3 miles northwest of, miles east of Greenville, 6 miles below Greenville 6% to 7 miles below, 7 to 7% miles below, and at Cherry Landing, 6% miles below Greenville 8 to 8% miles below. at Tafts Landing, 8 to 10 miles south of Greenville. Greensville County: 55. Grimesland, three-quarters of a mile north of. 25. Hitchcock. 56. Grifton, 3 miles east of. Southampton County: Beaufort County: 26. Biggs farm. 57. Chocowinity, 1% miles northwest of, 2 miles north 27. Delaware Park. west of, 2% miles northwest of. 28. Sycamore Church. Greene County: Nansemond County: 58. Lizzie, half a mile east of, 1 mile east of, and 29. Chuckatuck, a quarter of a mile north of. 4 miles east of (in Dog Swamp). 30. Everets, a quarter of a mile east of. 59. Castoria, 1 mile north of. 18 MOLLUSCA FROM MIOCENE AND LOWER PLIOCENE OF VIRGINIA AND NORTH CAROLINA FIGURE 4.—Index map showing Miocene and lower Pliocene localities in Virginia and North Carolina. The numbers refer to the list on pages 17 and 19. FASIT 1. PELOBCYPODA 19 North Carolina—Continued. obliquely forward. Anterior and posterior muscle Wayne County: scars subequal, inconspicuous. Pallial line simple. 60. Goldsboro, 6 miles west of. Craven County: Inner margin finely crenate in harmony with the 61. Rock Landing. radial lineation. Sampson County: ' Schenck 32 refers to Nucula s. s. the Lower Cretaceous 62. Clinton, 2% miles south of, 3 miles south of, and species, Nucul-a gaultana, J. Starkie Gardner, and 4 miles south of. Duplin County: closely related forms earlier included under Nucula 63. Natural Well and environs. have been described from the Paleozoic. The wide 64. Warsaw, 2 miles northeast of. distribution of the Recent species suggests a stock Robeson County: deeply rooted in the past. Though characteristic of 65. Lumberton, near the bottling works, 1 mile west the boreal and temperate oceans today, the group has of Lumberton, 2 miles below Lumberton, and 4 to 5 miles below Lumberton. also a meager representation in the tropical seas. It 66. Fairmont, 1% miles northeast of, 4 miles north- is found in both shallow and deep water and on both * east of, and Ashpole (near Fairmont). sandy and muddy bottoms. Bladen County: 67. Clarkton, 4 miles south of. Nucula proxima Say 68. Elizabethtown, 4 miles south of, and 4 miles ^ast of. Plate 1, figures 1, 2, 4, 5 69. Walkers Bluff. 1820. Nucula obliqua Say, Am. Jour. Sci., 1st ser., vol. 2, p. 40. 70. Black Rock Landing. Not Nucula obliqua Lamarck, 1819. Columbus County: 1822 (August). Nucula proxima Say, Acad. Nat. Sci. Phila 71. Cronly. delphia Jour.,. 1st ser., vol. 2, p. 270-. 72. Neills Eddy Landing. 1856. Nucula proxima Say. Tuomey and Holmes, Pleiocene 73. Lake Waccamaw. fossils of South Carolina, p. 53, pi. 17, figs. 7-9. New Hanover County: 1858. Nucula proxima Say. Holmes, Post-Pleiocene fossils of 74. Wilmington, city rock quarry near Wilmington. South Carolina, p. 17, pi. 3, fig. 6. 1889. Nucula, proxima Say. Ball, U. S. Nat. Mus. Bull. 37, p. SYSTEMATIC DESCRIPTIONS 42,, pi. 56, fig. 4. By JmiA GARDNER 3894. Nucula proxima Say. Whitfield, U. S. Geol. Survey Mon. 24, p. 50, pi. 7, figs. 7-10. Phylum MOLLUSCA 1898. Nucula proxima Say. Dall, Wagner Free Inst. Sci. Trans., vol. 3, pt. 4, p. 574. Class PELECYPODA 190i. Nucula proxima Say. Glenn, Maryland Geol. Survey, Order PRIONODESMACEA Miocene, p. 398, pi. 108, figs. 5, 6. 1906. Nucula proxima Say. Clark, idem, Pliocene and Pleisto Superfamily NUCTTLACEA cene, p. 207, pi. 65, figs. 1-4. 1932. Nucula proxima Say. Mansfield, Florida Geol. Survey Family NUCUIIDAE Bull. 8, p. 30, pi. 1, figs. 3, 4, 5. * Genus NUCUIA Lamarck Valves obliquely subtriangular, obsoletely striate trans versely, one or two of the striae more conspicuous; numerous, 1799. Nucula Lamarck, Prodrome d'une nouvelle classification hardly perceptible longitudinal striae; anterior and posterior des coquilles: Soc. histoire nat. Paris M6m., p. 87. sides forming an acute angle; umbo obtuse; apex % acute; Type by monotypy: Area nucleus Linneaeus. Recent in the teeth angulated, prominent, cavity at the apex of the hinge European seas. The group has been exhaustively treated by profound, rather long; basal margin denticulatocrenate. Schenck.31 Greatest length one-fifth of an inch.—Say, 1820. Valves not gaping: shell nacreous in texture, small, If a geographical series of this species be examined, it will trigonal to subcircular to elliptical. Umbones sub- be noticed that the northern specimens are almost smoothly central or posterior, proximate, opisthogyrate. Es truncate behind, the escutcheon is not impressed to any marked degree, and there is no angle at the margin below the escutch cutcheon, and more rarely the lunule, clearly indicated eon. On the other hand, the specimens from the southern though not sharply defined. External surface com coast, whence Say's type was derived, have a thinner shell monly concentrically striate or rugose with a more with an impressed escutcheon, the middle of which pouts more or" less obvious subcutaneous radial lineation. Two or less strongly; the valve margin below the escutcheon has a series of crowded, chevron-shaped hinge teeth, the projecting angle; the shell is somewhat compressed, compared with the northern form, and has a paler a"hd more delicate anterior the longer and the individual teeth diminish epidermis. * * * Most of tihe conchologists of the United ing rapidly in size along the margin of the chondro- States having resided north of Delaware, the northern form Is phore; the posterior series shorter and more uniform the more familiar both in books and collections, but it is not in size and direction. Chondrophore narrow, inclined the original type, and I have therefore given it a varietal name.—Dall, 1898. 31 Schenck, H. G., The classification of nuculid pelecypods: Mus. royal histoire nat. Belgique MSm., vol. 10, No. 20, pp. 1-78, pis. 1-5, 1934. 32 Idem, p. 22. 20 MOLLUSCA FROM MIOCENE AND LOWER PLIOCENE OF VIRGINIA AND NORTH CAROLINA Type locality: Upper Marlboro, Md., is cited as tlie below Tar Ferry, 3 to 4 miles below Tar Ferry, Dogwood type locality. The collector was Mr. J. Gilliams, of Landing, and Mount Pleasant Landing, Hertford County; Cole- rain Landing, Mount Gduld Landing, and % to % mile above Philadelphia, who submitted a specimen of a large Edenhouse Point, Bertie County; Palmyra Bluff, Halifax species of fossil "Perna" later referred to Melina max- County; Hamilton Landing, % mile below Hamilton Landing, illata. The Nucula and several other species were taken 2 miles southeast of Hamilton Landing, 4 miles northwest of from the. "compact earth" included between the two Williamston, and 2% miles northwest of Williamston, Martin "Perna" valves. No record of Melina magdllata from County; 2 miles west of Rocky Mount, y2 mile above Bells Bridge, Shiloh Mills, and Tarboro, Edgecombe County; 2 miles the immediate vicinity of Upper Marlboro has since below Toddy Station, 1*4 miles northeast of Farmville, 2*/3 been published. miles north of Standard, 3 miles southwest of Frog Level, 8 This exceedingly variable form is by far the most to 9 miles west of Greenville, Hardee Creek, 3*A miles from common Nucula of the east coast Miocene and (Pliocene. Tar River, 1 mile northwest of Galloway Crossroads, Pitt The range in the outline of the valves of the Recent County; 1 mile west of Wilson, Wilson County; 4 miles east species, coincident with the geographic range, has al of Lizzie, Greene County. Duplin marl, 4 miles south of Clinton, and 10 miles south of Clinton, Sampson County; J^atural Well ready been noted by Dall. One would scarcely expect and environs, Duplin County; 1% miles northeast of Fairmont, to find, as is the case, that the contour characteristic Robeson County. Pliocene, Waccamaw formation. Walkers of the northern inhabitants among the Recent species Bluff, Bladen County; Lake Waccamaw, Cronly; and Neills is, in the fossil representatives, limited for the most Eddy Landing, Columbus County; city rock quarry, Wilniington, part to the late Miocene and early Pliocene forms of New Hanover County. southern North Carolina. The species is common at most of these localities and in the environs of Hamilton Landing, N. C., is exceedingly abundant The number of the hinge teeth varies with the age. and practically the only form of. molluscan life represented. It is not uncommon to find young forms with only 4 Outside distribution: Miocene, Calvert formation, Shiloh, posterior and 10 anterior teeth nor adults with 12 Jericho, and Bridgeton, N. J.; Church Hill, 3 miles west of posterior and 25 anterior teeth. The radial sculpture Centerville, Fairhaven, Chesapeake Beach, Plum Point, and is another inconstant character, in both the number Trumans Wharf, Md. Choptank formation, Dover Bridge and Cordova, Md. Duplin marl, Darlington, Darlington County, and the prominence of the impressed lines. These are, S. C.; Porters Landing, Effingham County, Ga. Choctawhatcb.ee for the most part, visible only under magnification, but formation, northern Florida. Pliocene, Waccamaw formation, in occasional individuals they seem to be altogether Nixons and Tillys Lake, Horry County, S. C. Caloosahatchee wanting, while in others they may be readily noted with marl, Sanford, Seminole County, Fla.; Kissimmee, Osceola the naked eye. County, Fla.; Caloosahatchee River and Shell Creek, Fla.; Pleistocene, Dismal Swamp Canal, posts 15 to 16, Va.; quaran A single valve, quite certainly an abnormal Nucula tine station well, North Carolina; Wailes Bluff, near Cornfield proxima Say, was collected one-third of a mile below Harbor, Md.; Simmons Bluff, Savannah River, S. C.; Rose Bluff, Hamilton Landing. The shell is subquadrangular in Nassau County, Fla.; Eau Gallie, Brevard County, Fla.; Daytona, outline, with almost terminal beaks, sharply truncated Volusia County, Fla. Recent, Cape Hatteras to Charlotte Har bor, Fla., in 2 to 100 fathoms; variety trunculus Dall, from posteriorly, though rounded anteriorly. Nova Scotia south to Hatteras. The variety truncula, suggested by Dall, has not been separated from the true proodma, as the criteria which Nucula diaphana H. C. Lea he gives—the outline, convexity, escutcheon characters, Plate 1, figures 3, 9 etc.—have proved in the material under investigation to bear no constant relation to one another. 1846. Nucula diaphana H. C. Lea, Am. Philos. Soc. Trans., vol. 9, p. 243, pi. 34, fig. 26. Distribution: Virginia: Miocene, St. Marys formation (?) 1898. Nucula diuphana H. C. Lea. Dall, Wagner Free Inst. Sci. Nomini Cliffs, Westmoreland County'. St. Marys formation, Trans., vol. 3, pt. 4, p. 577. Union Mills, 2% miles south of Farnham, Richmond County; % mile above Jones Point, 1 to 2 miles below Bowlers Wharf, Essex Shell transverse, inequilateral, subelliptic, rounded anteriorly County ; Urbanna, Middlesex County. Yorktown formation. % and posteriorly, inflated, diaphanous, thin, smooth, polished, mile above Yorktown, Yorktown, York County; 1% miles west of pearly within; umbonial slope somewhat flattened ; basal margin Smithfleld, Benns t Church, 1% miles below Blackwater Bridge, curved; dorsal margin curved; beaks prominent; teeth very Blackwater River, Isle of Wight County; Hitchcock, Greensville arcuate, 5 anterior, 12 posterior; fosset rhomboidal, oblique; County; a quarter of a mile north of Chuckatuck, Exit, % mile internal margin crenulated. east of Everets, iy2 miles southeast of Reids Ferry, 1% miles Diameter 0.04, length 0.11, breadth 0.15 inch. north of Suffolk, 1% miles north of Suffolk, 5% miles northwest This little shell, in common with the preceding [Nucula of Suffolk, 2y> miles northwest of Suffolk, 1 mile west of Suffolk, dolabella H. C. Lea] has some resemblance to the, N. obliqua iy2 miles northeast of Suffolk, y^ mile below Suffolk water Say, but it may be distinguished by its elliptical shape, thin and works dam, and drainage ditch of Norfolk & Western Railway, diaphanous substance, smooth surface, and' rhomboidal fosset just below Jericho ditch, Nansemond County. The teeth are also more arcuate, and there is a greater disparity North Carolina: Miocene' Yorktown formation: 1 mile above between the posterior and anterior series. Branches Bridge, iy2 miles below Branches Bridge, and 1% In outline, this species is closely allied to the N. antiqua to 2 miles below Branches Bridge, Northampton County; Mur Mighels and Adams, from the post-Pliocene of Massachusetts.— freesboro, iy2 miles above Murfreesboro, Tar Ferry, 1% miles H. C. Lea, 1846. PART 1. PELECYPODA 21 Lea's illustration is so very poor that it is impossible Type locality: Maryland. to be sure whether or not the specimen, No. 1591, from The synonymy of this species gives evidence of the the Academy of Natural Sciences in Philadelphia, close resemblance to its Pleistocene and Recent de labeled ddaphana, and reproduced in figure 3, is that scendant, Yoldia limatula (Say). TJie outlines of both described and figured by Lea. The measurements forms vary widely, and little reliance can be placed closely correspond, and the species represented seems upon this character. As a rule, however, the Tertiary distinct from the common N. proximo, Say. It has species is relatively lower, more rostrate posteriorly, not, however, been identified in the later collections. , and with a less pronounced umbonal slope. The hinge Type locality: Petersburg, Va. teeth and the character of the chondrophore furnish the best distinctions. In Yoldia la&vis the teeth are Family NUCUXANIDAE more closely set and the series extends farther down toward the basal margin than in Yoldia limatula. In Genus YOLDIA Moller both forms the number of teeth varies with the age of 1842. Yoldia Moller, Index molluscorum Groenlandiae, p. 18. the individual. The chondrophore of Yoldia laevis is Type by subsequent designation (Verrill and Bush, Am. more conspicuous and tends to be transversely Jour. Sci., 4th ser., vol. 3, p. 55, 1897) : Yoldia arctica Moller elongated rather than subtriangular as in Yoldia (not Gray) —YQldia hyperborea (Loven) Gould. Recent in the limatula (Say). Arctic seas. The Tertiary species is common in the more north The genus differs from the old "Leda" in the ern localities but, like the Recent Yoldia, diminishes in posterior gape of the valves, the longer siphons, and prominence and finally disappears toward the south. the consequently deeper pallial sinus. It is more pro Distribution: Virginia: Miocene, Yorktown formation, Hitch duced transversely and more markedly rostrate than cock, Greensville County; % mile above Yorktown, York- the southern analog, Orthoyoldia Verrill and Bush, the town, York County; Claremont Wharf, Surry County; Fergu- length of the anterior and posterior series of teeth is sons Wharf, 1% miles west of Smithfield, and 5 miles northeast of Smithfield; 1% miles below Blackwater Bridge, 2% to 3 more discrepant, and the chondrophore is relatively miles south of Zuni, 7 to 7y2 miles below Zuni, Isle of Wight larger and higher. County; 2 to 2% miles below South Quay, Blackwater River, *4 mile north of Chuckatuck, y± mile east of Everets, Exit, 5% miles Yoldia laevis (Say) Conrad northwest of Suffolk, 2y2 miles northwest of Suffolk, 1% miles northwest of Suffolk; iy2 miles north of Suffolk, 1 mile west of Plate 1, figure 10 Suffolk, y2 mile below the Suffolk waterworks dam, 1 mile north east of Suffolk, and 1% miles northeast of Suffolk, Nansemond 1824. Nucula laevis Say, Acad. Nat. Sci. Philadelphia Jour., 1st County. ser., vol. 4., p. 141, pi. 10, fig. 5. North Carolina: Yorktown formation, 1 mile above Branches 1831. Nucula laevis Say, American conchology, pi. 12, right- Bridge, ]% to 2 miles below Branches Bridge, and Branches hand figures, descriptive test. Bridge, Northampton County; 2% miles northwest of Murfrees- 1845. Nucula limatula Conrad, Fossils of the medial tertiary boro, l 1^ miles above Murfreesboro, 1 mile above Murfrees- of the United States, p. 57, pi. 30, fig. 4. Not boro, Murfreesboro, Tar Ferry, and Mount Pleasant Landing, N. limatula Say, 1831. Hertford County; Durham's farm near Halifax, Palmyra Bluff, 1856. Nucula limatula Say. Tuomey and Holmes, Pleiocene and 3y2 miles below Palmyra Bluff, Halifax County; Hamilton fossils of South Carolina, p. 52, pi. 17, figs. 13-15. Not Bluff, ys mile below Hamilton Landing, 3 miles west of William- N. limatula Say, 1831. ston, 2y2 miles northwest of Williamston, and 1 mile northwest 1863. Yoldia laevis Say. Conrad, Acad. Nat. Sci. Philadelphia of Williamston, Martin County; 6 to 7 miles below Rocky Mount, Proc. for 1862, vol. 14, p. 581. 5 miles below New Bridge, 15y2 miles above Bells Bridge, % mile 1864. Yoldia laevis (Say) Conrad. Meek, Miocene check list; above Bells Bridge, mouth of Swift Creek, and Shiloh Mills, Edge- Smithsonian Misc. Coll., No. 183, p. 5. combe County; 2 miles below Toddy Station, 3 miles southwest of 1894. Yoldia "limatula" Whitfield, U. S. Geol. Survey Mon. 24, Frog Level; 8 to 9 miles west of Greenville, 3 miles west of p. 51 (part), pi. 7, figs. 11, 12. Greenville, 6 miles below Greenville, 6% miles below Green 1898. Yoldia laevis Say. Ball, Wagner Free Inst, Sci. Trans., ville, 8 to 9 miles south of Greenville, and 9 to 10 miles south vol. 3, pt. 4, p. 596. of Greenville, Pitt County; 1 mile west of Wilson, Wilson 1904. Yoldia laevis (Say). Glenn, Maryland Geol. Survey, County; 1 mile east of Lizzie, % mile east of Lizzie, and 4 Miocene', p. 397, pi. 108, figs. 3, 4. miles east of Lizzie in Dog Swamp, Greene County; y2 to % mile above Edenhouse Point, Bertie County. Duplin marl, iy2 Transversely elongate-subovate, rostrated, nearly smooth. miles northeast of Fairmont, Robeson County. Pliocene, Shell compressed, thin, fragile, polished, smooth, slightly Waccamaw formation, 4 miles south of Elizabethtown and wrinkled toward the base; beaks nearly central, hardly promi Walkers Bluff, Bladen County. nent beyond the hinge margin, rounded, approximate; series Outside distribution: Miocene, Calvert formation, Jericho and of teeth subrectilinear, a little arcuated behind; teeth promi Shiloh, Cumberland County, N. J.; Church Hill, Fairhaven, nent ; hinge margin exteriorly both before and behind the beaks Parker Creek, Lyons Creek, Plum Point, and Whites Landing, rather abruptly compressed; posterior margin rounded ; anterior Md. Hawthorn formation, Porters Landing, Savannah River, margin somewhat rostrated, the anterior hinge margin Effingham County, Ga. Choptank formation, Jones Wharf and rectilinear, very little reflected at tip; inner margin simple. Sand Hill, Md. St. Marys formation, Cove Point, St. Marys Length nearly half an inch, breadth nearly 1 inch—Say, 1824. River, and Langleys Bluff, Md. 22 MOLLUSCA FROM MIOCENE AND LOWER PLIOCENE OF VIRGINIA AND NORTH CAROLINA Superfamily ARCACEA The shell of Barbatia, like that of Area, is usually of at least moderate dimensions, inequilateral, transversely Family ARCIDAE elongate, with a byssal gape at the ventral margin, 1935 (August). Reinhart, P. W., Classification of the pelecypod anterior or subcentral beaks, a multivincular ligament, family Arcidae: Mus. royal histoire nat. Belgique Mem., vol. 11, No. 13, pp. 1-68. numerous taxodont teeth, rather large muscle scars, a simple pallial line, and, as a rule, a crenate inner Genus ARCA (Linnaeus) Lamarck margin. 17,58. Linnaeus, Systema naturae, 10th ed., p. 693. The shell is usually less deformed in Barbatia than 1799. Lamarck, Prodrome d'une nouvelle classification des co- it is in Area; the byssal gape is not so wide; the posterior quilles: Soc. histoire nat. Paris M6m., p. 87. portion of the shell is broadly rounded rather than Area noae Linnaeus, Recent in the Mediterranean, rostrate; the beaks are less prominent and the car and the Area cited in the Prodrome, was long accepted dinal area is @onsequently lower; the dentition is less as the type and has to its credit the authentic designa regular than that of Area and is usually obliterated tions of Schmidt, 1818, and Gray, 1847. The citation medially in the adult by the encroachment of the car- of Schumacher, 1817 (Essai d'un nouveau systeme des ^dinal area. The shells of both genera are radially habitations des vers testaces, p. 172), "Pour le type da sculptured, but that of Barbatia, though irregular in genre j'ai donne la fig. 2, pi. XIX, de la charniere de many species, is less sharply differentiated on the VArca antiquata Lin. qu'on trouve figuree dans Chemn. anterior and posterior areas. 7, pag. 201, tab. 55, fig. 548," may justly claim priority. True Barbatia has been recognized in the Upper Cre As Reinhart 33 remarked, however, "It is a debatable taceous of the east coast and Gulf regions (Stephen-* question -whether Schumacher was here designating a son, 1923; Wade, 1926) and the genotype is a Recent type species or merely illustrating a type of hinge species. structure." A request that Area noae be established Subgenus GRANOARCA Conrad as the type species has been presented to the Interna 1862. Granoarca Conrad, Acad. Nat. Sci. Philadelphia Proc., vol. tional Commission on Zoological Nomenclature by 14, p. 290. Reinhart.33 This stems on the whole a wiser method Type by inonotypy: Area propatiila Conrad. Miocene of Vir of salvaging a widely accepted type than an attempt ginia and the Carolinas. to invoke "virtual tautonomy" in its behalf. Barbatia (Granoarca) propatula (Conrad) Conrad In the hope of a favorable decision from the com Plate 2, figure 1 mission Area noae has been retained as the type of 1844. Area propatula Conrad, Acad. Nat. Sci. Philadelphia Proc., the genus in this report. vol. 1, p. 323. The Areas typified by A. noae are equivalve, inequi 1845. Area propatula Conrad, Fossils of the medial Tertiary of lateral, transversely elongate, rudely quadrate, or oval, the United States, p. 61, pi. 32, fig. 1. commonly irregular in outline, and gaping anteriorly. 1856. Area Mans Tuomey and Holmes, Pleiocene fossils of South The beaks are prominent, placed well forward and Carolina, p. 34, pi. 14, figs. 4, 5. Not Aroa hians Bronn, 1842, nor Reeve, 1844. separated by a wide cardinal area scarred with oblique, 1863. Barbatia, (Granoarca) propatula Conrad, Acad. Nat. Sci. discontinuous cartilage grooves. The radials that Philadelphia Proc. for 1862, vol. 14, p. 580. adorn the outer surface differ in prominence and spac 1898. Barbatia (Granoarca) propatula Conrad. Dall, Wagner ing on different parts of the shell. The hinge line is Free Inst. Sci. Trans., vol. 3, pt. 4, p. 627. straight; the teeth are numerous, short, subequal, and 1916. Area, propatula Conrad. Sheldon, Palaeontographica Americana, vol. 1, No. 1, p. IS, pi. 4, fig. 1. transverse. The adductor impressions are distinct, the 1932. Barbatia (Granoarca) propatula Conrad. Mansfield, pallial line is simple, and the inner margins are smooth Florida Geol. Survey Bull. 8, p. 43, pi. 4, figs. 1, 2, 3. or feebly crenate at the extreme edge in harmony with Rhomboidal, thick, and ponderous; posterior side produced; the radial ornamentation of the exterior. sides flattened, slightly concave toward the base; umbonial slope rounded, rather elevated; ribs about 32, square, not profoundly Genus BARBATIA Gray prominent, about equal in width to the interstices, which have transverse imbricated lines; ribs largest about the umbonial 184^. Barbatia Gray, Synopsis of the contents of the British slope, very distinct on the posterior slope, which is concave Museum, 44th ed., p. 81. Described but no species men- toward the hinge line; posterior margin oblique, concave, ex tioned.t tremity widely rounded; summit of umbo moderately elevated, 1847. Barbatia Gray, Zool. Soc. London Proc., pt. 15, p. 197. slightly retuse; cardinal area wide, with diverging grooves; Type by subsequent designation, Gray, 1847: Area, barbata series of teeth slightly sinuous anteriorly; teeth numerous; at Linnaeus. Recent in the Mediterranean. the posterior extremity the series suddenly becomes dilated and the teeth interrupted or tubercular; inner margin crenate, crenae The Barbatia, are elongated shells, covered with a hairy profound, and remote posteriorly. Length, 4 inches; height, periostraca; the teeth on the middle of the line are small, of rather more than 1% inches. the ends large and oblique.—Gray, 1842. Locality: James River below City Point, Petersburg, Mr. Tuomey, Ware River, Gloucester County, Va., Mr. Ruffin— 33 Eeinhart, P. W., op. cit., p. 16. Conrad, 1844. PART 1. PELECYPODA 23 This species strikingly illustrates the characteristic 1916. Area lienosa Say. Sheldon, Palaeontographica Americana, of the section—the disintegration of the distal teeth. vol. I, No. I, p. 35 (part), pi. 7, figs. 26-28; ? pi. 8, The shell is larger than Granoarca virginiae (Wagner), figs. 1, 2. 1932. Area (Anadara) lienosa Say (part). Mansfield, Florida the beaks are not so high and less tumid, the posterior Geol. Survey Bull. 8, p. 50, pi. 3, fig. 8. margin is less produced, and the ribs are more numer Shell rather thin, transversely oblong; ribs about 40, some ous. The byssal gape, though narrow, is distinct. what flattened and much broader than the intervening spaces, Mansfield has indicated the essential resemblance of which are very narrow, and with a longitudinal impressed line, Grranoarca propatula.to the much smaller G. campyla particularly on those of the posterior margin, Which are almost Dall, an abundant and diagnostic species of Florid- bifid; and with numerous slightly elevated transverse lines, which being divided by the longitudinal striae appear granu ian Pliocene. In Florida Gr. propatula is reported lated ; beak but little prominent, and nearly opposite to the only from the Cancellaria zone, the time equivalent of posterior [anterior] third of the length of the hinge margin; the upper beds of the Yorktown formation. area narrow and elongated; hinge margin rectilinear, angulated "Distribution: Virginia. Miocene, Yorktown formation, Peters at each extremity; teeth numerous, small; posterior [anterior] margin obliquely rounded inward, no part of it extending far burg, Dinwiddie County (Tuomey) ; below City Point on the James River, Prince George County (Tuomey) ; Ware River, ther backward than the angle; anterior [posterior] margin Gloucester County (Ruffin). obliquely truncate; inner margin crenate. A fossil shell from the same locality as the preceding [the Outside distribution: Miocene, Duplin marl, Darlington, S. C. Santee River, below the confluence of the Congaree and Choctawhatchee formation, Cancellaria zone in Leon County, Fla. Wateree Rivers] and also sent to me by Mr. Elliott.—Say, 1832. Genus ANADARA Gray This species has always been rather rare and has been con founded with its undoubted descendant, the Area floridana of 1847. Anadara Gray, Zool. Soc. London Proc., pt. 15, p. 198. Conrad, found living in Florida waters. Nevertheless, the 1925. Diluvarca Woodring, Carnegie Inst. Washington Pub. 366, recent and the fossil shells are readily distinguished on p. 40. Suppressed in favor of Anadara by Woodring, comparison. * * * In A. lienosa there are about 40 ribs in a Carnegie Inst. Washington Pub. 385, p. 18, 1928. specimen 108 millimeters long; these ribs are deeply grooved Type by monotypy: Area antiquata Linnaeus. Habitat not de down the center, and the ridges on either side of the grooves termined. are likewise longitudinally grooved with one or two incised lines. The interspaces between the ribs are narrower than the ribs; Anadara is a moderately heavy, transversely elongate the beaks are less anterior than in A. secticostata. [= A. shell with a rather wide range in size. The outline floridana Conrad]. In the latter the ribs are much narrower than and the sculpture are more regular than in Barbatia. their interspaces, fiat-topped, and distally for a little more than The byssal gape is much less pronounced and does not half their length in the adult the top of the rib has a broad, shallow channel. In no case are there any subsidiary grooves. warp the shell. The beaks are full, and the cardinal Minute concentric ridges are quite obvious in both species, area is relatively high 'and scarred with concentric but the fossil has the ridges more generally and conspicuously chevronlike ligament grooves diverging beneath the beaded. In other respects the shells are extremely similar.— tips of the umbones. The dental series is not broken Dall, 1898. medially, as it is in the adult Barbatia, but the distal Within the area under discussion there is no species teeth are larger than the medial, more oblique, and less with which this rare but very conspicuous form is closely spaced. In the larger shells the muscle scars readily confusable. are prominent and the inner margins deeply fluted. Anadara lienosa is essentially warm-temperate or The group includes a great number of our Tertiary subtropical in its distribution. The records from the and Recent east coast and Gulf species. cooler faunas of the Yorktown formation are fragmen Anadara lienosa (Say) Mansfield tary. This, in itself, is evidence against the inclusion Plate 2, figures 4, 7 in the synonomy of Area protracta, described by the Rogers brothers from Prince George County, Va. In 1832. Area lienosa Say, American conchology, pi. 36, fig. 1, and descriptive text. Florida, Mansfield reports Alienosa from several local 1856. Area lienosa Say. Tuomey and Holmes, Pleiocene fossils ities in both the Ecphora and the Cancellaria zones of of South Carolina, p. 40, pi. 15, figs. 2, 3. the Choctowhatchee. Related species include Area 1858. Area lienosa Say (part). 'Holmes, Post-Pleiocene fossils (Scapharca) Jienekeni from the Dominican Republic of South Carolina, p. 20. and the Machapoorie horizon in Trinidad and Barbatia 1858. Area, lienosa Say. Emmons, North Carolina Geol. Survey (Diluvarca) halidonta oresta Woodring from the Bow- Rept., p. 284, fig. 204. 1863. Scapharca lienosa Say. Conrad, Acad. Nat. Sci. Phila den of Jamaica. The middle Miocene West Indian delphia Proc. for 1862, vol. 14, p. 579. forms recall not only lienosa of the upper Miocene and 1864. Scapharca lienosa (Say) Conrad. Meek, Checklist of the Pliocene distribution but also the abundant and widely invertebrate fossils of North America, Miocene; Snaith- distributed group which includes hypomela (Dall) of sonian Misc. Coll., No. 183, p. 6. 1887. Area lienosa Say. Heilprin, Wagner Free' Inst. Sci. the Chipola and dodona (Dall) of the Oak Grove. Trans., vol. I, p. 97. Distribution: North Carolina: Miocene, Duplin marl, 1 mile 1898. Scapharca (Scapharca) lienosa Say. Dall, idem, vol. 3, south of Clinton, Sampson County; Natural Well, 1% miles north pt. 4, p. 636. of Magnolia, Duplin County; 4 miles northeast of Fairmont, Robe- 24 MOLLTJSCA FROM MIOCENE AND LOWER PLIOCENE OF VIRGINIA AND NORTH CAROLINA son County. Pliocene, Waccamaw formation, Neills Eddy Land 1916. Area callicestosa Dall. Sheldon, Palaeontographica ing, 3 miles north of Cronly, Columbus County; Wilmington, Americana, vol. 1, No. 1, p. 43, pi. 10, figs. 3-5. New Hanover County. 1932. fArca (Anadara) callicestosa (Dall). Mansfield, Florida Outside distribution: Miocene, Choctawhatchee formation, Geol. Survey Bull. 8, p. 49, pi. 5, figs. 7, 8. northern Florida. Duplin marl, Brunswick River bed, Bruns wick, Glynn County, Ga. Pliocene, Waccamaw formation. S.hell of moderate size, rather thin, rhbmboidal, with small, Nixons, Todds Ferry, and Tillys Lake, Horry County, S. C. prominent, mediosulcate, prosocoelous beaks situated at about Caloosahatchee marl. Caloosahatchee River, Shell Creek, and the anterior third of its length; left valve with about 37 Alligator Creek, Fla. Pleistocene, Simmons Bluff, Savannah squarish subequal radial ribs, separated by narrower channeled River, S. C. interspaces; on the tops of these ribs ajre 4 longitudinal threads, i the inner pair larger and more prominent but separated by a Anadara protracta (Rogers and Rogers) Gardner somewhat deeper sulcus than those external to the inner Plate 2, figure 5; plate 3, figure 3 threads; concentric sculpture of fine, close, rounded, slightly elevated threads, which overrun the whole shell, ribs, and 1837. Area protracta W. B. and H. D. Rogers, Am. Philos. Soc. interspaces, and at short intervals, at the intersection with the Trans., n. ser., vol. 5, p. 332. inner pair of rib threads they become minutely nodulous, while 1839. Area protracta W. B. and H. D. Rogers, idem., vol. 6, pi. the reticulations have a punctate appearance, giving a surface 26, fig. 5. somewhat like fine lace and peculiar, as far as observed, to this 1845. Area (Anomalocardia [in plate description only]) pro- species; cardinal area short, rather narrow, with sharply ele tracta Rogers. Conrad, Fossils of the medial Tertiary vated boundaries and a single incised set of grooves forming a of the United States, p. 58, pi. 30, fig. 5. lozenge-shaped figure anteriorly; hinge line short, teeth in two 1898. Area protracta Rogers. Dall, Wagner Free Inst. Sci. Trans., adjacent series, anterior with 15, posterior with 26 or 27 teeth set vol. 3, pt 4, p. 627. vertically, a little oblique at the distal ends of the series; each 1916. Area lienosa Say (part). Sheldon, Palaeontographica individual tooth more or less grooved or striate in the direction Americana, vol. 1, no. 1, p. 35, pi. 8, figs. 1, 2. of motion, as in some recent species; anterior end of shell pro duced, rounded; posterior end subtruncate, base slightly arched; Shell rather thick, very oblong transversely; ribs about 40, not inner margin of the valves with rather long, deep flutings, very prominent, hardly wider than the intercostal spaces, and corresponding to the external ribs. Longitude 32, altitude 27, longitudinally furrowed by three narrow grooves, the central diameter 20 millimeters (twice the diameter of the single valve). one much the widest; a very indistinct granulation of the A single valve of this very elegant species was obtained by ribs, arising from the numerous minute transverse line's of Mr. Burns. Its sculpture differentiates it from all our other growth crossing the longitudinal ridges of the ribs; beaks prom Tertiary species. Area callipJeura Conrad, in which the ribs inent and distant, opposite a point less than .one-third the have a minute nodular sculpture, has the radial threading length of the hinge margin from the posterior extremity; area predominant, while in this species the concentric threads over wide, with numerous distinct undulated grooves, parallel to the run all the rest. The two species aref entirely distinct hinge margin; hinge margin rectilinear, with numerous minute otherwise—Dall, 1898. straight teeth, those in the anterior half directed a little obliquely toward the anterior margin; posterior margin Holotype: U. S. Nat. Mus. 146264. rounded slightly outward, extending a little farther backward Type locality: U. S. G. S. station 2833. Upper bed than the angle; anterior margin much elongated, extending in (Miocene) at Gaskins Wharf, on the Nansemond River, an oval curve far in advance of the end of the hinge; basal margin contracted opposite the middle of the hinge, and deeply 16 miles below Suffolk, Va., F. Burns. crenate. Length, 3% inches. The specimens from the Ecphora and Cancellaria Locality, Shell banks, Prince George County, [Va.].—Rogers zones of the Choctawhatchee referred by Mansfield to and Rogers, 1837. A. callicestosa are not typical and may, as Mansfield In the orientation of the shell, the anterior and pos suggests, prove to be subspecifically distinct. The terior margins have been reversed. This species is un specimen figured by Mansfield seems closer to mag- doubtedly very close to Anadara lienosa (Say). The noliana than to the holotype of callicestosa^ but it is two may be identical but as the type has not been relatively higher than the North Carolina species and available for consultation it does not seem wise to has developed a much wider cardinal area. With so unite them. A. protracta has apparently a greater little material, it is difficult to discriminate between relative width than the normal A. lienosa of Say, with individual, age, and taxonomic differences. a more marked contraction of the basal margin Distribution : Virginia: Miocene, Yorktown formation, Gaskins and a wider cardinal area. Furthermore the known Wharf, Nansemond County. The type is still unique. distribution of A. lienosa does not include a fauna of so cool water as that indicated by the type locality of Anadara callicestosa wilsorii Gardner, n. subsp. protracta. Plate 3, figures 8, 9, 12 Distribution: The species is not represented in the material The subspecies is based on the following criteria:" under discussion nor in any of the collections to which access Anadara callicestosa subsp. wifeoni is a relatively higher has been gained. form than A. catticestO'S® (Dall), the base line is more Anadara callicestosa (Dall) Mansfield rounded, the anterior margin less produced, the pos Plate 3, figures 2, 6 terior margin more produced and more obliquely trun 1898. Scapharca (Scapharca) callicestosa Dall, Wagner Free cated, the umbones are more convex, the cardinal area Inst. Sci. Trans., vol. 3, pt. 4, p. 638, pi. 34, figs. 17, 18. is higher and marked with 2 or 3 irregular groovings PART 1. PELECYPODA 25 instead of a single half-diamond groove; the hinge crementals; interior flutings corresponding to exterior characters are practically identical; the ribs, however, costae. number 33 instead of 37 as in the type of the species, Dimensions of holotype: Height 34.3 millimeters, and the intercostal areas approximately equal the width 46.7 millimeters, convexity of single valve, 12.0 costae in width; the general type of sculpture of the millimeters. individual costae is the same, but the nodular effect is Holotype: U. S. Nat. Mus. 325486. somewhat lost by the wider separation of the ribs. Type locality: Natural Well, Duplin County, N. C. Dimensions of holotype: Height 30.6 millimeters, The peculiar lacelike pattern of the surface sculp width 34.3 millimeters, convexity of single valve, 12.5 ture, which was noted in the original description of A millimeters. callicestosa (Dall), is reproduced in magnolia/no,. The Holotype: U. S. Nat. Mus. 325488. shells differ widely, however, in outline and in the Type locality: Frank Wilson's) marl pit near characters of the cardinal area and hinge teeth. The Magnolia, N. C. species has not been observed, except from the marls Further material may show these variations to be in the vicinity of Magnolia, Duplin County, N. C. merely individual instead of subspecific, but in the ab The form has been described from a single valve— sence of a connecting series it seems better to keep the right. Another right valve, from near the same the forms separate. locality, exhibits a shorter and relatively higher out Distribution: North Carolina: Miocene, Duplin marl. The line ; the ribs are more closely crenulated than those of subspecies is described from a single left valve from the marl the type and, on the disk, exhibit 3 instead of 4 riblets; pit of Frank Wilson near Magnolia, Duplin County. the anterior and posterior costae, however, do not differ in sculpture detail from those of the type. Anadara magnoliana Gardner, n. sp. Distribution: North Carolina: Miocene, Duplin marl, Natural Plate 3, figures 1, 4, 5, 7 Well, and 1% miles north of Magnolia, Duplin County. Shell thin, inflated, inequilateral, roughly rhom- Anadara carolinensis (Wagner) Gardner boidal, gently rounded anteriorly, slightly produced Plate 2, figure 6 and obliquely truncated posteriorly. Umboues proso- 1848. Area carolinensis W. Wagner. Bronn, Handbuch Ge- coelous, fairly prominent, placed near the anterior schichte Natur, Index palaeontologicus, pt. 1, p. 93 third of the hinge line. Cardinal area narrow, sharply (nomen nudum). delimited, sculptured with 2 diamond-shaped grooves. 1849. Area carolinensis W. Wagner. Bronn, idem, pt. 2, p. 281 Length of hinge approximately three-fifths of the total (nomen nudum). Not Barbatia (Plagiarca) caro length of the shell. Teeth very short and close-set linensis Conrad, 1875. 1897. Area carolinensis Wagner, Wagner Free Inst. Sci. Trans., beneath the beaks, becoming larger and less crowded vol. 5, p. 9, pi. 1, fig. 4. Explanatory text by Dall. distally; anterior denticles 17, slightly concave for 1898. Scapharca (Scapharca) carolinensis Wagner. Dall, idem, ward ; posterior denticles 28; in the type the proximal vol. 3, pt. 4, p. 639, pi. 33, fig. 11. 10 are perpendicular to the hinge, the 10 behind them 1916. Area carolinensis Wagner. Sheldon, Palaeontographica with a slight backward slant, the final 8 slanting a lit Americana, p. 42, pi. 10, figs. 1, 2. tle forward; both anterior and posterior distal teeth, Shell laijge, solid, squarish, moderately inflated, with sub- grooved on each side. Radial sculpture of 37 costae, central, prosocoelous, rather elevated beaks; left valve with about 30 ribs, with subequal interspaces, the anterior ribs which over the greater part of the disk are strongly squarish, with a shallow median sulcus near the margin, and arched, becoming narrower and less prominent toward irregular concentric ripples; the ribs of the middle of the valve the anterior lateral margin and on the posterior por not sulcate, with less rippling, more closely adjacent, the inter tion of the shell broadening and flattening upon the spaces very squarely channeled; the posterior ribs smaller, summits; intercostal areas subequal to the costal and rounded, and more closely set; cardinal area short, rather wide, smooth or longitudinally striate, with 3 concentric lozenge- to one another, squarely channeled over the mesial shaped groovings; hinge line short, solid; the teeth not inter and posterior parts of the shell, though less angular rupted, strong, about 45 in all, the anterior more vertical, the anteriorly; each individual costal sculptured with 4 middle teeth inclining towards the middle line of the area, longitudinal riblets, of which the second and third are the posterior teeth distally more oblique and longer; margins of the most elevated; riblets strongest on the anterior the shell strongly fluted. Longitude 56, altitude 55, diameter 43 millimeters (type specimen). part of the disk, less prominent near the anterior As this species seems never to have been described, the refer lateral margin, and posteriorly becoming almost or ences in Bronn being merely to Wagner's unpublished plates, I altogether obsolete; characteristic effect of the sculp have given a diagnosis from Professor Wagner's original type ture due largely to the undulation of the crests of the specimen and refigured the interior of the left valve. The shell medial and anterior costae; riblets strongest upon the is r-ein'arkable for its squarish form, which is rather distantly approached by some specimens of A. idonea. , It is singular that crests of the waves, evanescent in their troughs, thus in all the years which have elapsed since this shell was collected lending a subnodular aspect to the radial ornamenta and figured by Professor Wagner no one has recognized or tion; entire surface of shell covered with crowded in- described it.—Dall, 1898. 26 MOLLUSCA FROM MIOCENE AND LOWER PLIOCENE OF VIRGINIA AND NORTH CAROLINA The species differs from Area idonea Conrad in the mon but the subgeneric characters. The real affinities more equidimensional outline and the lower cardinal are with Anadara scalarina (Heilprin) of the Pliocene area. The type locality is pot known, but Dall (1897) and A. incongrua Say of the Recent fauna. reports that "a valve in the collection of the United Anadara scalarina is larger and heavier but strik States National Museum was obtained from the upper ingly similar in general aspect, particularly as regards Miocene of Duplin County, N. C." the left valves. The right valve of the Pliocene species Distribution: Virginia: Miocene, St. Marys formation?, develops a secondary rib intermediate between the pri Nomini Cliffs, Westmoreland County. St. Marys formation, maries of the disk, and of this there is no trace on the Union Mill, 2% miles south of Farnham, Richmond County. earlier scalaris or on the Pleistocene and Recent incon Very rare at both localities. grua—a species much smaller, however, than scalaris North Carolina: Miocene, Duplin marl, 4 miles south of Clin ton, Sampson County; Natural Well and 1% miles north of and lacking the conspicuous inflation of the umbones. Magnolia, Duplin County. Mansfield reports the species from both the Ecphora and the Cancellaria zones of the Choctawhatchee. Section CUNEARCA Dall Distribution : Virginia : Miocene, Yorktown formation, Peters 1898. Cunearca Dall, Wagner.Free Inst. Sci. Trans., vol. 3, pt. 4, burg, pinwiddie County. Although Conrad's type was presum p. 618. ably collected at Petersburg, the species has not been reported Type by monotypy: Area incongrua Say. Recent from Hat- from this or any other Virginia locality since his day. teras to Aspinwall and the western Gulf of Mexico. North Carolina: Miocene, Duplin marl, W. H. Kornegay's The section Cunearca is characterized by the short, marl pit near Magnolia, Duplin County. Pliocene, Waccamaw formation, Walkers Bluff on the Cape Fear River, Bladen high outline, the inequality of the valves, the left the County. The species is extremely rare'at both these localities. larger of the two, the discrepancy in their sculpture, Outside distribution: Miocene, Choctawhatchee formation, and the full, erect umbones topping a high, sufosym- northern Florida. -* metrical cardinal area. Family GIYCYMERIDAE Anadara (Cunearca) scalaris (Conrad) Dall Genus GLYCYMEUIS Da Costa Plate 2, figure 2 1778. Glycymeris Da Costa, Historia naturalis testaceorum Bri- 1844. Area, scalaris Conrad, Acad. Nat. Sci. Philadelphia Proc., tanniae, or The British conchology, p. 168. vol. I, p. 324. Type by subsequent designation (Dall, Wagner Free Inst. 1845. Area scalaris Conrad, Fossils of the medial Tertiary of Sci. Trans.,-vol. 3, pt. 4, p. 607, 1898). Glycymeris orUoularis the United States, p. 59, pi. 31, fig. 1.. Da Costa=Arco. glycymeris Linnaeus. Recent off the British 1856. Area scalaris Conrad. Tuomey and Holmes, Pleiocene Isles and the coast of Europe. fossils of South Carolina, p. 43, pi. 16, figs. 1, 2. 1858. Area scalaris Conrad. Emmons, North Carolina Geol. Shell heavy, equivalve, equilateral or subequilateral, Survey Rept, p. 284. suborbicular; the anterior extremity usually the more 1863. Scapharea scalaris Conrad, Acad. Nat. Sci. Philadelphia produced and rounded. Beaks almost straight, only Proc. for 1862, p. 580. (Name only.) 1864. Scapharca scalaris Conrad. Meek, Checklist of inverte slightly incurved. Outer surface concentrically or ra brate fossils of North America ; Smithsonian Misc. Coll. dially striate or sulcate. Ligament amphidetic, multi- No. 183, p. 6. vincular, the ligament furrows arranged in concentric 1898. Scapharca (Cunearca) scalaris Conrad. Dall, Wagner rhombs. Hinge margin arcuate, set with two series of Free Inst. Sci. Trans., vol. 3, pt. 4, p. 634. strong transverse teeth, chevron-shaped medially, the 1916. Area scalaris Conrad. Sheldon, Palaeontographica Amer icana, vol. 1, No. 1, p. 57, pi. 13, figs. 10,11. distal teeth oblique to horizontal; teeth progressively 1932. Area (Cwiearca) scalaris Conrad. Mansfield, Florida obliterated during growth by the subsidence of the liga Geol. Survey Bull. 8, p. 53, pi. 7, fig. 4. ment area. Adductor scars distinct, the posterior but ' Obliquely rhomboidal, elevated, ventricose, ribs about 23, tressed. Pallial line simple or very, slightly sinuous. broad, square, prominent, profoundly and robustly crenate, Inner margins crenulate in harmony with the outer wider than the interstices, 7 on the posterior slope, prominent; ribbing. posterior slope flattened; umbonial slope angulated; summit The genus is first recognized in the Cretaceous; it elevated, narrowed; anterior margin obliquely truncated; an terior basal margin obliquely sub truncated; posterior extremity culminated in the mid-Tertiary and is represented in subangulated; beaks remote; area with transverse slightly im the Recent fauna by about 80 species, widely distributed pressed lines; cardinal teeth irregular, oblique toward the ex in the shallower waters of the warm and temperate seas. tremities of the hinge line; within with furrows corresponding to the ribs; margin profoundly crenate. Length 2 inches, Glycymeris laevis (Tuomey and Holmes) Dall height iy2 inches. Plate 1, figure 11 Locality: Petersburg, Va., Mr. Tuomey. Allied to A. incongrua Say. The description applies to the left valve only, as the 1848. Pectunculus virginiae W. Wagner. Bronn, Index paleon- opposite one has not yet been found—Conrad, 1844. tologicus, pt. 1, p. 940. 3849. Pectunculus virginiae W. Wagner. Bronn, idem, pt. 2, Tuomey and Holmes found it necessary to give the p. 283. criteria for discriminating this species from Area trans- 1856. Pectunculus laevis Tuomey and Holmes, Pleiocene fossils versa Say, a species with which it has nothing in com of South Carolina, p. 50, pi. 17, fig. 5. PART 1. PELECYPODA 27 1897. Pectunculus mrginiae Wagner. Wagner Free Inst. Sci. 44.7 millimeters, maximum convexity 28.4 millimeters. Trans., vol. 5, p. 11, pi." 3, fig. 5. Explanatory text by The presence of secondary radial striae recalls Ball. Glycymeris americana (Defrance). It is separable 1898. Glycymeris laevi$ Tuomey and Holmes. Ball, idem, vol. 3, pt. 4, p. 609. from that species, however, by the cuneate outline of the dorsal portion of the shell, the high, tumid Somewhat oval, thick, inequilateral, concentrically striate, or grooved ; buccal margin rounded ; anal side somewhat produced, umbones, and the less prominent radial sculpture. obliquely truncate; many teeth; lip crenate, The outline of the shell serves also to distinguish it The teeth extend without interruption around the hinge. from Glycymeris parilis (Conrad), the common The pallial and muscular impressions are well defined, and in Maryland representative of the group. young individuals the shell is slightly angular near the umbones. Umbones pointed and, closely approximating. Distribution: Virginia : Miocene, St. Marys, formation, Nomini Locality, Waccamaw.—Tuomey and Holmes, 1856. Cliffs, Westmoreland County. The species, is represented in the single formation at several localities. Wagner's name, though earlier, is not entitled to standing, as his figure was never published. The plate Glycymeris duplinensis Dall on which it appears is, according to Dall, 1898, in the Plate 2, figure 3; plate 5, figure 5 possession of the Wagner Free Institute of Science in 1898. Glycymeris duplinensis Dall, Wagner Free Inst. Sci. Philadelphia. Trans., vol. 3, pt. 4, p. 613, pi. 34, figs. 6, 7. The species is characterized by the absence of radiat Shell small, rounded-triangular, solid, moderately convex, ing sculpture. with pointed, small, low beaks and a flattened lunular area; Distribution: Wagner's locality is not known, and the species sculpture of strong, distally bifurcated radial ribs, separated is not represented in any of the later Virginia collections. by slightly narrower channeled interspaces; 9 anterior and 9 Outside distribution: Pliocene: Waccamaw formation, Wacca posterior ribs, on the lateral slopes are smaller, while on the maw, S. C. (Tuomey and Holmes). middle of the shell are about 10 larger ribs; transverse sculp ture of regularly spaced, elevated concentric lines overrunning Glycymeris tumulus (Conrad) Dall? the whole shell; cardinal area small and short, with 3 or 4 concentric angular grooves; teeth small, vertically striated, Plate 1, figures 6, 12-15 6 or 7 on each side, the line strongly arched and uninterrupted; anterior margin straight, base rounded, posterior slightly 1845. Pectunculus tumulus Conrad, Fossils of the medial arcuate; basal inner margin with about 10 flutings. Largest Tertiary of the United States, p. 72, pi. 41, fig. 4. valve, longitude 9, altitude 10, diameter 6.5 millimeters. 1898. Glycymeris americana (Defranee) (part). Dall, Wagner This pretty little species is readily distinguished from any Free Inst. Sci. Trans., vol. 3, pt. 4, p. 609. of the varieties of G. pectinata by its bifurcated and prettily Suborbicular, ventricose, surface with numerous radiating sculptured ribs. It seems to be rather abundant at the slight furrows and fine decussated striae; margins rounded, locality mentioned.—Dall, 1898. umbo and summit profoundly elevated; dorsal margin equally and profoundly oblique, beaks distant; cardinal area wide and Holotype: U. S. Nat. Mus. 114941. marked with well-defined diverging grooves; cardinal teeth Type locality: Natural Well, Dupliii County. large, robust, nearly straight, the series very oblique and Distribution: North Carolina: Miocene, Yorktown formation, widely interrupted in the middle by a crenulated rectilinear \ mile north of Castoria and 1 mile east of Lizzie, Greene space. County; 2 miles southwest of Maple Cypress and Rock Land-* Locality, near Petersburg, Va.—Conrad, 1845. ing, Craven County. Duplin marl, Natural Well, Duplin The collection of further material and the careful County. Pliocene, Waccamaw formation, Walkers Bluff, comparison with Conrad's type by W. C. Mansfield Bladen County. seem to justify the rehabilitation of this species, which Glycymeris americana (Defrance) Dall had been lost in the lengthy synonymy of G. americana. Shell evenly rounded ventrally, cuneate dorsally, de Plate 1, figures 16-21 cidedly tumid in the umbonal region. Radial 1826. Pectunculus americanus Defrance, Dictionnaire des sculpture absent laterally, obsolete ventrally, consisting sciences naturelles, vol. 39, p. 225. of about 21 feebly impressed grooves; faint secondary 1832. Pectunculus pulvinatus Lamarck. Conrad, Fossil shells striae occasionally discernible on the interareas. of the Tertiary formations of North America, p. 17, Growth lines prominent near the ventral margin. pi. 2, fig. 2. Not P. pulvinatus Lamarck, 1819. Cardinal area high, ornamented with broad, shallow 1835. Pectunculus lentiformis Conrad, Idem, 2d ed., p. 36, corrigenda. furrows. Hinge line strongly arched. Hinge teeth in 1841. Pectunculus quinquerugatus Conrad, Am. Jour. Sci., 1st two discrete series, 12 or 13 in each; denticles coarse, ser., vol. 41, p. 346. obliquely set, the dorsal surface finely striated hori 1845. Pectunculus lentiformis Conrad, Fossils of the medial zontally. Muscle scars conspicuous, semielliptical, Tertiary of the United States, p. 64, pi. 36, fig. 1. united by a simple pallial line. Marginal flutings 1845. Pectunculus tricenarius Conrad, idem, p. 63, pi. 35, fig. 1 (immature shell). corresponding in number to the primary lines of the 1845. f Pectunculus quinquerugatus Conrad, idem, p. 63, pi. 34, exterior surface. fig. 3. Figured specimen: Height 44.5 millimeters, width 1845. Pectunculus passus Conrad idem, p. 64, pi. 35, fig. 3. 28 MOLLUSCA FROM MIOCENE AND LOWER PLIOCENE OF VIRGINIA AND NORTH CAROLINA 1856. Pectunculus lentiformis Conrad. Tuomey and Holmes, zones of the Choctawhatchee formation, the Pleiocene fossils of South ^arolina, p. 48, pi. 17, fig. 2. supposed time equivalents of zones 1 and 2 of the 1856. ? Pectunculus quinquerugatus Conrad. Tuomey and Holmes, idem, p. 49, pi. 17, fig. 4. Yorktown. 1858. Pectunculus carolinensis Holmes, Post-Pleiocene fossils of Distribution: Virginia: Miocene, Yorktown formation. South Carolina, p. 15, pi. 3, fig. 4. Not P. carolinensis Yorktown, York County; Petersburg, Dinwiddie County; 1% Conrad, 1841. miles northeast of Smithfield and % mile northeast of Smith- 1858. Pectunculus lentiformis Emmons, North Carolina Geol. field, Isle of Wight County; V2 to % mile above the lower Sea Survey Rept., p. 286. board Railway bridge, Southampton County; *4 mile north of 1886. Pectunculus undatus Linnaeus. Dall, Harvard Coll. Mus. Chuckatuck, l1^ miles north of Suffolk, 1 mile northeast of Comp. Zoology Bull., vol. 12, p. 238. Suffolk, % mile below the Suffolk waterworks dam, Suffolk, 1898. Glycymeris americana Defranee (part). Dall Wagner and the drainage ditch of the Norfolk & Western Railway just Free Inst. Sci. Trans., vol. 3, pt. 4, p. 609. ' east of Jericho ditch, Nansemond County. 1932. Glycymeris americana (Defranee). Mansfield, Florida North Carolina: Miocene, Yorktown formation. Halifax, Geol. Survey Bull. 8, p. 39, pi. 2, fig. 7. Halifax County; 2% miles northwest of Williamston and \ mile northwest of Williamston, Martin County; % mile above P6toncle americain. Petunculus americanus Defrance. Bells Bridge and % mile below Bells Bridge, Edgecombe Coquille suborbiculaire, aplatie et couverte de larges cStes longi- County; 2% miles north of Standard, 3 miles south of Farm- tudinales peu elevees et finement striees. Longueur plus de 2 ville, Pinelog Branch, 8 to 9 miles west of Greenville, 3 miles pouces. On la trouve a la Caroline du Nord.—Defrance, 1826. west of Greenville, 2 miles west of Greenville, 1% miles west A very.careful and conscientious scrutiny of a large number of Greenville, 8 to 9 miles south of Greenville, and 9 to 10 < of specimens has resulted in the above synonymy. G. imssa miles south of Greenville, Pitt County; 2% miles northwest of is the normal adult; G. lentiformis, the senile adult; G. tricenaria Chocowinity and 2 miles northwest of Chocowinity, Beaufort is a half-grown, well-developed form; G. carolmensis Holmes is a County; \ mile west of Wilson and 3 miles east-southeast of variety with feeble ribbing, obsolescent at the ends of the shell; Wilson, Wilson County; % mile east of Lizzie, 2 miles north G. transversa, Tuomey and Holmes (non Deshayes) is founded east of Lizzie, 4 miles east of Lizzie, Greene County; 1% on the internal cast of a rather wide young shell; G. tumulus miles below Tar Ferry and 3 to 4 miles below Tar Ferry, and Conrad is founded" on a rather inflated half-grown specmen. The Dogwood Landing, Hertford County; Colerain Landing, Bertie only form which may possibly be varietal, but which I am in County; Rock Landing, Craven County. Duplin marl, Natural clined to refer to some pathologic cause, is G. quinquerugata. Well and marl pits in the immediate vicinity, Duplin County; This is almost entirely confined to Duplin County, N. C. Well- 1 mile west of Lumberton, Lumberton, 2 miles below Lumberton, marked specimens have on each dorsal slope, from the beaks 4 to 5 miles below Lumberton, and Ashpole, Robeson County; laterally, 3 to 6 little irregular ripples, which are much more 4 miles south of Clarkton, Bladen County. Pliocene, Wacca- conspicuous in the young. These might indicate the presence of maw formation, Walkers Bluff, Bladen County; Lake Wacca- some parasite in the individual. They are never uniform or maw, Cronly, and Neills Eddy Landing near Cronly, Columbus regular; some specimens have them only on one side, in others County; Wiimington and the city rock quarry near Wilming- they are obsolete, and, finally, others do not have them; ton, New Hanover County. and between the normal americana and the quinquerugata Outside distribution: Miocene, Duplin marl, Darlington, without rugae there is absolutely no distinction to be made. Darlington County, S. C. Pliocene, Waccam'aw formation, The recent shell is identical with Miocene specimens and Nixons, Tillys Lake, and Todds Ferry, Horry County, S. C.; reaches fully as large a size.—Dall, 1898. Waccamaw, S. C., Choctawhatchee formation, northern Florida. Pectunculus tumulus Conrad, however, incltided by Caloosahatchee marl, Caloosahatchee River, Fla. Pleistocene, Dall under this species, is undoubtedly distinct. Simmons Bluff, S. C. Recent, Hatteras to Santa Marta, Brazil, in 15 to 63 fathoms. Of the bivalves occurring within the area under con sideration, the only one confusable with G. americana Superfamily MYTILACEA is the very rare pennacea (Lamarck). Though re The Mytilacea were included by Dall under a group sembling each other in the general character of the which he called the dysodonta—the imperfectly toothed fine radiate sculpture, they are readily separable by forms—a term first used by Neumayr but in a more more basic differences in outline and hinge. G. ameri .comprehensive sense. In the early generic separations cana reaches a much greater maximum diameter, the the teeth were perhaps considered too casual a charac valves are normally equilateral, and the umbonal slopes ter, an$ the form and surface sculpture too heavily are evenly rounded. In the smaller G. pennacea the weighted. However, Dall recognized /the dentition to anterior lateral margin is more or less sharply trun be of major importance in determining the relative cated and the anterior umbonal slopes are more or position of the dysodonts and considered the dysodont less angular. The cardinal area of pennacea is wider hinge to be essentially a taxodont hinge modified by than in an americana of the same size, the hinge is umbonal torsion. The full significance of the mytiloid thicker, the teeth are fewer and heavier and set in a hinge in establishing the mode of development of the higher curve. lamellibranch dentition was first perceived by The young of americvma are pretty little forms, Bernard,34 who detected in it the key to the problem subcircular in outline, except for the hinge truncation, 3* Bernard, Felix, Troisieme note sur le development et la morpholo- with a dainty, minutely granular, radiate sculpture. gie de la coquille chez les lamellibranches (anisomyaires) : Soc. g6ol. In Florida Mansfield found that the distribution of France Bull., s6r. 3, vol. 24, pp. 412-449, 1896; Recherches ontogfiniques et morphologiques sur la coquille des lamellibranches: Annales scl. nat. the species was restricted to the Ecphora and Can- zool. et pal., ser. 8, yol. 8, pp. 1-208, pis. 1-12, 1898. PART 1. PELECYPODA 29 of evolution of the bivalve hinge by reason of the lack Subgenus ISCHADIUM Jukes-Browne of acceleration in its development and the ease with 1905. Ischadium Jukes-Browne, Malacol. Soc. London Proc., which the stages of growth may be separated one from vol. 6, p. 223. the other. Bernard made no attempt to incorporate Type by original designation: Ischadium hamatum (Say). his results in the current systematic classifications, but Miocene to Pleistocene along the eastern seaboard; Recent from Jukes-Browne,35 impressed by their importance, "recon Rhode Island to the West Indies and Texas. sidered the generic values of the characters presented Shell oblong or pyriform in outline, sculptured all over with by the shells of the Mytilidae" and realined the strong raised divaricating ribs. Umbones slightly divergent; genera. In his revision the position of the umbones anterior riblets well marked and corresponding with a variable and the surface sculpture were treated as characters of number of dysodont teeth. Ligament long, without crenula- tions behind it. Anterior adductor scar absent, and anterior secondary importance, whereas the dentition, which byssal scar small. Posterior byssal scar large and broadly commonly reflects an important embryonic character, united to that of the posterior adductor. Type, /. hamatum the position of the ligament, and the number and char (Say).—Jukes-Browne, 1905. acter of the muscle impressions were given primary Brachidontes (Ischadium) recurvus (Rafinesque) Gardner consideration. The resulting classification is based on wider study than the earlier taxonomic arrangements Plate 1, figures 7, 8 and has been followed in the present paper. 1820. Mytilus recurvus Rafinesque, Monographic des coquilles bivalves fluviatiles de la riviere Ohio, Annales gen. Family MYTILIDAE . sci. phys. Bruxelles, vol. 5, p. 320. Genus BRACHIDONTES Swainson 1822. Hytilus hamatus Say, Acad. Nat. Sci. Philadelphia Jour., 1st ser., vol. 2, p. 265. Binney's reprint of Say, pp. 91, 1840. Brachidontes Swainson, Treatise on malacology, p. 384. 204, pi. 1. 1905. Brachyodontes, Jukes-Browne, Malacol. Soc. London Proc., 1832. Mytilus hamatus Say, American conchology, pi. 50, figs. 1, vol. 6, p. 222. 2, and unpaginated test. 1837. Modiola carolinensis Conrad, Acad. Nat. Sci. Philadelphia Type by monotypy: Modiola sulcata Lamarck. Recent in the Jour., 1st ser., vol. 7, p. 243, pi. 20, fig. 6. Indian Ocean. 1869. Brachydontes hamatus Perkins, Boston Soc. Nat. History BracMdontes has been commonly considered a sub- Proc., vol. 13, p. 156. genus or section of Modiolus signalized by a radially 1898. Mytilus (Hormomya) hamatus Say. Dall, Wagner Free Lost. Sci. Trans., vol. 3, pt. 4, p. 789. sulcate sculpture. It was given generic status by 1906. Mytilus hamatus Say. Clark, Maryland Geol. Survey, Jukes-Browne because of the crenulate posterior Pliocene and Pleistocene, p. 203, pi. 60, figs. 5, 6. margin, an important embryonic character retained in Moule recourb£e. Test obovale, cunelforme, recourb§, 9, the adults of this group. Another constant feature of stries longitudinales de trois longueurs; epiderme noiratre; the genus as defined and restricted by Jukes-Browne is nacre-violette; bees obliques, a un angle decurrent, de chaque the musculature, indicated by a small but distinct cote; bord inferieur et interieur stri£, crenele; largeur 7-12;- anterior adductor scar and by a much larger posterior diametre 5-12 de la longueur, longueur 1 a 2 pouces. Elle ge trouve dans le Mississippi pres de la Nouvelle-Orleans. Les adductor to which is united the scars of the median and stries sont souvent bifides. Partie batllante oblongue, laterale.— posterior byssal retractors. The hinge line is for the Rafinesque, 1820. most part straight and its union with the posterior Shell very much contracted and incurved at the base, which lateral margin angular. The ligament is short and is acute; valves striated on every part of the exterior with marginal or submarginal. The position of the longitudinal, elevated lines, which are bifid and sometimes trifid toward the tip; color dark fuscous; within dark purpurescent, umbones varies with the development of the anterior with a whitish margin. portion of the shell, and although the external surface Length 1% inches, breadth nearly % inch. is characteristically sculptured with a fine bifurcate Inhabits the Gulf of Mexico. ribbing, a few species are wrinkled or smooth. Cabinet of the Academy and Philadelphia Museum. The form otf Swainson's name has bothered the A common species in the Gulf of Mexico, and is frequently carried to market at New Orleans attached to the common classical scholars who have followed him. Brachydontes oyster.—Say, 1822. has been commonly used in place of Braohidontes, and Jukes-Browne has further purified the barbarism by Undoubtedly the species can be definitely determined converting it to Brachyodontes. However, article 19 from Eafinesque's description published in the obscure of the International Rules of Zoological Nomenclature, monograph on the bivalves of the Ohio River, and for Monaco, 1913, provides that "the original orthography that reason it should receive his name, which antedates of a name is to be preserved unless an error of the commonly accepted Mytilus hamatus of Say by 2 transcription, a lapsus calami, or a typographical error years. is evident." Distribution: Virginia: Miocene, Yorktown formation, lorn- town and Bellefield, York County. North Carolina: Pliocene, Waccamaw formation, Walkers 85 Jukes-Browne, A. J., A review of the genera of the family Mytilidae: Malacol. Soc. London Proc., vol. 6, pp. 211-224,1905. Bluff, Bladen County; Neills Eddy Landing, Columbus County. 401033—43———3 30 MOLLUSCA FROM MIOCENE AND LOWER PLIOCENE OF VIRGINIA AND NORTH CAROLINA Outside distribution: Pliocene, Caloosahatchee marl, Galoosa- cardinal margin of the right auricles curved down hatchee River, Fla. Pleistocene, Sankaty Head, Mass.; Wailes ward. Resilium central, internal, triangular; inter Bluff, near Cornfield Harbor, St. Marys County, Md. Recent, locking grooves and ridges diverging from the apex Rhode Island to Costa Rica in less than 50 fathoms. of the resilial pit. Pallial line simple. Monomyarian. Genus CRENELLA Brown Adductor impression rounded, posterior. 1827. Crenella Brown, Illustrations of the conchology of Great The earliest Pecten known is from the Cretaceous. Britain and Ireland, pi. 31, figs. 12-14. The Recent species exceed 200 in number, and their dis 1844. Crenella Brown, Illustrations of the Recent conchology tribution is world-wide. of Great Britain and Ireland, 2d ed., p. 75, pi. 23, figs. 12-14. Subgenus EUVOLA Ball Type by monotypy: Mytilus decussatus Montagu. Recent 1898. Euvola Dall, Wagner Free Inst. Sci. Trans., vol. 3, pt. 4, off the coast of Greenland and in North Atlantic waters. p. 694. Crenella precursor Gardner, n. sp. Type by original designation: Pecten zicsac Linnaeus. Southern Florida and the West Indies. Plate 3, figures 14-16 Shell both large and heavy for the genus; evenly Euvola is characterized by the high inflation of the ovate, moderately inflated. Umbones acute, prosogy- right valve, the flat or slightly concave left valve, a rate, incurved. Sculpture of about 70 low, flat, radiat radial sculpture that is less strong and less regular than ing lirations, rarely dichotomous toward the ventral that of Pecten s. s., and the development of a single margin; interareas slightly narrower; increirientals pair of cardinal crurae. mostly microscopic, 3 or 4 of them exaggerated. Inner Pecten (Euvola) raveneli Dall margin obscurely crenulated. Interior lined with a cal Plate 4, figure 4 careous layer continued to the pallial line. Hinge non- 1898. Pecten (Pecten) raveneli Dall, Wagner Free Inst. Sci. crenulate. Ligament furrow shallow, extending from Trans., vol. 3, pt. 4, p. 721, pi. 29, fig. 10. beneath the umbones about one-fourth the distance 1934. Pecten raveneU Dall. Johnson, Boston Soc. Nat. History down the posterior margin. Anterior adductor muscle Proc., vol. 40, No. 1, p. 23 (synonymy in part excluded). impression elongated; posterior semioval. Pallial line 1936 (March). Pecten (Pecten) raveneli Dall. Tucker, Am. faintly sinuous. Midland Naturalist, vol. 17, No. 2, p. 483, pi. 2, fig. 4. 1936 (April). Pecten (Euvola) raveneli Dall. Mansfield, Jour. Dimensions of holotype: Height 7.6 millimeters, Paleontology, vol. 10, pp. 174,182,184,185. width 6.4 millimeters, convexity 2.1 millimeters. Holotype, a right valve: U. S. Nat. Mus. 325498. Shell much of the size and form of P. medius Lamarck but with 21 or 22 strong ribs; dichotomous in the right valve but Type locality: 1 mile northeast of Suffolk, Nanse- rounded and simple in the left, with 3 or 4 finer threads on the mond County, Va. submargins; interspaces of the right valve smaller than the Crenella precursor has little but the generic charac squarish ribs, on the left subequal; right valve with subequal ters in common with the minute Crenellas of the C. ears, each with 3 or 4 strong, rounded riblets; notch shallow; divaricata type. Its nearest relative and its probable ears of the left valve concave, 2-ribbed, with less pronounced sculpture; surface of both valves covered with close-set, con descendant is the Recent C. glandula Totten of the centric, elevated lines; interior fluted, crura moderately devel North Atlantic coast. It is separated from this by the oped. Altitude 42, latitude 47, diameter 13 millimeters. more regularly ovate outline, the more acute, prosogy- This neat little species differs from P. medius in its coarser rate beaks, the fewer, broader, flatter, less divaricate sculpture, and from the young of P. hemicyclicus by its more radials. The single valve from which the description numerous ribs and details of surface.—Dall, 1898. has been made is probably senile. Younger individ Holotype, a right valve: U. S. Nat. Mus. 107750. uals would doubtless show a crenulated hinge and a Type locality: Pliocene of the Caloosahatchee River, more strongly crenulated margin. Fla. Distribution: Virginia: Miocene, Yorktown formation, \ mile The right valve of Pecten raveneli Dall is very much northeast of Suffolk, Nansemond County. inflated, the left valve slightly concave. The species is represented in the area under consideration by a single Superfamily PECTINACEA Reeve adult right valve and a valve of a young form. The Family PECTINIDAE Lamarck dichotomous ribs, the small, squarish auricles, and the Genus PECTEN Mtiller delicate concentric sculpturing are, however, sufficient 1776. Peoten Mu'ller, Zoologiae danicae prodromus, p. 248. to characterize it. Type by subsequent designation (Schmidt, C. F., Versuch tiber Distribution: North Carolina: Miocene, Duplln marl, Fair- die beste Einricht., etc., pp. 67,177, Gotha, 1818) : Ostrea maxima, mont, Robeson County. The species is represented by a single Linnaeus. Recent in the north European seas. valve. Outside distribution: Pliocene, Caloosahatchee marl, Caloosa Shell approximately equilateral, inequivalve, auricu- hatchee River, Fla. (?) Recent, dredged off Cape Fear with late; right valve, as a rule, the more convex, not adher other fossil species in 15 fathoms. Johnson, 1934, reports the ent but attached by a byssus. Hinge line straight, the species from North Carolina to the West Indies. PART 1. PELECYPODA 31 Subgenus PIAGIOCTENIUM Ball River, and 3 miles southeast of Folkston, Nassau County, Fla. 1898. PlagiQCtenium Dall, Wagner Free Inst. Sci. Trans., vol. Pleistocene, Simmons Bluff, S. C.; Orient, Hillsborough County, 3, pt. 4, p. 696. Fla.; North Creek, Manatee County, Fla.; Kissimmee (at a depth of 96 feet), Osceola County, Fla.; and Torch Key,. Fla. Type by original designation: Pecten ventricosus Sowerby= Recent, Hatteras to Brazil in less than 50 fathoms; Hatteras Pecten circularis Sowerby. Pleistocene of California. Recent down to and including west Florida, the Gulf of Mexico, the from Monterey, Calif., to the Gulf of California and Paita, Peru. West Indies, and the Antilles, all in more than 50 fathoms. Resembling Aequipecten but without radial striation; the Genus CHLAMYS (Bolten) Roeding concentric sculpture in looped lamellae; the ribs strong, fre 1798. Chlamys (Bolten) Roeding, Museum boltenianum, pt. 2, quently smooth above; the submargins impressed below the Conchylia, p. 161. subequal auricles; the valves well inflated with a tendency to oblique growth in the adult. Type by subsequent designation, Dall, Wagner Free Inst. To this very natural group belong nearly all the shallow- Sci. Trans., vol. 3., pt. 4, p. 695, 1898: Pecten islandicus Miiller. water pectens of our own coasts.—Dall, 1898. Pleistocene of the boulder clays of the northeast coast and Recent from the Arctic region to the Chesapeake Bay. Plagioctenium differs further from Aequipecten, under which it was included by Verrill and the earlier Shell small or of moderate dimensions; inequilateral. systematists, in the stronger, more regular ribbing and Right valve slightly more compressed than the left but in the relative convexity of the valves. In Plagioc not conspicuously so. Dorsal margins steeply sloping. tenium, as in Pecten s. s., the right valve is the more Sculpture radial, the lirae usually numerous and in inflated. In Chlamys and in the subgenus Aequipecten creasing by intercalation, imbricated by the concentric the left valve is more convex than the right. Because sculpture, persistent to the ventral margins, which are of the form and outline the group has been referred to scalloped by the ribbing. Anterior auricles larger than Pecten rather than to Chlamys. the posterior, the right anterior notched for the extrusion of the byssus. The margin below the byssal Pecten (Plagioctenium) gibbus (Linnaeus) Dall notch pectinated. The cardinal margin of the auricles Plate 5, figure 3 of both valves bent inward over the inconspicuous liga 1758. Ostrea gWba Linnaeus, Systema naturae, 10th edition, ment—those of the right valve more forcibly - so. p. 698. Resilium short and strong. Chondrophore small, 1822. Pecten dislocatus Say, Acad. Nat. Sci. Philadelphia Jour., trigonal, and subumbonal. Cardinal crurae not con 1st ser., vol. 2, p. 260. 1858. Pecten dislocatus Say. Holmes, Post-Pleiocene fossils of spicuous. Characters of interior usually obscure, South Carolina, p. 12, pi. 2, fig. 12. usually with ribs and double flutings corresponding to 1889. Pecten irradians var. dislocatus Say. Dall, U. S. Nat. the external ribbing. Mus. Bull. 37, p. 34. Chlamys is widely distributed. Many of the species 1898. Pecten (Plagioctenium) gilibus Linnaeus. Dall, Wag are active swimmers and very brightly colored, ner Free Inst. Sci. Trans., vol. 3, pt. 4, p. 745. 1936. Pecten (Chlamys) gibbus Linnaeus. Mansfield, Jour. especially those living in the warmer waters. Paleontology, vol. 10, pp. 174, 182, 185. Chlamys decemnaria (Conrad) Dall O. testa radiis 20 glabris, gibba. Habitat in M. Americano.— Plate 5, figures 1, 2, 6, 7 Linnaeus, 1758. Closely related but not specifically identical forms 1834. Pecten decemnarius Conrad, Acad. Nat. Sci. Philadelphia Jour., 1st ser., vol. 7, p. 151. have been recovered from a few localities in the 1840. Pecten decemnarius Conrad, Fossils of the medial tertiary Miocene of Virginia and North Carolina. Pecten of the United States, p. 49, pi. 24, fig. 2. gibbus gibbus has not, however, been recorded from 1845. Pecten dispaiatus Conrad, idem, p. 74, pi. 42, fig. 3 (very beds below the Pliocene. The distribution of the group poor). is governed largely by temperature. In both the 1863. Pecten decemnarius Conrad, Acad. Nat. Sci. Philadelphia Proc. for 1862, vol. 14, p. 581. Tertiary and the Kecent it is widely distributed and 1898. Pecten (Chlamys) decemnarius Conrad. Dall, Wagner diversified in the Floridian and mid-American faunas. Free Inst. Sci. Trans., vol. 3, pt. 4, p. 741. The waters in which the middle and late Tertiary de 1936 (April). Pecten (Chlamys) decemnarius Conrad. Mans posits of Virginia and North Carolina were laid down field, Jour. Paleontology, vol. 10, pp. 174, 178, 184. were apparently too cold for its favorable development. 1936 (November). Chlamys (Chlamys) decemnarius (Conrad). Rowland, Am. Midland Naturalist, vol. 17, p. 1009, pi. Distribution: North Carolina: Pliocene, Waccamaw forma 8, figs. 5, 6. tion, Lake Waccamaw, Columbus County; Wilmington, New Shell ovate, slightly convex, with about 10 broad, flattened Hanover County. ribs disappearing on the umbo, some of them sulcated; radiat Outside distribution: Pliocene, Caloosahatchee marl, De Leon ing striae numerous, distinct, subscabrous; ears unequal. Springs, Volusia County, Fla.; Kissimmee well (at a depth of I possess but a single superior valve of each of these pectens. 150 feet), Osceola County, Fla.; Caloosahatchee River, Shell Locality, same as the preceding [James River, Va.].—Conrad, Creek, Alligator Creek, and Myakka River, Fla. Croatan sand, 1834. Slocums Creek and Mallisons, Craven County, N. C. This species is notably irregular in its sculpture, the disk Pliocene (?), Charlton formation, Orange Bluff, St. Marys being sculptured either by numerous more or less distinctly 32 MOLLUSCA FROM MIOCENE AND LOWER PLIOCENE OF VIRGINIA AND NORTH CAROLINA fasciculated, small, radial threads, or the fasciculi may be re 1840. Pecten madisonius Say. Conrad, Fossils of the medial placed partially by stout, elevated, rounded ribs, with wide, Tertiary of the United States, p. 48, pi. 24, fig. 1. radially threaded interspaces. The radial sculpture may be 1858. Pecten madisonius Say. Emmons, North Carolina Geol. nearly smooth or covered with a conspicuous, dense, concentric Survey Kept., p. 282, fig. 200. lamellation. Three or four of the ribs may be more prominent 1863. Pecten madisonius Say. Conrad, Acad. Nat. Sci., Phil than the others, and the smaller ones uneven in size and rugose, adelphia Proc. for 1862, vol. 14, p. 581. forming the variety dispalatus. When the fasciculi are riblike 1894. Pecten madisonius Say. Whitfield, U. S. Geol. Survey they are usually dichotomous. The umbonal region in typical Mon. 24, p. 30, pi. 2, fig. 8; pi. 4, figs. 1-5. decemnarius is usually feebly sculptured, but in the variety 1898. Pecten (Lyropecten) madisonius Say. Dall, Wagner Free dispalatus the ribbing approaches the beaks more nearly. The Inst. Sci. Trans., vol. 3, pt. 4, p. 724 (synonymy type of the 'latter has been carefully compared, and the ears excluded). and surface agree exactly with those of the decemnarius form. 1904. Pecten (Chlamys) madisonius Say. Glenn, Maryland Large valves of the latter attain a height and width of 68 Geol. Survey, Miocene, p. 377, pi. C, fig. 1. millimeters; the type of dispalatus measures 24 millimeters. 1909. Pecten (Chlamys) madisonius Say. Grabau and Shimer, The cardinal crura are parallel with the hinge line and mod North American index fossils, vol. 1, p. 502, fig. 673c. erately developed. The byssal notch is wide and conspicuous, 1928. Pecten madisonius Say. Mansfield, U. S. Nat. Mus. Proc., the posterior ears small. No. 2759, vol. 74, p. 10, pi. 2, fig. 1; pi. 3, fig. 1. In sculpture this form almost exactly parallels the recent 1936. Pecten (Chlwnys) madisonius Say. Mansfield, Jour. northwest American P. hericeus in its mutations.—Dall, 1898. Paleontology, vol 10, pp. 174, 176,177,184. The plates represent end members of complete series Much compressed, with about 16 striated ribs. of this exceedingly variable form. Shell rounded, much compressed; the whole surface cov ered with scaly striae; ribs elevated, rounded, with about 3 Distribution: Virginia: Miocene, Yorktown formation. In striae on the back of each; intervening grooves rather pro dian Field Point, Yorktown, and Bellefield, York County; found ; ears equal, sinus of the ear of the superior valve pro Sycamore and a quarter to half a mile below Sycamore, South found, extending at least one-third of the length of the ampton County. ear. North Carolina: Miocene, Yorktown formation. 1% miles Length rather more than 4% inches; breadth 4% inches. In above Murfreesboro and \ mile above Murfreesboro, Hertford magnitude this shell is justly entitled to compare with the pre County; Halifax, Halifax County; % mile above Bells Bridge ceding [Pecten jeffersonius Say]; but it differs, in being much and V8 mile below Bells Bridge, Edgecombe County; 2 miles less convex, and in having a much more profound sinus in the west of Greenville, Pitt County. ear of the superior valve.—Say, 1824. Subgenus IYROPECTEN Conrad Type locality, Maryland. ]862. Lyropecten Conrad, Acad. Nat. Sci. Philadelphia Proc. for 1862, p. 291. Chlamys (Lyropecten) madisonia, when properly discriminated, is confined to the Calvert and Choptank Type by subsequent designation, Dall, Wagner Free Inst. Sci. Trans., vol. 3, pt. 4, p. 695, 1898: Lyropecten estrellanus formations. The later C. jeffersonia may, through Conrad. Miocene of the Pacific coast. santamaria Tucker and the subspecies middlesexensis Inequivalve, radiately costate; hinge with a triangular pit Mansfield, be in the direct line of descent. as in Pecten and diverging prominent teeth on each side the Typical Chlamys (Lyropecten) madisonia are rela ligament cavity.—Conrad, 1862. tively wide—wider than C. jeffersonia—and usually The valves are generally large and coarse and both with 15 or 16 ribs. Each rib bears 3 scabrous lirae; and convex, the left valve slightly more inflated than the other lirae, less elevated than those upon the summits right. The costals, unlike those of Chlamys s. s., are of the primaries, crowd the sides and the intercostal relatively few in number but very heavy and not channels. The ears are low but wide, the byssal notch dichotomous. is very deep and the ctenolium coarse. Lyropecten is the dominant group in the Chesapeake Distribution: Virginia: Miocene, Calvert and Choptank for Miocene, conspicuous both by reason of its abundance mations, Nomini Cliffs, Westmoreland County. and by the large size of the individuals. The begin Outside distribution: Miocene, Calvert formation, Shiloh and Jericho, Cumberland County, N. J.; Church Hill, Centerville, nings in the lower Miocene are very modest, possibly Reeds and Wye Mills, Queen Annes County, Md.; Fairhaven and because the group had not reached the peak of its de Lyons Creek, Anne Arundel County, Md.; Whites Landing, velopment, or possibly because the cooler climate of the Magruders Ferry, and Trumans Wharf, Prince Georges County, Chesapeake was more favorable. The heavy pectens of Md.; Chesapeake Beach and Plum Point, Calvert County, Md. the Miocene of south Europe, Gigantopecten Rovereto Choptank formation, Greensboro, Caroline County, Md.; Skip- ton, Cordova, Peach Blossom Creek, Dover Bridge, Trappe and its synonym Macrochlamys Sacco, are referable to Landing, and Sand Hill, Talbot County, Md.; Governor Run, Pecten rather than Chlamys because of the absence of Flag Pond, and St. Leonard Creek, Calvert County, Md.; Jones a byssus. They differ from Pecten s. s. only in the Wharf, Cuckold Creek, Turner, and Pawpaw Point, St. Marys slight convexity of the left valve. County, Md. Chlamys (Lyropecten) madisonia (Say) Glenn Chlamys (Lyropecten) jeffersonia (Say) Glenn Plate 4, figure 5; plate 9, figure 7 Plate 4, figure 2 1824. Pecten madisonius Say, Acad. Nat. Sci. Philadelphia Jour., 1824). Pecten jeffersonius Say, Acad. Nat. Sci. Philadelphia 1st ser., vol. 4, p. 134. Jour., 1st ser., vol. 4, p. 133, pi. 9, fig. 1. PART 1. PELECYPODA 33 1840. Pecten, jeffersonius Say. Conrad, Fossils of the medial Within the limits of the species, in the restricted Tertiary of the United States, p. 46, pi. 22, fig. 1. sense, the most conspicuous variations occur in the de 1858. Pecten jeffersonius Say. Emmons, North Carolina Geol. Survey Kept., pp. 281, 282, figs. 199, 201. gree of inflation of the valves; in the character of the 1883. Pecten jeffersonius Say. Conrad, Acad. Nat. Sci. Phila byssal notch, which may approach that of Lyropecten delphia Proc. for 1862, vol. 14, p. 581. madisonius Say in depth, though in such individuals 1898. Pecten (Lyropecten) jeffersonius Say. Dall, Wagner Free the ear is higher and its dorsal margin more rounded Inst. Sci. Trans., vol. 3, pt. 4, p. 722. than in the letter; in the primary ribs, which range in 1904. Pecten (Chlamys) jeffersonius Say. Glenn, Maryland Geol. Survey, Miocene, p. 378, pi. C., fig. 2. number from 9 to 15 and in character from broad and 1909. Pecten (Chlamys) jeffersonius Say. Grabau and Shimer, gently undulatory costae to sharply angular ones sepa North American index fossils, vol. 1, p. 502, fig. 673f. rated by equally angular interspaces, a type commonly 1932. Chlamys (Lyropecten) jeffersonius Say. Mansfield, Flor exemplified in the young but rarely in the adults; and ida Geol. Survey Bull. 8, p. 59, pi. 11, fig. 1. in the secondary threads, which may be almost smooth 1936. Pecten (Chalmys) jeffersonius Say, Jour. Paleontology, vol. 10, pp. 174, 178, 179, 181, 184, 185. or may become minutely spinose. Subequivalve, with from 9 to 11 striated ribs. Pecten magnolia Conrad, 1857, from the Miocene of Shell rounded, convex, not quite equivalved, one of the valves California, so closely resembles C. jeffersonia that Grant being a little more convex than the other; the whole surface and Gale considered them specifically identical. Mans covered with approximate, scaly striae; ribs elevated, rounded, field (op. cit., p. 179) has indicated the differences. with 6 or 7 striae on the back of each; intervening grooves pro Lyropecten was one of the widely distributed and char found; ears equal; sinus of the ear of the superior valve not profound, being barely one-eighth part of the length of the ear; acteristic elements in the Miocene faunas of the New within with broad, rounded, flattened ribs. World, particularly in the cooler waters. Length 5%0 inches, breadth 5%o inches.—Say, 1824. The following table shows the range in the number Type locality: Maryland [?]. of ribs of 323 Lyropecten valves from 64 localities. Chlamys jeffersonia s. s. is a subcircular, somewhat The number seems to be fairly constant in a single inflated shell; the byssal ear is separated from the disk locality, a fact that would invalidate the results unless by a rather shallow notch and an ill-defined fasciole; the collection were very well balanced. The Chlamys the primary ribs number from 9 to 12 and are, in the jeffersonia material is, in all probability, sufficiently adults, rather low, broad, and evenly rounded; in the abundant and representative to correct all such errors. young they are more angular; the secondary lirae, both It is interesting to note the clear definition of the nodes, on the disk and on the auricles, are subequal, fine, and which indicate the triple separation of the species. minutely laminated; 4 to 7 is the usual number on the The italicized figures are quoted from Dall's com top of each primary. putations. Number of ribs 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 9 14 37 36 33 26 14 13 20 29 7 1 1 1 0 1 Chlamys (Lyropecten) jeffersonia (Say)- ______a> 11 10 9Q i& 7 1 5 ff> & 1 t 07 qc Chlamys (Lyropecten) jeffersonia (Say) s. s______/ 3? 94 4 3 3 1- 1 Q &Q i& Q 13 (Say). ——— ____ — _ ———— ___ — ____ ——— ___ {.. S 11 Chlamys (Lyropecten) jeffersonia subsp. edgecombensis {" 1 1 ?, 10 10 17 29 7 1 1 1 0 1 (Conrad) ______7 1 5 * 9. 1 Chlamys (Lyropecten) jeffersonia (Say) s. s. is most Zuni, 7 to 7% miles below Zuni, and 8 to 8% miles below Zuni, abundantly represented in the Yorktown formation in Isle of Wight County; Hitchcock, Greensville County; Delaware Park, Maddelys Bluff, 3 to 4 miles above the lower Seaboard Virginia at Lanexa, along the James River, and in Railway bridge, and % to % mile above the lower Seaboard Rail Southampton County; and in North Carolina in Hert way bridge, Southampton County; % mile east of Everets, Exit, ford, Halifax, Edgecombe, and Pitt Counties. In Vir 1% miles southeast of Reids Ferry, iy2 miles north of Suffolk, ginia the usual number of primary ribs is 9 or 10; in 5% miles northwest of Suffolk, 1 mile west of Suffolk, and % North Carolina, 11 or 12. mile below the Suffolk waterworks dam, Nansemond County. North Carolina: Miocene, Yorktown formation, 1% miles Distribution: Virginia: Miocene, Yorktown formation, Lanexa, above Branches Bridge, 1 mile above Branches Bridge, Branches New Kent County; Yorktown, Bellefield, and Indian Field Point, York County; 3 miles northeast of Walkerton, King and Queen Bridge, Northampton County; 2% miles northwest of Murfrees- County; near the mouth of Baileys Creek, Prince George County; boro, iy2 miles above Murfreesboro, 1 mile above Murfreesboro, Petersburg, Dinwiddie County; Kings Mill, James City County; near Murfreesboro, Dogwood Landing, Hertford County; Hali old Claremont Wharf, Claremont Wharf, Schmidts Bluff, 6% fax, iy2 miles northeast of Enfield, y2 mile west of Enfield, and miles below Claremont Wharf, Sunken Marsh Creek, Cobham Palmyra Bluff, Halifax County; Compass Creek (1 mile from Wharf, Surry County; iy2 miles west of Smithfield, iy2 miles mouth), 15% miles above Bells Bridge, y2 mile above Bells above Zuni, 2% to 3 miles northwest of Zuni, 6x/6 to 7 miles below Bridge, y8 mile below Bells Bridge, 1 mile below Bells Bridge, 34 MOLLUSCA FROM MIOCENE AND LOWER PLIOCENE OF VIRGINIA AND NORTH CAROLINA Tarboro, 1 mile above old Sparta Bridge, and Shiloh Mills, Chlamys (Lyropecten) planicosta Gardner, n. sp. Edgecombe County; 8 to 9 miles west of Greenville, 3 miles Plate 9, figure 1 west of Greenville, 2 miles west of Greenville, 1% miles west of Greenville, and Greenville (just south of the county bridge), Valves large, subcircular, slightly convex; primary Pitt County; 1% miles northeast of Chocowinity, Beaufort radials 19 in number, very low, broad, rectangular in County; 6 miles west of Goldsboro, Wayne County; 4 miles east cross section, reaching a maximum of 7 millimeters in of Lizzie, Greene County. breadth, sculptured with very faint striae, obsolete ex Outside distribution: Duplin marl, Porters Landing on the Savannah River, Effingham County, Ga.; Brunswick River bed, cept toward the margin; interradials half as wide as Brunswick, Glynn County, Ga. Choctawhatchee formation, the radials, filled mostly with a strongly rounded inter northern Florida. calary tending to bifurcate near the ventral margin; concentric sculpture very fine, visible principally in the Chlamys (Lyropecten) jeffersonia septenaria (Say) Mansfield spaces between the primaries and the midrib; anterior Plate 4, figure 1 right ear only preserved and that badly broken; notch probably rather deep; fascicle conspicuous, lamellar; 1824. Pectcn septenarius Say, Acad. Nat. Sci. Philadelphia Jour., right auricle sculptured with 7 unequal striae separated 1st ser., vol. 4, p. ]36, pi. 9, fig. 3. 1840. Pecten septenarius Say. Conrad, Fossils of the medial by unequal interspaces; resilial pit wide and rather Tertiary of the United States, p. 47, pi. 22, fig. 2. shallow; ligamental groove deep, bounded on the inner 1856. Pecten septenarius Say. Tuomey and Holmes, Pleiocene margin by a cardinal rib which, however, becomes fossils of South Carolina, p. 31, pi. 13, figs. 1-4. obsolete anteriorly; two pairs of narrow, pinched ridges 1863. Pecten septenarius Say. Conrad, Acad. Nat. Sci. Phila radiating from the apex of the pit—one at the margin delphia Proc. for 1862, vol. 14, p. 581. 1898. Pecten jeffersonius var. septenarius Say. Dall, Wagner of the pit, the other halfway down the sides—which Free Inst. Sci. Trans., vol. 3, pt. 4, p. 722. may or may not be an accidental character. 1901. Pecten jeffersonius var. septenarius Say. Glenn, Mary Dimensions of holotype: Height 111.0 millimeters, land Geol. Survey, Miocene, p. 379, pi. C, fig. 4. width 118.0±millimeters. Holotype, a right valve: 1936. Pecten (Chlamys) jeffersonius septenarius Say. Mans U. S. Nat. Mus. 325493. field, Jour. Paleontology, vol. 10, pp. 174, 179, 184, 185. Type locality: 3 miles southwest of Frog Level (on Shell convex, suborbicular; auricles subequal; surface with J. A. Noble's branch), Pitt County, N. C. numerous slightly scaly striae, and about 7 remote ribs, of The single valve, though badly battered, is so distinct which the 3 intermediate ones are much elevated, rounded, or slightly flattened on the top. and so well characterized that it has seemed worth Length nearly 2.7 inches. The striae are equally distinct on while to describe it. It may be readily isolated by the the ribs and in the intermediate spaces. The scales are rather rectangular cross section of the primary ribs, their very thick, very small, and not confined to the striae, but are also fine radial striation, and the prominence of the inter observable in the spaces between the striae.—Say, 1824. calated midrib. Type locality: Maryland[?]. Distribution: North Carolina: Miocene, Yorktown formation, 3 miles southwest of Frog Level (on J. A. Noble's branch), Chlamys (Lyropecten) jeffersonia subsp. septenaria Pitt County. is characterized by fewer primary ribs, normally 7 or Section NODIPECTE1T Dall 8, rarely only 6. As might be inferred, these are 1898. Nodipecten Dall, Wagner Free Inst. Sci. Trans. vol. 3, broader and usually stronger than in the forms on pt 4, p. 695. which the costae are more numerous. Type by original designation: Ostrea nedosa Linnaeus. Plio The subspecies is less abundant and more restricted cene of Florida, Pleistocene and Recent of the Gulf of Mexico stratigraphically than Chlamys jeffersonia. (See Mans and the Antilles. field, op. cit., p. 179.) Shell-like Lyropecten, but the ribs intermittently nodose, with more or less prominent hollow nodes or bullae; radial Distribution: Virginia: Miocene, Yorktown formation. La- striation pronounced; ears unequal, the posterior smaller, the nexa, New Kent County; Clareniont Wharf, Schmidts Bluff, valves often more or less oblique; imbricate surface layer 8~y2 miles below Claremont Wharf, Sunken Marsh Creek, Surry sometimes very marked.—Dall, 1898. County; Petersburg, Dinwiddie County; James River, 7 to 7^ miles below Zuni, Isle of Wight County; 3 to 4 miles above Chlamys (Lyropecten) ernestsmithi (Tucker) Tucker the lower Seaboard Railway bridge, at the lower Seaboard Plate 6, figures 6-8 Railway bridge, Southampton County; Exit, 1 mile west of 1931. Pecten ernestsmithi Tucker, Indiana Acad. Sci. Proc., vol. Suffolk, and % mile below Suffolk, Nansemond County. North Carolina: 1 mile above Branches Bridge, Northamp 40, p. 244, pi. 1, figs. 1, 3, 4. ton County; Miocene, Yorktown formation. Halifax and 1933. Pecten ernestsmithi Tucker, Bull. Am. Paleontology, vol. Palmyra, Halifax County; y8 mile below Bells Bridge, % mile 18, p. 66, pi. 11 (2), fig. 13. 1936. Pecten (Chlamys) ernestsmithi Tucker. Mansfield, Jour. below Bells Bridge, 1 mile below Bells Bridge, and Shiloh Mills, Edgecombe County; 8 to 9 miles west of Greenville and Paleontology, vol. 10, pp. 174,183,185. at Greenville, Pitt County. Duplin marl, Natural Well?, Duplin Shell ovate, rather large, heavy, with 5 ribs, 3 of which are County. better developed. The ribs are broad and rounded on their PART 1. PELECYPODA 35 summits and show a marked tendency to become nodose from cated; left ear in some individuals joined to the disk the umbonal region to the periphery. Interspaces wider than by a sharp angulation, in others by a concave area. the ribs and deeply channeled. Both ribs and interspaces strongly radially threaded. A fragment of a right valve shows Byssal notch probably deep; fasciole conspicuous. a strongly developed, concentric sculpture of scaly lamellae Ctenolium well-developed. Resilial pit narrow, deep, over both ribs and interspaces. Beak narrow and quite pointed. somewhat oblique. Hinge area in young furnished Submargins narrow, the outer margins nearly smooth, the inner with feeble cardinal crura, which become obsolete in radially threaded like the rest of the disk. Ears large, unequal, adults and are replaced by a wide ligamental area. and radially threaded. Anterior byssal ear quite pointed and somewhat corrugated along the cardinal margin. Posterior ear Muscle scar slightly posterior and dorsal. Inner sur somewhat less strongly threaded. Byssal sinus deep, narrow, face of valves strongly undulated by primaries. Ven and inconspicuous. Fascicle broad. Interior fluted to the um- tral margin crenulated by secondaries. bones. Margins crenulated. Ctenolium consists of 6 prominent Dimensions of figured specimens (U. S. Nat. Mus. denticles. Resilial pit narrow, trigonal; lateral margins ele No. 325492) : Right valve: Height 70.0 millimeters, vated. Cardinal margin of the right valve bent over the left. Provinculum strongly developed. Valve retains traces of a width 67.0 millimeters. Left valve of another indi blotchy color pattern. Height 85, length 82.5, length of hinge vidual: Height 101.5 millimeters, width 100.0 line 60. and convexity about 20 millimeters. millimeters. This species differs from P. caloosaensis Dall in the shape of Both the figured specimens were collected from the the ears, in the width of the interspaces, and in sculpture. P. Waccamaw formation at Walkers Bluff, Bladen ernestsmithi shows a well-developed sculpture of radial threads, County, N. C. while in caloosaensis the interspaces are sculptured only with feeble concentric lines. The anterior byssal ear of ernestsmithi This fine species is separated from G. caloosaensis is much more pointed at the cardinal margin than that of Dall, of the Florida Pliocene, by the sculptured inter- caloosaensis. coastal areas; and from C. peedeensis (Tuomey and Holotype: Deposited Museum Paleontology, Cornell University. Holmes) (pi. 6, fig. 5), of the South Carolina Miocene, Range: Pliocene. and from C. nodosa Linnaeus, of the Recent fauna of Locality: Keith's marl pit, Neills Eddy Landing, Cape Fear the east coast, by the absence of well-defined nodes, by River, 5 miles from Acme, N. C.—Tucker, 1931. the fewer, coarser primaries, and by the stronger, more The specimens figured from the collections in the crowded concentric imbrications. United States National Museum are rather better than Distribution: North Carolina: Pliocene, Waccamaw forma the holotype. tion, Walkers Bluff, Bladen County; Neills Eddy Landing, Shell large, moderately convex. Primary radial Columbus County. This species, though by no means abundant, sculpture of 4 or 5 strong, undulating ribs and of 2 is fairly well represented at these two localities. slightly less. prominent ones near the submargins; Subgenus AEaTTIPECTElT Fischer secondary, of strong, rounded cords numbering 6 to 8 1886. Fischer, Manuel de conchyliologie, p. 944. on each primary, equal in strength on the radial and interradial areas, separated from one another mostly by Type by monotypy: Ostrea opercularis Linnaeus. Recent in European waters. linear interspaces; the medial riblet of the intercostals occasionally made more conspicuous than the others by Shell rather thin, brittle, of moderate dimensions, wider channels, which set it apart from the adjacent the circumference between the dorsal margins an arc secondaries. The concentric sculpture—the character of not far from 270°. Left valve more inflated than istic feature of the shell—consists of very close-set the right and more deeply colored. Primary ribbing imbrications that override the secondaries of both the regular, the number not increased by intercalation; a costal and the intercostal areas; in many individuals a secondary liration frequently developed on both radial suggestion of concentric undulations on the primaries, and interradial areas. Auricles fairly large, subequal. but these are never so strongly developed as in the type Byssal notch deep; Ctenolium strong. Dorsal margin of Nodipecten. Submargins rather wide, not very of right valve bent sharply downward to contact the sharply differentiated; inner submargins sculptured erect margins of the left valve. Inner dorsal margins with concentrically imbricated lirations, usually 5 to reinforced by a single pair of cardinal crurae. 8; outer submargins smooth, the posterior wider than Marginal ligament grooves shallow, the chondrophore the anterior, the latter often obsolete in the right valve. rather small and not very deep. Single muscle im Auricles large, widest at the cardinal margin; distal pression obscure, circular, and included mostly within angles acute; right ear sculptured with 5 or 6 strong the upper posterior quadrant. Inner margins crenate, radial threads, separated by linear interspaces and in harmony with the primary ribbing. overrun by concentric imbrications similar to those on Aeguipecten is set apart by the not very marked the disk; left auricle sculptured with 8 to 12 feeble difference in the inflation of the valves, the gently striations, unequal in width and separated by unequal sloping dorsal margins, and the absence of intercalated interspaces, concentrically wrinkled but not imbri primaries. 36 MOLLUSCA FROM MIOCENE AND LOWER PLIOCENE OF VIRGINIA AND NORTH CAROLINA Chlamys (Aequipecten) eborea (Conrad) Mansfield The length of the locality lists is conclusive evidence Plate 7, figures 1, 5, 6, 8 of the extensiveness of its occurrence. In most beds— 1833. Pecten eboreus Conrad, Am. Jour. Sci., 1st ser., vol. particularly toward the south and in the later forma 23, p. 341. tions—it is by far the most profuse representative of 1840. Pecten eboreus Conrad, Fossils of the medial Tertiary of the genus. the United States, p. 48, pi. 23, fig. 2; pi. 24, fig. 3. 1843. Wecten vicen&rius Conrad, Acad. Nat. Sci. Philadelphia Distribution: Virginia: Miocene, Yorktown formation, 3 Proc., vol. 1, p. 306. (Immature shell.) miles northeast of Walkerton, King and Queen County; Peters 1844. Wecien holbrookii Ravenel, idem, vol. 2, p. 96. burg, Dinwiddie County; 2 miles northwest of Smithfield, 1% 1855. Pecten eboreus Conrad. Tuomey and Holmes, Pleiocene miles west of Smithfield, % mile northeast of Smithfield, 1% fossils of South Carolina, p. 28, pi. 11, figs. 1-5. miles northeast of Smithfield, 5 miles northeast of Smithfield, 1858. Pecten eboreus Emmons, North Carolina Geol. Survey at Benns Church, 6% to 7 miles below Zuni, 7 to 7% miles be Kept., p. 279, fig. 197. low Zuni, Isle of Wight County; Hitchcock, Greensville County; 1898. Pecten (Plagioctenium) eboreus Conrad. Dall, Wagner Sycamore and % to % mile above the lower Seaboard Railway bridge over Meherrin River, Southampton County; }4 mile Free Inst. Sci. Trans., vol. 3, pt. 4, p. 749. north of Chuckatuck, % mile east of Everets, Exit, iy2 miles 1932. Chlamys (Plaffioctenium) eboreus eboreus Conrad. southeast of Reids Ferry, 5% miles northwest of Suffolk, 2% Mansfield, Florida Geol. Survey Bull. 8, p. 60, pi. miles northwest of Suffolk, 1% miles northwest of Suffolk, 1% 12, fig. 11. miles north of Suffolk, 1% miles north of Suffolk, 1% miles 1936. Pecten (Chlamys) eboreus eboreus Conrad. Mansfield, northeast of Suffolk, 1% miles southeast of Suffolk, and the Jour. Paleontology, vol. 10, pp. 174, 180, 181, 184. drainage ditch of the Norfolk & Western Railway just east of Shell suborbicular, compressed, thin, a little oblique; ribs Jericho ditch, Nansemond County. about 22, rounded, little elevated, and smooth; inferior valve North Carolina: Miocene, Yorktown formation, Branches nearly flat. Length 2 inches. Locality, Suffolk, Va., Upper Bridge, Northampton County; 2*£ miles northwest of Murfrees- marine.—Conrad, 1833. boro, 1% miles above Murfreesboro, near Murfreesboro, 3 to 4 miles below Tar Ferry, Tar Ferry, 1% miles below Tar Ferry, Computations on the primary radials of 404 valves Dogwood Landing, and Mount Pleasant Landing, Hertford of this species yield the following results: County; Colerain Landing, Mount Gould Landing, and % to % mile above Edenhouse Point, Bertie County; Halifax, 17 _ _ 2 24 __ _„ __ 95 Palmyra Bluff, and 3% miles below Palmyra Bluff, Halifax 18 __ _ _ .. __ __ 2 25 _ _ _ 59 County; Hamilton Bluff, 4 miles northwest of Williamston, 19 _ _ 7 26 _ __ _ _ 31 2% miles northwest of Williamston, and 1 mile northwest of 20 __ _ . 26 27 5 Williamston, Martin County; 3% miles northwest of Rocky 21 „ __ . __ _ _ 32 28- _ _ 2 Mount, 2 miles west of Rocky Mount, % mile north of New 22 _ . __ _ 70 29 ______1 23 . __ _ _ 72 Bridge, 5 miles below New Bridge, 6 ^ miles below New Bridge, 15% miles above Bells Bridge, y2 mile above Bells Bridge, As in Lyropecten, the number of ribs at a single lo % mile below Bells Bridge, 1 to 1^4 miles below Bells Bridge, cality is fairly constant; furthermore, the tendency to Shiloh Mills, Tarboro, and 1 mile below old Sparta Bridge, Edgecombe County; 2 miles below Toddy Station, 2 miles south ward uniformity is exhibited not only by all individ east of Tugwell, 1% miles northeast of Farmville, 3 miles uals of a species but also by all species of a group. south of Farmville, 2% miles north of Standard, 3 miles south Thus in the very fine, clean, sandy marls of Lanexa, east of Frog Level, 8 to 9 miles west of Greenville, 3 miles in which the 8-, 9-, and 10-ribbed Chlamys (Lyro- west of Greenville, 2 miles west of Greenville, iy2 miles north pecten) jeffersonia were very abundant, the primary west of Greenville, Greenville (just south of the county bridge), 1% miles east of Greenville, 6 miles below Greenville (at Cherry costae of G. (Aequipecten) chorea run as follows: Landing), 6% miles below Greenville (at Taft's Landing), 9 19 22. 14 to 10 miles south of Greenville, Hardees Creek (about 3% miles 20 23. 3 from the Tar), 1 mile northwest of Galloway Crossroads, % 21. 24. 1 mile north of Grimesland, Grifton, and 3 miles east of Grifton, Pitt County; 2% miles northwest of Chocowinity and In the coarser and slightly higher sands iy2 miles 1% miles northwest of Chocowinity, Beaufort County; Hominy north of Suffolk, on the other hand, the many-ribbed Swamp near Wilson, 1 mile west of Wilson, 3 miles east- forms of G. jeffersonia are abundant, and the follow southeast of Wilson, 5 miles south of Wilson, and 1 mile north west of Stantonsburg, Wilson County; 1 mile north of Castoria, ing table shows the prevalence of the more numerous % mile east of Lizzie, 1 mile east of Lizzie, 2 miles northeast costae among the specimens of eborea: of Lizzie, and 4 miles east of Lizzie, Greene County; 6 miles west of Goldsboro, Wayne County; Rock Landing, Craven 22 1 26 ______7 County. Duplin marl, 2% miles south of Clinton, 3 miles 23 1 27 ______0 south of Clinton, and 4 miles south of Clinton, Sampson County; 24 28 ______0 2 miles northeast of Warsaw, Natural Well and environs, 25 29 ______1 Duplin County; 1 mile west of Lumberton, Lumberton (near The subdivisions established by Dall on the varia the bottling works), 2 miles below Lumberton, 4 to 5 miles tions in the minor details of the sculpture have not below Lumberton, Fairmont, 1% miles northeast of Fairmont, been used here because of the many intermediate forms and 4 miles northeast of Fairmont, Robeson County. Pliocene, Waccamaw formation, Black Rock Landing, 4 miles east of and the almost endless combinations of minor Elizabethtown, and Walkers Bluff, Bladen County; Neills Eddy differences, Landing, Columbus County; Wilmington, New Hanover County, PART 1. PELECYPODA 37 Outside distribution: Miocene, Choctawhatchee formation, tively greater compression of the right valve. In true northern Florida. Duplin marl, Darlington, Darlington County, Pecten the right valve is more highly inflated than the S. C.; Porters Landing on the Savannah River, Effingham County, left. The byssal sinus of Placopecten is more shallow Ga., Pliocene, (?) Santa Rosa and Santa Maria Tetetla, Vera Cruz, Mexico; Tuxtepec, Oaxaca, Mexico. Waccamaw formation, than that of true Chlamys, and the pectenidial teeth Todds Ferry, Horry County, S. C., Caloosahatchee marl, Caloosa- are usually obsolete in the adults. In form and texture hatchee River, and Shell Creek, Fla. the Placopecten approach Amusium, but they are Chlamys (Aequipecten) comparilis (Tuomey and Holmes) sharply separable by the absence of internal ribbing. Mansfield Chlamys (Placopecten) clintonia (Say) Verrill Plate 7, figures 2, 3, 4, 7 Plate 6, figures 1, 4 1855. Pecten comparilis Tuomey and Holmes. Pleiocene fos 1824. Pecten clintonius Say, Acad. Nat. Sci. Philadelphia Jour., sils of South Carolina, p. 29, pi. 11, figs. 6-10. 1st ser., vol. 4, p. 135, pi. 9, fig. 2. 1898. Pecten eboreus var. comparilis Tuomey and Holmes. Dall, 1834. Pecten magellanicus Conrad, idem, 1st ser., vol. 7, p. 153. Wagner Free Inst. Sci. Trans., vol. 3, pt. 4, p. 750. Not Ostrea magellanica Gmelin, 1792. 1932. Chlamys (Plagioctenium) comparilis Tuomey and 1840. Peoten clintonius Say. Conrad, Fossils of the medial Ter Holmes. Mansfield, Florida Geol. Survey Bull. 8, p. tiary of the United States, p. 47, pi. 23, fig. 1. 61, pi. 11, figs. 5, 6. 1858. Pecten princepoides Emmons, North Carolina Geol. Sur 1936. Pecten (Chlamys) comparilis Tuorney and Holmes. vey Rept., p. 280, fig. 198. Mansfield, Jour. Paleontology, vol. 10, pp. 174, 180, 1863. Pecten clintonius Say. Conrad, Acad. Nat. Sci. Philadel 181, 184, 185. phia Proc. for 1862, vol. 14, p. 581. Shell orbicular, convex, somewhat thick, equivalve, with con 1897. Chlamys (Placopecten) clintonius Say (part). Verrill, centric lines of growth, ears nearly equal. Lower valve, buccal Connecticut Acad. Arts and Sci. Trans., vol. 10, p. 78. ear notched, radiately and coarsely ribbed, with 5 to 6 ribs; 1898. Pecten (Placopecten) clintonius Say. Dall, Wagner Free anal ear, ribs smaller and more numerous. Upper valve, ears Inst. Sci. Trans., vol. 3, pt. 4, p. 725. with the radiating lines equal, ribs and interstices nearly equal. 1904. Pecten (CMamys) clintonius Say. Glenn, Maryland Geol. This fossil is distinguished from P. eboreus by having the Survey, Miocene, p. 375, pi. 99, fig. 5. ribs more raised and convex, both valves more convex, and by 1936. Pecten (Chlamys) clintonius Say. Mansfield, Jour. Pale the coarse ribs of the buccal ear of the lower valve.—Tuomey ontology, vol. 10, pp. 174, 178,184, pi. 22, fig. 4. and Holmes, 1855. Auricles equal; surface with from 140 to 180 elevated longi The characters that separate C. comparilis from C. tudinal lines. Shell suborbicular, compressed, with very numerous, regular, eborea, with which it has been commonly confused, elevated striae, which are muricated with minute scales formed are well illustrated in the original figures. by transverse wrinkles that are sparse in the middle of the The species is restricted to a few localities at the length and crowded on each side of the shell; the intervening top of the Miocene and the base of the Pliocene scat spaces are regularly concave and in parts very distinctly wrin tered from southern Virginia to Florida. In Florida kled ; auricles equal, striated like the general surface; within simple, margin striated. C. comparilis has been recognized only in the Length 4 inches, breadth rather more. Cancellaria zone. This is a very fine shell comparable with the mageUanica; but the sides below the auricles decline much more rapidly toward Distribution: The recorded distribution of Pecten comparilis the base, and the striae, judging from Bruguiere's figure, are Tuomey and Holmes (Pleiocene fossils of South Carolina, p. 29, much more prominent and distinct.—Say, 1824. pi. 11, figs. 6-10) is as follows: Yorktown formation at Peters burg and 16 miles below Suffolk, Nansemond River, Va., one Type locality: Maryland [ ?]. specimen in the United States National Museum collected by Verrill united the Miocene species with the Recent the late Frank Burns from each locality; upper Miocene at Pecten magellanicus, its undoubted descendant, but Darlington, S. C. (Tuomey and Holmes) ; Pliocene at Goose Creek, S. C.; upper Miocene bed at Porters Landing on the Dall, op. cit, 1898, later excluded the Recent species be Savannah River, Ga.; and upper Miocene (Cancellaria zone), cause of "the shorter hinge line, higher auricles, much Florida.—Mansfield, W. C., Jour. Paleontology, vol. 10, No. 3, narrower resiliary pit, and usually the smaller and less p. 180, April 1936. central adductor scar of the Recent shell. * * * As Subgenus PLACOPECTEN Verrill a rule the radiating threads in the fossil are markedly coarser than those of the living species. In both, the 1897. Placopecten Verrill, Connecticut Acad. Arts and Sci. Trans., vol. 10, p. 69. byssal notch of the adult is represented by a shallow sinuation, and the ctenolium, present in the immature Type by original designation : Pecten clintonius Say. Miocene stages, is usually buried in shelly matter in the adult." of Virginia. The species is well characterized by the thin, com Verrill describes Placopecten as a subgenus of pressed shell, the hyaline texture of the interior surface, Chlamys. A number of authors, including Dall, have and the very numerous, irregularly wrinkled, radial considered it closer to Pecten, although Dall mentions lirations of the exterior surface, which are coarser than the similarity of a Placopecten clintonius to a hypo those of the Recent magellanica. The concentric orna thetical Lyropecten jeffersonius with obsolete primary mentation is visible only in the interspaces and on the ribbing. Placopecten resembles Chlamys in the rela auricles and submargins, where it is sometimes strong 38 MOLLUSCA FROM MIOCENE AND LOWER PLIOCENE OF VIRGINIA AND NORTH CAROLINA enough to muricate the lirae. It is interesting to note 1904. Pecten (Chlamys) marylandicus Wagner (part). Glenn, that in the closely allied Recent species the individuals Maryland Geol. Survey, Miocene, p. 376, pi. 99, fig. 6. that develop a sculpture most nearly akin to that of 1936. Pecten (Chlamys) marylandicus Wagner. Mansfield, Jour. Paleontology, vol. 10, pp. 174, 176, 177, 184. Placopecten clintonius (Say) come from warmer waters. Shell ovate, compressed; ribs numerous, consisting of narrow, nearly smooth striae disposed in pairs; interstitial spaces each The pectens described by Say in 1824 are among with a carinated line; ears unequal; inferior valve very slightly the most common in the Miocene faunas of the middle convex; ribs similar to those of the opposite valve; inner States of the Atlantic seaboard. They were included margin of the valve with profoundly elevated lines. Locality, Mehering [Meherrin] River, N. C. [ ?] This Pecten is in "a very large and fine collection of fossil shells allied to Pecten madisonius Say but can readily be distinguished which Mr. John Finch obtained with much labor and by its want of broad, elevated ribs and a surface destitute of some expense in Maryland and which that gentleman scales.—Wagner, 1839. with great liberality submitted" to Thomas Say for In external ornamentation the species ranges from examination. The following footnote attends Pecten individuals showing uniform radiating lirae similar Clintonius: "Mr. Finch requested that three species to those of Placopecten clmtonius—though stronger of his collection that might prove to be new should be and consequently less numerous—to individuals exhibit dedicated to the distinguished men whose names these ing true ribs that recall those of Lyropecten and that shells bear." Thomas Jefferson, James Madison, and are sufficiently strong to crenulate the interior of the DeWitt Clinton were thus honored. DeWitt Clinton valves. The ribs do not, however, become so strong was in 1824 a prominent national figure. He had been as in the typical madisonius, nor are they ever reduced United States Senator from New York, mayor of New to interareas between impressed lines, as in virginianus York City, governor of New York, and in 1812 a and certain representatives of tenuis. The delicate, formidable candidate for the presidency. The Great concentric sculpture is visible in the interspaces, as in Lakes to Hudson River Canal was begun and com clintonius, but it does not imbricate the radial stria- pleted largely through his efforts. He was an educator tions, as in many individuals of tenuis. and a naturalist, the second president of the American Academy of Art, and the founder and an early Distribution: Virginia: Miocene, Choptank formation, Nomini Cliffs, Westmoreland County. president of the New York Historical Society. Outside distribution: Miocene, Choptank formation, Dover Mansfield (op. cit., p. 178) has expressed on the Bridge, Queen Annes County, Md.; Governor Run, Flag Pond, printed page the doubt held by many students that • and St. Leonard Creek, Calvert County, Md.; Jones Wharf, the Finch collection included only Maryland shells. Patuxent River, St. Marys County, Md. It is highly probably that not only Pecten clintonius Chlamys (Placopecten) virginiana (Conrad) Tucker Say but also Say's P. jeffersonius and P. septenarius came from the Yorktown formation in Virginia, at Plate 4, figure 3 a horizon higher than any recognized in the Miocene 1840. Pecten virginianus Conrad, Fossils of the medial Tertiary section of Maryland. of the United States, p. 46, pi. 21, fig. 10. 1863. Pecten virginianus Conrad, Acad. Nat Sci. Philadelphia Distribution: Virginia: Miocene, Torktown formation. Proc. for 1862, vol. 14, p. 582. Lanexa, New Kent County; Indian Field Point and Torktown, 1898. Pecten (Placopecten) virginianus Conrad. Dall, Wagner York County; mouth of Baileys Creek, Prince George County; Free Inst. Sci. Trans., vol. 3, pt. 4, p. 727. old Claremont Wharf, Schmidts Bluff, 8% miles below Clare- 1934. Chlamys (Placopecten) virgmianum Conrad (part). mont Wharf, Sunken Marsh Creek, and Cobham Wharf, Surry Tucker, Am. Midland Naturalist, vol. 15, p. 617. County; Kings Mill, James City County; 1 mile above Zuni, 1936. Pecten (Chlamys) viriginianus Conrad. Mansfield, Jour. just south of Zuni, 6% to 7 miles below Zuni, and 7 to iy2 Paleontology, vol. 10, pp. 174, 178, 184. miles below Zuni, Isle of Wight County; Sycamore, Southampton County. Shell orbicular; inferior valve convex, with numerous irregu North Carolina: Miocene, Torktown formation, 1% miles lar, impressed, radiating lines; sinus of the ear profound, and above Branches Bridge, Northampton County, 2y% miles above a deep groove margins the ear to the apex; the groove minutely Murfreesboro, 1 mile above Murfreesboro, and near Murfrees- pectinated. boro, Hertford County; Halifax, Halifax County; 3 miles west Locality, near City Point, Va.—Conrad, 1840. of Greenville and 2 miles west of Greenville, Pitt County. Later collections have revealed this species at sev Chlamys (Placopecten) marylandica (Wagner) Glenn eral localities of the Yorktown though it is nowhere an abundant form. It shares with C. clintonia (Say) Plate 5, figure 4; plate 6, figures 2, 3 the thin convex valves and hyaline texture, though it 1839. Pecten marylandicus Wagner, Acad. Nat. Sci. Phila exhibits a peculiar translucency not noted in any re delphia Jour., 1st ser., vol. 8, p. 51, pi. 1, fig. 2. presentative of C. clintonia. It differs, furthermore, 1863. Pecten marylandicus Wagner. Conrad, Acad. Nat- Sci. in the smaller size, the deeper byssal notch, the more Philadelphia Proc. for 1862, vol. 14, p. 581. strongly developed ctenolium, and the details of the 1898. Pecten (Placopecten?} marylandicus Wagner (part). Dall, Wagner Free Inst. Sci. Trans., vol. 3, pt. 4, external sculpture. In place of the raised lirae of p. 728. C. clintonia, it has irregular impressed lines that are PART 1. PELECYPODA 39 irregularly spaced and that number 75 on the type. 1936. Amusium mortoni Ravenel. Mansfield, Jour. Paleon The dimensions are. as follows: Height 57.8 milli tology, vol. 10, pp. 174, 180, 184, 185. meters, width 58.8 millimeters, semidiameter 4.1 Orbicular, thin, both valves moderately convex, one more millimeters. so than the other; outside, with numerous concentric obsolete striae; inside, with from 18 to 24 radiating double ribs, slightly Distribution: Virginia: -Miocene, Yorktown formation, City elevated; ears large, subequal, striated externally. Point (Conrad) and the mouth of Baileys Creek, Prince George This species is nearly allied to the P. pleuronectus and P. County; 12 to 14 miles below Zuni, Isle of Wight County; japonicus. It is found on my plantation, The Grove, in St. Delaware Park, Southampton County. Thomas' Parish, about 17 miles from Charleston, and also on North Carolina: Miocene, Yorktown formation, 1% miles Goose Creek, at Mr. Henry Smith's, about 7 miles southwest above Murfreesboro, Hertford County. from The Grove deposit, and 11 miles from Charleston; Cooper River being between these localities. Genus AMTTSITTM (Bolten) Reeding This shell is abundant at The Grove, but being large and 1798. Amusium (Bolten) Reeding, Museum boltenianum, pt. 2, p. thin it is generally broken in getting out the marl, and with 165). the exception of a few small specimens I have not been able to procure a perfect valve. Type by subsequent designation (Herrmannsen, Indicis gen- The largest specimen in my possession, although not perfect, erum Malacozoorum, vol. 1, p. 47, 1846) : Ostrea pleuronectes is sufficiently so to determine its size; it is 8% inches in Linnaeus. Recent in the Indo-Pacific. diameter. The valves are commonly large, thin, feebly convex, I take much pleasure in designating this shell by the name and, like those of the true pectens, not attached by a of our distinguished geologist, Dr. Samuel George Morton, of byssus. Eadial sculpture is sometimes suggested by Philadelphia.—Ravenel, 1844. the color pattern but is rarely developed and is never Mansfield reports fragments of the species from a strong. A concentric imbrication may be observed in number of localities in the Ecphora and Cancellaria some species, particularly toward the ventral margin. zones of northern Florida. The discrepancy in ornamentation so common in Distribution: North Carolina: Miocene, Duplin marl, Natural Ps&udafmMssiimb is reflected in the discrepant coloring Well, 1% miles north of Magnolia, Duplin County. Pliocene, in Amusium s. s. In A. papyraceum, the Recent Antil- Waccamaw formation, Lake Waccamaw, Columbus County; lean .shell, the right valve is white or bordered with Black Rock Landing on the Cape Fear River, Bladen County. pale yellow, but the left is a deep reddish or purplish Outside distribution: Miocene, Santa Rosa and Santa Maria Tetetla, Vera Cruz, Mexico. St. Marys formation, Cove Point brown. This general type of color holds throughout and Drum Point, Calvert County, Md. Choctawhatchee forma Amusium s. s. The lirae developed upon the inner sur tion, northern Florida. Pliocene, Waccamaw formation, Todds face of the disk are perhaps the most constant feature Ferry, Horry County; The Grove, Cooper River, and Smith's, of the genus. Goose Creek, Berkeley County, S. C. Caloosahatehee marl,- Like Pecten, Amusiurm may be traced back to the Caloosahatchee River and Shell Creek, Fla. Mesozoic. The thin, internally lirate shells of Amus ium require a much more specialized habitat than the Family SPONDYLIDAE heavy, externally ribbed shells of most of the Pecten Genus PLICATTTLA Lamarck group, and perhaps for this reason the genus is rela 1801. PHcatula Lamarck, Syst§me des animaux sans vertebres, tively rare. p. 132. Type by subsequent designation (Schmidt, C. F., Versuch Amusium mortoni (Ravenel) Conrad iiber die beste Einricht, etc., pp. 61, 177, Gotha, 1818) : Spondy- Plate 8, figures 1, 2 lus plicatus Linnaeus. Recent in the Orient. 1844. Pecten mortoni Ravenel, Acad. Nat. Sci. Philadelphia Shell small, inequivalve, flattened or slightly convex, Proc., vol. 2, p. 96. trigonal-ovate to subcircular, often irregular, attached 1855. Pecten mortoni Ravenel. Tuouiey and Holmes, Pleiocene as a rule in the adult by the umbo of the right valve, fossils of South Carolina, p. 27, pi. 10, figs. 1, 2. 1858. Pecten mortoni Emmons, North Carolina Geol. Survey which is the larger. Outer surface generally plicate, Rept, p. 281. the folds commonly bifurcating. Ligament internal, 1863. Amusium mortoni Ravenel. Conrad, Acad. Nat. Sci. Phil lodged in a subumbonal cartilage pit between the twp adelphia Proc. for 1862, vol. 14, p. 582. heavy, divergent, transversely striated cardinal crurae. 1898. Pecten (Amusium) mortoni Ravenel. Dall, Wagner Free A single muscle impression in the adult, excentric and Inst. Sci. Trans., vol. 3, pt. 4, p. 757. 1904. Pecten (Amusium) mortoni Ravenel. Glenn, Maryland posterior. Pallial line entire. Margin fluted in har Geol. Survey, Miocene, p. 372, pi. 99, fig. 1. mony with the outer ribbing. 1906. Amussium mortoni Ravenel. Bose, Inst. geol. Mexico Bol. Plicatula differs from Spondylus in its small size, 22, pp. 24, 74, pi. 1, figs. 3, 6, 7, 9; pi. 8, figs. 1, 2; pi. 9, less ornate sculpture, and absence of auricles. fig 3. The genus, which is recorded in the early Mesozoic, 1909. Pecten (Amusium) mortoni Ravenel. Grabau and Shinier, culminated in the late Mesozoic and is represented by North American index fossils, vol. 1, p. 508, fig. 680. 1932. Amusium mortoni Ravenel. Mansfield, Florida Geol. Sur fewer than a dozen Recent species, mostly oriental in vey BuU. 8, p. 64, pi. 11, figs. 2, 4. habitat. 40 MOLLTJSCA FROM MIOCENE AND LOWER PLIOCENE OF VIRGINIA AND NORTH CAROLINA Plicatula marginata Say and Queen County; Yorktown and Bellefield, York County; Clare- mont Wharf and old Claremont Wharf, Surry County; 2 miles Plate 11, figures 6, 8, 13, 14 below Peters Bridge, Sussex County; 1 mile north of Zuni, 7 to 7y2 miles below Zuni, 12 to 14 miles below Zuni, 2 miles 1824. Plicatula marginata Say, Acad. Nat. Sci. Philadelphia Jour., 1st ser., vol. 4, p. 136, pi. 9, figs. 4a, b. northwest of Smithfield, iy2 miles west of Smithfield, % mile 1845. Plicatula marginata Say. Conrad, Fossils of the medial northeast of Smithfield, 1% miles northeast of Smithfield, 5 miles northeast of Smithfield, and Benns Church, Isle of Wight Tertiary of the United States, p. 75, pi. 43, fig. 5. County; Sycamore, 14 to % mile below Sycamore, Maddelys 1855. Plicatula marginata Say. Tuomey and Holmes, Pleio- Bluff, Southampton County; a quarter of a mile north of cene fossils of South Carolina, p. 24, pi. 7, figs. 11-14. Suffolk, iy2 miles northeast of Suffolk, 1 mile northeast of 1858. Plicatula marginata Emmons, North Carolina Geol. Sur Suffolk, and half a mile below the Suffolk waterworks dam, vey Kept., p. 283, fig. 203. 1863. Plicatula marginal a Say. Conrad, Acad. Nat. Sci. Phila Nansemond County. delphia Proc. for 1862, vol. 14, p. 582. North Carolina: Miocene, Yorktown formation, 1% miles 1898. Plicatula marginata Say. Dall, Wagner Free Inst. Sci. above Branches Bridge, 1 mile above Branches Bridge, and Branches Bridge, Northampton County; iy2 miles above Mur- Trans., vol. 3, pt. 4, p. 764. 1932. Plioatula marginata Say. Mansfield, Florida Geol. Sur freesboro, 1 mile above Murfreesboro, and near Murfreesboro, Hertford County; Palmyra Bluff, Halifax County; 3 miles west vey Bull. 8, p. 66, pi. 12, figs. 9,10. of Williamston, 2% miles northwest of Williamston, 1 mile Shell ovate-cuneiform, somewhat arcuated at base; with northwest of Williamston, and Hamilton Bluff, Martin County; about 3 much elevated folds, producing very profound undula Qy2 miles below New Bridge, Swift Creek, 15^ miles above tions on. the edge of the shell; the intermediate fold is bifid; Bells Bridge, % mile above Bells Bridge, % mile below Bells the whole surface is marked by rather gross concentric wrin Bridge, Shiloh Mills, Tarboro (at L. E. Fountain's farm), and kles ; inner margin dusky or blackish, with a series of granules 1 mile below old Sparta Bridge, Edgecombe County; 2 miles on one valve, received into corresponding cavities in the op below Toddy Station, 1*4 miles northeast of Farmville, 3 miles posite valve. south of Farmville, 2% miles north of Standard, 8 to 9 miles Length 1% inches, breadth 1 inch.—Say, 1824. west of Greenville (on the east side of Pinelog Branch), 3 miles Type locality: Maryland (?). west of Greenville, 2 miles west of Greenville, iy2 miles west of Greenville (on Schoolhouse Branch), Greenville (just east So far as the form of the shell is concerned, this species of the county bridge), 8 to 9 miles southeast of Greenville, cannot be discriminated from P. gibtosa, but none of the speci 9 to 10 miles south of Greenville, and 1 mile northwest of mens show any trace of the dark venous lines which are so Galloway Crossroads, Pitt County; 2 miles northwest of Cho- characteristic of both recent and fossil specimens of gibbosa. cowinity, Beaufort County; 2 miles southwest of Maple Cypress, In a very large series of the recent shell a few specimens will Craven County; 1 mile west of Wilson (at Hominy Swamp), usually be found which have a diffused brownish blush instead 1 mile south of Wilson, 3 miles east-southeast of Wilson, 1 mile of the brown lines; but these are so exceptional that I have northwest of Stantonsburg, Wilson County; 1 mile north of felt the present species might be separated with propriety. In Castoria, y% mile east of Lizzie, 2 miles northeast of Lizzie, both, the differences of sculpture due to situs pass through a 4 miles east of Lizzie, and 1% miles east of Ormonds- parallel series of mutations.—Dall, 1898. ville, Greene County, 1% miles below Tar Ferry, 3 to 4 miles below Tar Ferry, and Dogwood Landing, Hertford This species is the only common representative of County; Colerain Landing and Mount Gould Landing, Bertie the genus occurring within the Virginia-North Caro County; Rock Landing, Craven County. Duplin marl, 2% miles lina area. As is normal with attached forms, it shows south of Clinton, 3 miles south of Clinton, and 4 miles south of a considerable amount of variation in outline and in Clinton, Sampson County; 3 miles northeast of Warsaw, Mag nolia, and Natural Well and environs, Duplin County; 4 miles the number and character of the radial plications. north of Lumberton, 1 mile west of Lumberton, Lumberton The narrow trigonal outline is characteristic of the (near the bottling works), 2 miles below Lumberton, 4 to 5 forms with few ribs; the subcircular, of the forms with miles below Lumberton, Fairmont, and 1% miles northeast of many. The species is exceedingly abundant along the Fairmont, Robeson County. Pliocene, Waccamaw formation, Tar River, in Pitt County, N. C., and farther south Lake Waccamaw, Cronly, and Neills Eddy Landing, Columbus County; Wilmington, New Hanover County. east, in the vicinity of Lizzie, in Greene County, N. C. Outside distribution: Miocene, Choctawhatcb.ee formation, A particularly large collection was made by L. W. northern Florida. Duplin marl, Darlington, Darlington Stephenson at Dog Swamp, 4 miles east of Lizzie. County, S. C.; Porters Landing on the Savannah River, The range of variation in the number of ribs at this Effiingham County, Ga. Pliocene, Waccamaw formation, Nixons, locality is as follows: 3 ribs, 2 right valves, 1 left Tillys Lake, and Todds Ferry, Horry County, S. C. Caloosa- valve; 4 ribs, 22 right valves, 40 left valves; 5 ribs, 77 hatchee marl, De Leon Springs, Volusia County, Fla. Caloosa- hatchee River, Shell Creek, and Alligator Creek, Fla. right valves, 101 left valves; 6 ribs, 54 right valves, 36 left valves; 7 ribs, 14 right valves, 10 left valves; 8 Superfamily A1TOMIACEA ribs, 1 right valve, 3 left valves. The data, based on the consideration of 170 right valves and 191 left valves, Family ANOMIIDAE indicate that 5 is the average number of ribs and that Genus PODODESMUS Philippi 1837 there is a tendency toward fewer ribs in the left valve 1837. Pododesmus Philippi, Wiegmann, Archiv Naturgeschichte, than in the right. Jahrgang 3, Band 1, p. 385. Distribution: Virginia: Miocene, Yorktown formation, 4 miles Type by monotypy: Pododesmus decipiens Philippi=Po(Zo Superfamily ANATINACEA 1825. Thracia (Leach ms.) De Blainville, Manuel de malacologie, p. 564. Family PEBJPLOMATIDAE 1827. Thracia De Blainville, idem, planches, p. 660, pi. 76, fig. 7. Genus PERIPLOMA Sehumaeher 1839. Thracia Leach. Couthouy, Boston Jour. Nat. History, vol. 2, p. 129. 1817. Periploma Sehumaeher, Essai d'un nouveau systeme des 1903. Thracia Blainille. Dall, Wagner Free Inst. Sci. Trans., habitations des vers testace"s, p. 115. vol. 3, pt. 6, p. 1522. Type by monotypy: Periploma, inaequwalvis Sehumaeher. Recent in the West Indies. Type by elimination: Thracia corbuloidea De Blainville. Recent in the Mediterranean. Shell subnacreous, inaequivalve, nearly closed, oval or rounded; umbones opisthogyrate. Ligament inter In 1824 De Blainville described at length the shell nal, supported by two vertically or anteriorly directed of Thracia and placed under it two sections: (A) chondrophores. Hinge edentulous. Muscle impres Species that have a spoon-shaped process (cuilleron) sions unequal. Pallial sinus broad and shallow. in one valve only;, sole example, T. corbuloidea; (B) The genus is rare in the Tertiary, and the Eecent species that have a spoon-shaped process in each valve; forms are mostly confined to the eastern coasts of the sole example, T. pubescens Leach =Mya pubescens Lin Americas. naeus. De Blainvilles description in 1825 was a rep lica of that of 1824 except that in the next to the last Subgenus COCHLODESMA Couthouy line of the description of 1824 he wrote "une ligule ab- 1839. Cochlodesma, Couthouy, Monograph on the family Osteo- dominale;" in 1825, "une ligule palleale." In 1827 De desmacea: Boston Jour. Nat. History, vol. 2, p. 170. Blainville published the figures to accompany the text of 1825 and also a few pages of "Nouvelles additions Type by monotypy: Anatma leana Conrad. Recent from the Gulf of St. Lawrence to North Carolina. et corrections au genera," in which he made the follow ing note on Thracia "Supprimez la division B, etablie The subgenus is characterized by the compressed, sur une coquille que je n'avais pas vue, et qui parait tellinif orm outline and by the absence of a calcified rib n'etre autre chose que celle qui sert de type au genre supporting the chondrophore. OSTfiODESME * * *." Periploma (Cochlodesma) antiqua Conrad As De Blainville's observations were not entirely cor Plate 10, figure 3 rect, his A and B divisions are no longer recognized; but he clearly expressed the wish to eliminate the shell 1834. Anatina, antiqua Conrad, Acad. Nat. Sci. Philadelphia he had not seen. T. corbuloidea, then, remains the Jour., 1st ser., vol. 7, p. 130. 1838. Periploma antiqua Conrad, Fossils of the medial Tertiary unique example. of the United States, p. 16, pi. 8, fig. 3. The shell of Thracia is thin, not nacreous but cellulo- 1863. Periploma antiqua Conrad, Acad. Nat. Sci. Philadelphia crystalline, transversely ovate to ovate-trigonal, broadly Proc. for 1862, p. 572. rounded in front, more or less produced, truncate, and 1873. Cochlodesma antiquatum Conrad, Verrill, Invertebrate gaping posteriorly. The right valve is larger and animals of Vineyard Sound: U. S. Comm. Fish and Fisheries Rept, p. 673. more inflated than the left, the right umbo higher than 1903. Periploma (Cochlodesma) antiqua Conrad. Dall, Wag the left, and the ventral margin of the right valve ex ner Free Inst. Sci. Trans., vol. 3, pt. 6, p. 1530. tends beyond that of the left. The umbones are broad, Shell ovate, rather elevated, convex, thin, and fragile; with placed a little in front of the medial line, inrolled, and obsolete concentric sulci; beaks slightly prominent; fosset not at the extreme tips turned slightly backward. They oblique, elongated. Length 2 inches, height about 1% inches. are so closely in contact in some of the species, notably Locality, Yorktown, Va.—Conrad, 1834. Thracia conradi Couthouy, that the shell is frequently The type remains unique. The fragment of a valve worn through by friction of the opposing surfaces. strongly suggesting Conrad's species but not possessing The anterior lateral margin is, as a rule, broadly sufficient characters for a definite determination was rounded, the ventral margin broadly constricted in collected from the Waccamaw marls at Walkers Bluff, front of the obtuse rostrum, and the posterior truncate in Bladen County, N. C. Another fragment, unlike or rounded. The only sculpture is a concentric wrin any known species of Periploma but too imperfect to kling, incremental in character, and a surficial granu describe, has been found in the Yorktown S1/^ miles lation. The living species are in some degree protected northwest of Chocowinity, in Beaufort County, N. C. by a delicate periostracum. The ligament is short, Distribution: Virginia: Yorktown formation, Yorktown, marginal, and sunken. It is attached on each side to York County. modifications of the posterior dorsal margins, which in the closed valves are spoon-shaped. The hinge is Family THRACIIDAE edentulous. In some species—but not in all—the inner Genus THRACIA (Leach ms.) De Blainville extremity of the anterior dorsal margin of the left 1824. Thracia (Leach ms.) De Blainville, Dictionnaire des valve is raised into an inconspicuous subumbonal tu sciences naturelles, vol. 32, p. 347. bercle, and in other species an inconspicuous ossicle is PART 1. PELECYPODA 43 developed on the anterior dorsal margin a little in sion very superficial like the others, with a profound, subangular front of the umbo. In most Thracia the shell is so thin excavation posteriorly. Length 21%0, height 2%0, diameterl%0 inches. Inhabits prob that the muscle scars and moderately insinuated pallial ably the whole coast of New England.—Couthouy, 1839. line are difficult to observe. The individuals from Maryland are more com Thracia is reported from the early Mesozoic on to the pressed than either the. Tertiary representatives in the Recent. The Tertiary species, like the Recent, are area to the south or the Recent form and should prob widely scattered, but individuals are rarely abundant. ably be excluded altogether from T. oonradi Couthouy Many of the east coast American forms are associated s. s., although the material is too imperfect to serve with northern faunas. as a foundation of a new species. In the Choctawhatchee of Florida, Thracia conradi Thracia conradi Couthouy has been recognized from the upper part of the middle Plate 10, figure 4 Miocene—the Area zone through the Ecphora zone. 1831. Thracia declivis Conrad, Am. marine conchology, No. 2, Distribution: Virginia: Miocene, Yorktown formation, 5 p. 44, pi. 9, fig. 2. Not Mya declivis Pennant, 1778. miles northeast of Smithfield, Isle of Wight County; % to % 1839. Thracia conradi Couthouy, Boston Jour. Nat. History, mile below Sycamore, Southampton County; 1^ miles north vol. 2, p. 153, pi. 42, fig. 2. of Suffolk, Nansemond County. 1869. Thracia conradi Couthouy, Am. Jour. Conchology, vol. 4, North Carolina: Miocene, Yorktown formation, (?) 1 mile app. p. 54. above Branches Bridge, and Branches Bridge over the Meher- 1870. Thracia conradi Couthouy. Gould, Invertebrata of Massa rin River, Northampton County; Watsons Mill on Kirbys chusetts, Binney ed., p. 69, fig. 384. Creek, 2% miles northwest of Murfreesboro, and 1% miles 1889. Thracia, conradi Couthouy. Dall, U. S. Nat. Mus. Bull. above Murfreesboro on the Meherrin River, Hertford County; 37, p. 64, pi. 69, fig. 9. Halifax (on Quankey Creek) and Palmyra Bluff (on the 1903. Thracia conradi Couthouy. Dall, Wagner Free Inst. Sci. Roanoke River), Halifax County; % mile above Bells Bridge Trans., vol. 3, pt. 6, p. 1524. over the Tar River, Edgecombe County. Duplin marl, 1% 1904. (?) Thracia conradi Couthouy. Glenn, Maryland Geol. miles northeast of Fairmont, Robeson County. Survey, Miocene, p. 359, pi. 95, fig. 4. Outside distribution: Miocene, Calvert formation, Fairhaven, 1906. Thracia conradi Couthouy. Rogers, Shell book, p. 329, Lyons Creek, Plum Point, and Chesapeake Beach, Md. Chocta pi. 74, opp. p. 323, fig. 1. whatchee formation, northern Florida. Recent, Labrador to 1932. Thracia c Shell transversely ovate, ventricose, very light, brittle, and Thracia transversa H. C. Lea thin, rather faintly diaphanous by reason of its want of thick Plate 10, figures 5-10 ness, subequilateral, slightly gaping at both extremities, in- equivalve, the right valve being the more convex, its whole 1846. Thracia transversa H. C. Lea, Am. Philos. Soc. Trans., margin projecting considerably beyond that of the left; beaks new ser., vol. 9, p. 237, pi. 34, fig. 11. proturberant, large, and cordiform, inclining a little backward, 1863. Thracia? transversa H. C. Lea. Conrad, Acad. Nat. Sci. the summit of the right one excavated or emarginate to receive Philadelphia Proc. for 1862, p. 572. the opposing one; incremental striae numerous and distinct, 1903. Thracia transversa H. C. Lea. Dall, Wagner Free Inst. occasionally forming feeble concentric ridges; the anterior por Sci. Trans., vol. 3, pt. 6, p. 1525. tion of the shell is regularly rounded and its superior margins Shell subelliptical, very inequilateral, acuminately rounded very thin; the posterior extremity is rather narrower and posteriorly, truncate anteriorly, subcompressed, thin, smooth somewhat truncated, with an obtuse carination extend centrally, striate posteriorly and anteriorly; umbonial slope ing obliquely from the beaks to the angle of the basal rounded; basal margin curved; dorsal margin angular in the and posterior margins; between this carination and the superior middle, posteriorly convex, anteriorly concave; beaks somewhat and posterior margins, the shell is slightly compressed. The acute; nymphal callosity small, oblique. Diameter 0.10, length basal margin is sinuous, curving outwardly in its central por 0.18, breadth 0.28 of an inch. tion, corresponding to the most convex part of the shell. Liga- From the shape of the anterior margin, I conclude that the mep* externally very prominent, and prolonged in a thin shell must have gaped considerably there, but as I have no pair ruembrane the whole length of the corselet, which is strongly of valves I cannot be certain. The sinus of the palleal im marked and extends from the beaks to the extremity; the in pression is deep and near the anterior cicatrix. In this char ternal portion of the ligament is attached to a strong, thick, acter it differs from the rest of the genus. nymphal callosity, projecting obliquely along the cardinal edge This is, I believe, the first Thracia found in our Tertiary in each valve, wider toward the beaks, and having its surface deposits. Deshayes, in his tables, gives 4 as the number of but very slightly hollowed. Hinge destitute of a cardinal ossi- European Tertiary species. The present one is the smallest culum. External color a pale ashy white, surface covered with of the genus.—H. C. Lea, 1846. a thin, light, cinereous epidermis, strongly adherent and forming numerous irregular, minute corrugations at the extremities, Figured specimens: Acad. Nat. Sci., Philadelphia especially on the posterior one, but not shagreened as in T. 1585; U. S. Nat. Mus. 325509. corbuloides. Internal color a chalky white, not glossy, but Type locality: Petersburg, Ya. somewhat inclining to nacre near the cardinal edge. Muscular impressions tolerably large, remote; the anterior narrow, Lea has confused the anterior and posterior ends of elongated, contracted, and tapering to a point toward the hinge the shell. The posterior end is shorter and is squarely margin; the posterior subtriangular or pyriform; pallial impres truncated. 44 MOLLUSCA FROM MIOCENE AND LOWER PLIOCENE OP VIRGINIA AND NORTH CAROLINA The true affinities of the small Thracias in our study Sinus very broad, semielliptical, projected forward collections are very puzzling. They occur in the Cal- almost to the median vertical. Inner margins entire. vert, the St. Marys, the Yorktown, and the Waccamaw Dimensions of holotype: Height 4.0 millimeters, formations, and, though showing considerable varia width 5.0 millimeters, convexity 1.05 millimeters. tion among themselves, show no more perhaps than Holotype, a right valve: U. S. Nat. Mus. 325508. might be covered by a species in which the valves are Type locality: Maddelys Bluff, Southampton County, unequal in size and convexity. They can be very Va. closely matched among the young of Thracia truncata Except for its small size, this species shows no indi Mighels and Adams and of T. phasianella Lamarck— cation of being the young of a larger form. The shell both of them Recent species in which the young vary is moderately heavy for the genus, and the character rather widely. The Tertiary individuals are, how of the incremental sculpture suggests an adult rather ever, fairly uniform in size, and none of them exceed than a young individual. It is very much higher, rela 10 millimeters in latitude. No trace of any larger tively, than Thracia transversa H. C. Lea and differs forms except T. conradi Couthouy, a species with a from T. conradi Couthouy, which it most closely rather shallow and angular pallial sinus, has been resembles in general proportions, by the very broad, found. deep, and evenly rounded pallial sinus—a character T. maddelysensis n. sp. is relatively higher and which in the latter is angular and much more shallow. shorter; the incrementals are strong and regular on The species is known only from a single right valve the umbones that evanesce distally; in Lea's form the collected at Maddelys Bluff, on the Meherrin River. incremental sculpture is least feeble near the distal Distribution: Virginia: Miocene, Yorktown formation, Mad margins, particularly the posterior margin; the sinus delys Bluff on the Meherrin River, Southampton County. of T. transversa, though almost equally profound and evenly rounded as that of T. maddelysensis, is decid Family PANDOBIDAE edly less broad. Genus PANDORA (Bruguiere) Lamarck Distribution: Virginia: Miocene, Yorktown formation, (?) 1798. Pandora Bruguiere, Tableau encyclope"dique et m&hodique, Yorktown, York County; Petersburg, Dinwiddie County; (?) vol. 1, pi. 250, figs. a-c. (No text.) Everets farm, Everets, and (?) 1% miles north of Suffolk, 1799. Pan&ora Lamarck, Prodrome d'une nouvelle classification Isle of Wight County. des coquilles, Soc. histoire nat. Paris M6m., p. 88. North Carolina: Miocene, Yorktown formation, half a mile Type by monotypy: Tellina inaequivalvis Linnaeus. Recent above Bells Bridge, Edgecombe County. Pliocene, Waccamaw from the Channel Islands to the Mediterranean. formation, (?) NeiUs Eddy Landing, Columbus County. The shells are highly nacreous, transversely elongate, Thracia maddelysensis Gardner, n. sp. and rather alate, inequivalve, and inequilateral. The Plate 10, figures 1, 2 right valve is flattened or even slightly concave; the left, rather convex. The flattened, erect beaks are set Shell small, rather heavy, inflated, irregularly and far forward, and the anterior extremity is usually transversely ovate, inequilateral, probably gaping pos broadly rounded. The posterior dorsal margin is, in teriorly. Umbones tumid, rather prominent, the apices many species, slightly concave, the arcuate base line proximate and directed toward each other and situated curving winglike to meet it. A narrow posterior area about two-thirds of the distance across to the posterior cut off by a cordate rostrum is developed in both valves. margin. Lunule and escutcheon absent. Anterior end There is no lunule, but the narrow escutcheon is well produced, broadly and evenly rounded; posterior end defined. A narrow cartilage extends obliquely down squarely truncate; dorsal slope very low; base line ward and backward from the tips of the umbones and gently arcuate. Posterior area defined by an obtuse is lodged in a shallow groove with slightly raised mar angulation extending from the umbones to the junction gins. The lithodesma, developed in some but not in of the truncated posterior lateral margin and the base all groups of Pandora, is on the anterior side of the line. Incrementals close, strong, and regular in the ligament. The teeth are crude and vary in number umbonal region, becoming discontinuous and eva and position in different subgenera. The mantle is nescent toward the margins. Ligament external, opis- loosely attached to the inner surface so that the pallial thodetic, mounted on delicate linear nymphs; valve line may be discontinuous. The margin of the convex fissured beneath the umbones, probably for the recep left valve commonly extends beyond the slightly re- tion of the internal ligament; all traces of the litho- flexed basal margin of the right valve, and there is a desma lost. Hinge edentulous; anterior margin raised, slight gape at the narrow truncated extremity of however, into a triangular toothlike process just in the posterior area. The adductor scars are small, front of umbones. Adductor muscle impressions small distinct, and strongly dorsal in position. and rather high, the anterior angular and irregular in The genus includes only about 20 Recent species, but outline, and posterior oval. Pallial line obscure. these are distributed from the Arctic seas to the Indian PART 1. PELECYPODA Ocean. In time, the group extends backward to the sculpture and, in the left, by the. less feeble incre- Cretaceous. mentals and the slight but abruptT depression, which is marked chiefly by a sharp break in the growth lines. Submenus KENNERLIA Carpenter Radial sculpture absent or obsolete in the convex 1864. Kennerlia, Carpenter, Zool. Soc. London Proc., p. 602. valve; in the flattened right valve about 11 sharp, Type by subsequent designation (Stoliczka, India Geol. Sur irregular, and often bifurcating sulci in the exterior vey Mem., Cretaceous fauna southern India, vol. 3, p. 61, 1871) : prismatic layer, not radiating directly from the um- Pandora, (Kennerlia) bicarinata Carpenter, 1864=P 1863. Pandora, crassidens Conrad, Acad. Nat. Sci. Philadelphia Pandora (Clidiophora) crassidens majorina Gardner, n. subsp. Proc. for 1862, p. 572. 1867. Cleidiophora crassa Conrad, Am. Jour. Conchology, vol. Plate 10, figures 25, 28 3,.p. 269. (Lapsus.) The shell attains a size double that of the average 1903. Pandora (Clidiophora) crassidens Conrad. Dall, Wagner 'Pandora crassidens; roughly rectangular in outline; Free Inst. Sci. Trans., vol. 3, pt. 6, p. 1519. 1904. Pandora (Clidiophora) crassidens Conrad. Glenn, Mary the right valve flat, the left valve moderately com land Geol. Survey, Miocene, p. 357, pi. 95, figs. 1, 2. pressed. TJmbones anterior, subterminal. Lunule ab 1932. Pandora (Clidiophora) crassidens Conrad. Mansfield, sent. Escutcheon linear-lanceolate, wider in the left Florida Geol. Survey Bull. 8, p. 73, pi. 12, figs. 4, 7. valve than in the right, strongly angulated on its outer Shell perlaceous, concentrically wrinkled*; the large valve border. Anterior margin of valve broadly rounded to extending much beyond the posterior base of the lesser; ante subtruncate. Posterior lateral margin subtruncate, rior side very short, margin widely subtruncate; posterior ob rounding evenly into the base. Dorsal margin slightly tusely rounded inferiorly, terminating above in a very short concave. Submarginal carina rather narrow, empha and obtuse rostrum; dorsal submargin of the larger valve with 2 approximate carinae; lesser valve with only one distinct sized, particularly in the right valve, by the shallow carina placed very near the margin; anterior cardinal tooth sulcus below it and extending from the umbones to the of the larger valve very long, thick, and slightly oblique, the posterior lateral margin. Differentiation of anterior posterior one very near the dorsal line, sulcate or fosset- area less feeble in left valve than in right; area marked shaped; the middle one short and linear; in the flat valve, two oblique, very thick and prominent teeth, anterior to which by a change in the direction of the growth lines—most is a shallow groove, bounded anteriorly by a rudimentary linear obvious in the contour of the base line—and by the tooth; muscular impressions impressed; pallial impression abrupt obsolescence of the resting changes. External punctate. surface sculptured with fine, irregular, discontinuous, Locality, James River, near Smithfield, Va. incrementals and, in the older forms, undulated by the This species is very rare; I formerly referred it to the recent P. trilineata, but it differs greatly in the teeth and also in pronounced resting stages; a radial sculpture of faintly having the valves very unequal, the superior valve being slightly impressed, more or less dendritic sulci developed in the concave and the lower half of the inferior valve inflated, giving external, prismatic layer of the right valve and some it a capacious interior. Say remarks of the trilineata that there times discernible on eroded surfaces in the left. Liga is not much difference in the convexity of the valves.—Conrad, ment internal; lodged in the right valve between the 1838. middle and posterior cardinals; surface of attachment Conrad has apparently considered the raised margin in the left valve bilobed, produced obliquely backward of the resilial pit as the left posterior cardinal. The and more or less concealed by the overhanging dorsal young of P. crassid/e-ns are relatively lower and more margin. Dentition of right valve consists of a very alate in outline than the adults. They are not, how heavy, hatchet-shaped, middle cardinal; a linear, ante ever, so slender and winglike as in P. tuomeyi, nor are rior cardinal in front of it; and at an equal distance they so thin or so compact in texture. The tendency behind it, an obliquely produced, cuneiform cardinal. toward an impressed radial striation in the right valve Dentition of left valve limited to an anterior dorsal is very much stronger in the P. crassidens s. s. and'con- process—heavy, rude, and expanded dorsally into a stitutes one of the best criteria for the separation of the wide flange—and a low, sublinear, posterior process young of the species from the very similar adults of the placed at the anterior edge of the resilial pit, and in subspecies. The subspecies prodromos is shorter and the adults fused with it. Inner surface of anterior more quadrate than crassidens s. s., with a more concave margin in front of the anterior cardinal usually planed dorsal margin and more of a flip to the posterior dorsal off so that all the concentric layers that make up the extremity. shell are exposed. Adductor impressions sunken—the P. crassidens is rare in the Ecphora zone of the Choc- anterior subrotund and rather high, the posterior ver tawhatchee formation in Florida. tically elliptical and higher than the anterior. Pallial line punctate, only moderately distant from the base. Distribution: Virginia: Miocene, Yorktown formation, 5 miles northeast of Smithfield and at Smithfield, Isle of Wight County; Dimensions of holotype: Height 37.8 millimeters, Sycamore, Southampton County; 1% miles northeast of Suffolk width 59.6 millimeters, semidiameter (left valve) 8.2 and 1 mile northeast of Suffolk, Nansemond County. millimeters. North Carolina: Miocene, Yorktown formation, 6 to 7 miles Holotype, U. S. Nat. Mus. 325501; paratype, U. S. below Rocky Mount, 15% miles above Bells Bridge, and % Nat. Mus. 325500. mile above Bells Bridge over the Tar River, Edgecombe County; 6 miles below Greenville and 6% miles below Greenville (at Type locality: Holotype, Halifax on Quankey Creek, Tafts Landing), Pitt County. Pliocene, Waccamaw forma Halifax County, N. C.; paratype, Sycamore, South tion, Walkers Bluff on the Cape Fear 'River, Bladen County. ampton County, Va. Outside distribution: Miocene, St. Marys formation, Cove Pandora crassidens majorina seems to be something Point and St. Marys River, Md. Choctawhatchee formation, upper bed of Alum Bluff (on the Apalachicola River), Cal- more than merely the gerontic phase of P. crassidens houn County, Fla. Conrad. The diagnostic characters are the much 48 MOLLUSCA FROM MIOCENE AND LOWER PLIOCENE OP VIRGINIA AND NORTH CAROLINA heavier and larger shell and the conspicuous flange close relationship that apparently exists between the borne on the left anterior cardinal. The incipient Tertiary Pandoras of the east coast and those of flange in some individuals referable to P. crassidens the Recent. In the Recent the subgenus Clidiophora s. s. and more frequently in the closely related Recent is represented south of the Hatteras axis by the deli P. gouldiana Dall indicates that this character is not cate, alate little form, Pandora trilineata Say. The of specific value. northern analog, P. gouldiana Dall, is larger, heavier, Distribution: Virginia: Miocene, Yorktown formation, Mad- and rudely rectangular in outline. The differences be delys Bluff on the Meherrin River and Sycamore, Southampton tween the northern and southern analogs have appar County. ently been inherited from their Tertiary precursors, North Carolina: Miocene, Yorktown formation, Halifax on P., tuomeyi of the Duplin and Waccamaw faunas and the Roanoke River, Halifax County; Shiloh Mills on the Tar P. prodromes of the Yorktown. P. prodromos is a River, Edgecombe County. little higher relatively than P. gouldiana Dall, and the Pandora (Clidiophora) prodromes Gardner and Aldrich posterior margin in it is not so sharply constricted Plate 11, figures 2, 3, 11, 12 below the submarginal keel. The dentition of the Ter tiary species is very much heavier than that of the 1919. Pandora, (Clidiophora) prodromos Gardner and Aldrich, Acad. Nat. Sci. Philadelphia Proc., p. 44, pi. 4, figs. Recent. The middle and posterior cardinals of the 9, 11, 12, 14. right valve and the anterior cardinal of the left are, Shell of moderate dimensions, rather heavy, com in P. gouldiana Dall, compressed into little more than pressed, inequivalve, strongly inequilateral, subquad- linear ridges, whereas in P. prodromos they are decid rate in outline. Umbones very low and inconspicuous, edly heavy and robust. P. prodromos is neither so often perforate, strongly anterior. Lunule not devel-' large nor so heavy, however, as the coexistent P. cras sidens Conrad; it shows no trace of the linear radial oped. Escutcheon persists to the extremity of the sculpture that characterizes crassidens, and the dorsal posterior dorsal margin and is sublinear and sharply portion of the anterior cardinal of its left valve is not delimited. Anterior extremity broadly rounded. Pos expanded into a well-defined flange as in Conrad's terior extremity quite squarely truncate. Dorsal mar species. gin feebly concave. Ventral margin broadly arcuate. Submarginal carina outlined in the right valve by a Distribution: Virginia: Miocene, Yorktown formation, York- linear sulcus and in the left by a subacute ridge. An town, York County; 1% miles north of Suffolk, 1% miles east terior area very obscurely differentiated, occupying of Suffolk, 1 mile northeast of Suffolk, 1 mile west of Suffolk, and % mile below the waterworks dam at Suffolk, Nansemond approximately one-third of the entire valve. Radial County. sculpture not developed. Incremental sculpture some North Carolina: Miocene, Yorktown formation, Tar Ferry on what undulatory on the early portion of the valve, Wiccacon Creek (opposite Harrellsville), Hertford County. laminar and crowded toward the ventral margin. Collections: United States National Museum, Johns Hopkins Ligament internal; lodged in the right valve between University, and Academy of Natural Sciences of Philadelphia. the middle and posterior cardinals and, in the left Pandora (Clidiophora) tuomeyi Gardner and Aldrich valve, in a bilobed pit posteriorly produced along the dorsal margin. Hinge dentition robust; anterior car , • Plate 10, figure 27; plate 11, figures 9, 10 dinal of right valve almost entirely obsolete; middle 1856. Pandora trilineata Say. Tuomey and Holmes, Pleiocene cardinal elongate, rhombic, strongly and abruptly ele fossils of South Carolina, p. 76, pi. 20, fig. 13. Not P. trilineata Say, 1822. vated. Posterior cardinal compressed, elongate-cune- 1903. Pandora- (Clidiophora) trilineata Say (part). Dall, Wag ate, wedging out dorsally. Anterior cardinal of left ner Free Inst. Sci. Trans., vol. 3, pt. 6, p. 1519. valve, which extends from the apex of the umbones to 1919. Pandora (Clidiophora) tuomeyi Gardner and Aldrich, the anterior adductor scar, is uniformly elevated and Acad. Nat. Sci. Philadelphia Proc., p. 45, pi. 4, figs. 8, widens slightly toward the umbones. Posterior car 10, 13. dinal linear, inconspicuous, outlining the anterior Shell of medium size, rather thin, transversely alate margin of the resilial pit. Adductor impressions small, in outline, slightly flexuous, compressed, inequivalve, slightly sunken, irregularly rotund, placed well up but only to a slight degree; strongly inequilateral. toward the dorsal margin. Pallial line punctate^ Umbones very low, the apices usually perforate, broadly arcuate, remote from ventral margin. strongly anterior but not terminal. Lunule absent. Dimensions of holotype: Height 21.0 millimeters, Escutcheon sublinear, almost as long as the posterior width 33.0 millimeters, diameter 6.0 millimeters. dorsal margin, strongly angulated on its outer border. Holotype, double valves of a single individual: U. S. Anterior end of valve rounded or obtusely pointed. Nat. Mus. 325499. - Posterior dorsal margin gently concave; submarginal Type locality: Yorktown, York County, Va. York- carinae very sharp, wider and more depressed posteriorly town formation. in the left valve than in the right. Ventral margin curved The species was described in order to bring out the winglike from the anterior expansion to the posterior PART 1. PELECYPODA 49 rostrum; margin in front of rostrum contracted in left lia; its anterior limit is often ill defined, and the hiatus valve by the anterostral depression. Right carina out between such a tooth and the incurved and calloused lined by a linear suleus. Anterior area between one- inner surface of the anterior margins of Kennerlia is third and one-half the entire valve, differentiated only not great; the cardinal in P. tuomeyi, furthermore, is in the left valve and then merely by a somewhat ob not expanded dorsally into a flange and is placed far solete, linear sulcus, and by the abrupt upcurving of ther forward so that its ventral termination is at the the growth lines toward the front. Incremental sculp medial line of the adductor impression. ture fine, irregular, often discontinuous, with no very The young of Pandora crassidens s. s., though similar pronounced resting stages. Radial sculpture usually in dentition, are relatively higher, less alate, heavier, absent even in the right valve. Ligament internal; and less compact in shell texture, and show a stronger lodged in the right valve between the middle and pos tendency toward a radial sculpture in the right valve. terior cardinals and, in the left valve, in a bilobed pit, The individual selected as the type is unusually wide. obliquely produced beneath the dorsal margin. Hinge Distribution: Virginia: Miocene, Yorktown formation, York- dentition moderately robust; anterior cardinal of right town, York County; 1% miles north of Suffolk, 1% miles valve obsolete; middle cardinal compressed, rhomboidal, northeast of Suffolk, 1 mile northeast of Suffolk, 1 mile west or hatchet-shaped; posterior cardinal compressed, of Suffolk, and % mile below the Suffolk waterworks dam, obliquely produced, often acutely pointed medially or Nansemond County. ventrally; anterior cardinal of left valve a moderately North Carolina: Miocene, Yorktown formation, Tar Ferry on Wiccacon Creek (opposite Harrellsville) , Hertford County. prominent ridge of uniform elevation that extends Pliocene, Waccamaw formation, Walkers Bluff on the Cape Fear from the umbones to a point just dorsal to the medial River, Bladen County. line of the anterior adductor; posterior tooth linear, Outside distribution: Miocene, Duplin marl, Darlington, inconspicuous, merely the upraised anterior margin of Darlington County, S. C. the resilial pit. Adductor muscle impressions slightly Pandora (Clidiophora) trilineata Say sunken, irregularly rotund. Pallial line punctate, non- Plate 11, figure 7 sinuous, nearer the jbase anteriorly than posteriorly. 1822. Pandora trilineata Say, Acad. Nat. Sci. Philadelphia Jour., Dimensions of holotype, a left valve: Height 9.5 1st ser., vol. 2, p. 261. millimeters^ width 21.0 millimeters, convexity 2.0 milli 1830. Pandora trilineata Say, American conchology, pi. 2, and meters. Paratype, an incomplete right valve: Height unpaginated text. 11.0 millimeters, convexity 1.5 millimeters. 1842. Pandora trilineata Say. Conrad, Nat. Inst. Promotion Sci/ Holotype (a left valve) and paratype (an incomplete Proc., 2d Bull., p. 190. 1886. Pandora (Clidiophora) trilineata Say. Dall, Harvard right valve): U. S. Nat. Mus. 325502. Coll. Mus. Comp. Zoology Bull., vol. 12, p. 312. Type locality: Walkers Bluff on the Cape Fear River, 1886. Pandora (Clidiophora) floridana (Dall ms.). Dall, idem, Bladen County, N. C. p. 312. Pandora tuomeyi is confused in the old collections 1889. Pandora (Clidiophora) trilineata Say. Dall, U. S. Nat. with the Recent P. trilineata of Say, a rather smaller, Mus. Bull. 37, p. 68. 1902. Pandora (Clidiophora) trilineata Say. Dall, U. S. Nat. relatively lower species, more tapering in outline pos Mus. Proc. 1264, vol. 24, p. 511, pi. 31, fig. 4. teriorly. The chief difference, however, is in the 1903. Pandora (Clidiophora) trilineata Say (part). Dall, dentition. In general, the cardinals of the Recent Wagner Free Inst. Sci. Trans., vol. 3, pt. 6, p. 1519. species are more compressed, more produced, and more Not Pandora trilineata Say. Tuomey and Holmes, 1856. sharply cut; in particular, the inner surface of the right Not Pandora trilineata Say of New England authors valve of the Tertiary form, in front of the middle to 1870=P. gouldiana Dall. cardinal, is not thickened but is often feebly channeled; Shell white, subpellucid, concentrically wrinkled; hinge the middle cardinal is hatchet-shaped or rhomboidal placed at the posterior slope, which is very abrupt, and forming a very considerably obtuse angle with the hinge margin; hinge and is shorter than the elevated laminar tooth of P. margin concavely much arquated, the surface flattened, and trilineata; the posterior cardinal is shorter, heavier, and bounded on its edges by two elevated approximate lines, origi less uniform in elevation, and the inequality between nating at the beak and continued to, the tip, which is rostrated; the two right cardinals is much more marked in the rostrum ascending; a distinct, slightly impressed line originates fossil than in the Recent species. In the left valve the at the beaks and passes to the middle of the basal margin; right valve a little convex; left valve flat. resilial pit in P. tuomeyi is broader and less produced, Length %o inch, greatest breadth x%o inch. and the upraised anterior margin is shorter and less Inhabits the American coast. sharp; the left cardinal in P. trilineatd has strongly Cabinet of the Academy and Philadelphia Museum. defined margins, bears a flange on the dorsal half of its I first discovered a single valve of this curious shell several inner surface, and terminates ventrally near the dorsal years ago at Great Egg Harbor, on the shores of New Jersey; 'since which, I have found two or three others on the coast of end of the anterior adductor impression; the anterior Georgia and east Florida, so that it may be said to inhabit our cardinal of P. tuomeyi, on the other hand, suggests whole southern and middle coast. The inner edge of the hinge much more strongly1 a kinship to the subgenus Kenner- margin of one valve closes over that of the other,—Say, 1823, 50 MOLLUSCA FROM MIOCENE AND LOWER PLIOCENE OF VIRGINIA A1STD NORTH CAROLINA Pandora trilineata Say has been reported from a evenly rounded radials on the anterior and medial parts number of localities in both the Duplin and the Wacca- of the valve, separated mostly by narrower interspaces maw formations. All the Carolinian individuals ex but tending to widen posteriorly; 2 similar radials on amined, however, both in the material under study and the posterior submargin separated by triple or quad in the available reference collections, show specific dif ruple interspaces from those in front of them; entire ferences and have been assigned to P. crassidens and its external surface sculptured with microscopic radial subspecies tuomeyi. granulation. Ligament inset, linear, continued under the apices of the umbones. Subumbonal cardinal of Superfamily POKOMYACEA right valve short, moderately stout. Right posterior Family VERTICORDIIDAE margin grooved down to the median horizontal for Genus VERTICOKDIA (Searles Wood ms.) Sowerby the reception of the elongated, posterior lateral of the 1844. Verticordia (Searles Wood ms.) Sowerby, Mineral con- left valve. Hinge of left valve not definitely known, chology, vol. 7, pi. 639. but bearing, in all probability, the normal Trigonulina Type by monotypy: Verticordia carditfornis Sowerby. Plio dentition. Adductor impressions and pallial line ob cene (Coralline Crag) of Suffolk, England. scure. Margins strongly denticulated by external Shell nacreous, equivalve, usually though not always costae. small, and suborbicular. Umbones subcentral or ante Dimensions of holotype: Height 2.5 millimeters, rior, prominent, prosogyrate,' and often strongly invo width 2.8 millimeters, convexity 0.7 millimeters. lute. Lunule false, somewhat depressed. External Holotype, a right valve: U. S. Nat. Mus. 325506. sculpture strongly radial. Ligament submarginal, Type locality: Three quarters of a mile northeast of continued to apices of umbones; internal cartilage Smithfield, Isle of Wight County, Va. , supported by lithodesma. Strong subumbonal cardinal Verti&ordia rogersi n. sp. is differentiated from the usually present in the right valve. Posterior lateral entire group of forms closely allied to the V. emmonsi developed in one group. Left valve often devoid of by its smaller size, its much more inflated valves, its true teeth, sometimes developing a posterior lateral, transversely oval outline, and its relatively broad and more rarely a subumbonal cardinal; valvular margins rounded radials, which are separated by narrower somewhat modified to function as laterals. Adductor interradials. The radials are, furthermore, less nu impressions small, often obscure. Pallial line simple merous than in V. emmonsi Conrad, though, unlike or feebly sinuous. Inner margins denticulated by the those of the latter, they corrugate the entire valve with radiating costae. the exception of a smooth area in front of the posterior Verticordia has, as might be inferred, only a meager submargin. The hinge is decidedly less vigorous than representation in the east coast Tertiary deposits. in the other Tertiary Trigonulinas, though the differ The genus is characteristically a deep-water form, one ence is of 'degree rather than of kind. species occurring at a depth of almost 1,700 fathoms, The species is known only from two right valves, whereas the Miocene and Pliocene of Virginia and both collected from the Yorktown marls along the North Carolina are essentially shallow-water deposits. James River, in Isle of Wight County. The species was named in honor of W. B. Rogers, Subgenus TRIGONULINA D'Orbigny the eminent director of the Geological Survey of Vir 1846. Trigonulina D'Orbigny, in De la Sagra, Histoire physique, ginia from 1835 to 1842 and one of the founders and politique et naturelle de rile de Cuba; Mollusques, vol. 2, p. 291. the president of the Massachusetts Institute of Tech Type by monotypy: Trigonulina ornata D'Orbigny. Recent nology from 1862 until his death in 1882. in the West Indies. Distribution: Virginia: Miocene, Yorktown formation. % Trigonulina is set apart from Verticordia s. s. by mile northeast of Smithfield (on Mrs. Chalmers' farm; type the less regularly spaced radials, the deeper lunule locality) and Benns Church, % mile from the old church, Isle and ligament groove, and the greater development of of Wight County; 1 mile west of Suffolk, Nansemond County. the dental process in the right valve and of the dorsal Verticordia (Trigonulina) emmonsii Conrad lamina in the left. Plate 10, figure 14 Verticordia (Trigonulina) rogersi Gardner, n. sp. 1858. Verticordia sp. Emmons, North Carolina Geol. Survey Plate 10, figures 12, 13 Kept., p. 286, fig. 206. 1862. Verticordia emmonsii Conrad, Acad. Nat. Sci. Philadelphia Shell very small, moderately inflated, tranversely Proc. for 1862, vol. 14, p. 289. oval, inequilateral. Anterior end expanded in front 1863. Verticordia emmonsii, Conrad, idem, p. 579. of the lunule. Posterior a parabolic curve. Umbones 1903. Verticordia (Trigonulina) emmonsii Conrad. Dall, Wag subcentral, acute, prosogyrate. Lunule minute but ner Free Inst. Sci. Trans., vol. 3, pt. 6, p. 1512. deeply excavated.' External sculpture very conspicu Conrad gave no description but merely affixed a ous; 7 subequal, strongly elevated, moderately broad, name to Emmons' unnamed figure. PART 1. PELECYPODA 51 Shell with 9 anterior and 2 posterior widely separated ribs, gently curved, narrow, much elevated costae on the the surface covered with a coarse granulation arranged in anterior half of the valve; intercostal spaces fully radial lines. Longitude 6.5, altitude 5.3, diameter 2.5 milli twice the width of the costals except on the extreme meters. The teeth are strong, and the sinuation of the pallial line [is] conspicuous though shallow. anterior margin; 2 proximate radials, slightly less This is the largest of the species of this division of the prominent than those in front of them, midway be genus and with much the most conspicuous granulation. From tween the median vertical and posterior margin; pos the recent V. (T.) ornata Orbigny it is distinguished by its terior marginal and submarginal costae of normal size and by the fact that the recent species has such minute strength; radial granulation and incrementals micro granulation that it is difficult to make it out.—Ball, 1903. scopic. Interior of only the right valve is known. Shell nacreous, small, compressed, subcircular, in Hinge similar to that of V. emmonsi Conrad—a deeply equilateral. Umbones subcentral, the apices acute and inset ligament continued to the apices of the umbones, prosogyrate. Margin directly in front of urnbones a moderately stout subumbonal cardinal, a deeply deeply excavated by false lunule. Escutcheon absent. grooved dorsal margin for the reception of the left Anterior end somewhat expanded. Posterior margin lateral, and a lunular margin modified to assist in a parabolic curve from the umbones to the arcuate the dentition. Adductor muscle impressions small, base. External sculpture conspicuous; nine subequal, rather obscure. Pallial line conspicuously distant from strongly elevated, linear lirae radiating from the um margin; feebly sinuated. Margins strongly denticulate. bones to the anterior hemicircle in gentle curves, con Dimensions of holotype: Height 5.1 millimeters, vex posteriorly; interradials no wider than the radials width 5.6 millimeters, convexity, 1.0 millimeter. anteriorly, broadening to more than double their width Holotype, a right valve: U. S. Nat. Mus. 325507. toward the medial portion of the valve; a single Type locality: Colerain Landing on the Chowan isolated radial more feeble than any of those in front River, Bertie County, N. C. Yorktown formation. of it a little less than halfway between the median Only the type and topotypes are known. vertical and posterior margin; posterior submarginal Verticordia cJiowtmensis differs • from V. emmonsi radial of normal strength. Entire external surface Conrad in the more compressed, obliquely elliptical covered with microscopic radial granulation; incre- outline, the more uniform and somewhat closer spacing mentals sometimes discernible on 'the summits of the of the costae on the anterior half of the shell, the two costae. Ligament deeply inset, continued to the apices ribs (instead of only a single rib) on the midposterior of the umbones. Right subumbonal cardinal mod half, and the presence of both a marginal and a sub- erately stout, tubercular; posterior dorsal margin sul- marginal posterior rib. The group of forms closely cated almost to the base to receive the elongated lateral allied to V. emmonsi Conrad is peculiar in that each of the left valve; lunular margin of left valve thick locality exhibits a perfectly well defined local vari ened to function as a denticle; no left cardinal devel ation. The material is, unfortunately, so meager that oped. Adductor impressions small. Pallial line con it is difficult to know just how much value should be spicuously distant from margin; sinus very shallow. placed on these mutant characters. Until intergrading Margin strongly denticulated by external costae. individuals have been reported, it seems better, how Dimensions of figured specimen: Height 6.0 milli ever, to keep the forms quite distinct. meters, wi^th 6.8 millimeters. Figured specimen, a right valve: U. S. Nat. Mus. Order TELEODESMACEA 145332. Type locality: North Carolina. Su'perfamily ASTARTACEA Distribution: North Carolina: Miocene, Duplin marl, Natural Family ASTARTIDAE Well, 1% miles north of Magnolia, Duplin County. Pliocene, Waccamaw formation, Wilmington, New Hanover County. Genus ASTARTE Sowerby Outside distribution: Miocene, Duplin marl, 5 miles southeast 1816. Astarte Sowerby, Mineral conchology of Great Britain, of Mayesville, Sumter County, S. C. Pliocene, Caloosahatchee vol. 2, p. 85, pi. 137. marl, Caloosahatchee River, Fla. Type by original designation: Venus scotica Maton and Rack- Verticordia (Trigonulina) chowanensis Gardner, n. sp. ett = Pectunculus sulcatus Da Costa. Recent off the British Plate 10, figures 11, 15 coast. Shell nacreous, obliquely elliptical, greatly com Astarte symmetrica Conrad Plate 12, figures 1-4 pressed. Umbones subcentral, acute, prosogyrate; mar gin directly in front of umbones deeply excavated by 1834. Astarte symmetrica, Conrad, Acad. Nat. Sci. Philadelphia false lunule. Escutcheon absent. Anterior end evenly Jour., 1st ser., vol. 7, p. 134. 1840. Astarte symmetrica Conrad, Fossils of the medial Tertiary expanded in front of lunule. Posterior end a para of the United States, p. 44, pi. 21, fig. 7. bolic curve from the umbones to the arcuate base. 1863. Astarte symmetrica Conrad, Acad. Nat. Sci. Philadelphia External sculpture radial, very conspicuous; nine Proc. for 1862, p. 578, 52 MOLLUSCA FROM MIOCENE AND LOWER PLIOCENE OF VIRGINIA AND NORTH CAROLINA 1894. Astarte symmetrical, Conrad. Whitficld, U. S. Geol. Sur 1904. Astarte vicina Say (part). Glenn, Maryland Geol. Sur vey Mon. 24, p. 54, pi. 8, figs. 1, 2. vey, Miocene p. 350. 1903. Astarte symmetrica Conrad (part). Dall, Wagner Free Obovate, acute, convex; umbo sulcated; apex very prominent; Inst. Sci. Trans., vol. 3, pt. 6, p. 1488. lunule elongated and profound. Height and length equal, % 1904. Astarte symmetrica Conrad. Glenn, Maryland Geol. Sur inch.—Conrad, 1841. vey, Miocene, p. 352. Figured specimens, a right and left valve of different Shell subtriangular, convex, with concentric impressed lines or undulations; anterior, posterior, and basal margins regularly individuals, U. S. Nat. Mus. 325519. rounded; apex rather prominent, acute, nearly central; lunule Type locality: Calvert Cliffs, Md. concave, ovate-acute; cardinal teeth very prominent, striated; Shell rather small for the genus but conspicuously margin crenulated. Length three-quarters of an inch, height heavy. Outline high, rounded-trigonal, inflated. An rather less. terior end concavo-convex, deeply excavated in the Locality, Yorktown, Va. This species may be distinguished from A. vicina Say by the lunular region, sharply bowed from the lunule to the lunule, which is much less excavated; and the shell is also base. Posterior dorsal slope steep; lateral margin less convex than in the latter species.—Conrad, 1834. obscurely truncate. Ventral margin broadly ar The outline is usually subrotund rather than sub- cuate medially; upturned distally. Umbones sub- triangular, and the valves are less convex than might be central, elevated, rather narrow and somewhat gib bous, and very prominent—-the apices acute and proso- surmised from Conrad's unmodified adjectives. Both the lunule and the escutcheon are narrow and not very gyrate. Lunule very wide and deeply sunken. conspicuously defined. The teeth are normal for the Escutcheon also wide, clearly delimited, coincident in genus—an obsolete anterior cardinal, a prominent, sub- length With the dorsal margin. External surface quite trigonal middle cardinal, and a laminar posterior cardi strongly undulated from the umbones to the base; nal in the right valve; a vigorous anterior, subequal sculpture sharply defined only in the young and on the apices of the umbones. Ligament external, opisthode- middle, and an obsolete posterior cardinal in the left valve. tic; nymph narrow, bordered dorsally by the angular, Astarte symmetrica Conrad is the most nearly dis- ligamentary groove. Hinge plate narrow. Dentition vigorous; anterior cardinal of right valve obsolete; coidal of all the coexistent Astartes. A. coheni Conrad, middle cardinal robust, cuneiform; posterior cardinal which sometimes approaches it, is larger, relatively higher, as a rule, and exhibits narrower and more prom thin and laminar. Anterior and middle cardinals of inent umbones and a much more deeply channeled con left valve divergent on each side of the profound -sub- umbonal socket—the anterior cardinal slightly the centric grooving. A. arata Conrad, which has been shorter and stouter of the two. Posterior cardinal of erroneously used as a synonym of A. symmetrica, is decidedly higher, more convex, and sculptured with an left valve obsolete or fuse,d with the ligamentary nymph. Muscle impressions distinct—the anterior sub- irregular incremental undulation that is supplemented with faint but distinct secondary striations. rotund or reniform, the posterior rudely quadrate. Pal- lial line entire. Inner margins strongly denticulated. Distribution: Virginia: Miocene, Yorktown formation, City One of the best distinctions of Astarte exaltata Con Point, Prince George County; Yorktown, York County; Peters burg, Dinwiddie County; a quarter of a mile north of Chucka- rad is the character implied in its name. Its elevated tuck, Nansemond County. umbones, together with the stoutness of 'the small North Carolina: Miocene, Yorktown formation, 2^ miles valves, are usually sufficient to isolate the species. A. northwest of Murfreesboro, near Murfreesboro, and 1% miles roanokensis Gardner, the only other form that equals above Murfreesboro on the, Meherrin River, Hertford County; it in the degree of elevation of the umbones, is decidedly Palmyra Bluff, Halifax County; 15% miles above Bells Bridge over the Tar River, Edgecombe County; 8 to 9 miles west of larger and has more strongly arcuate basal and lateral Greenville, Pitt County; 2 miles northeast of Lizzie, Greene margins and a less strongly undulated external surface. County. A. arata Conrad and the closely allied A. stephensoni Astarte exaltata Conrad Gardner are also larger, decidedly more oblique, and Plate 12, figures 5-8 less profoundly excavated in the lunular region. 1841. Astarte exaltata Conrad, Acad. Nat. Sci. Philadelphia Distribution: Virginia: Miocene, Yorktown formation, mouth Proc., vol. 1, p. 29. of Baileys Creek, Prince George County; Claremont Wharf, 1842. Astarte exaltata Conrad, Acad. Nat. Sci. Philadelphia Schmidts Bluff, 8% miles below Claremont Wharf; and near Jour., 1st ser., vol. 8, p. 185. the mouth of Sunken Marsh Creek, Surry County; Zuni, 6% 1845. Astarte exaltata Conrad, Fossils of the medial Tertiary of miles below Zuni, and 7 to 7% miles below Zuni on the Black- the United States, p. 66, pi. 37, fig. 6. water River, Isle of Wight County. 1863. Astarte exaltata Conrad, Acad. Nat. Sci. Philadelphia North Carolina: Miocene, Yorktown formation, 1% to 2 miles Proc. for 1862, p. 578. above Branches Bridge over the Meherrin River, Northampton 1903. Astarte exaltata Conrad. Dall, Wagner Free Inst. Sci. County. Trans., vol. 3, pt. 6, p. J489, Outside distribution: Miocene, Calvert formation, Maryland. PART 1. PELECYPODA 53 Astarte coheni Conrad apices of the umbones, on which the concentric undu lations are quite strong and regular. Apical sculpture Plate 12, figure 15 quickly and abruptly replaced by the irregular and 1840. Astarte coheni Conrad, Fossils of the medial Tertiary of feeble undulation'due to the resting stages; a faint the United States, p. 43, pi. 21, fig. 5. secondary striation usually introduced near the ven 1863. Astarte coheni Conrad, Acad. Nat. Sci. Philadelphia Proc. tral margin in the adults; suggestions of faint radials for 1862, p. 57& often visible toward the posterior margin. Ligament 1903. Astarte coheni Conrad (part). Dall, Wagner Free Inst. Sci. Trans., vol. 3, pt. 6, p. 1489. marginal, opisthodetic; ligamentary nymph sublinear; groove behind it deep. Hinge plate narrow, trigonal. Shell suborbicular, thick, slightly ventricose, equilateral; disks with wide, angulated, somewhat regular undulations; Dentition vigorous. The right valve has an obsolete posterior extremity obtusely rounded; beaks prominent, curved anterior, a stout, trigonal middle, and a compressed forward; lunule large, cordate, very profound; inner margin posterior cardinal; the left v,alve, has subequal anterior crenulated. and middle cardinals—the latter a little more com Locality, Lancaster County, Va. pressed and produced—and a posterior cardinal fused This species was presented by Dr. Cohen, of Baltimore. The matrix is sand, mixed with a very large proportion of the with the ligamentary nymph; contiguous surfaces of green grains derived originally from the secondary Green-sand cardinals transversely striate. Posterior dorsal margin formation.—Conrad, 1840. of right valve and lunular margin of left beveled to Astarte coheni Conrad is larger, relatively higher, function as laterals. Adductor muscle impressions dis and more evenly rounded than A. symmetric^ Conrad. tinct—the anterior oblong or slightly reniform, the Among the rest of the coexistent species of the group, posterior roughly quadrate. Pallial line entire. Inner it is remarkable for the rather compressed valves, the margins crenate at the resting stages. subcentral umbones, and the arcuate ventral and lateral Dimensions of a cotype, a right valve: Height 24.4 margins. The lunule is only moderately wide and not millimeters, width 23.9 millimeters, convexity 7.2 milli at all "profound" in the sense in which the lunule of meters. Left valve of another individual: Height 24.2 A. exaltata is profound. The concentric sulci are millimeters, width 23.9 millimeters, convexity 6.5 milli deeper, more sharply channeled, and more uniform meters. over the surface of the disk than in any other member Type material: 2 cotypes, the right and left valves of of this feebly sculptured group; and the sculpture, different individuals: U. S. Nat Mus. 325523. combined with an outline suggesting roughly the quad Type locality: Halifax, Halifax County, N. C. rant of a circle, forms the most valuable diagnostic Astart& roanokensis is remarkable for its narrow, of the species. The hinge is normal arid the inner prominent umbones, which, though they range in posi margin crenate at the resting stages. tion from the median vertical to the anterior third, never lose their diagnostic beaklike aspect. The valves Distribution: Virginia: Miocene, Yorktown formation, Peters burg, Dinwiddie County; Cobham Bay, Surry County; 1 mile1 are more compressed and usually thinner than in any north of Zuni, Isle of Wight County; Sycamore on the Notto- of the closely related, obliquely trigonal forms, such as way River, and % to % mile below Sycamore, % to % mile A. stephensoni, n. sp. A. roanokensis occurs in the above the lower Seaboard Railway bridge, and Maddelys Bluff Yorktown marls along the Nottoway, Meherrin, Roa- on the Meherrin River, Southampton County; (?) 1 mile noke and Tar Rivers, but it is abundant only at the type northeast of Suffolk and (?) the drainage ditch of the Norfolk & Western Railway just east of Jericho ditch, Nansemond locality—Halifax, on the Roanoke River, in Halifax County. County. Distribution: Virginia: Miocene, Yorktown formation, Syca Astarte roanokensis Gardner, n. sp. more on the Nottoway River, % to % mile above the lower Plate 12, figures 9, 10 Seaboard Railway bridge over the Meherrin River, Southamp ton County. Shell large for the group, not very heavy, elevated North Carolina: Miocene, Yorktown formation, 1 mile above and rounded, or somewhat obliquely trigonal in out Branches Bridge, Northampton County; 1% miles above Mur- freesboro, Hertford County; Halifax on Quankey Creek, Mr. line. Anterior margin concave in the lunular region, Durham's farm, % mile above the Atlantic Coast Line Railroad bowed outward in front of the lunule. Posterior dor bridge, and Palmyra Bluff, Halifax County; 15% miles above sal slope very steep and usually exceeding half the Bells Bridge and % mile above Bells Bridge over the Tar total height. Lateral margin rounded or obscurely River, Edgecombe County. truncate. Basal margin feebly arched, upturned more Astarte hertfordensis Gardner, n. sp. strongly and evenly toward the anterior than toward Plate 12, figures 11, 12, 21 the posterior end. Umbones subcentral, conspicuous by reason of their elevation, their apices acute and Shell of medium size and thickness, moderately in prosogyrate. Lunule smooth, rather wide, cordate, and flated, ovate-trigonal. Anterior end concavo-cbnvex. excavated. Escutcheon relatively wide, clearly delim Posterior end obliquely produ'ced and narrowly ited. External sculpture very feeble, except at the rounded; basal margin feebly arcuate, more broadly 54 MOLLTTSCA FROM MIOCENE AND LOWER PLIOCENE OF VIRGINIA AND NORTH CAROLINA and evenly upcurved anteriorly than posteriorly. Um- A narrower lunule and escutcheon concomitant with bones prominent, set a little in front of the median line, the more compressed valve. Surface sculpture varies flattened and pointed at the slightly prosogyrate somewhat in the extent of the concentric undulations in apices. Lunule elongate-cordate, excavated, slightly the umbonal region and in the strength and uniformity wider in the left valve than in the right. Es of the resting stages. Hinge and adductor characters cutcheon lanceolate, slightly wider in the right valve are normal for the species but vary slightly with the than in the left. External surface smooth except for the outline of the shell. ' concentric undulations of the apices, the irregular and Dimensions of the holotype: Height 23.0 millimeters, rather ill-defined resting stages—most conspicuous, width 24.8 millimeters, convexity 6.3 millimeters- toward the anterior margin—the faint, discontinuous, Holotype, a right valve: U. S. Nat. Mus. 325531. concentric striations developed near the ventral and Type locality: Branches Bridge over the Meherrin posterior margins, and a feeble suggestion of radials River, Northampton County, N. C. 1 on the posterior half of the shell. Ligament marginal, The peripheral individuals of this thinner, flatter, opisthodetic; nymph linear; groove behind it sharply and usually higher subspecific type sometimes approach channeled. Hinge plate heavy. Dentition robust; Astarte roanokensu on the one hand, and A. stephen anterior cardinal of right valve obsolete; middle cardi soni on the other. The subspecies does not attain, how nal stout, trigonal; posterior cardinal greatly com ever, the relative height of the form from the Roanoke pressed, almost laminar. Anterior cardinal of left River, nor are the umbones, ever so narrow or so valve cuneiform; middle cardinal slightly more pro hooked. It is usually a little heavier than A. duced and more compressed than the anterior and stephensoni and less produced posteriorly, with wider separated from it by a deep, triangular, subumbonal and more nearly erect umbones. The secondary con socket; posterior cardinal obsolete, fused with the centric striation is very faint and often obsolete alto ligamentary nymph; posterior dorsal margin of right gether, whereas the posterior rays, which have not been valve and lunular margin of left beveled to function noted in any of the A. stephensoni, are often quite as laterals, and received by corresponding grooves in distinct; the resting stages are also more uniform in the opposite valve. Adductor impressions of medium A< hertfordensis meherrinensis. The subspecies occurs size, largely below the median horizontal—the anterior along the Meherrin River, in both Virginia and North oblong or slightly reniform, the posterior quadrate. Carolina. Pedal adductor a small rotund depression just dorsal Distribution: Virginia: Miocene, Yorktown formation, 12 to to the upper limit of the anterior adductor. Pallial 14 miles below Zuni on the Blackwater River, Isle of Wight line entire. Inner margins strongly crenate. County; Maddelys Bluff, 3 to 4 miles above the lower Sea Dimensions of holotype (paired valves): Height 23.0 board Railway bridge, and % to % mile above the lower millimeters, width 25.7 millimeters, diameter 14.4 milli Seaboard Railway bridge over the Meherrin River, Southampton County. meters. North Carolina: Miocene, Yorktown formation. 1% miles Holotype: U. S. Nat. Mus. 325526. above Branches Bridge, 1 mile above Branches Bridge, Type locality: Murfreesboro, Hertford County, N. C. Branches Bridge, Northampton County; Watsons Mill on Astarte h^rtfordensis s. s. is the most convex of all Kirbys Creek, 2% miles northwest of Murfreesboro, 1% miles the obliquely trigonal Astartes of the region under northwest of Murfreesboro, 1 mile above Murfreesboro, and discussion, except A. arata Conrad, a relatively higher at Murfreesboro, Hertford County. and less inequilateral form. Its nearest relative is Astarte stephensoni Gardner, n. sp. probably A. stephensoni Gardner, a less inflated and Plate 12, figures 16, 17 usually less solid shell, with more oblique umbones and, as a rule, noticeably more narrow in the umbonal Shell of medium size, compressed, inequilateral, region. obliquely trigonal. Anterior end shorter than the A. hertfordensis Gardner is apparently limited in posterior, concavo-convex in outline. Posterior end distribution, for it has been found only in the York- obliquely produced, rounded, or obscurely truncate town marls in the vicinity of Murf reesboro, in Hertford laterally. Ventral margin feebly arcuate medially, County. gently upturned distally. Umbones rather narrow. Apices acute, anterior, prosogyrate. Lunule elongate- Distribution: North Carolina: Miocene, Yorktown formation, cordate, smooth, sunken, moderately wide, slightly Watsons Mill on Kirbys Creek, 2% miles northwest of Murfreesboro, and near Murfreesboro, Hertford County. wider in the left valve than in the fight. Escutcheon lanceolate, slightly wider in the right valve than in Astarte hertfordensis meherrinensis Gardner, n. subsp. the left. Surface sculpture well defined only on the Plate 12, figure 18 apices of the umbones, which are deeply furrowed con Shell less inflated and usually less solid than that of centrically; resting stages usually 'indistinct and un Astarte hertfordensis s. s. Relative proportions some equally spaced; a very fine and irregular secondary what variable but less so than in the type of the species. striation developed near the ventral margin. Liga- PART 1. PELECYPODA 55 ment marginal, opisthodetic, mounted on a linear Prince George County; DelawareJPark, Delaware, and a quar nymph bounded dorsally by an angular groove. ter to half a mile below Sycamore on the Nottoway River, Southampton County. Dentition normal. The right valve has an obsolete North Carolina: Miocene, Yorktown formation, 1% miles anterior cardinal, a stout, trigonal middle cardinal, above Murfreesboro on the Meherrin River, Hertford County; and a laminar posterior cardinal; the left valve, a Halifax on the Roanoke River, Halifax County. robust anterior cardinal, and, on the other side of the Astarte arata Conrad deep subumbonal socket, an almost equally strong and slightly more produced middle cardinal; left posterior Plate 12, figures 13, 14 cardinal fused with the ligamentary nymph. Ad 1840. Astarte arata Conrad, Fossils of the medial Tertiary of ductor impressions usually distinct—the anterior the United States, p. 42, pi. 20, fig. 8. 1863. Astarte arata, Conrad, Acad. Nat. Sci. Philadelphia Proc. obliquely oblong or somewhat reniform, the posterior for 1862, vol. 14, p. 577. roughly quadrate. Pedal scar a rotund depression just 1903. Astarte symmetrica Conrad (part). Dall, Wagner Free dorsal to the anterior adductor. Pallial line entire, Inst. Sci. Trans., vol. 3, pt. 6, p. 1488. inner margins crenate. Shell ovate-trigonal, convex, with concentric scalariform Dimensions of holotype: Height 22.7 millimeters, sulci and fine intermediate striae; lunule very large, ovate, deeply concave; base very regularly arched; posterior extremity width 24.2 millimeters, convexity 6.3 millimeters. subtruncated; margin crenulated. Holotype, a left valve: U. S. Nat. Mus. 325528. Locality, near City Point, Va.; rare.—Conrad, 1840. Type locality: Halifax on Quankey Creek, Halifax County, N. C. Shell heavy, relatively inflated, high, rounded, tri Astarte stephensoni is characterized by the com gonal. Anterior end concavo-convexo. Posterior end pressed valves, obliquely trigonal outline, obliquely with a steep dorsal slope and an obscure lateral traunca- directed umbones, and the faint but distinct secondary tion. Base line evenly but not strongly arched. Um striation developed near the ventral margin. A. roano- bones prominent, inflated; apices acute and prosogy- kensis Gardner is higher both relatively and absolutely, rate. Lunule smooth, deeply sunken, elongate-cordate. usually less inequilateral, and more strikingly narrow Escutcheon clearly delimited, moderately wide, lanceo and excavated in the umbonal region. A. hertfordensis late. Surface sculptured with irregular, concentric s. s. is characterized by the heavy, inflated valves, but undulations—strongest and most regular near the um the subspecies meherrinensis is often quite as com bones, evanescent ventrally, particularly on the pos pressed, though rarely so thin, as A. stephensoni. The terior half of the shell. Fine, irregular, discontinuous, latter is quite constantly more produced and more angu concentric striations developed in the adults—most con lar posteriorly, usually narrower toward the umbones, spicuous near the basal and posterior margins. Liga and less regularly (though more vigorously) sculp ment external; nymph narrow; ligamentary groove tured. The resting stages, which in the species from sharply channeled. Dentition vigorous. In the right the Meherrin River are almost always distinctly though valve an obsolete anterior cardinal, a stout, triangular not strongly defined and uniform in strength, are in A. middle cardinal, and a laminar posterior cardinal; in stephensoni almost or altogether obsolete; the secondary the left valve a robust, somewhat cuneiform anterior striation, on the other hand, is characteristic of the cardinal, a slightly more compressed middle cardinal, latter, though not confined exclusively to it. and an obsolete posterior cardinal; posterior margin of right valve and lunular edge of left valve modified to Certain higher, more rounded, and less inequilateral function as laterals. Muscle impressions distinct, more forms from the vicinity of Murfreesboro have been re than half their area below the median horizontal. ferred rather dubiously to this species. It is quite pos Anterior adductor ellipsoidal or slightly reniform; sible that they should be given subspecific or perhaps posterior, semielliptical to rudely quadrate. Pallial even higher rank, but the imperfect state of preserva line entire. Inner margins crenate. tion of the material makes their exact relationship Astarte arata Conrad is heavier and higher, more doubtful. triangular, and less rotund than A. symmetric^ Conrad, The species is named in honor of Dr. L. W. Stephen- with which it has been rather unaccountably confused son of the Federal Geological Survey, who-stands alone in the synomymies. The lunule is wider and more in his detailed and general information on the Upper deeply sunken. The secondary concentric striation, Cretaceous from Maryland to Texas. which is apparently a constant character in A. arata,, It is remarkable that Astarte stephensoni, as well as has not been noted in any individuals of A. symmetrica. the two forms to which it is most closely related, should, The diagnostic features of Astarte arata Conrad are with the exception of a single occurrence, be confined the high, inflated umbones, the irregular wrinkling of to the Yorktown marls of southern Virginia and the external surface by the growth sculpture, and the northern North Carolina. very distinct secondary striation. The two species Distribution: Virginia: Miocene, Yorktown formation, mouth most readily confounded with it are A. stephensoni—a of Baileys Creek near its confluence with the James River, relatively lower and more compressed form—and A. 56 MOLLUSCA FROM MIOCENE AND LOWER PLIOCENE OF VIRGINIA AND NORTH CAROLINA hertfordensis, n. sp., which is also lower and more subspecies meherrinensis^ by the more rounded outline. feebly, though m'ore regularly sculptured. The valves are also heavier and the umbones more in Distribution: Virginia: Miocene, Yorktown formation, near flated than in the majority of individuals referable to the mouth of Baileys Creek, Prince George County; a quarter the latter group of species. In general outline A. to half a mile below Sycamore on the Nottoway River, 'berryi suggests Conrad's A. coheni, though it differs Southampton County. ' North Carolina: Miocene, Yorktown formation, Halifax on conspicuously in its larger size, heavier and more in the Boanoke River, Halifax County. flated valves and umbones, and much less sharply defined and uniform concentric sculpture. Astarte berryi Gardner, n. sp. I am pleased to name this Astarte in honor of Dean Plate 12, figures 23, 24 Berry, of Johns Hopkins University, who, though best known for his paleobotanical studies on the Cretaceous Shell relatively large for the genus, thick and heavy, and Tertiary of the east coast and the Gulf, has col rather strongly inflated, particularly toward the apices lected extensively and most effectively from the faunas of the umbones. Subrotund or transversely oblong. of the eastern and southern Tertiary deposits. Posterior dorsal slope moderately steep, merging into A. berryi is most abundant in the Yorktown marls the rounded or obscurely truncated lateral margin. of Pitt and Beaufort Counties, N. C., particularly in Anterior end convex in the vicinity of the lunule, the environs of Chocowinity, and in the Yorktown at bowed out in front of the lunule. Base evenly and Colerain Landing, on the Chowan Eiver- rather strongly arched. Umbones subcentral, often a little in front of the median line, moderately promi Distribution: Virginia: Miocene, Yorktown formation. % to nent ; apices acute, turned toward each other. Lunule % mile above the lower Seaboard Railway bridge over the Meherrin River, Southampton County; 1% . miles north of strongly depressed, elongate-cordate. Escutcheon Suffolk, Nansemond County. elongate-lanceolate, well defined by the angulation of North Carolina: Miocene, Yorktown formation, 1% miles the valve and by the abrupt weakening and change above Murf reesboro, Mount Pleasant Landing, Hertford County; in direction of the growth lines- External surface Colerain Landing, Bertie County; 2 miles below Toddy Sta sculptured near the apices of the umbones with strong, tion, 2 miles southeast of Tugwell (on Jacobs Branch), 1% miles northeast of Farmville, 2% miles north of Standard, 2 rather regular concentric furrows, which quickly miles west of Greenville (on Harris Mill Run), 1^ miles west broaden and flatten into ill-defined undulations that of Greenville (on Schoolhouse Branch), 9 to 10 miles south are most distinct near the anterior margin; secondary, of Greenville, and 1 mile northwest of Galloway Crossroads, irregular, concentric striations usually present; traces Pitt County; 2% miles northwest of Chocowinity, 1*4 miles northeast of Chocowinity, 1 mile northeast of Chocowinity, of obscure radials often faintly visible in front of the Beaufort County; 1 mile north of Castoria, Greene County. escutcheon. Ligament marginal, opisthodetic; nymph moderately robust; groove behind it deep and angular. Subgenus ASHTAROTHA Ball Dentition vigorous. Anterior cardinal of right valve 1903 (July). AsMarotha Dall, U. S. Nat. Mus. Proc., vol. 26, almost altogether obsolete; middle cardinal stout, p. 936. cuneiform, its distal surfaces transversely striate; Type by original designation: Astarte undulata Say. Miocene posterior cardinal laminar, often broken away. of the middle Atlantic seaboard. Anterior cardinal of left valve prominent, laterally Umbones concentrically sculptured and conspicuously flat sulcated, separated from the shorter and more com tened; disk smoother outside of the flattened area; otherwise pressed middle cardinal by the wide and deep sub- like Astarte.—Dall, 1903. umbonal socket; posterior cardinal of left valve almost Astarte (Ashtarotha) rappahannockensis Gardner, n. sp. obsolete; posterior dorsal margin of right valve and anterior lunular margin of left valve beveled to func Plate 12, figures 19, 20 tion as laterals. Muscle impressions very distinct, ex Shell moderately large, heavy, and convex for the tending but little above the median horizontal. section. Bounded trigonal, not strongly inequilateral. Anterior impression elliptical or slightly reniform. Anterior end slightly expanded in front of the lunule, Posterior irregularly oblong to subquadrate. Pedal rounding broadly and gently into the base. Posterior impression an irregular rotund dent dorsal to the dorsal margin descends uniformly and rather rapidly anterior adductor. Pallial line entire. Inner margins from the umbones almost to the upcurved base line, strongly crenate at the resting stages. Lateral margin very short, obscurely truncate. Base Dimensions of holotype: Height 25.0 millimeters,, line arcuate. Umbones subcentral, moderately flat width 27.2 millimeters, convexity 8.8 millimeters. tened, the apices acute and feebly prosogyrate. Lu Holotype, a left valve: U. S. Nat. Mus. 325533- nule smooth, elongate-cordate, depressed. Escutcheon Type locality: 2y2 miles northwest of Chocowinity, smooth, lanceolate, delimited by the posterior angula Beaufort County, N. C. tion. External sculpture confined to the flattened parts Astarte 'berryi is separated from the obliquely of the umbones, which are concentrically ridged with trigonal si, stephensoni and A. hertfordensis, with its 10 to 15 relatively fine, subequal, and sub-equispaced PART 1. PEtECYPODA elevations. Feeble incremental usually discernible on short. Umbonal region sculptured with 2 to 5 concen the anterior part of the shell and near the ventral mar tric undulations, which rapidly broaden and flatten gin. Ligament marginal, short, deeply inset. Hinge away from the umbones and evanesce altogether half vigorous; anterior and posterior cardinals of right way down to the ventral margin, leaving the gently valve feeble or almost obsolete; middle cardinal stout, convex surface smooth except for faint, linear, concen cuneiform, inserted in the deep subumbonal socket of tric striations. Ligament marginal, opisthodetic; the left valve between the strong, subequal, anterior and groove behind the nymph angular and deeply chan middle left cardinals; posterior left cardinal obsolete. neled. Dentition vigorous and clean cut. Anterior Adductor muscle impressions distinct and submedial, cardinal of right valve obsolete; middle cardinal stout, the anterior slightly oval, the posterior irregularly cuneiform; posterior cardinal laminar, fused with the quadrate. Pedal impression a small dent just dorsal ligamentary nymph. Anterior and middle cardinals of to the anterior adductor. Pallial line distinct, more left valve subequal, cuneiform, divergent on each side distant from the ventral margin anteriorly than pos of the deep, subumbonal socket; posterior tooth obso teriorly. Inner margins finely and rather feebly lete; contiguous surfaces of all the cardinals trans crenate at the resting stages, apparently smooth during versely striate. Muscle impressions large, submedial; the growing stages. anterior slightly renif orm; posterior roughly quadrate. Dimensions of holotype: Height 25.8 millimeters, Pallial line entire, rather distant. Inner margins finely width 28.6 millimeters, convexity 7.2 millimeters. crenate. Holotype, a right valve: U. S. Nat. Mus. 325527. Dimensions of holotype: Height, 23.8 millimeters^ Type locality: Kappahannock Eiver Bluffs near width, 27.0 millimeters; convexity, 6.8 millimeters. Urbanna, Va. Holotype, a left valve: U. S. Nat. Mus. 325524. Astarte rappahannockensis is probably the St. Marys Type locality: 2 miles east of Grifton, Pitt County, descendent of the A. obruta Conrad of the lower part N. C. of the Chesapeake group. It differs in the relatively Astarte griftonensis is remarkable for its regular and higher, heavier, more convex shell, the more nearly equi rounded outline and its low, broad, concentric undula lateral outline—owing to the less produced posterior tions, very few in number and limited to the dorsal half end—and the finer, closer, and more uniform sculptur of the valve. A. u/ndulata Say is usually heavier and ing on the umbones. It is separated from A. undulata more angular, the posterior dorsal slope is relatively Say, the only other coexistent member of the subgenus longer and distinctly shouldered near the apices of the Ashtarotha, by the less conspicuously flattened umbones umbones, and the concentric undulations are more nu and by the uniform slope of the posterior dorsal merous, narrower, and much sharper. A. thisphUa margin. Glenn is also distinctly shouldered and much more vig The species is confined apparently to the drainage orously sculptured. A. rappahannockensis is more con basin of the Kappahannock Eiver. vex and is ornamented with an umbonal sculpture of 10 to 15 subequal concentric lirae instead of the 2 to 5 Distribution: Virginia: Miocene, St. Marys formation, % mile low rounded undulations that rapidly broaden away below Jones Point, Essex County; 2J/£ miles south of Farn- from the apices. A. obruta Conrad is a heavier and ham, at Union Mill, Richmond County; Urbanna, Middlesex County. slightly more convex shell, with a more produced pos terior dorsal margin; it differs, furthermore, in the Astarte (Ashtarotha) griftonensis Gardner, n. sp. flattening of the umbones, which are almost at right Plate 12, figures 22, 28 angles to the vertical plane instead of following the uniform curvature ,of the valve from the apices to the Valves compressed, trigonal, subequilateral, suggest ventral margin, as in the A. griftonensis; the apical ing rudely the quadrant of a circle. Anterior end sculpture is much sharper in the Calvert species and feebly excavated in the lunular region, broadly and usually more limited in extent and more abruptly evenly arched in front of the lunule. Umborial angle evanescent. only a little over 90°. Posterior dorsal slope approxi The species is fairly abundant at the single locality at mately uniform although somewhat broken by the which it is represented, the Yorktown sands, 2 miles slight, almost imperceptible, forward bend of the um east of Grifton, in Pitt County, N. C. bones. Posterior lateral margin obscurely truncate, merging gradually into the broad arch of the base. Distribution: North Carolina: Miocene, Yorktown formation, Umbones subcentral, low, flattened, and with a tendency 2 miles east of Grifton (on the property of J. F. Brooks), Pitt County. toward a forward twist. Apices acute and slightly prosogyrate. Lunule smooth, rather narrow, its length Astarte (Ashtarotha) undulata Say often not exceeding one-third of the total height of the Plate 12, figures 25, 31 valve, sharply defined by the angulation of its dorsal 1824. Astarte undulata Say, Acad. Nat. Sci. Philadelphia Jour., margin. Escutcheon also rather narrow and relatively 1st ser., vol. 4, p. 150, pi. 9, fig. 5. 58 MOLLUSCA FROM MIOCENE AND LOWER PLIOCENE OF VIRGINIA AND NORTH CAROLINA 1834. Astarte undulata Say. Conrad in Morton, Synopsis of peripheral forms would not be surmised without the organic remains, App., p. 3. complete intergrading series, which establishes the con 1840. Astarte undulata Say (part). Conrad, Fossils of the sanguinity of the widely separated end members. The medial Tertiary of the United States, p. 41, pi. 20, flg. 7; pi. 21, fig. 4 (young excluded). umbones constitute the most characteristic feature of 1856. Astarte undulata, Say. Tuomey and Holmes, Pleiocene the species. These are conspicuously flattened, strongly fossils of South Carolina, p. 70, pi. 20, figs. 1, 2. sculptured, and bent forward just ventral to the apices, 1858. Astarte undulata Say. Emmons, North Carolina Geol. so that they give to the posterior dorsal margin a Survey Kept., p. 289, fig. 213. diagnostic hunch. 1863. Astarte undulata Say. Conrad, Acad. Nat. Sci, Phila delphia Proc. for 1862, vol. 14, p. 578. The representatives of two of the most striking lines 1903. Astarte (Ashtarotlia) undulata Say (part). Ball, Wagner of variation have been isolated subspecifically. Free Inst. Sci. Trans., vol. 3, pt. 6, p. 1491. Distribution: Virginia: Miocene, St. Marys formation, 2^ Shells trigonate, umbones flattened, and with profound miles below Bayport and Urbanna, Rappahannock River, undulations; apices very acute. Middlesex County. Yorktown formation, Yorktown, York Basal half of the shell coarsely wrinkled, the remaining County; near the mouth of Baileys Creek, near its conflu half deeply, regularly, and widely undulated on the flattened ence with the James River, Prince George County; Lieutenant umbo; lunule large, oblong, subovate, concave, separated from Run, Petersburg, Dinwiddie County; 5 miles northeast of the disk, particularly near the beaks, by an acute angle; beaks Smithfield, 1% miles northeast of Smithfield, % mile north prominent, approximate, acute, turned a little backward at east of Smithfield, % mile from Benns Church, 8 to 8% miles tip; ligament margin "concave nearly to the basal angle, and below Zuni, 12 to 14 miles below Zuni, Blackwater River, Isle separated from the disk, near the beaks, by an acute angle; of Wight County; Sycamore, % to % mile below Sycamore, on ligament very short; teeth regularly crenated on each side; the Nottoway River, Maddelys Bluff, lower Seaboard Railway basal angles rounded; basal edge nearly rectilinear or very bridge, and % to % mile above the lower Seaboard Railway obtusely arcuated; within finely crenated; smaller muscular bridge over the Meherrin River, Southampton County; % mile impression very distinct. north of Chuckatuck, Nansemond County. Length four-fifths of an inch, breadth rather less than nine- North Carolina: Miocene, Yorktown formation, 1^ to 2 miles tenths of an inch. above Branches Bridge, 1 mile above Branches Bridge, at A very distinct species, unlike any other yet described. It Branches Bridge, Northampton County; 2% miles northwest varies in proportional length, some being longer than broad, of Murfreesboro, 1% miles above Murfreesboro, 1 mile above and others broader than long.—Say, 1824. Murfreesboro, near Murfreesboro, 3 to 4 miles below Tar Ferry, Hertford County; Colerain Landing on the Chowan River, Shell varies widely in relative proportions and thick Bertie County; Halifax and Palmyra Bluff on* the Roanoke ness. Umbones central or slightly anterior, con River, Halifax County; Swift Creek, 15% miles above Bells spicuously flattened and bent forward, thus giving to Bridge, % mile above Bells Bridge, % mile above Bells Bridge, the posterior margin a gibbous aspect that is very 1 mile above Bells Bridge, 1% miles above Bells Bridge over characteristic. Apices of umbones acute, proximate. the Tar River, Shiloh Mills, and 1 mile below old Sparta Bridge, Edgecombe County; 2 miles below Toddy Station, 2 miles south Lunule and escutcheon always smooth and clearly de east of Tugwell (on Jacobs Branch), 1% miles northeast of fined but varying in width with the outline of the Farmville, 3 miles south of Farmville, 2% miles north of individual. External sculpture exceedingly inconstant Standard, 3 miles southwest of Frog Level (on J. A. Noble's in strength and character; a few sharp, constant con branch), 8 to 9 miles west of Greenville (on the east side of Pinelog Branch), 3 miles west of Greenville (on Harris Mill centric ridges on the umbones; ridges sometimes, as in Run), 2 miles west of Greenville, 1% miles west of Greenville Say's figured type, covering the entire valve to the (on Schoolhouse Branch), Greenville (just east of the country ventral margin; more frequently broadening, flatten bridge), 8 to 9 miles southeast of Greenville, 9 to 10 miles south ing, and finally evanescing about halfway down the of Greenville, 1 mile northwest of Galloway Crossroads, and 3 valve. Ligament marginal, mounted on a narrow, miles north of Grifton (on the property of James Dawson), Pitt County; 2% miles northwest of Chocowinity, 1*4 miles oblique nymph but little longer than the cardinals. northeast of Chocowinity, 1 mile northeast of Chocowinity, Anterior cardinal of right valve almost obsolete; Beaufort County; 3 miles east-southeast of Wilson, 1 mile posterior cardinal very feeble; middle cardinal robust, northwest of Stantonsburg, Wilson County; 6 miles west of cuneiform, inserted in the deep, subumbonal pit of the Goldsboro, Wayne County; 1 mile north of Castoria, half a left valve between the vigorous anterior and middle mile east of Lizzie (on the property of David Summeril), Greene County; Rock Landing on the Neuse River, Craven left cardinals; posterior left cardinal obsolete. Muscle County. Duplin marl, Lumberton (near the bottling works), impressions distinct; anterior adductor oval or reni- Robeson County. form; posterior, subquadrate; pedal an irregularly Outside distribution: Miocene, Choctawhatchee formation, rotund dent just dorsal to the anterior adductor. northern Florida. Duplin marl, Sumter district, S. C.; Pallial line simple, distinct, distant from the base; Porters Landing on the Savannah River, Effingham County, Ga. inner margins finely crenate. Astarte (Ashtarotha) undulata vaginulata Dall Type locality: "Maryland" (?). Plate 12, figures 26, 27 This protean species is by far the most abundant of 1903. Astarte undulata var. vaginulata Dall, Wagner Free Inst. the genus in the Yorktown of Virginia and North Sci. Trans., vol. 3, pt. 6, p. 1491. Carolina. Its manifestations in outline and sculpture This differs from the typical undulata in being more triangu are so diverse that specific relationship between the lar, with a straighter base, smaller, flattened area on the beaks, PART 1. PELECYPObA 59 with finer concentric sulcation which extends in most specimens remarkable for their high deltoid outline. They are to the base of the shell, though somewhat irregularly.—Dall, further characterized, as a rule, by a heavier shell, and 1903. by broader, less numerous, and more rapidly evanescing Dimensions of lectotype: Height 22.4 millimeters, concentric undulations. width 27.5 millimeters, convexity 8.3 millimeters. Distribution: Virginia: Miocene, Yorktown formation, Indian Lectotype, a right valve: U. S. Nat. Mus. 146121. Field Point, York County; mouth of Baileys Creek, Prince Type locality: Grove Wharf on the James River, Va. George County; Claremont Wharf, Schmidts Bluff, 8% miles The subspecies is notably thick and convex, the pos below Claremont Wharf, Sunken Marsh Creek, and Cobham terior end more or less produced, the area behind the Bay on the James River, Surry County; Kings Mill, James City County; Fergusons Wharf, James River, 1 mile north of posterior keel abnormally wide, the escutcheon less Zuni, Zuni (near the pumping station), 6% to 7 miles below clearly defined and occupying a smaller proportion of Zuni, 7 to 7^ miles below Zuni, Blackwater River, Isle of Wight the entire posterior slope than in A. undulata s. s. The County; Delaware (on the Nottoway River) and Maddelys flattening of the umbones, which is made more promi Bluff (on the Meherrin River), Southampton County. nent in vaginulata by the thickness and convexity of North Carolina: Miocene, Yorktown formation, 1% miles above Murfreesiboro, 1 mile above Murfreesboro, and near the shell, gives to the finely sculptured subspecies a Murfreesboro on the Meherrin River, Hertford County. transversely flexuous aspect that is distinct from the more angular contour of the normal compressed type Astarte (Ashtarotha) concentrica Conrad with its sharp, concentric, umbonal ridges rapidly Plate 12, figure 32-34, 40 broadening ventrally. 1834. Astarte concentrica, Conrad, Acad. Nat. Sci. Philadelphia Distribution: Virginia: Miocene, Yorktown formation, 3 miles Jour., 1st ser., vol. 7, p. 133. northeast of Walkerton, Mattapony River, King and Queen 1840. Astarte concentrica Conrad, Fossils of the medial County; Lanexa, New Kent County; Claremont Wharf, Tertiary of the United States, p. 44, pi. 21, fig. 6. Schmidts Bluff, 8% miles below Claremont Wharf, James River, 1863. Astarte concentrica Conrad, Acad. Nat. Sci. Philadelphia Surry County; 6% to 7 miles below Zuni, 7 to 7i/2 miles below Proc. for 1862, vol. 14, p. 578. Zuni, 8 to 8% miles below Zuni, 12 to 14 miles below Zuni on 1903. Astarte (Ashtarotha) concentrica Conrad. Dall, Wagner the Blackwater River, Isle of Wight County; Delaware on the Free Inst. Sci. Trans., vol. 3, pt. 6, p. 1492. Nottoway River and 3 to 4 miles above the lower Seaboard Shell subtriangular, compressed, with numerous concentric Railway bridge over the Meherrin River, Southampton County. rounded costae, crowded on the basal margin; umbones slightly flattened; apex acute, central; lunule large, concave, lanceolate; Astarte (Ashtarotha) undulata deltoidea Gardner, n. subsp. posterior margin concave; submargin acutely angular, straight; Plate 12, figures 29, 30, 35, 36 extremity obtusely rounded; cardinal teeth strongly striated; margin crenulated. Length 1% inches, height % inch. 1840. Astarte undulata Say var. Conrad, Fossils of the medial Locality, Yorktown, Va.—Conrad, 1834. Tertiary of the United States, p. 41, pi. 21, fig. 4. Outline ovate-trigonal, compressed, inequilateral. Shell heavy, conspicuously elevated. Umbonal angle Posterior end rounded. Anterior end expanded in as small as 30°. Posterior slope very steep, rounding front of the lunule, rounding broadly and evenly into rather abruptly into the rectilinear ventral margin. the ventral margin. Umbones low, not conspicuous. Anterior end very slightly expanded in front of the Apices acute, feebly prosogyrate. Lunule smooth, lunule, broadly and evenly arching into the .base. Um sharply defined, narrow-elongate. Escutcheon lanceo bones slightly anterior, flattened, and bent forward late, about half the total height of the valve. Surface near the apices. Tips of umbones sculptured with a sculptured with 30 to 35 equal, concentric lirae, sep few sharp ridges, which rapidly broaden and flatten and arated by linear interspaces; lirae mostly uniform and become in some individuals altogether obsolete less than continuous across the disk, though tending to break up halfway down the valve. Hinge formula normal for near the posterior margin. Ligament external; the species but with the cardinals much more produced nymphs rather short and slender. Dentition robust; and relatively more slender. anterior cardinal of right valve feeble; middle cardinal Dimensions of holotype: Height 23.5 millimeters, cuneiform, strong, and prominent; posterior cardinal width 24.7 millimeters, convexity 6.0 millimeters. Di obliquely produced, compressed. Posterior cardinal of mensions of paratype, an extreme individual: Height left valve obsolete; middle and anterior cardinals vigor 22.5 millimeters, width 19.0 ± millimeters, convexity 6.5 ous, diverging beneath the umbones. Inner margins millimeters. of hinge teeth of both right and left valves transversely Types: Holotype, a right valve: U. S. Nat. Mus. striated. Anterior lunular margin of right valve and 325525; paratype, a right valve: U. S. Nat. Mus. 325532. posterior margin of left feebly sulcated to receive cor Conrad's figured A. undulata Say var. was collected responding beveled edges of opposite valves. Adductor near City Point, on the James Elver, Va. The holotype impressions rather large—the anterior oval or slightly is from 7 to 7% miles below Zuni; the paratype from reniform, the posterior semielliptical or rudely Zuni, Isle of Wight County, Va. quadrate. Pallial line simple. Inner margins more The subspecies includes those A. undulata that are or less strongly crenate. 60 MOLLUSCA FROM MIOCENE AND LOWER PLIOCENE OF VIRGINIA AND NORTH CAROLINA Astarte • concentricffi Cdnrad is unique among its River, Bladen County; Neills Eddy Landing, 3 miles north of congeners in the possession of a lirate concentric Cronly, Columbus County. Outside distribution: Miocene, Duplin marl, Porters Land sculpture that covers the entire valve. The species, ing on the Savannah River, Effingham County. Pliocene, Wac which varies somewhat in outline and strength of camaw formation, Nixons and Todds Ferry, Horry County, sculpture, gives rise to Conrad's A. ~betta, an ab S. C. normally high type with an abnormally fine and close Astarte (Ashtarotha) concentrica conradi Gardner, n. subsp. sculpture. Plate 12, figures 37, 41 The form prevalent in the Duplin and Waccamaw formations seems also sufficiently distinct to be worthy Shell relatively small, low, heavy, and convex; of isolation, characterized as it is by a relatively low, slightly flexuous posteriorly. Anterior end more heavy, and somewhat flexuous shell, with a more pro strongly produced and contracted than is normal for duced posterior end and a less uniform, concentric the species. Base line broadly arcuate. xUmbones set sculpture. a little in front of the median line, slightly incurved A. concentrica Conrad, though present throughout and prosogyrate. Lunule elongate-cordate; both lunule the Miocene and Pliocene of Virginia and North and escutcheon relatively broad. Sculpture rather Carolina, is most abundant in the Yorktown formation. more elevated than in A. concentrica s. s., and less uni form. Dentition vigorous and clean-cut; transverse Distribution: Virginia: Miocene, Yorktown formation, York- striations on the inner surfaces of the cardinals very town and 1% miles below Yorktown, York County; Petersburg, distinct. Character of adductor impressions and pal- Dinwiddie County; 2 miles northwest of Smithfield, 1^ miles northeast of Smithfield, % mile northeast of Smithfield, % lial line normal. Inner margins finely crenate. mile from Benns Church, and Everet's farm near Benns Dimensions of cotypes: Right valve, height 15.7 mil Church, Isle of Wight County; % mile north of Chuckatuck, limeters, width 19.0 millimeters, convexity 5.3 milli 1% miles southeast of Reids Ferry, 1% miles north of Suffolk, meters, left valve of another individual, height 16.8 1% miles north of Suffolk, 1 mile northeast of Suffolk; % millimeters, width 21.3 millimeters, convexity 6.0 mile below the Suffolk waterworks dam, drainage ditch of the Norfolk & Western Railway just east of Jericho ditch, millimeters. Nansemond County. Cotypes: U. S. Nat. Mus. 325530. North Carolina: Miocene, Yorktown formation, Tar Ferry Type locality: 4 to 5 miles below Lumberton, Eobeson on Wiccacon Creek (opposite Harrellsville), 1% miles below County, N. C. Tar Ferry, 3 to 4 miles below Tar Ferry, Dogwood Landing Astarte concentrica conradi is remarkable for its rela on the Chowan River, Mount Pleasant Landing, Hertford tively small, heavy shell, which is inflated anteriorly, County; Colerain Landing and % to % mile above Edenhouse Point on the Ghowan River, Bertie County; Palmyra Bluff, slightly depressed, produced, and contracted posteriorly, Halifax County; 2^ miles northwest of Williamston (on the and ornamented with rather coarse, crowded, concentric land of Joseph Cherry), 1 mile northwest of Williamston, 1 lirae that lack the uniformity normal to the species. mile southeast of Williamston, Martin County; 15% miles The subspecies, though occurring at a few isolated above Bells Bridge, % mile above Bells Bridge, % mile below Bells Bridge, 1 mile below Bells Bridge, Shiloh Mills, Tar- localities in the St. Marys formation and north of the boro, Tar River, Edgecombe County; 2 miles below Toddy Hattaras axis, is particularly characteristic of the Station, 2 miles southeast of Tugwell (on Jacobs Branch), 1*4 Duplin marl south of the Hattaras. miles northeast of Farmville, 2% miles north of Standard, 8 Distribution: Virginia: Miocene, St. Marys formation, a to 9 miles west of Greenville (on the east side of Pinelog quarter of a mile below Jones Point on the Rappahannock Branch), 3 miles west of Greenville (on Harris Mill Run), 2 River, Essex County. Rare. miles west of Greenville, 1% miles west of Greenville (on North Carolina: Miocene, Yorktown formation, 9 to 10 miles Schoolhouse Branch), 8 to 9 miles southeast of Greenville, 9 south of Greenville, Pitt County. Duplin marl, 2% miles south to 10 miles south of Greenville, 3 miles north of Grifton (on of Clinton (on Gum Chimney Branch) and 4 miles south of James Dawson's farm), Pitt County; 2% miles northwest of Clinton, Sampson County; Natural Well, 1% miles north of Chocowinity, 1 mile northeast of Chocowinity, Beaufort County; Magnolia, and W. H. Kornegay's marl pit near Magnolia, Duplin 1 mile west of Wilson (on Frank Barnes' land at Hominy County; 4 miles north of Lumberton ' (on the Berry Godwin Swamp), Wilson County; 1 mile east of Lizzie (on the land plantation), 1 mile west of Lumberton (on the property of of T. N. Lassiter), Greene County. 2 miles southwest of Maple Charles Rowland), Lumberton (near the bottling works), 2 miles Cypress on the Neuse River, Rock Landing on the Neuse River, 'below Lumberton, 4 to 5 miles below Lumberton, 1% miles north Craven Cou'nty. Duplin marl, 3 miles south of Clinton^ (on Gum Chimney Branch), 10 miles south of Clinton (on the east of Fairmont (on the land of Andrew Jones), and at Fair property of J. N. Powell), Sampson County; Natural Well, mont (Ashpole), Robeson County. Pliocene, Waccamaw forma 1% miles north of Magnolia and Frank Wilson's and W. H. tion, Lake Waccamaw and Neills Eddy Landing (3 miles north Kornegay's marl pits near Magnolia, Duplin County; 4 miles of Cronly), Columbus County. north of Lumberton (on the Berry Godwin plantation), 1 Astarte (Ashtarotha) concentrica bella Conrad mile west of Lumberton (on the property of Charles Rowland), Lumberton (near the bottling works), 2 miles below Lumberton, Plate 12, figures 38, 39 4 to 5 miles below Lumberton, Fairmont (Ashpole), 1% miles 1846. (?) Astarte lineolata H. C. Lea, Am. Philos. Soc. Trans., northeast of Fairmont (on the land of Andrew Jones), 4 miles 2d ser., vol. 9, p. 241, pi. 34, fig. 20. northeast of Fairmont (at D. E. Lewis'), Robeson County. 1856. Astarte concentrica Conrad. Tuomey and Holmes, Pleio- Pliocene, Waccamaw formation, Lake Waccamaw, Cape Fear cene fossils of South Carolina, p. 71, pi. 20,, fig. 3. PART 1. PELECYPODA 61 1858. Astarte concentric® Conrad. Emmons, North Carolina Kriiger's description of sinuatus with Lamarck's gib Geol. Survey Kept., p. 289, fig. 212. bosula and the much closer correspondence of that 1863. Astarte lella Conrad, Acad. Nat. Sci. Philadelphia Proc. for 1862, pp. 577, 585. description to Lamarck's plumbea. From an exami 1863. (?) Astarte lineolata H. C. Lea. Conrad, idem, p. 578. nation of the descriptions of, Deshayes, 1860, and 1866. Astarte compsonema Conrad, Am. Jour. Conchology, vol. the illustrations of Cossmann and Pisarro, 1906, 2, p. 72, pi. 4, fig. 18. Stewart observed 8e that "of the eight species of 1903. Astarte concentrica var. ~bella Conrad. Dall, Wagner *''Crassatella'' cited by Deshayes from Grignon, only one, Free Inst. Sci. Trans., vol. 3, pt. 6, p. 1492. ^Crassatella plumbeaj corresponds to the meager de Triangular, compressed; marked by very regular, closely scription of ''Crassatellites .sinuatus^ " of Kriiger. This arranged, fine, concentric lines. is doubtless true, though Deshayes included in his A. concentrica Tuomey and Holmes (not Conrad), Pleiocene fossils of South Carolina, 71, 20, 3; Emmons, North Carolina synonymy of Crassatella plumbea, Crassatella tumida, Geol. Survey Kept. 289, 212. which Stewart has accepted as a distinct species and Locality, Virginia. - as the type of 'Crassatella Lamarck. Differs from concentrica in being proportionally shorter and In our collections from Grignon the heavy shells in its much finer and more regular lines.—Conrad, 1863. labeled C. tumida Lamarck might well pass for the The lineolata of H. C. Lea is a very young shell and original of Kriiger's description. C. tumida Lamarck, is undeterminable, even specifically. The subspecies 1807, is considere'd synonomous with C'. gibba Lamarck, bella is separated from A. concentrica s. s. by its higher 1801 (gibbosa Lamarck of Deshayes, 1860, by an error), outline and by its finer, closer, and even more regular and has been designated as the type of Crassatella. As concentric sculpture—all of which characters are of lit the French bossue is a literal translation of the Latin tle systematic importance in the Astartes. The form has gibba, it seems reasonable to suppose that Kriiger had a place in the literature, however, arid though rare is before him an example of C. gibba Lamarck, 1801. readily recognizable. His reason for selecting sinuatus as the specific name of his species is not obvious. It seems to have nothing Distribution: Virginia: Miocene, Yorktown formation, to do with Crassatella sinuata Lamarck, 1818, from the Petersburg, Dinwiddie County. ' North Carolina: Miocene, Yorktown formation, Branches environs of Bordeaux. If the description and situs of Bridge over the Meherrin River, Northampton County. his species were not so closely in accord with the heavy Outside distribution: Pliocene, Waccamaw formation, crassatellids of the Paris Basin, it might be reasonably Waccamaw, S. C. conjectured that Kriiger had two rather than a single species in mind and that Crassatellites sinuatus and Family CRASSATELLITIDAE Crassatelle bossue referred to different forms. Access Genus CRASSATELLITES Kriiger to larger collections and knowledge of the relative 1799. Crassatella of authors, not Crassatella Lamarck (Soc. abundance and distribution of the forms in question are histoire nat. Paris Mem., p. 85. Sole species, Mactra necessary for an adequate identification of Kriiger's cygnea Chemnitz). type. 1823. Crassatellites Kriiger, Geschichte der Urwelt, vol. 2, p. 466. There is a conspicuous lack of uniformity in usage Type by monotypy?: Crassatellites sinuatus Kriiger. Eocene of the generic name to be given to the group under dis of the Paris Basin. cussion. It is admitted by all workers that Crassa- t&lla Lamarck, 1799, was founded on a Mactra. The Through the kindness of W. J. Fox, the assistant French school have retained Crassatella on the plea librarian and editor at the Academy of Natural that Lamarck cited in 1801, under practically the same Sciences in Philadelphia, I received the following copy description, Crassatella gibba=Crassatella tumida of Kriiger's original description: Lamarck, 1807. The name Crassatellites is also in Crassatellites simiatus. Crassatelle bossue. disfavor because Kriiger, like Schlotheim, used the Mit sehr dicken Schaalen, tiefen Muskeleindrueken und suffix ites to indicate merely the occurrence of the given einzelnen Querreifen, welche auf der Oberflache mit dem genus in the fossil state. There has been no uniformity untern Rande der Schaalen gleichlaufen. Haiifig bei Grignon. in the acceptance or rejection of names so compounded. Dall, following Bronn, and many others including Cox 87 probably takes the most easily tenable position, myself, following Dall, have considered Kriiger's C. in holding that "the adoption of Crassatellites seems, sinuatus as synonymous with Crassatella gibbosula however, to be the easiest solution of the problem Lamarck. This doubtless arose from Deshayes' cita caused by Lamarck's inconsistency." tion in 1824 of Crassatella ~bossue as Crassatella Shell slightly inequivalve, inequilateral, subquadrate gibbosula Lamarck. or subtrigonal in outline. Umbones anterior and Stewart 86 indicated the difficulty in reconciling usually prominent. Lunule and escutcheon distinctly depressed. Surface sculpture concentric, usually fee- 36 Stewart, R. B., Gabb's California Cretaceous ahd Tertiary type La- mellibranchs: Acad. Nat. Sci Philadelphia, Special Pub. 3, p. 136, 1930. w Cox, L. R., India Geol. Surrey Mem., n. ser., vol. 15, p. 210, 1930. 401033—43———5 62 MOLLUSCA FROM MIOCENE AND LOWER PLIOCENE OF VIRGINIA AND NORTH CAROLINA ble, and commonly confined to the umbonal area. acute, opisthogyrate, central or slightly anterior. Lu Ligament and resilium internal. Dentition vigorous; nule and escutcheon sublinear, the latter slightly more three cardinals in the right valve—the posterior fre expanded; both of them coextensive .with the dorsal quently effaced by the resilium—and two in the left. margins; clearly defined by the angulation of the valve Anterior margin of right valve and the posterior mar and the abrupt disappearance of the sculpture. Sur gin of the left grooved to receive the beveled edge of face ornamentation of 11 to 15 equisized and eqiiispaced the opposite valve. Muscle scars distinct, impressed. concentric folds, which are pinched into sharply ele Pallial sinus simple. Ventral inner margins dentate. vated free lamellae toward the margins and often over The distribution of Crassatellites is without new the entire disk; feeble and irregular secondary concen stratigraphic significance. As the group was well es tric striations sometimes present; crowded radial stria- tablished in the Seaboard and the Gulf Provinces in the tions also visible in well preserved individuals and Upper Cretaceous, there is no reason to doubt that the under high magnification, least feeble on the Tertiary represeneatives are autochthonous. The Re dorsal slopes of the lamellae near the base. Liga cent forms are included in about 40 species, the majority ment internal; resilial pit narrow, somewhat oblique. tropical in habitat. Dentition of right valve reduced to a couple of simple, Genus CRASSINELLA Guppy compressed cardinals in front of the ligament pit; anterior dorsal margin feebly sulcated; posterior dor 1874. Crassinella Guppy, Geol. Mag., new ser., dec. 2, vol. 1, p. 450. sal margin beveled to function as a lateral. Two 1875. Crassinella Guppy, idem, vol. 2, p. 42. cardinals present also in the left valve—the posterior nothing more than a low laminar ridge bordering the Type by monotypy: Crassinella, martinicensis d'Orbigny= ? resilium, the anterior simple, obliquely produced, Thetis parva C. B. Adams. Eecent in the West Indies. moderately robust. Anterior dorsal margin beveled and The genus is characterized by the small, trigonal, grooved slightly toward the ventral margin; posterior compressed outline; the acute, erect, or slightly opstho- lateral lamina strongly developed, parallel to the dorsal gyrate subcentral umbones; the internal ligament; the margin throughout its length; more prominent near 2 delicate cardinals in each valve; and some form of the ventral end. Adductor impressions small, often lateral armature. Although it has been commonly con obscure, the anterior irregularly rotund, the posterior sidered as a subgenus of Crassatellites, the characters oval or slightly reniform. Pallial line entire, rather that separate the 2 groups seem sufficiently important distant from the base. Inner margins simple. to be considered generic. Figured specimen, U. S. Nat. Mus. 6123, from the Crassinella lunulata (Conrad) Dall Natural Well, Duplin County, N. C. Height 5.9 milli Plate 19, figure 30 meters, width 6.7 millimeters. Crassinella lunulata (Conrad) exhibits within its 1834. Astarte lunulata Conrad, Acad. Nat. Sci. Philadelphia Jour., 1st ser., vol. 7, p. 133. narrow limits a wide range of variation. The charac 1840. Astarte lunulata Conrad, Fossils of the medial Tertiary ters are, on the whole, more stable in the fossil than of the United Sates, p. 44, pi. 21, fig. 8. in the Recent forms, though they are inconstant at all 1856. Astarte lunulata Conrad. Tuomey and Holmes, Pleiocene ages. The species varies in convexity, in thickness, in fossils of South Carolina, p. 72, pi. 20, fig. 4. relative proportions, and in the curvature of the base 1858. Astarte lunulata Conrad (part). Holmes, Post-Pleiocene fossils of South Carolina, p. 32, pi. 6, fig. 9. line; the posterior dorsal slope may be oblique and simi 1863. Oouldia lunulata Conrad, Acad. Nat. Sci. Philadelphia lar to the anterior, or, as is frequently true of the Proc. for 1862, p. 578. young, it may be convex and more produced than the 1903. Crassatellites (Crassinella) lunulatus Conrad. Dall, anterior. The variations in sculpture are the most Wagner Free Inst. Sci. Trans., vol. 3, pt. 6, p. 1477, pi. obvious. The concentric sculpture, which is typically 49, fig. 15. 1932. Crassinella lunulata (Conrad). Mansfield, Florida Geol. sharpest and strongest near the margins, broadens Survey Bull. 8, p. 82, pi. 15, fig. 6. slightly and flattens medially; in many of the young, in a few of the adults, and in many of the senile forms Shell small, triangular, compressed, with about 13 acute, concentric, prominent lines; anterior slope rectilinear, angular the sculpture is either undeveloped or obsolete on the at the extremity; basal margin rounded; beaks central, apex medial portion of the disk and usually less conspicuous acute; lunule much elongated. Length and height nearly anteriorly than posteriorly. This tendency is so ex equal, about a quarter of an inch. Locality, Suffolk, Va.— treme in some individuals that it has seemed wise to Conrad, 1834. isolate them under the subspecies harrisi. In a few of Shell minute, moderately compressed, cuneiform, the relatively higher and heavier forms, on the other subequilateral in the adult stages. Dorsal slopes steep, hand, the laminae may number up to 18 or 20 and may subequal, the posterior sometimes slightly concave and persist with undiminished strength across the entire produced. Basal margin strongly arcuate, forming valve. The radial sculpture—supposed to have been with the dorsal slopes a 30° to 45° segment. Umbones developed only in the Recent representatives of the PART 1. PELECYPODA 63 species—is discernible on the fossils also if the indi (ys mile east of the factories), and Neills Eddy Landing (3 vidual is sufficiently well preserved and the magnifi miles north of Cronly), Columbus County; Wilmington, New Hanover County. cation sufficiently high. Outside distribution: Miocene, Duplin marl, Darlington, The species is among the most abundant, the most Darlington County, S. C. Choctawhatchee formation, northern widely distributed, and the most readily recognizable Florida. Pliocene, Waccamaw formation, Nixons and Todds of all the minute bivalves. It is particularly prolific Ferry, Horry County, S. C. Caloosahatchee marl, Caloosa- in the Yorktown along the York River, in Nansemond hatchee River, Shell Creek, and Alligator Creek, Fla. Croatan sand, Slocums Creek, Craven County, N. C. Pleistocene, (?) County in the environs of Suffolk, along the Chowan Labelle, Caloosahatchee River, Fla. (Vaughan). River, in Hertford and Bertie Counties, and in the Duplin and Waccamaw formations. It is recognized Crassinella lunulata harrisi Gardner, n. subsp. also in both the Area zone and the Cancellaria zone of Plate 14, figure 45 the Choctawhatch.ee of Florida. 1903. Crassatellites (Crassinella) 'galvestonensis Harris. Dall, Distribution : Virginia : Miocene, Yorktown formation, 4 miles Wagner Free Inst. Sci. Trans., vol. 3, pt. 6, p. 1478, pi. northeast of Walkerton on the Mattapony River, King and 49, fig. 14. Not Eriphyla, galvestonensis Harris, 1895. Queen County; % mile above Yorktown, Yorktown, 1^4 miles Shell subject to the same variation in outline as that below Yorktown, and 2 miles below Yorktown, York County; old Claremont Wharf on the James River, Surry County; Lieu of Crassinella lunulata (Conrad) but generally higher tenant Run near Petersburg, Dinwiddie County; % mile north and decidedly heavier. Umbones of the thicker forms east of Smithfield, Benns Church (14 mile from the old church), flattened above. Subspecies based primarily on obso J. J. Everet's farm near Benns Church, % mile north of Zuni, lete external sculpture; traces of low but regular con and 12 to 14 miles below Zuni on the Blackwater River, Isle centric undulations, which are visible along the of Wight County; Maddelys Bluff, %' to % mile above the lower Seaboard Railway bridge, and 2y2 to 3 miles below the posterior dorsal margin and, more feebly, along the lower Seaboard Railway over the Meherrin River, Southampton anterior, sometimes persist across the disk near the County; y± mile north of Chuckatuck, iy2 miles southeast of base, but are never pinched into free lamellae as in C. Reids Ferry, Exit, 5% miles northwest of Suffolk, 2% miles lunulata s. s. Hinge and pallial characters normal for northwest of Suffolk, iy2 miles north of Suffolk, 1% miles north the species. west of Suffolk, iy2 miles northeast of Suffolk, 1 mile east of Suffolk, 1 mile west of Suffolk, y2 mile below the Suffolk water Dimensions of holotype: Height 5.1 millimeters, works dam, and y2 mile, from the drainage ditch of the Nor width 5.2 millimeters. folk & Western Railway just east of Jericho ditch, Nansemond Holotype, a left valve, U. S. Nat. Mus. 1630. County. Type locality: Yorktown, Va. North Carolina: Miocene, Yorktown formation, iy2 miles above The form figured by Dall in the Transactions of the Branches Bridge and Branches Bridge, Northampton County; iy2 Wagner Free Institute under the name C. galvestonen miles above Murfreesboro, 1 mile above Murfreesboro, Tar Ferry on Wiccacon Creek (opposite Harrellsville), 1% miles below Tar sis may serve as a type for the subspecies. Harris' type Ferry, 3 to 4 miles below Tar Ferry, Dogwood Landing and from the Galveston well and all the individuals in the Mount Pleasant Landing (on the Chowan River), Hertford available reference collections are very young. They County; Colerain Landing and % to % mile above Edenhouse are, however, more heavy and rude in both outline and Point, Bertie County; Palmyra Bluff, Halifax County; 15y2 dentition than any of the young of C. lunulata in the miles above Bells Bridge, 100 yards below Bells Bridge, % mile below Bells Bridge, 1 mile below Bells Bridge, Shiloh extensive collections of east coast materials, and there Mills, L. E. Fountain's farm at Tarboro, Tar River, Edge- are no intermediate forms to warrant their union with combe County; 2 miles below Toddy Station, 3% miles northeast those from Yorktown. On the other hand, a complete of Farmville, 3 miles south of Farmville, 2ys miles north of intergrading series has been established that unites the Standard, 8 to 9 miles west of Greenville (on the east side of forms in which the sculpture is quite obsolete—except Pinelog Branch), 8 to 9 miles southeast of Greenville, and 9 to 10 miles south of Greenville, Pitt County; 1 mile west of along the posterior dorsal margin—with those in which Wilson (in Hominy Swamp, on the farm of Frank Barnes), the sharply elevated lamellae continue with undimin- Wilson County; 1 mile north of Castoria, % mile east of Lizzie ished strength from the posterior across to the anterior (on the farm of David Summeril), 1 mile east of Lizzie (on margin. the farm of T. N. Lassiter), Greene County; 2y2 miles north The tendency toward an evanescent sculpture, though west of Chocowinity, Beaufort County; 2 miles southwest of Maple Cypress, and Rock Landing, Craven County. Duplin widespread in time and space, is strongest in the York- marl, 2y2 miles south of Clinton (on Gum Chimney Branch, on town of Virginia, and all of the forms to which sub- the land of Hugh Moore), 10 miles south of Clinton (on the specific rank has been given are confined to that forma land of J. N. Powell), Sampson County; 1% miles north of tion and area. In the Recent representatives, unlike Magnolia, at the Natural Well, and W. H. Kornegay's marl those of the Tertiary, the sculpture often lingers longest pit, Duplin County; Fairmont and 1% miles northeast of near the umbones. Fairmont (on the farm of Andrew Jones), Lumberton (near the bottling works), 2 miles below Lumberton, and 4 to 5 miles Distribution: Virginia: Miocene, Yorktown formation, % below Lumberton, Robeson County. Pliocene, Waccamaw mile above Yorktown, Yorktown, and 1% miles below York- formation, 4 miles south of Elizabethtown (on Hammond town, York County; */4 mile north of Chuckatuck, 1% miles Creek, on the land of Mrs. Clark) and at Walkers Bluff on the southeast of Reids Ferry, 1 mile northeast of Suffolk, and % Cape Fear River, Bladen County; Lake Waccamaw, Cronly mile below the Suffolk waterworks dam, Nansemond County. 64 MOLLUSCA fROM MIOCENE AND LOWER PLIOCENE OF VIRGINIA AND NORTH CAROLINA Crassinella galvestonensis (Harris) its union with the arcuate ventral margin abrupt; 1895. Eriphyla galvestonensis Harris, Bull. Am. Paleontology, anterior dorsal slope more gentle, rounding evenly into vol. 1, No. 3, pi. 1, figs. 2, 2a, 2b. the base. Umbones low; apices acute, proximate, opis- Form as indicated by the figures; hinge as in E. lunulata; thogyrate. Lunule and escutcheon sublinear, coexten exterior smooth, slightly undulating concentrically near the sive with the dorsal margins, clearly defined by the beaks; beaks, as in many species of Astarte and Crassatella, angulation of the valves and the abrupt disappearance slightly flattened at the very apex but very gibbous just below.— Harris, 1895. of the surface ornamentation. Sculpture of 15 to 20 equal, continuous, concentric lirae, separated by linear Locality: Galveston well, Texas, from 300 to 2,600 interspaces. Dentition normal for the subgenus; re- feet. silial pit narrow, oblique; hinge of right valve armed No convincing evidence for the existence of the with 2 simple, oblique, compressed cardinals, the species from the Galveston well, in the east coast Ter posterior cardinal being stronger; posterior cardinal of tiary deposits, has been presented. The forms figured left valve merely a low, laminar elevation bordering the under that name in the Wagner papers have proved to resilium; anterior cardinal simple, comparatively be a subspecies of Crassinella Iwiulata and have robust; dorsal margins strongly modified to function received the name harrisi. as laterals; anterior dorsal margin of right valve feebly Outside distribution: Miocene, Galveston well, Texas, 300 sulcated; posterior dorsal margin strongly beveled; feet to 2,600 feet. anterior dorsal margin of left valve, beveled, the pos Crassinella dupliniana Dall terior lateral lamina strongly developed, parallel to the dorsal margin throughout its length. Adductor Plate 13, figures 10, 11 impressions rotund, submedial, often obscure. Pallial 1903. Crassatellites (Crassinella) duplinianus Dall, Wagner line entire. Inner margins simple. Free Inst. Sci. Trans., vol. 3, pt. 6, p. 1478, pi. 50, Dimensions of types: Right valve (paralype), height figs. 5, 6. 1932. Crassinella dupliniana Dall. Mansfield, Florida Geol. 2.7 millimeters, width 3.1 millimeters, sem diameter 0.5 Survey Bull. 8, p. 83, pi. 15, fig. 9. millimeter. Left valve of another individual (holo- Shell small, subtriangular, solid, with markedly acute beaks, type), height 3.3 millimeters, width .3.5 millimeters, which incline backward; anterior slope convexly arcuate, long; semidiameter 0.5 millimeter. posterior slope nearly a straight or slightly concave line, Types Holotype, U. S. Nat. Mus. 325534; paratype, shorter; lunule and escutcheon extending the whole length of U. S. Nat. Mus. 325515. their respective slopes, long and narrow, the latter more ex Type localities: Holotype, y2 mile below the Suffolk cavated than the former and wider; both "are smooth; base arcuate; disk sculptured with rather close-set, regular, sub- waterworks dam on the Nansemond River; para- equal, flattish, concentric ridges with narrower interspaces; type, 1% miles southeast of Reids Ferry, Nansemond these are sometimes feebly elevated but preserve their general County, Va. close-set, regular character; hinge well developed, the pos Crassinella nansemondensis n. sp. of the Yorktowff terior cardinal in the left valve often conspicuous. Height 3.2 fauna is the analog of C. dupliniana Dall'of the Duplin [3.1], breadth 3.2, diameter 1.7 millimeters. This species is especially characterized by the closeness, and Waccamaw faunas. The former is, however, a regularity, and smoothness of its concentric ridges and the long trifle less minute, decidedly more compressed, and and narrow luflule and escutcheon.—Dall, 1903. more inequilateral than the southern species and shows Holotype (double valves) : U. S. Nat. Mus. 114922. less variation in the character and strength of the Type locality: Natural Well, Duplin County, N. C. concentric sculpture. Mansfield reports the species from the Cancellcma Distribution: Virginia: Miocene, Yorktow,n formation, 1% zone of the Choctawhatchee formation of Florida. miles southeast of Reids Ferry and % mile below the Suffolk waterworks dam, Nansemond County. Distribution: North Carolina: Miocene, Duplin marl, Natural Well, l1/^ miles north of Magnolia, and W. H. Kornegay's Superfamily CYRENACEA , marl pit near Magnolia, Duplin County; 2 miles below Lum- Family CYEENIDAE berton, Robeson County. Pliocene, Waccamaw formation, 4 miles south of Elizabethtown (on Hammond Creek, on the Genus CORBICTJLA Megerle von Miihlfeldt property of Mrs. Clark), Bladen County; Neills Eddy Landing, 1811. Corbicula Megerle von Mtihlfeldt, Entwurf eines neuen 3 miles north of Crouly, Columbus County. Systems der Schalthiergehaiise, Magazin der Gesell- Outside distribution: Miocene, Duplin marl, Porters Landing schaft Naturforschender Freunde, 5ter Jahrgang, Ber on the Savannah River, Effingham County, Ga. Pliocene, Wac lin, p. 56. camaw formation, Tillys Lake, Horry County, S. C. Type by monotypy: Tellina fluminalis Miiller. Recent in the Crassinella nansemondensis Gardner, n. sp. Euphrates River. Plate 13, figures 18, 27 Shell usually heavy, subtrigonal or cordate; not Shell minute, compressed, ovate-trigonal, inequilat markedly inequilateral. Umbones subcentral, high, eral. Posterior end somewhat shorter and more and prominent. Lunule and escutcheon not defined. angular than the anterior; posterior dorsal slope steep, External surface smooth or concentrically furrowed. PART 1. PELECYPODA 65 Epidermis polished. Cardinals 3 in each valve, diverg of the left valve sharply elevated, transversely striated, ing fanlike beneath the umbones. Both anterior and with gently arcuate ridges extending almost to the posterior laterals developed, finely striate transversely. median horizontal and received between the double Pallial line little or not at all sinuated. laterals of the right valve. Adductor impressions ir Corbicula is abundantly represented in the nonma- regular, submedial. Pallial line entire, distant from rine Cretaceous and Lower Tertiary deposits of the the base. Western Interior, in a few restricted localities in the This species, the only representative of the genus in marine Tertiary of the east coast and Gulf, and in the the east coast Tertiary, is conspicuous for the sym Eocene of the Paris Basin. The Eecent species are metrical arrangement of the triple cardinals and the confined exclusively to rivers and lakes of the Eastern very strong, curved laterals. World. Distribution: North Carolina: Miocene, Yorktown forma Corbicula densata (Conrad) Emmons tion, 3 miles south of Farmville, Pitt County; 1 mile west of Plate 15, figures 3, 4, 7, 8 Wilson (in Hominy Swamp, on the property of Frank Barnes), Wilson County. Duplin marl, 2 miles below Lumberton, Robe- 1844. Cyrena densata, Conrad, Acad. Nat. Sci. Philadelphia son County. Pliocene, Waccamaw formation, Neills Eddy Proc., vol. 1, p. 324. Landing (3 miles north of Cronly) and Lake Waccamaw, 3545. Cyrena densata Conrad, Fossils of the medial Tertiary Columbus County; Wilmington, New .Hanover County. of the United States, p. 68, pi. 39, fig. 2. Outside distribution: Miocene, Duplin marl, Darlington dis 1856. Cyrena densata Conrad. Tuomey and Holmes, Pleiocene trict, Darlington County, S. C. Pliocene, Waccamaw forma fossils of South Carolina, p. 77, pi. 20, fig. 14. tion, Nixons, Horry County, S. C. Croatan. sand, Slocums 1858. Corbicula densata Conrad. Emmons, North Carolina Geol. Creek, Craven County, N. C. Survey Rept., p. 290, fig. 215A. 1863. Corbicula densata Conrad, Acad. Nat. Sci. Philadelphia Superfamily CYPRI1TACEA Proc. for 1862, p. 576. Family EULOXIDAE 1865. Cyrena densata Conrad. Prime, Monograph Am. Corbicu- ladae, Smithsonian Misc. Coll., No. 145, p. 31. Genus ETTLOXA Conrafl 1903. Corbicula densata Conrad. Dall, Wagner Free Inst. Sci. 1863. Euloxa Conrad, Acad. Nat Sci. Philadelphia Proc. for Trans., vol. 3, pt. 6, p. 1450. 1862, pp. 578, 585. Subtriangular, thick, convex, with robust lines of growth; Type by monotypy: Venus latisulcata Conrad. Miocene of anterior margin obtusely rounded; basal margin profoundly Virginia. and regularly curved to the posterior extremity, which is sub- truncated, direct, and greatly above the line of the base; Subtriangular, posteriorly sulcated; cardinal teeth three In beaks central, summits elevated; teeth large, robust, very the left valve, the two posterior teeth oblique; two teeth in prominent, three in one valve and two in the opposite; middle the right valve, the posterior one oblique; sinus of pallial tooth of the right valve bifid; lateral teeth elongated, robust; impression truncated or slightly emarginate posteriorly.—• anterior tooth truncated, suddenly deflected at the extremity; Conrad, 1863. posterior tooth distant. Length l1/^ inches, height 1% inches. Euloxa has been shuttled about from the Astartidae Locality, vicinity of Petersburg, Va.; Mr. Tuomey; rare.— Conrad, 1844. to the Veneridae and the Cyprinidae. It certainly is closer to the Astartes than to the venerids and prob Shell of medium size, rounded-trigonal to oblate- ably closer to the cyprinoids than to the Astartes, The spheroidal, strongly inflated in the umbonal region, heavy chalky shell and the simple pallial line suggest subequilateral. Anterior end quite evenly rounded, Astarte and Corbicula. The definition of the lunule nearly semielliptical. Posterior dorsal margin more and escutcheon is less clear than that of Astarte but oblique and more steeply descending than the anterior. much more decided than that of Corbicula or the Posterior slope more or less depressed, often obscurely cyprinoids. The cardinal dentition approaches most carinated. Umbones strongly gibbous, involute, proxi closely that of the cyprinoids. The conspicuously mate, often very much eroded. Surface sculptured heavy, trigonal cardinal is the middle cardinal of the with fine, irregular, and discontinuous incrementals left valve and not that of the right, as in Astarte. and stronger resting stages, many of which are only There is no trace of a lateral dentition. The cyprinoids on the anterior half of the shell and become obsolete include a number of genera of diverse characters and near the median vertical. Ligament marginal, seem much less uniform in their development than the opisthodetic, mounted on a short but conspicuously Astartes. The family apparently permits a wider strong nymph. Three cardinals in each valve diverge variation within its ranks than that of the Astartes, fanlike beneath the umbones—the middle and posterior and Eulooea has been left tentatively under that cardinals in the right valve and the anterior and heterogeneous group. middle cardinals in • the left valve robust, subequal, feebly sulcate; the middle cardinals somewhat stouter Euloxa latisulcata (Conrad) Conrad and more regularly sulcate than the distal; and the Plate 15, figures 1, 2 anterior cardinal of right valve and the posterior 1840. Venus latisulcata Conrad, Fossils of the medial cardinal of the left very slender and laminar. Laterals Tertiary of the United States, p. 40, pi. 20, fig. 6. 66 MOLLUSCA FROM MIOCENE AND LOWER PLIOCENE OF VIRGINIA AND NORTH CAROLINA 1852. Astarte latisulcata D'Orbigny, Prodrome pale"ontologie, exceedingly rare, for it is not probable that a species vol. 3, p. 112, No. 2089. of medium dimensions so strongly characterized would 1863. Euloxa latisulcata Conrad, Acad. Nat. Sci. Philadelphia pass unnoted. Proc. for 1862, pp. 578, 5&x 1872. Euloxa latisulcata Conrad, Acad. Nat. Sci. Philadelphia Distribution: Virginia: Miocene, St. Marys formation, Proc., p. 52, pi. 1, fig. 5. Urbanna, Middlesex County (Conrad); half a mile below Jones 1903. Euloxa latisulcata Conrad. Dall, Wagner Free Inst. Sci. Point on the Rappahannock River, Essex County; old Clare Trans., vol. 3, pt. 6, p. 1502. mont Wharf on the James River. A single .valve has been Shell subtriangular, with coarse lines of growth and a few collected at each of these three localities. deeply impressed lines; posterior side with a wide concave Family PLETTROPHORIDAE Dall furrow bounded by the umbonial slope, which is profoundly angulated; posterior extremity truncated obliquely inward, and Genus CORALLIOPHAGA de Blainville emarginate; inferior angle slightly prominent; lunule large, 1824. Coralliophaga de Blainville, Dictionnaire sci. nat, vol. ovate, not well defined; cardinal teeth thick and prominent. 32, p. 343. Locality, Middlesex County, near Urbanna, Va.—Conrad, 1840. Type by tautonomy: Coralliophaga coralliophaga Gmelin. Pliocene of Florida; Pleistocene and Recent of mid-America. Shell heavy, porcellanous, subtriangular to sub- quadrate, convex, strongly inequilateral. Umbones Shell thin, slightly gaping posteriorly. Outline ir strongly anterior, in some individuals set within the regular, very inequilateral, oblong, subcylindrical, often anterior sixth, their apices slightly flattened, acute, modiolariform. Umbones low, not far from the prosogyrate. Lunular area cordate, depressed, but not anterior margin. Surface smooth, radially or con sharply delimited. Escutcheon outlined by an obtuse centrically sculptured. Hinge with two very oblique carina. Anterior end of valve slightly expanded in cardinals, one of them bifid, and one posterior laminar front of the lunule. Posterior dorsal margin oblique lateral. Pallial sinus broad but shallow. <• or subrectilinear. Lateral margin squarely truncate Coralliophaga, as may be inferred from the name, is but contracted medially by the broad and deep gutter a boring form inhabiting the hard parts of other that depresses the valve from the umbones to the lateral organisms, especially corals and even rocks. margin—limited posteriorly by the fold that outlines A number of species have been recorded from the the escutcheon, anteriorly by a more angular ridge that Eocene; the Recent forms are mostly inhabitants of persists with uniform vigor from the umbones to the southern seas. posterior ventral margin. Base line subrectilinear, Coralliophaga? microreticulata Gardner, n. sp. feebly warped in front of the posterior keel. Surface sculptured only by incrementals, which are stronger Plate 9, figures 2-6 and more crowded toward the ventral margin. Liga Shell exceedingly thin, gaping posteriorly. Outline ment external, opisthodetic, mounted on a narrow modiolariform. Umbones strongly anterior but not nymph a, little longer than the posterior cardinal. terminal; umbonal region sculptured with a fine micro Hinge armature of right valve reduced to an isolated, scopic reticulation, which becomes obsolete posteriorly. sturdy middle cardinal and to an obliquely elongated Posterior end irregularly corrugated by the incre and compressed posterior cardinal. Three unequal mentals. Hinge and pallial characters lost. Burrows cardinals in the left valve—the anterior cardinal short, funicular, averaging about 17.0 millimeters in maxi compressed, almost vertical; the middle stout, tri mum diameter and about 40.0 millimeters in length angular, somewhat oblique; the posterior oblique, very above the stem. Stem slightly constricted medially, slender, and elongate. Posterior dorsal margin of suggesting in cross section a figure 8. Larger diameter, right valve slightly modified to fit into shallow sulcus 5 millimeters; smaller diameter, 2 millimeters. Matrix of left valve; no true laterals developed. Anterior ad apparently a bryozoan colony. ductor impression semielliptical, more prominent than Cotypes: U. S. Nat. Mus. 325560. the irregularly quadrate posterior adductor. Pallial Type locality: Half a mile below the Suffolk water line simple. Inner margins entire. works dam, Nansemond County, Va. Figured specimen, U. S. Nat. Mus. 214407, from the Though the evidence at hand does not conclusively lower bed at old Claremont Wharf on the James Eiver, establish Coralliophaga in the east coast Tertiary, yet Va.; Height 20.0 millimeters, width 23.4 millimeters. all the known facts indicate that microreticvlata should Until the discovery of two additional valves by Dr. be referred to this genus. The shells are so thin and L. W. Stephenson of the United States Geological so much less resistant than the burrows to which they Survey—one valve from the St. Marys formation of closely adhere that it was found impossible to extract the Rappahannock River, the other from the James even one of them in good condition. As the frag River—Conrad's type from the Rappahannock Riyer at mentary nature of the types is due less to the want of Urbanna remained unique. The form is apparently material than to the mode of occurrence, it has seemed PART 1. PELECYPODA 67 best to give the data already available, unsatisfactory tions and in the degree of obliquity. The umbones are and inconclusive though it may be. tumid, flattening near their tips, rather distant, strongly Distribution: Virginia: Miocene, Yorktown formation, half involute and prosogyrate. The depression in front of a mile below the Suffolk waterworks tlam, Nansemond County. the posterior fold is usually, though not always, strong enough to undulate the shell from the umbones to the Superfamily ISOCARDIACEA base. The growth lines are prominent and rather Family ISOCARDIIDAE crowded toward the ventral margin. The opisthodetic Genus ISOCARDIA Lamarck ligament is deeply inset and the ligamentary nymph 1799. Isocardia Lamarck, Prodrome d'une nouvelle classification very heavy. The hinge is rude and massive; the two des coquilles, Soc. hist&ire nat. Paris M&n., p. 86. cardinals of the right valve are lamelliform and sub- Type by monotypy: Chama cor Linnaeus, 1767=<7fflreZwm hu- equal, the ventral cardinal bem|* a little shorter, stouter, manum Linnaeus, 1758. Recent off the European coasts and and more anterior than the dorsal. There are no right fossil in the Pliocene and Pleistocene of the Celtic Province. laterals, but a profound groove is placed about halfway Shell equivalve, heavy, cordiform, inflated. Umbones down the posterior slope for the reception of the lateral distant, prominent, prosqgyrate. Lunule not clearly of the opposite valve. The ventral cardinal of the left delimited. Surface smooth or concentrically furrowed; valve is stout and subconical, the dorsal very much com inner margins entire. Ligament entirely external, pressed and elongated parallel to the arcuate dorsal sunk in a deep groove. Teeth cyclodont; cardinals two margin; the posterior lateral is the solitary shelly peak, in each valve, erect, lamelliform, .approximately paral approximately midway between the umbones and the lel to the dorsal margin. Posterior lateral of left valve base. The muscle impressions are strongly defined, the received in toothlike socket of right; anterior lateral posterior being much larger than the anterior; the pal- rarely present. Adductor impressions subequal. lial line connecting them is simple and moderately Pallial line entire. distant from the basal margin. This genus of large, heavy, cordate shells originates Distribution: Virginia: Miocene, St. Marys formation, Ur- apparently in the Jurassic. From that time on it has banna on the Rappahannock River, Middlesex County. York- been represented, by a few conspicuous species. The town formation, Sunken Marsh Creek and Schmidts Bluff (8% Eecent species, including the type, are most abundant miles below Claremont Wharf), Surry County. along the European shores. Isocardia fraterna Carolina Dall Isocardia frateVna Say Plate 11, figure 5; plate 23, figure 39 , Plate 11, figure 15 1900. Isocardia Carolina Dall, Wagner Free Inst Sci. Trans., vol. 3, pt. 5, p. 1067, pi. 46, fig. 22. 1824. Isocardia fratema Say, Acad. Nat. Sci. Philadelphia Jour., 1st ser., vol. 4, p. 143, pi. 11, figs, la, Ib. Shell large, solid, rotund, rather thin for its size, with in 1838. Isocardia rustica Conrad (part), Fossils of the medial volute beaks, inflated and inequilateral valves; anterior end Tertiary of the United States, p. 20, pi. 11, fig. 1. short, subangular above, rounding evenly into the base below; 1852. Isocardia conradi D'Orbi|iiy\ Prodrome paleontologie, vol. hinge line forms a segment of a circle; and, except the anterior 3, p. 121. angle, the outline of the valve is nearly suborbicular; near the 1854. Glossus rusticus Sowerb^. Conrad, Acad. Nat. Sci. Phil umbo behind are traces of two radial ridges separated by a adelphia Proc., vol. 7, g. 29. shallow sulcus, but these rapidly become obsolete and the 1863. Bucardia fraterna Say. Cjbnrad, Acad. Nat. Sci. Philadel surface of the valves smooth except fof incremental lines, which phia Proc. for 1862, p. 576. become stronger and more disposed in undulations near the 1900. Isocardia fraterna Say. Pall, Wagner Free Inst. Sci. anterior base in senile specimens; hinge normal, strong—the Trans., vol. 3, pt. 5, p. 1066. lateral smooth and well developed, the left cardinal duplex,' compressed, with a small deep pit for the opposite cardinal Cordate-globose, slightly obliqtie, with rather large concentric below the junction; anterior adductor scar small, impressed; wrinkles, and lines of growth; an elevated undulation on the posterior scar much larger. Longitude 95, altitude 92, anterior submargin, marking the greatest length of the shell; diameter 74 millimeters. umbones not very prominent, ap£x rather suddenly incurved, This species is represented by two left valves in the acute; impressed space behind tlie beaks, dilated and rather National collection, obtained from North Carolina and Vir profound; anterior tooth striated externally and placed on ginia. It forms a marked contrast to /. fraterna in its nearly the middle of the anterior margin. Large specimen, greatest smooth subglobular form and greater size. It may be that to length (taken obliquely) 3% inches, breadth rather less. specimens of this species Conrad referred when in his descrip Small specimen, greatest length rather over 1% inches, tion of 7. rustica (=fraterna) he said that it "attains in breadth nearly 1% inches.—Say, 1824. North Carolina a larger size than the 7. cor with which Deshayes considers it identical." If Deshayes had specimens Type locality: Maryland [ ?]. of this sort his conclusion would not seem so unreasonable as The umbones are anterior, the "impressed space be it does when one compares a good series of 7. fraterna with hind the beaks" is the lunule, and the "anterior tooth" 7. cor (=humana). The present species, though very much is the posterior lateral. less ponderous than 7. fraterna, is thicker than 7. humana and has its hinge less compressed, especially the cardinals, of The shell is heavy, often massive, but rather crum which the profile forms a broad M with a conical pit below bly; the valves vary somewhat in the relative propor it; the lateral is also stronger and proportionately more distant 68 MOLLUSCA FROM MIOCENE AND LOWER PLIOCENE OF VIRGINIA AND NORTH CAROLINA from the cardinals; the posterior adductor scar is larger than posteriorly. Anterior lateral margin produced in front in humana of the same dimensions, while the umbo of /. Carolina of the lunular area, broadly and evenly rounded or is smaller, more pointed, less involute, and is distant 6.5 milli obscurely truncate. Posterior lateral margin also meters from the hinge margin; while, in a specimen of J. humana slightly larger than that of /. Carolina, the umbo of rounded to subtruncate along a line parallel to the the same valve is 18 millimeters from the margin. Correla- vertical axis. Base line straight medially, upcurved tively, the excavation in front of the beaks is considerably laterally. Umbones strongly anterior, flattened on smaller in /. Carolina. The largest senile specimens of /. their summits, involute, and prosogyrate. Posterior humana are higher and less orbicular than the types of carina clearly defined, so sharp dorsally that the um I Carolina, which are evidently senile specimens also. 1 On the whole, in spite of the fact that the material is scanty, bones are distinctly angulated, becoming increasingly there seems to be reason to think that in the Upper Miocene broader, lower, and more rounded ventrally, but per there is a type of Isocardia, leading from the older Miocene sistent to the basal margin; a second-keel developed forms of Maryland in the direction of the /. humana of the behind the carinal ridge but more feeble and usually European fauna.—Dall, 1900. evanescent about halfway down to the base. Valves Holotype: U. S. Nat. Mus. 1657. slightly contracted in front of the posterior keel by a Type locality: Edgecombe County, N. C. broad and very shallow depression. Lunular area The type of Isocardia Carolina Dall is distinct from strongly excavated but not sharply differentiated. 7. fratema Say. The shell of the former is much thin Sculpture restricted to incrementals and, near the basal ner and more evenly inflated; the flattening of the margin, to well defined and crowded resting stages. central umbones is less pronounced, and usually their Ligament opisthodetic; ligamentary groove deeply tips are less strongly incurved; the posterior angulation channeled, undercutting the umbones to their very is merely suggested and does not affect the contour of tips; nymphs heavy. Dentition rude. Two cardinals the shell, whereas in 7. fraterna not only the fold is in each valve; those of the right valve lamelliform, the clearly defined but the depression in front of it is ventral cardinal a little sharper, more compressed usually strong enough to contract the base to a slight laterally, and more anterior than the dorsal cardinal; degree; the hinge is less robust, but the difference is groove between them profound. No true laterals in no greater than normal for a form with a thinner shell. right valve; toothlike socket developed just dorsal to The connecting series is so complete and so convinc the posterior truncation. Cardinals of left valve un ing, however, and the combination of characters so di equal, the dorsal cardinal very much compressed and verse, that the specific rank of 7. Carolina can scarcely elongated parallel to the arcuate hinge margin, the be maintained. None of the supposedly diagnostic ventral cardinal much shorter and less compressed. characters of the form are constant; individuals with Adductor muscle impressions often obscure, the anterior heavy shells—presenting the typical outline of Say's sometimes sunken, rather small, and rudely semiellipti- species—attain a height of 87 millimeters, a length of cal in outline; the posterior larger, more irregular and 113 millimeters, and a semidiameter of 44 millimeters; usually more obscure. Pallial line entire, and usually the outline varies from obliquely-ovate to subrotund to not very distinct. subquadrate; the shell may be thin or massive and, Dimensions of holotype: Height 59 millimeters, concomitant with the thinner shell, are less conspicuous width 73 millimeters, convexity 29 millimeters. incrementals. Holotype: Maryland Geological Survey, Johns Hop- Distribution: Virginia: Miocene, Yorktown formation (?), kins University, Baltimore, Md. Grove Wharf, Surry County (U. S. National Museum) ; Dela Type locality: Jones Wharf on the Patuxent,River, ware Park and Delaware, Southampton County. St. Marys County, Md. Choptank formation. North Carolina: Miocene, Yorktown formation, Murfreesboro, Hertford County. "Edgecombe County." C. Dall. Isocardia fratema glenni is remarkable for its angu lar subquadrate outline, strongly defined posterior Isocardia fraterna glenni Gardner, n. subsp. keel,, antecarinal undulation, and flattened umbones. Plate 16, figures 1, 2 It is not known to occur south of the Nomini Cliffs 1904. Isocardia fraterna Say. Glenn, Maryland Geol. Survey, on the Potomac Eiver. Miocene, p. 317, pi. 85, figs. 3, 4. Superfamily CAEDITACEA 1909. Isocardia. fraterna Say, Grabau and Shimer, North American index fossils, vol. 1, p. 561, fig. 770. Family CAEDITIDAE Specimens from Maryland are smaller and less rounded and Genus CARDITAMEBA Conrad have a more pronounced ridge and a basal angle where the 1838. Carditamera Conrad, Fossils of the medial Tertiary of the dorsal and posterior slopes and margins meet. These differ United States, p. 11. ences seem constant but are not deemed of sufficient importance to justify separating the Maryland forms from those from Type by subsequent designation (Dall, Wagner Free Inst. Virginia.—Glenn, 1904. Sci. Trans., vol. 3, pt. 6, p. 1408, 1903) : Cypricardia arata Conrad. Shell rather thin, crumbly. Valves rudely quadrate Shell equivalve, oblong; cardinal tooth in the right valve in outline; inflated anteriorly, somewhat depressed single, much elongated, compressed and nearly parallel with PART 1. PELECYPODA 69 the basal margin; in the left valve 2, profoundly diverging, the south of Greenville, where it occurs together with the posterior one corresponding with that in the opposite valve; normal C. arata (Conrad) and intergrading indi lateral teeth two, distant, short, pyramidal; muscular im pressions large; pallial impression entire. viduals. The young, which are rather abundant, are The genus is nearly allied to Cypricardia but wants the all normal. In Florida Carditamera arata occurs in three cardinal teeth and the long lateral tooth of that genus; the Cancellaria zone of the Choctawhatchee formation from Cardita it is distinguished by the lateral teeth. The and possibly in the Ecphora zone. projection of the lunule in the right valve gives it the appear ance of having two cardinal teeth. I know of this fossil species Distribution: North Carolina: Miocene, Yorktown formation, only, and a recent one nearly allied to it on the coast of 8 to 9 miles southeast of Greenville, and 9 to 10 miles south Florida.—Conrad, 1838. of Greenville (on the property of Fred Haddock), Pitt County; Rock Landing on the Neuse River, Craven County. Superficially, Carditamera recalls some of the mem bers of Mytilicardita Anton, notably Cardita variegata Carditamera columbiana Gardner, n. sp. Brugui&re. Laterals are lacking in the Recent species, Plate 15, figures 9, 10 whereas in Carditamera the short remote anterior lateral of the left valve is well developed and is re Shell heavy, convex. Umbones broad, high, inflated, ceived within a clasping socket of the right valve, very much less strongly anterior than in C. arata. and a similar socket in the left valve receives the short Kadial sculpture of 15 to 17 costae, their summits but sharp posterior lateral of the right valve. In both rounded, rather conspicuously imbricated, subequal in the clasping sockets the inner margin is elevated and size and spacing, the ribs on the ill-defined posterior acute. Such a departure from the dentition of those area slightly more narrow. Dentition normal for the groups that develop only cardinals is of generic value. genus in number and general arrangement but abnor mally concentrated and equilateral, consequent on the Carditamera arata verdevilla Gardner, n. subsp. outline of the valve. Plate 15, figures 5, 6 Dimensions of holotype: Height 27.5 millimeters, Shell compressed, strongly inequilateral, transversely width 37.0 millimeters. oblong, broadly and feebly contracted medially. Um- Holotype, a right valve: U. S. Nat. Mus. 325510. bones low, flattened on their summits, involute, slightly Type locality: Neills Eddy Landing on the Cape prosogyrate, only about one-fifth of the way back from Fear Kiver, Columbus County, N. C- the anterior margin. Approximately 15 radial costae, There is a strong tendency in the later and more the 4 anterior ones rounded and closely, rather con southern members of this species toward a heavier, spicuously imbricated; the medial costae low, broad, shorter, and much more convex shell, but it is not cer and flat, and even less affected by the incrementals tain whether this is a variation that is due to age or than their subequal interspaces; the 2 costae that radi to latitude. The type of the subspecies from the Wac- ate from the umbones to the posterior ventral margin camaw at Neills Eddy Landing is certainly very dis the most conspicuous on the valve, their summits tinct from the individuals collected abundantly in strongly arched and coarsely imbricated; 2 smaller Virginia, but the gradational series is so complete that primaries and an adventitious secondary behind them. there is no doubt about the true relations of the forms. Hinge and pallial characters normal to the species and Carditamera colwrribiana may well be the precursor subgenus. of C. tamiamiensis Mansfield, described from the early Dimensions of holotype: Height 22.3 millimeters, Pliocene of the Tamiami Trail, 42 miles west of Miami, width 46.0 millimeters. Fla. It is a smaller shell, possibly a little higher rela Holotype, a right valve: U. S. Nat. Mus. 325511. tively, with more elevated umbones and less prominent Type locality: 8 to 9 miles south of Greenville, Pitt radials. County, N. C. Distribution: North Carolina: Pliocene, Waccamaw forma The absence of concentric imbrications on the low, tion, Neills Eddy Landing on the Cape Fear River (3 miles broad, medial costae strongly emphasizes the very north of Cronly), Columbus County. feeble medial depression and, together with the rela tively produced and compressed outline, suggests Car Genus GLANS Megerle von Miihlfeld dita protracta Conrad rather than C. arata. The 1811. Glans Megerle von Muhlfeld, Gesellschaft Naturforschen- medial ribs of the former, however, are characteristi der Freunde zu Berlin, Magazin fur die neuesten cally trigonal and often imbricated, whereas the sum Entdeckungen in der gesammten Naturkunde, year 5, p. 68. mits of the latter are very low, very broad, and very flat, and destitute of sculpture. In the type, the con Type by monotypy: Chama trapezia Linnaeus. Recent in the centric sculpture is abruptly discontinued on the fourth Mediterranean. rib and abruptly reintroduced on the posterior half of Crlans s, s. differs from most of the other carditids the eleventh rib. by the small size, subquadrate outline, and the develop The type of the subspecies was collected a few miles ment of both anterior and posterior laterals. 70 MOLLTJSCA FROM MIOCENE AND LOWER PLIOCENE OF VIRGINIA AND NORTH CAROLINA Subgenus FLEUROMERIS Conrad more evenly rounded. Posterior dorsal margin 1867. Pleuromeris Conrad, Am. Jour. Conchology, vol. 3, p. 12. obliquely truncate, merging inf eriorly into the rounded, lateral margin. Base line straight or slightly arcuate, Type by monotypy: Pleuromeris decemcostata Conrad= upturned distally. Umbones subcentral or somewhat Glans (Pleuromeris) tridentata (Say) var. decemcostata Con rad. Recent off the Florida coast; fossil in the Pliocene and anterior, varying widely in height and degree of prom Pleistocene of the southern Atlantic coast. inence; the apices acute and feebly prosogyrate. Lu- Equivalve, triangular, radiately ribbed; hinge in the right valve nule minute, cordate. Escutcheon minute, lanceolate. with one broad, nearly direct, concave or broadly furrowed Surface sculptured with rather low, gently arched recurved tooth, the upper extremity acute and opposite or above radiating costae, averaging about 15 and separated by the apex of the shell; hinge in the left valve with three teeth, narrower and mostly linear interspaces. Radials over the anterior one small and fitting into a cavity in the opposite ridden by crowded, concentric lirations, most conspicu valve.—Conrad, 1867. ous anteriorly, obsolete in the interradial channels. Also in the left valve is a short anterior lateral that Ligament external, opisthodetic. Dentition of right is received within a double socket in the right valve; valve reduced apparently to a single cardinal, the a very low posterior lateral in the right valve is re anterior cardinal being fused, except in the very young, ceived within a double socket in the left valve. with the anterior margin of the valve and the posterior Pleuromeris is generically distinct from Cardita^ fused with the ligamentary nymph; middle cardinal with which it has been commonly united. The type strong and prominent, triangular,, the apex of the tri designation of Cardita has been the object of much dis angle directly beneath the apices of the umbones; cussion. Possibly the most comprehensive resume is anterior lateral socket short, double; posterior lateral that of Stewart.38 Stewart attributes Cardita to tooth very low and inconspicuous; two cardinals in the Bruguiere, 1792, and considers Cardita sylcata Bru- left valve, of which the anterior is shorter and stouter, gu.ie>re=Chama antiquata Linnaeus, as the type of divergent on each side of the large subumbonal socket. genus. The designation was made by Children, 1823. Anterior left lateral short, posterior lateral socket shal The small size and the development of a lateral denti low. Adductor impressions usually obscure. Pallial tion ally Pleuromeris with Glans rather than with line simple. Inner margins denticulated in harmony Cardita. with the external ribbing. Glans (Pleuromeris) tridentata (Say) Gardner Say's species includes 2 distinct races in the fossil 1826. Venericardia tridentata Say, Acad. Nat. Sci. Philadelphia faunas, and these same distinctions, though somewhat Jour., 1st ser., vol. 5, p. 216. less obvious, persist in the Kecent represenatives: the 1832. Cardita Jridentata Say, American conchology, pi. 40, one a moderately heavy and convex shell with not very figs. 1-5 with explanatory text. conspicuous umbones ancl about 15 rather low costae 1858. Cardita tridentata Say. Holmes, Post-Pleiocene fossils overridden by concentric lirae, which are not strong of South Carolina, p. 31, pi. 6, fig. 8. 1863. Actinobolus tridentata Say. Conrad, Acad. Nat. Sci. Phil enough to nodulate the ribs; the other, a very heavy adelphia Proc. for 1862, p. 578. \ and convex little bivalve with very high and very 1889. Cardita (Venericardia) tridentata Say. Dall, U. S. Nat. prominent umbones and 10 to 13 or 14 vigorous radials Mus. Bull. 37, p. 46. overriden by nodulose concentric lirae. The smaller, 1903. Venericardia (Pleuromeris) tridentata Say (part). Dall, less ornate form prevails north of the Hattaras atis Wagner Free Inst. Sci. Trans., vol. 3, pt. 6, p. 1433. Not Cardita tridentata Reeve, 1843. during the Tertiary and off the Carolina coast in the Recent waters. The larger, more heavily sculptured Shell suborbicular, subequilateral, thick, and ponderous, with about 18 convex longitudinal ribs cancellate by concentric ele race is especially characteristic of the Duplin and Wac- vated lines, which do not penetrate into the interstitial narrow camaw formations, and its somewhat reduced descend spaces, and which are obsolete on the umbo and oh the anterior ants stiir exist along the Florida coast and among the side; inner margin deeply crenate; hinge with 2 diverging Keys. teeth, separated by a large cavity on one valve, and on the other, a single large triangular prominent recurved tooth, closing The young, particularly in the Yorktown, are much into the cavity. less angular than the adults and quite frequently Length a quarter of an inch, breadth rather more. present a regularly transverse oval outline. The con This curious shell was discovered by Mr. Stephen Elliott on centric lirae are usually strongest in the young, though the coast of South Carolina. * * * This species will be re in some of the northern individuals—both young and garded as an interesting addition to the fauna of the present adult—they are almost obsolete. world. The first recent species was described by Lamarck as a native of New Holland. All other known species are found Distribution: Virginia: Miocene, Yorktown formation, York- only in the fossil state.—Say, 1826. town, York County; ^4 mile northeast of Smithfield, Benns Shell rounded, trigonal, subequilateral, moderately Church, % mile from the old church and at Mr. Everet's farm near Benns Church, Isle of Wight County; % mile north convex. Anterior erid a little shorter, as a rule, and of Chuckatuck, 1% miles southeast of Reids Ferry, 5% miles 38 Stewart, R. B., Gabb's California Cretaceous and Tertiary type northwest of Suffolk, 1 mile west of Suffolk, 1% miles northeast Lamellibranclis: Acad. Nat. Sci. Philadelphia, Special Pub. 3, p. 149,1930. of Suffolk, 1 mile northeast of Suffolk, % mile below the Suf- PART 1. PELECTPODA 71 folk waterworks dam and along the drainage ditch east of umbones; interradial channels deep and narrower than Jericho ditch, Nansemond County. the radials. Radials overridden and more or less nodu North Carolina: Miocene, Yorktown formation, Palmyra lated, particularly on the anterior half of the shell, by Bluff, Halifax County; 4 miles northwest of Williamston, Mar tin County; 6% miles below New Bridge, 1 mile below Bells the vigorous, concentric lirae which, however, do not Bridge on the Tar River, Edgecombe County; 2 miles southeast penetrate the interradial channels. Dentition normal of Tugwell, 1% miles northeast of Farmville, 3 miles south of in number for the species, but much more robust, es Farmville, 2% miles north of Standard, 3 miles west of Green pecially the subumbonal cardinal of the right valve. ville, 8 to 9 miles south of Greenville, 9 to 10 miles south of Muscle impressions submedial or a little below the Greenville, 3 miles north of Grifton, and 2 miles east of Grifton, Pitt County; 2^ miles northwest of Chocowinity, Beaufort median horizontal and rather small—the anterior reni- County; 1 mile west of Wilson (in Hominy Swamp, on the form, the posterior roughly rotund or elliptical. Pal- farm of Frank Barnes), Wilson County; 1 mile north of Cas- lial line simple, rather distant. Inner margins strongly toria, and 1 mile east of Lizzie (on the farm of T. N. Lassiter), fluted by the external costae. Greene County; Tar Ferry on Wiccacon Creek (opposite Har- This stout, ornately sculptured form of Pleuromeris rellsville) and l1/^ miles below Tar Ferry, Hertford County; Colerain Landing and y2 to % mile above Edenhouse Point, tridentata Say apparently reaches its maximum size Bertie County; Rock Landing on the Neuse River, Craven and vigor of sculpture during the Waccamaw. The County. Duplin Marl, Natural Well, 1% miles north of Mag same features, however, that have led to its subspecific nolia, and W. H. Kornegay's marl pit near Magnolia, Duplin isolation from the type prevalent north of the Hatteras County. Pliocene, Waccamaw formation, Lake Waccamaw, axis still persist, though to a lesser degree, and charac Cronly (half a mile east of the factories), and Neills Eddy Landing (3 miles north of Cronly), Columbus County. terize the representatives of the species that inhabit the Outside distribution: Miocene, Duplin marl, Porters Landing Florida shores and Keys. on the Savannah River, Efflngham County, Ga. Pliocene, Wac In Florida in the Choctawhatchee, Glans (Pleuro camaw formation, Nixons and Tillys Lake, Horry County, S. meris) tridentata dec&mcostata is common in both C. Caloosahatchee marl, De Leon Springs, Volusia County, EcpJwra and Cancellaria zones. Fla.; Kissimmee well (at a depth of 150 feet), Osceola County, Fla.; Caloosahatchee River, Fla. Croatan sand, Slocums Creek Distribution: North Carolina: Miocene, Yorktown formation, and Mallisons, Craven County, N. C. Pleistocene, Dismal 3 miles southwest of Frog Level, Pitt County. Duplin marl, Swamp canal, posts 15 to 16, Virginia; Simmons Bluff and 2% miles south of Clinton, Sampson County; Natural Well, Wadmalaw, S. C.; Kissimmee well (at a depth of 96 feet), 1% miles north of Magnolia and the marl pits of Frank Osceola County, Fla.; Eau Gallie, Brevard County, Fla.; La- Wilson and W. H. Kbrnegay, Duplin County; 4 miles north of belle, Hendry County, Fla. Recent off Hatteras in both shallow Lumberton (on the Berry Godwin plantation), 1 mile west of and deep water; off the Florida coast in shallow water only. Lumberton (on the property of Charles Rowland), Lumberton (near the bottling works), 2 miles below Lumberton, 4 to 5 Glans (Pleuromeris) tridentata decemcostata (Conrad) Gardner miles below Lumberton, 1^ miles northeast of Fairmont, and at Fairmont (Ashpole), Robeson County; 4 miles south of Plate 13, figures 1-4 Clarkton, Bladen County. Pliocene, Waccamaw formation, 50 miles above Wilmington and at Walkers Bluff, on the Cape 1845. Cardita tridentata Say (part). Conrad, Fossils of the Fear River, Bladen Cdunty; Lake Waccamaw and Neills Eddy medial Tertiary of the United States, p. 76, pi. 43, Landing (3 miles riorth of Cronly on the Cape Fear River), fig. 11. Columbus County; Wilmington (on Smiths Creek and at the 1856. Cardita tridentata Say. Tuomey and Holmes, Pleiocene city rock quarry), New Hanover County. fossils of South Carolina, p. 67, pi. 19, figs. 9, 10. Outside distribution: Miocene, Duplin marl, Sumter district, 1858. Cardita abbreviata Emmons, North Carolina Geol. Survey Sumter County, S. C. Choctawhatchee formation, northern Rept, p. 302, fig. 236. Not C. abbreviata Conrad, 1841. Florida. Pliocene, Waccamaw formation, Nixons and Tillys 1867. Pleuromeris decemcostata Conrad, Am. Jour. Conchology, Lake, Horry County, S. C. Caloosahatchee marl, Caloosa vol. 3, p. 12. hatchee River, Fla. Recent off the coast of Florida in shallow 1903. Venericardia (Pleuromeris) tridentata Say (part). Dall, water. Wagner Free Inst. Sci. Trans., vol. 3, pt. 6, p. 1433. 1932. Venericardia (Pleuromeris) tridentata decemcostata Con Subgemis? PTEROMERIS Conrad, 1862 rad. Mansfield, Florida Geol. Survey. Bull. 8, p. 89, pi. 16, figs. 3, 4. 1862. Pteromeris Conrad, Acad. Nat. S«i. Philadelphia Proc. for 1862, vol. 14, p. 290. Triangular; ribs 12, rounded, ornamented by numerous angu Type by original designation: Cardita perplana Conrad. lar or transverse tubercles over all the ribs.—Conrad, 1867. Triangular, not oblique, with radiating ribs; beaks medial: Shell very heavy, convex, trigonal, subequilateral. hinge of left valve, anterior tooth direct or directed slightly Anterior end rather evenly rounded. Posterior end toward the anterior margin; posterior tooth double or bifid.— obliquely truncate dorsally, rounded laterally. Base Conrad, 1862. line straight. Umbones high, heavy, prominent, and Only faint traces of a lateral dentition can be ob erect except at the apices, which are slightly prosogy- served in this small group. It does not seem sufficiently rate. Lunule minute, stoutly cordate. Escutcheon important to be given generic rank, but it differs so minute, lanceolate. Surface strongly corrugated, with markedly in form and dentition from Glans, probably about 13 elevated costae radiating fanlike from the its closest ally, that I hesitate to unite them generically. 72 MOLLUSCA FROM MIOCENE AND LOWER PLIOCENE OF VIRGINIA AND NORTH CAROLINA Glans (Pteromeris) perplana (Conrad) Gardner scarcely thicker than the outer shell covering. In the Plate 13, figures 6-9 Kecent species, the radials rarely number fewer than 12 or more than 14, whereas in the Miocene they may 1841. Cardita perplana Conrad, Am. Jour. Sci., 1st ser. vol. 41, number as few as 10 and, if the subspecies abbreviata p. 347, pi. 2, fig. 16. be included, up to 18 or 20. In the Waccamaw, the 1845. Astarte radians Conrad, Fossils of the medial Tertiary of the United States, p. 77, pi. 43, fig. 13. species attains its maximum size and compression. The 1846. Astarte fiabella Conrad, Acad. Nat. Sci. Philadelphia Proc., dimensions of a valve from Walkers Bluff are as fol vol. 3, p. 24, pi. 1, fig. 3. lows: Height 10.3 millimeters, width 9.6 millimeters, 1856. Cardita perplana Conrad. Tuomey and Holmes, Pleiocene convexity 1.6 millimeters, thickness of shell itself 1.0 fossils of South Carolina, p. 68, pi. 19, fig. 11. millimeter. Individuals pursuing this line of develop 1858. Cardita perplana Conrad. Emmons, North Carolina Geol. Survey Kept., p. 302, fig. 235. ment are further characterized, as a rule, by a more 1863. Actinobolus (Pteromeris) radians Conrad, Acad. Nat. distant and angular radial sculpture and by a broader, Sci. Philadelphia Proc. for 1862, p. 578. less elevated hinge dentition. 1885. Venericardia oblique, Bush, Connecticut Acad. Trans., vol. Bistribution: Virginia: Miocene, Yorktown formation, York- 6, p. 478. town, York County; 5% miles northwest of Suffolk, 1 mile west 1903. Venericardia (Pteromeris) perplana Conrad. Ball, Acad. of Suffolk, 1 mile northeast of Suffolk, and at Suffolk (^ mile Nat. Sci. Philadelphia Proc. for 1902, p. 705. below the waterworks dam), Nansemond County. 1903. Venericardia (Pteromeris) perplana Conrad. Ball, Wag North Carolina: Miocene, Yorktown formation, 1% miles ner Free Inst. Sci. Trans., vol. 3, pt. 6, p. 1434. northeast of Farmville, 8 to 9 miles southeast of Greenville, Trigonal, nearly flat; ribs about 11, angular, minutely and 9 to 10 miles south of Greenville, Pitt County; 3 to 4 granulated.—Conrad, 1841. miles below Tar Ferry, Hertford County; Colerain Landing on the Chowan River, Bertie County; Rock Landing on the Neuse Type locality: Natural Well, Duplin County, N. C. River, Craven County. Buplin marl, 10 miles south of Clinton, Shell small, trigonal-ovate, compressed to apparent Sampson County; Natural Well, 1% miles north of Magnolia, flatness. Lunule and escutcheon sublinear-lanceolate, and W. H. Kornegay's marL pit near Magnolia, Buplin County; the latter only a little longer and narrower than the Lumberton and 2 miles below Lumberton,»Robeson County. Pliocene, Waccamaw formation, Walkers Bluff on the Cape former. Umbones high, compressed, with acute and Fear River, Bladen County; Lake Waccamaw, Cronly, and feebly prosogyrate apices, placed about one-third the Neills Eddy Landing on the Cape Fear (3 miles north of length in front of the posterior margin; apical angle Cronly), Columbus County; city rock quarry near Wilmington, running between 70° and 85°. Anterior end obliquely New Hanover County. produced. Dorsal margins slightly concave in lunular Outside distribution: Miocene, Buplin marl, Porters Landing, Effingham County, Ga. Pliocene, Waccamaw formation, Nixons region. Lateral margin evenly rounded. Posterior and Tillys Lake, Horry County, S. C. Caloosahatchee marl, dorsal slope much more steep than anterior, merging Caloosahatchee River and Shell Creek, Fla. Croatan sand, rather abruptly into the base. Ventral margin hori Slocums Creek, Craven County, N. C. Pleistocene, Kissimmee zontal medially, strongly upcurved distally. Surface well (at a depth of 96 feet), Osceola County. Recent, Hatteras corrugated with 10 to 15 or 16 rather low, broadly to Charlotte Harbor in 14 to 52 fathoms. arched, radial costae, separated mostly by linear inter- Glans (Pteromeris) perplana abbreviata (Conrad) Gardner radials; radials overridden by microscopic undulatory growth lines. Ligament external, opisthodetic; nymph Plate 13, figures 19-22 relatively broad, bounded dorsally by a deep groove. 1841. Cardita abbreviata Conrad, Am. Jour. Sci., 1st ser., vol. Hinge dentition vigorous; in the right valve, a feeble 41, p. 347, pi. 2, fig. 17. laminar anterior cardinal and a very stout, triangular, 1845. Astarte abbreviata Conrad, Fossils of the medial Tertiary medially sulcate, middle cardinal; posterior right cardi of the United States, p. 77, pi. 43, fig. 12. 1856. Cardita abbreviata Conrad. Tuomey and Holmes, Pleio- nal fused with ligament nymph; in the left valve, two . cene fossils of South Carolina, p. 69, pi. 19, fig. 12. bifid cardinals—the anterior shorter and more com 1863. Actinobolus (Pteromeris) abbreviata Conrad, Acad. Nat. pressed—separated by the deep subumbonal socket; Sci. Philadelphia Proc. for 1862, p. 578. anterior lateral margin of right valve and posterior 1903. Venericardia (Pteromeris) perplana var. abbreviata Con margin of left feebly grooved to receive the more or rad. Ball, Wagner Free Inst. Sci. Trans., vol. 3, pt. 6, p. 1435. less beveled edges of the opposite valve. Adductor 1932. Venericardia (Pleuromeris) perplana var. abbreviata muscle impressions usually distinct, the posterior semi- (Conrad). Mansfield, Florida Geol. Survey Bull. 8, p. elliptical and slightly higher than the reniform ante 88, pi. 16, fig. 5. rior scar. Pallial line entire, distant. Inner margin Trigonal, elevated, convex-depressed, ribs about 11, convex, crenulated in harmony with the external ribbing. minutely granulated; posterior extremity angulated. This and Pteromeris perplana Conrad is notably unstable dur the preceding species [Cardita perplana} belong to the genus ing the Late Tertiary. The species varies in convexity Venericardia of Lam.—Conrad, 1841. and outline from relatively high and less compressed Type locality: Wilmington, N. C. forms, which are isolated under the subspecies abbre Venericardia perplana abbreviata Conrad is a little , to broader individuals in which the cavity is less compressed than perplana s. s., is higher, and never PART 1. PELECYPODA 73 attains the size of the latter. The radials vary in num Genus ERYCINELLA Conrad ber from 10 to 20, and their prominence is inversely 1845. Erycinella, Conrad, Fossils of the medial Tertiary of the proportional to their. number. Concomitant with the United States, p. 74. variation in outline is also a variation in the character of the hinge—particularly toward a narrow liga- Type by monotypy: Erycinella, ovalis Conrad. mentary nymph—and a greater inequality of the two This genus is nearly allied to Erycina of Lamarck but has left cardinals. four teeth in the left valve. In the opposite valve the two teeth diverge, are rather long, and curving slightly inward, and Both the subspecies and the species originated ap the posterior one inclining to be double.—Conrad, 1S45. parently in the Yorktown formation. North of the Shell small, oval, radially sculptured, with an external liga Hatter as axis abbreviata is distinctly the prevailing ment and internal resilium situated between the cardinals, of type; south of it perplana s. s. is equally prominent in which there are 2 in each valve; in the left valve the edges the Duplin and Waccamaw and, after the close of the of the resiliary chondrophore are somewhat raised, so that when worn the valve appears to contain four cardinals, but I Pliocene, quite excludes th'e relatively higher and more think these ridges are not of the nature of true teeth; in the inflated form. In Florida abbreviata is common in the right valve the posterior cardinal is stout and triangular Ecphora zone of the Choctawhatchee formation and and feebly grooved; there is a feeble, elongate, posterior right rare in the Cancellaria zone above it. , and anterior left lateral, which fits into a groove in the margin of the opposite valve; the inner margins of the valves are Distribution: Virginia: Miocene, Yorktown formation, York- crenulated.—Dall,40 1903. town, York County; Benns Church, ^4 mile from the old church This genus includes a few Tertiary and Recent and Everet's farm near Benns Church, Isle of Wight County; species from the cooler waters. 14 mile north of Chuckatuck, 1% miles southeast of Reids Ferry, 5% miles northwest of Suffolk, 1 mile west of Suffolk, In addition to the 2 well-developed cardinals in the 1 mile northeast of Suffolk, Suffolk, and 1% miles below the right valve, there is a third—a laminar, somewhat rudi Suffolk waterworks dam, Nansemond County. mentary anterior cardinal. It is the middle and not North Carolina: Miocene, Yorktown formation, 3 to 4 miles the posterior cardinal that is stout and trigor.al. below Tar Ferry, Hertford County; 3 miles south of Farmville, 8 to 9 miles south of Greenville, 9 to 10 miles south of Green Erycinella ovalis Conrad ville, 2 miles east of Grifton (on J. F. Brooks' farm), Pitt County; 2 miles southwest of Maple Cypress, Bock Landing, Plate 14, figure 46 Craven County; 1 mile west of Wilson (on Frank Barnes prop erty in Hominy Swamp), Wilson County; 1 mile north of 1845. Erycinella, ovalis Conrad, Fossils of the medial Tertiary Castoria, Greene County. Duplin marl, Natural Well, 1% of the United States, p. 74, pi. 42, fig. 5.' miles north of Magnolia, and W. H. Kornegay's marl pit near 1857. Erycina ovalis (Conrad). D'Orbigny, Prodrome pale"on- Magnolia, Duplin County; 1 mile west of Lumberton (on the tologie, vol. 3, p. 115. property of Charles Rowland), Lumberton (near the bottling 1863. Erycinella ovalis Conrad, Acad. Nat. Sci. Philadelphia works), 2 miles below Lumberton, and 1% miles northeast of Proc. for 1862, p. 578. Fairmont (on the property of Andrew Jones), Robeson County. 1864. Erycmella ovalis Conrad. Acad. Nat. Sci. Philadelphia Pliocene, Waccamaw formation, Walkers Bluff on the Cape Fear Proc. for 1864, p. 212. River, Bladen County; Lake Waccamaw and Neills Eddy Land 1903. Erycinella ovalis Conrad. Dall, Wagner Free Inst. Sci. ing, on the Cape Fear River (3 miles north of Cronly), Trans., vol. 3, pt. 6, p. 1438, pi. 53, fig. 2. Columbus County; and city rock quarry near Wilmington, New Not Erycinella ovalis S. V. Wood, 1853. Hanover County. Very small, obliquely ovtel from beak to base, convex, with Outside distribution: Miocene, Hawthorn formation, Porters indistinct radiating lines; posterior side shorter than the Landing, Effingham County, Ga. Duplin marl, Darlington, Dar anterior; basal margin obliquely rounded; cardinal tet'th robust; lington County, S. C. Choctawhatchee formation, northern inner margin crenulated. Locality, Yorktown, Va.—Conrad, Florida. Pliocene, Waccamaw formation, Nixons and Tillys 1845. Lake, Horry County, S. C. Caloosahatchee marl, Shell Creek, Fla. Croatan sand, Slocums Creek, Craven County, N. C. Shell minute, moderately convex, but heavy and rude, oval, slightly oblique, and inequilateral. Anterior Family CONDYLOCARDIIDAE Bernard margin descending at a very steep angle from the um- This family was instituted by Bernard for some extremely bones almost to the base^, with which it unites in a minute bivalves, related to the Carditidae but which retain broad, even curve. Posterior dorsal margin a trifle in the adult state the immaturity of hinge characters which convex and produced. Lateral margin squarely or characterizes the nepionic shells of Ca!r 88 Dall, W. H., Wagner Free Inst. Sci. Trans., vol. 3, pt. 6, p. 1436, 40 Dall, W. H., Wagner Free Inst./Sci. Trans., vol, 3, pt. 6, p. 1436, 1903. 1903. 74 MOLLUSCA FROM MIOCENE AND LOWER PLIOCENE OF VIRGINIA AND NORTH CAROLINA relatively broad radials that are least feeble near the cated on its ventral margin; posterior cardinal either ventral margin and are, as a rule, quite obsolete in the rudimentary or broken, probably the former, as the umbonal region; 3 or 4 resting stages usually discern two valves were found united; anterior cardinal of ible under magnification. Ligament both external and left valve also laminar and elongated but less than that internal; external ligament mounted on minute linear of the right; medial cardinal moderately heavy, simple; nymphs, which run parallel to the posterior dorsal posterior cardinal placed near the medial, very short margin; internal ligament lodged in a subumbonal re- and quite slender. Muscle scars obscure, the anterior silial pit between the cardinals. Hinge of right valve pyriform and placed a little below the median hori armed with 3 cardinals—the anterior cardinal rudi zontal, the posterior elliptical, subniedial in position. mentary and laminar; the middle rude but robust, Pallial line indistinct, entire. Inner margins simple. roughly trigonal, simple, or feebly sulcate; the posterior Dimensions of figured specimen: Height 1.7 milli simple, oblique, and compressed. Left cardinals 2 in meters, width 1.8 millimeter; diameter 1.0 ± millimeter-. number—the anterior cardinal oblique, compressed, Figured specimen: U. S. Nat. Mus. 325557. sometimes longitudinally sulcate; the posterior some Even the more distant affinities of this minute bi what shorter and more compressed than the anterior; valve are exceedingly doubtful. The diagnostic char distal edges of resilial pit raised, thus simulating cardi acters are the posterior position of the obtuse umbones; nals, particularly in the more weathered individuals. the smooth external surface; the internal resilium JMuscle impressions small, slightly below the median placed behind the cardinals and not between them; the horizontal—the anterior somewhat reniform, the pos peculiar, short, slender, posterior cardinal of the left terior oval-elongate. Inner margins feebly crenulated. valve; and the absence of any pallial sinus. ErycineTla, ovalik Conrad is the only representative The form is persistently suggestive of ErycineTla of this minute but well-characterized genus in the east Conrad in spite of quite radical differences, and for coast Miocene. Though not confined exclusively to that reason it has been placed tentatively with the the Yorktown formation of Virginia, it is abundant only latter near the Condylocardiidae of Bernard. It differs along the York River and in the environs of Suffolk. from other members of the family by the establishment of the resilium behind the cardinals instead of between Distribution: Virginia: Miocene, Yorktown formation, York- them; by the presence of 3 left cardinals instead of 2; town, York County; Benns Church, 1,4 mile from the old church and Mr. Everet's farm near Benns Church, Isle of Wight and by the absence of any suggestion of radial sculpture County; 14 mile north of Chuckatuck, 1% miles southeast of either externally or on the inner ventral margins. The Reids Ferry, 1 mile west of Suffolk, 1 mile northeast of Suf absence of a lunule or escutcheon, the blunt posterior folk, half a mile below the Suffolk waterworks dam, and along umbones, and the entire pallial line suggests, however, the drainage ditch just east of the Jericho ditch, Nansemond a comparatively primitive form. The absence of later County. als and the discrepant cardinals exclude it from the North Carolina: Miocene, Yorktown formation, Greenville (just east of the county bridge) and 9 to 10 miles south of Cyrenacea. It has therefore been placed among the Greenville, Pitt County (very rare) ; Tar Ferry on Wiccacon primitive Carditacea, although its position is by no Creek (opposite Harrellsville), Hertford County; Colerain means assured. Landing, Bertie County. Distribution: Virginia: Miocene, Yorktown formation, Suffolk, Nansemond County. Pelecypoda (incertae sedis) Superfamily LUCINACEA Plate 14, figures 33-36 Family LUCINIDAE Shell minute but solid. Valves evenly inflated, ob liquely ovate in outline. Umbones low and very obtuse, A comprehensive and valuable study of the relation placed within the posterior third of the shell. Lunule ships of the lucinoids has been made by Chavan,41 who and escutcheon not differentiated. Posterior end quite illustrates the genera and offers a chronological table evenly rounded from the umbones to the ventral mar of the evolution of the Lucinas. gin. Anterior end obliquely produced, but rounding Genus CTENA Morch evenly into the base. Ventral margin less strongly upcurved before than behind. Outer surface with a 1861. Ctena Morch, Malakozoologische Blatter, vol. 7, p. 201. dull luster, devoid of sculpture. Hinge moderately 1869. Jagonia Recluz, Soc. linneenne Bordeaux Actes, vol. 27 (ser. 3, vol. 7), p. 37. heavy for the size of the shell. Ligament external, lodged in a short, shallow, marginal groove behind the Type by subsequent designation (Dall, Bartsch, and Rehder,. B. P. Bishop Museum Bull. 153, p. 128, 1938) : Oodakia pectinata umbones. Resilium internal, lodged in a small resilial Carpenter (not Gmelin)=Cf. mesdcana Dall. Lower California pit behind the cardinals, separated from the ligament to Panama and Ecuador. by a shelly buttress. Cardinals three in number in each valve; anterior cardinal of right valve elongated, °- Chavan, A., Bssai critique de classification des Lucines: Jour, con- chyliologie, vol. 81, pp.. 133-153, 198-216, 237-282, 1937; vol. 82, pp. laminar; middle cardinal heavy, trigonal, feebly sul- 59-97, 105-130, 215-241, 1938. PART 1. PELECYPODA 75 Shell of medium size, suborbicular to transversely oval, North Carolina: Miocene, Duplin marl, Natural Well and 1% moderately compressed. Beaks small, pointed, median miles north of Magnolia, Duplin County. Outside distribution: Miocene, Duplin marl, Darlington, Darl or slightly posterior. Lunule narrow, lanceolate, de ington County, S. C. Pliocene, Caloosahatchee marl, Caloosa- pressed. Ligament covered with a calcareous coating hatchee River and Shell Creek, Fla. Pleistocene, Labelle, Hendry and typically inset with the resilium. Two cardinals County, Fla. (Vaughan). and anterior and posterior laterals in each valve. An terior muscle scar elongated, the posterior rudely quad Ctena magnoliana (Dall) Gardner rate. Pallial line simple. Outer surface radially 1903. Codakia (Jagonia) magnoliana, Dall, Wagner Free Inst. corded and concentrically threaded. Inner margin Sci. Trans., vol. 3, pt. 6, p. 1349, pi. 52, fig. 17. smooth or feebly crenate. 1932. Codakia (Jagonia) magnoliana Dall. Mansfield, Florida The group, formerly referred to Codakia (Jagonia}, Geol. Survey Bull. 8, p. 93, pi. 20, fig. 1. is separated from Codakia Scopoli by its more promi Shell small, thin, inequilateral, the beaks five-elevenths of the nent, more posterior umbones, larger lunule, relatively whole length in front of the posterior end; both ends rounded, base arcuate, lunule narrow, lanceolate, no distinct dorsal areas; stronger radial sculpture, and its heavier posterior sculpture of numerous, even, fine, close-set, rarely divaricate, laterals. similar, radial riblets, crossed by fine, rounded, equal, close-set Both the Tertiary and the Recent species of Ctena threads, narrower than the riblets, and which in crossing the are restricted in number of both species and individuals latter are slightly arcuate convexly towards the beaks, making but have a fairly wide distribution in the tropical and a very elegant though minute type of sculpture; hinge thin and delicate, but the teeth, especially the right laterals, very distinct; > temperate faunas. scars normal; margins delicately crenulate. Height 9.5, length 11.5, diameter 4.5 millimeters. Ctena speciosa (Rogers and Rogers) Gardner This species is of the fully differentiated Jagonia type, and its Plate 13, figure 33 sculpture is notably elegant.—Dall, 1903. 1837. Lucina speciosa Rogers and Rogers, Am. Philos. Soc. Trans., Holotype, a right valve: U. S. Nat. Mus. 115113. new ser., vol. 5, p. 333, pi. 26, fig. 6. Type locality: Magnolia, Duplin County, N. C. 1840. Lucina squamosa Conrad, Fossils of the medial Tertiary Duplin marl. of the United States, p. 38, pi. 20, fig. 1. Not L. squamosa The distribution of Ctena magnoliana in Florida is Lamarck, 1818. restricted to the Cancellaria zone of the Choctawhatchee 1856. Lucina squamosa Lamarck. Tuomey and Holmes, Pleio- cene fossils of South Carolina, p. 57, pi. 18, figs. 6, 7. formation. 1858. Lucina squamosa Lamarck. Emmons, North Carolina Geol. Distribution: North Carolina: Miocene, Duplin marl. Natural Survey Rept, p. 291 (name only). well and 1% miles north of Magnolia, Duplin County. Rare. 1863. Codakia speciosa Rogers. Conrad, Acad. Nat. Sci. Phila delphia Proc. for 1862, p. 577. Ctena microimbricata Gardner n. sp. 1803. Codakia (Jagonia) speciosa "Rogers. Dall, Wagner Free Inst. Sci. Trans., vol. 3, pt. 6, p. 1350. Plate 13, figures 31, 32 Shell subelliptical, inequilateral, inflated, rather thin, with Shell small, thin, moderately inflated, transversely equal, close-set, rather elevated, longitudinal ribs and regular, ovate, inequilateral. Umbones rather tumid, only a lit very close, concentric striae; lunule small, very distinct, and tle more than one-third the total length in front of the ovate-lanceolate; beaks small, pointed, and slightly prominent posterior margin, their apices flattened and proximate. beyond the general curve of the margin, placed about one-third the transverse length of the shell from the anterior end; cardinal Lunule elongate-lanceolate, smooth,- depressed, but teeth small, diverging; lateral teeth equal, distinct, and nearly not bounded by an incised line. Escutcheon absent. equidistant from the anterior cardinal; hinge margin regularly Anterior end more produced than the posterior; semi- arcuated; the rest of the margin, especially the posterior side, elliptical. Posterior dorsal margin more oblique than crenate within; posterior muscular impression elongated and the anterior dorsal, merging gradually into the rounded slightly curved. Diameter three-tenths, length eleven-twenti lateral margin. Base line arcuate. Entire external eths, height nine-twentieths of an inch. This very beautiful shell occurs in nearly all the localities of surface covered with closely appressed concentric im the Miocene in the James River region.—W. B. and H. D. Rogers, brications, overlapping dorsally, and evenly and mi 1837. nutely crenulated by the fine, crowded radials. Liga A right valve (U. S. Nat. Mus. 145067) from the ment inset, opisthodetic, mounted on a narrow, obliquely Yorktown formation at Bellefield, Va., is figured. It elongated nymph. Anterior cardinal of right valve measures 14.1 millimeters in height and 16.4 millimeters short and thin; right posterior cardinal subumbonal, in width. moderately compressed, feebly sulcated. Anterior and The Rogerses' species is larger than Ctena magnoU- posterior laterals sharp, distant, triangular, and prom ana (Dall), is decidedly convex, and the sculpture, inent though slender. Muscle impressions obscure. Pal though of the same general type, is much coarser. lial line entire. Marginal crenulations delicate. Dimensions of holotype: Height 9.8 millimeters, Distribution: Virginia: Miocene, Yorktown formation, York- town on the York River, York County: "James River region" width 11.2 millimeters, convexity 2.8 millimeters. (W. B. and H. D. Rogers). Holotype, a right valve: U. S. Nat. Mus. 325540. 76 MOLLUSCA FROM MIOCENE AND LOWER PLIOCENE OF VIRGINIA AND NORTH CAROLINA Type locality: Natural Well, Duplin County, N. C. Subgenus CARDIOLTICINA Sacco Duplin marl. 1901. Cardiolucina Sacco, I Molluschi dei Terreni Terziarii del Otena rmcroimbricata^ n. sp., constitutes the end mem Piemonte e della Liguria, pt. 29, p. 89. ber of a very interesting series, which includes C. speci- osa (Rogers and Kogers) and C. magnoliana (Dall), Type by original designation: Cardium agassizii Michelotti. Middle and upper Miocene of northern Italy. and in which the sculpture, though of the same general type throughout, becomes increasingly fine and more C' ardiolucina, as Woodring indicated in 1925, includes delicate. The Duplin forms never-equal the Rogerses' many of the common east coast Miocene and Pliocene species in size or degree of convexity. The radials in lucinoids formerly referred to Cavilucina. They are all three of the species are approximately uniform in characterized by small, commonly inflated valves, strength over the entire external surface and are fre broadly rounded and produced anterior margins, a short, quently bifurcating. In valves of the same size, the deep, lunular depression, inconspicuously differentiated radials of C. speciosa number 2% to the millimeter, dorsal areas, a strong concentric sculpture, with or those of C. magnoliana 3, and those of 0. microimbricata without a feeble radial component, a well-developed car 4. The concentric elevations run about 6 to the milli dinal and lateral dentition, and a finely crenate inner meter in C. speciosa, 9 in C. magnoliana, and 13 in C. margin. , * Tmcroimbricata. A corresponding increase in regular Chavan,42 1937, considered Cardiolucina a synonym of ity and in closeness of the appression to the surface is Bellucina Dall, 1901. evident. In the new species the detail of the sculpture In order to place some of the species from the Ameri is microscopically fine. Concomitant with the thinner can Tertiary, he erected the genus Cavilinga and desig shell is the thinner and more delicate hinge and the nated as the type Lucina trisulcata Conrad of the upper finer marginal crenulation. The hiatus between C. spec Miocene and Pliocene faunas of the southeastern United iosa and C. magnoliana is very much less obvious than States. He included under Cavilinga not only the group that between C. magnoliana and C. microimbricata. of Upper Tertiary forms commonly referred to Cardio- The species is described from a single right valve. lucina but also a number *)f middle and upper Eocene species, such as L. pomilia Conrad and L. alveata Con Distribution: North Carolina: Miocene, Duplin marl, Natural Well, Duplin County. rad. There are no examples of Sacco's subgenotype in the collections of the U. S. National Museum, and the Genus PHACOIDES Blainville acceptance of Chavan's subgenus is delayed in the hope of later consulting material upon which Sacco bas;ed 1825. Phacoides Blainville, Manue.1 de malacologie et de conchyli- ologie, vol. 1, p. 550. his Cardiolucina. Woodring observed that Cardiolucina is one of many Type by monotypy: Lucina jamaicensiq Lamarck=Tellina pec- Middle and Upper Tertiary groups persistent in the tinata Gmelin. Recent in the West Indies. Recent West Indian faunas but not recorded from Euro Shell more or less lenticular; compressed, as a rule, or pean seas. only slightly tumid. Umbones low, subcentral, erect or prosogyrate. Lunule commonly profound. Escutcheon Phacoides (Cardiolucina) trisulcatus multistriatus (Conrad) obsolete. Anterior and posterior dorsal* areas usually Plate 13, figures 25, 26 differentiated. Sculpture dominantly concentric. Lig ament external, in many specimens deeply sunken; nor 1843. Lucina multistriata Conrad, Acad. Nat. Sci. Philadelphia Proc., vol. 1, p. 307. mal dentition of right valve consisting of a simple an 1863. Codakia multistriata Conrad (part), Acad. Nat. Sci. Phila terior cardinal, a bifid posterior cardinal, and heavy delphia Proc. for 1862, p. 577. anterior and posterior laterals; normal dentition of 1903. Phacoides (Cavilncina) trisulcatus var. multistriatus Con left valve consisting of a bifid anterior cardinal, a sim rad. Dall, Wagner Free Inst. Sci. Trans., vol. 3, pt. 6, ple posterior cardinal, and heavy anterior and posterior p. 1370. 1932. Phaooides (Cwrdiolkicina,) trisulcatus multistriatus (Con lateral sockets; laterals in many specimens, and cardi rad). Mansfield, Florida Geol. Survey Bull. 8, p. 96, nals in some, obsolete. Muscle impressions strongly pi. 20, figs. 15, 16. marked, the posterior oval, the anterior narrow, elon Oval, equilateral, slightly ventricose, with fine, prominent, gated, parallel to the pallial line. Pallial line entire. closely arranged, concentric, and minute radiating lines; disk Inner margins smooth or crenulated. with 2 or more distinct undulations on the inferior half; beaks The genus is abundantly represented in the Tertiary, prominent; dorsal margins profoundly declining; anteripr lateral and related forms are present in the Mesozoic and tooth distinct, remote; inner margin minutely crenulated; lunule elliptical, slightly impressed. Height, one-third of an inch. possibly in faunas even more ancient. The living species Locality, Wilmington, N. C.—Conrad, 1843. number more than 100, and, though most prolific in the tropics, they are present in the temperate seas as 42 Chavan, A., Essai critique de classification des Lucines (Suite), Jour, well. conchyliologie, vol. 81, p. 205, 1937. 1. PELECYPODA 77 The figured left valve (U. S. Nat. Mus. 325538), meas Outside distribution: Miocene, ChoctawhatChee formation, ures 5.8 millimeters in height and 6,3 millimeters in northern Florida. width. It is from the Waccamaw formation in the city Phacoides (Cardiolucina) postalveatus Gardner, n. sp. rock quarry at Wilmington, N. C. Plate 13, figure 17 Shell small, rudely circular or ellipsoidal, moderately Shell small, heavy, subglobose., Umbones central with gibbose. Lunule very small but very deepty excavated. prosogyrate apices, high enough to break the even curve Escutcheon absent. Umbones usually a little behind the of the valvular margins. Lunule subrotund; depressed median line, acute, prosogyrate, thrown into prominence but not excavated. Surface concentrically sculptured by the profound lunular pit in front of them. Anterior with broad, heavy, tabulated elevations, which are more end produced, very broadly rounded or obscurely trun or less fused in the adult. Ligament opisthodetic, elon cated laterally. Posterior end shorter. Posterior dorsal gated, sunken. Dentition rude but vigorous. Left an margin oblique or slightly convex; lateral margin terior cardinal feebly bifid; posterior simple; anterior broadly rounded or squarely truncate. Base line and posterior lateral pits small but deep. Dentition of broadly arcuate. Posterior dorsal area defined by an right valve unknown. Inner margins finely crenulate. obscure carina and by a change in direction and char Dimensions of holotype: Height 3.3 millimeters, width acter of the concentric lamination. Surface sculptured 3.4 millimeters, convexity 1.4 millimeters. with strong, closely spaced, concentric lirae, which are Holotype, a left valve: U. S. Nat. Mus. 325539. . finer and more crowded on the adolescent shell; a feeble Type locality: Yorktown, York County, Va. York- radial striation, which is absent in the trisulcatus s. s., town formation. is rather evident in the subspecies. Ligament marginal. This sturdy little species is set apart from the coex Normally, a simple anterior cardinal and a bifid poste istent Cardiolucinas by the broadly tabulated concen rior cardinal in the right valve; a bifid anterior and a tric elevations. It is, however, differentiated with simple posterior cardinal in the left valve; anterior greater difficulty from certain mutants of the Eocene cardinals becoming obsolete with age, and even the P. (Cardiolucina) alveatus Conrad, prolific in the sands posterior cardinals sometimes affected; laterals rude of the Claiborne group. Only 2 valves—both left but prominent; short anterior and posterior lateral den valves—of the Yorktown species have been recovered. ticles in the right valve; anterior and posterior lateral The larger of these is apparently adult. It is smaller grooves in the left valve—the inner margins raised into than the average alveatus and is more regular in out toothlike prominences. Adductor impressions often line because of the less prominent umbones. The fusion obscure; the anterior linguiform, the posterior oval. of the concentric sculpture is seemingly more complete Pallial line simple. Marginal denticulation very fine. in the later form, for in alveatus some trace of the com Phacoides (Cardiolucina) crenulatus (Conrad), the ponent costae is usually retained in more or less feeble only species with which P. trisulcatus is confusable, is striations that are continuous across the disk.- These a much thinner and usually smaller shell with a more do not occur in postalveatus except on the extreme distal evenly rounded outline, and with more uniformly cen margins. On the contrary, the 3 broad elevations tral and less prominent umbones, a much less deeply formed by the fusion of the costae on the lower two- excavated lunule, a finer concentric sculpture, and a less thirds of the valve are smooth and polished and are rude and vigorous dentition. The aspect of the interior slightly undercut by the channels behind them. of the valve of P. trisulcatus is very characteristic— P. (Cardiolucina) postalveatus may possibly be the the posterior dorsal margin ascending with a slight con much reduced descendant of the flourishing alveatus of vexity to the acute apices, the small but almost semi the Early Tertiary. circular lunule pit in front of the umbones, and the anterior dorsal margin sloping gently to the lateral Distribution: Virginia: Miocene, Yorktown formation, York- town on the York River, York County. truncation. The subspecies differs from the normal type only in Submenus LUOINISCA Ball having a feeble radial sculpture. Unlike P. trisulcatus 1901. Lucinisca Dall, U. S. Nat. Mus. Proc., vol. 23, p. 805. s. s., it is apparently restricted in the Carolinas to 1937. Lucinisca Chavan, Jour, conchyliologie, vol. 81, p. 238. the Duplin and Waccamaw formations. In the Choc- Type by original designation: Lucina nassula Conrad. Hat- tawhatchee of Florida it has been reported only from the teras to Cuba and west to Mobile Bay in 7 to 200 fathoms. CanceUari/- zone. The P. (Cardiolucina,) trisulcatus Shell lentiform, white, with well-marked dorsal areas, the group is reported by Olsson from both Tertiary and sculpture reticulate and muricate, the right anterior cardinal Recent faunas of mid-4-merica. obsolete.—Dall, 1901. Distribution: North Carolina: Miocene, Duplin marl, 4 miles Phacoides (Lucinisca) cribrarius (Say) Dall north of Lumberton and 1% miles northeast of Fairmont, Robeson County. Pliocene, Waccamaw formation, Walkers Bluff on the Plate 13, figures 23, 24, 29, 30 Gape Fear River, Bladen County; city rock quarry near Wil 1824. Lucina cribraria Say, Acad. Nat. Sci. Philadelphia Jour., mington, New Hanover County. 1st ser., vol. 4, p. 147, pi. 13, fig. 1. 401033—43———6 78 MOLLUSCA FROM MIOCENE AND LOWEfc PLIOCENE OF VIRGINIA AND NORTH CAROLINA 1856. Lucina cribraria Say. Tuomey and Holmes, Pleiocene inset. Anterior cardinal of right valve obsolete; poste fossils of South Carolina, p. 58, pi. 18, figa 8, 9. rior not very stout; anterior cardinal of left valve af 1863. Codakia cribraria Say (part). Conrad, Acad. Nat. Sci. fected somewhat by the invagination of the lunule; pos Philadelphia Proc. for 1862, p. 577. 1903. Phacoides (Lucinisca) cribrarius Say (part). Ball, Wag terior left cardinal very slender; posterior right and ner Free Inst. Sci. Trans., vol. 3, pt. 6, p. 1372. anterior left cardinals bifid only in the young. Ante 1904. Phacoides (Lucinisca) cribrarius (Say). Glenn, Mary rior and posterior laterals distant, sharp little teeth land Geol. Survey, Miocene, p. 341. cut off from the margin by a moderately deep sulcus; 1932. Phacoides (Lucinisca) cribrarius (Say). Mansfield, Flor receiving pits of left valve small but moderately deep, ida Geol. Survey Bull. 8, p. 97, pi. 21, figs. 22, 23. 1937. Lucina- (Lucinisca) cribraria Say. Chavan, Jour, con- their inner edges elevated into toothlike prominences. chyliologie, vol. 81, p. 240, fig. 6. Anterior adductor impression very narrow, elongated Orbicular, convex, with numerous longitudinal costae, and dis to fully half the total altitude; posterior irregularly tinct elevated concentric lines. oval or quadrate. Inner margins strongly denticulated Shell with close-set, longitudinal, equal, granulated ribs, and in harmony with the external costae. more or less elevated, distinct, concentric lamellae; hinge margin No other coexistent Phacoides combines so vigorous obtusely and not prominently angulated at its anterior and a radial sculpture with so conspicuous a concentric orna posterior terminations; anterior margin with a dilated, slightly impressed, and not very obvious groove; lunule oblong-oval, mentation. Mansfield reports that Phacoides (Luci very distinct, the edge near the beaks extending inward beside the nisca) occurs in abundance in the Cancellaria zone of primary teeth; lateral teeth very distinct, the posterior one the Choctawhatchee formation and, less commonly, in placed nearly under the middle of the lunule; within crenate on the Ecphora zone. the edge; posterior muscular Impression rectilinear. Length half an inch, breadth u/£o of an inch. Distribution: Virginia: Miocene, Yorktown formation, York- Type locality: Maryland.—Say, 1824. town, York County; mouth of Bailey's Creek, Prince George County; Claremont Wharf (upper bed), Surry County; Zuni, The figured right valve (U. S. Nat. Mus. 325536) is Ferguson's Wharf (on the James River), and 5 miles northeast from the Yorktown formation, 5 miles northeast of of Smitlifield, Isle of Wight County; a quarter to half a mile Smithfield, Va., and measures 12.8 millimeters in height below Sycamore (on the Nottoway River), Southampton County. and 12.9 millimeters in width. The figured left valve North Carolina: Miocene, Yorktown formation, l1/^ to 2 miles (U. S. Nat. Mus. 325535), from the Yorktown formation above Branches Bridge, % mile below Branches Bridge, and Maddelys Bluff (on the Meherrin River), Northampton County; at Yorktown, Va.r measures 10.0 millimeters in height Murfreesboro, Hertford County; Halifax, y2 mile above the and 10.6 millimeters in width. Atlantic Coast Line Railroad bridge (on Mr. Durham's farm), and Phacoides cribrarius is one of several species de Palmyra Bluff, Halifax County ; 2% miles northwest of Williams- scribed by Say in 1824 which were collected, according ton (on Joseph Cherry's farm), Martin County, 15% miles above to him, in Maryland by John Finch but which have not Bells Bridge and % mile above Bells Bridge, Edgecombe County. Duplin marl, 4 miles south of Clinton, Sampson County. been noted by later observers. It is probable that they Outside distribution: Miocene, Choctawhatchee formation, came from Virginia. northern Florida. Duplin marl, Darlington, S. C.; Porters Shell of medium size, moderately compressed, subcir- Landing on the SaA-annah River, Effingham County, Ga. cular in outline. Umbones subcentral, low and not very conspicuous, their apices acute and prosogyrate. Lu Submenus PARVILTICINA Dall nule, a small but profoundly excavated pit in front of 1901. ParvUucina Dall, U. S. Nat. Mus. Proc., vol. 23, p. 806. the umbones. False lunule, or anterior dorsal area, 1937. ParvUucina Chavan, Jour, conchyliologie, vol. 81, p. 208. depressed, elongate-cordate, defined by an incised line Type by original designation: Lucina tenuisculpta Carpenter. and an abrupt change in ornamentation; posterior dor Nunivak Island, Bering Sea, to the Coronado Islands. sal area sharply defined by a depression of the valve and Shell small, plump, often inequilateral; sculpture more or less a conspicuous change in the character of the sculpture. reticulate but not muricate, teeth small, but all usually .present.— Surface ornamented with about 30 radial lirae, low and Dall, 1901. flat-topped on the medial part of the disk, more elevated Phacoides (Parvilucina) multilineatus (Tuomey and Holmes) and arched toward the anterior and posterior margins; Dall interspaces sublinear medially, widening somewhat dis- Plate 13, figures 34-37 tally; radials overriden by 12 to 18 sharply elevated, concentric lamellae, which, though completely fused 1856. Lucina multilineata "Conrad". Tuomey and Holmes, Pleio cene fossils of South Carolina, p. 61, pi. 18, figs. 16, 17. medially, are somewhat broken up into concentric im 3858. Lucina multilineata Emmons, North Carolina Geol. Survey brications toward the distal margins; anterior dorsal Kept., p. 291 (name only). area sculptured with & or 4 closely imbricated radials; 1858. Lucina multilineata "Conrad." Holmes, Post-Pleiocene sculpture on posterior dorsal area inconstant; usually fossils of South Carolina, p. 29, pi. 6, fig. 6. 4 or 5 low, crowded lirae, with 1 to 3 more promi 1901. Pftacoides (Parvilucina) crenella Dall, U. S. Nat. Mus. Proc., vol. 23, pp. 810, 825, pi. 39, fig. 2. nent radials behind them; concentric lamellae fused 1903. Phacoides (Parvilucina) multilineatits Tuomey and except on the stronger marginal ribs, where they break Holmes. Dall, Wagner Free Inst. Sci. Trans., vol. 3, up into free scales. Ligament opisthodetic, elongated, pt. 6, p. 1384. PART 1. PELECYPODA 1932. Phacoides (Parvilucina) multilineata (Tuomey and the Miocene. It is, however, abundant and widely dis Holmes). Mansfield, Florida Geol. Survey Bull. 8, p. tributed in the Oancellaria zone of the Choctawhatchee 101, pi'. 20, figs. 6, 7. formation and is present in the Area zone. 1937. ParvHudna multilineata Tuomey and Holmes. Chavan, Jour, conchyliologie, vol. 81, p. 210. Distribution: Virginia: Miocene, Yorktown formation, 1% miles northeast of Suffolk, Nansemond County. Shell orbicular, concentrically and closely ribbed, radiately striate. North Carolina: Miocene, Yorktown formation, 100 yards be This little fossil has the outline and general characters of low Bells Bridge on the Tar River, Edgecombe County; Tar L. crenulata, from which it can only be distinguished by the Ferry on Wiccacon Creek (opposite Harrellsville), Hertford radiating lines, which give the shell a cancellated appearance.— County; Rock Landing on'the Neuse River, Craven County. Tuomey and Holmes, 1856. Duplin marl, Natural Well and 1% miles north of Magnolia, Duplin County; 2 miles below Luniberton and 4 to 5 miles below Type locality: Waccamaw, S. C. Waccamaw forma Lumberton, Robeson County. Pliocene, Waccamaw formation, 4 tion. miles south of Elizabethtown (on Hammond Creek) and Walkers Bluff (on the Cape Fear River), Bladen County; Lake Wacca A right and a left valve of different individuals maw, Cronly (% mile east of the factories), and Neills Eddy (U. S. Nat. Mus. 325537) are figured. They were col Landing (3 miles north of Cronly), Columbus County; Wil- lected from the Waccamaw formation at Neills Eddy mington, New Hanover County. Landing on the Cape Fear River, N. C. The right valve Outside distribution: Miocene, Duplin marl, Porters Landing, measures 6.5 millimeters in height and 6.6 millimeters Effingham County; Brunswick River bed, Brunswick, Ga. Choc in width; the left valve measures 7.5 millimeters in tawhatchee formation, northern Florida. Pliocene, Waccamaw formation, Waccamaw and Tillys Lake, Horry County, S. C. height and 7.3 millimeters in width. Caloosahatchee marl, Nashua and % mile above the Atlantic Tuomey and Holmes, by a happy blunder, identified Coast Line Railroad bridge over the St. Johns River, Putnam their species with L. multilineata of Conrad. Conrad's County, Fla.; De Leon Springs, Volusia County, Fla.; Sanford, form was not named "muttiUneata" but "multtstriata" Seminole County, Fla.; Caloosahatchee River, Shell Creek, and Myakka River, Fla. Croatan sand, Croatan beds, Craven County, and it was later relegated to subspecific rank under N. C. Pliocene (?), Charlton formation, Orange Bluff, St. Marys P. trisuLcO'tus. River, Nassau County, Fla. Pleistocene, Simmons Bluff and Shell small, globose. Outline roughly circular, the Wadmalaw Sound, S. C.; Rose Bluff, St. Marys River, Nassau County, Fla.; Orient, Hillsborough County, Fla.; Manatee Sta dorsal margins forming a chord of the circle; lateral tion and North Creek near Osprey,-Manatee County, Fla.; Kis- margins often a little contracted by the depression of simmee well (at a depth of 96 feet), Osceola County, Fla.; Eau the dorsal areas. Umbones central, moderately inflated; Gallie, Brevard County, Fla.; Labelle, Hendry County, Fla. their apices acute and prosogyrate. Lunule small, Recent, (?) Indian Pass, Fla., to Horn Island, Miss., in less than smooth, cordate, depressed, but not excavated. Ante 50 fathoms. rior and posterior dorsal areas defined by a slight de Family DIPLODONTIDAE , pression of the valve, a very low and obscure, radial Genus DIPLODONTA Bronn fold, and an abrupt disappearance of the radial sculp ture. Surface ornamented with sublinear radiations, 1831. Diplodonta Bronn, Italiens Tertiar-Gebilde, p. 9. separated by interradials of scarcely greater width; Type by subsequent designation (Herrmannsen, Indicis gen- radials obsolete in the umbonal region; concentric lirae erum Malacozoorum, vol. 1, p. 392) : Venus lupina Brocchi. very fine, overriding the radials and minutely cancellat- Miocene and Pliocene of the Piedmont of Italy. ing them. Ligament opisthodetic, mounted on a linear Shell equivalve, not gaping, subcircular, the beaks nymph. Anterior cardinal of right valve almost obso subcentral and not prominent. Lunule and escutcheon lete; posterior subumbonal, robust, cuneiform; laterals not defined. External surface smooth or incrementally vigorous; hinge of left valve armed with a moderately sculptured. Ligament chiefly external, supported on. strong, anterior cardinal, a simple, compressed, poste marginal nymphs. Hinge of right valve armed with rior cardinal, and deep grooves for the reception of the a simple anterior and a bifid posterior cardinal; hinge strong right laterals. Adductor muscle impressions of left valve armed with a bifid anterior and a simple small, a little above the median horizontal. Inner mar posterior cardinal, so that in the closed valves the two gins crenulated in harmony with the external radials, outer cardinals are simple, the two inner ones bifid. much finer on the dorsal areas than on the intermediate Laterals absent. Adductor impressions oval, the an disk. terior longer and narrower than the posterior. Pallial Parvilucina multilineatus is larger and more inflated line entire. Inner margins of valves smooth. than Phacoides crenulatus, the only species with which The genus is first noted in the Cretaceous; from that it might be confused. The radial sculpture is stronger time on it has constituted one of the less conspicuous and more uniform than in the latter, and the concentric elements in the bivalve faunas. The forty-odd Recent sculpture is more feeble and more inconstant. species have a wide distribution in the warmer waters The species does not appear until almost the close of of the globe. MOLLUSCA FROM MIOCENE AND LOWER PLIOCENE OF VIRGINIA AND NORTH CAROLINA Diplodonta caloosaensis Dall Shell suborbicular, almost equilateral, rounded anteriorly and posteriorly, convex, thin, striate; striae concentric, very small; Plate 14, figures 40, 41 beaks prominent, nearly straight; left valve with 2 cardinal 1900. Difrtod&tota caloosaensis Dall, Wagner Free Inst. Sci. teeth, i of which is bifid, and no lateral ones. *Trans., vol. 3, pt. 5, p. 1188, pi. 44, fig. 16. Diameter 0.15, length 0.31, breadth 0.35 of an inch. Type locality: Petersburg, Dinwiddie County, Va.—H. C. Shell large, moderately inflated, sculptured with somewhat Lea, 1846. irregularly prominent incremental lines; beaks low, pointed, inconspicuous; anterior end shorter, smaller, evenly rounded Dall's leana is nothing more than a replacement into the evenly arcuate base; posterior end squarish, longer, name for the preoccupied lucinoides of H. C. Lea. larger, more inflated; in the young the form is even more Diplodonta leana Dall s. s. possesses none of the more inequilateral and sometimes rounded trigonal with the anterior end attenuated; hinge line short, with hardly any hinge plate; striking features that characterize the coexistent Diplo- ligamentary groove sharp, but the nymph not prominent; teeth dontas. It is larger and much leNss globose than D. and scars normal. Altitude 25, latitude 27, diameter 17 milli nucleiformis (Wagner) ; is smaller, thinner, more cir meters. cular, and more inflated than D. acclinis (Conrad); This species is larger and less equilateral than D. Leana; is smaller, thinner, and less inflated in the umbonal specimens of the same size are less inflated. It resembles D. punctata Say which is a smaller shell, but has not the region than D. caloosaensis Dall; and lacks the diag microscopic surface sculpture.—Dall, 1900. nostic shagreened surface of D. soror C. B. Adams. Holotype, a left Valve: U. S. Nat. Mus. 112865. Distribution : Virginia: Miocene, Yorktown formation, Peters Type locality: Caloosahatchee River, Fla. Caloosa- burg, Dinwiddie County; Cobham Bay, Surry County; 2% miles northwest of Suffolk and 1 mile northeast of Suffolk, hatchi marl. Nansemond County. Dimensions of figured specimen: Height 20.6 milli Norh Carolina: Miocene, Duplin marl, 1% miles northeast meters, width 22.3 millimeters, convexity 6.5 of Fairmont, Robeson County. millimeters. Figured specimen, a left valve: U. S. Nat. Mus. Diplodonta leana eoleana Gardner, n. subsp. 325553. Plate 14, figures 37, 38 Locality of figured specimen: Neills Eddy Landing, Shell of moderate dimensions, subcircular and rather 3 miles north of Cronly, Columbus County, N. C. strongly inflated for the group. Umbones scarcely in Waccamaw formation. terrupting the broad arc of the dorsal margins, the The figured shell is decidedly heavier than Dall's tips acute and turned toward each other, subcentral. holotype, but the differences are probably no more than Anterior end of shell broadly and obscurely truncate, individual. The Waccamaw species closely resembles the posterior portion broadly rounded from the um- the St. Marys form, D. leana eoleana, which is larger bones to the base. Incremental fairly strong and reg and less inflated than the Yorktown species D. leana. ular. Ligament groove deep. Dentition delicate but D. caloosaensis is less evenly rounded posteriorly than normal; two divergent cardinals in each valve, the pos-H D. leana eoleana and more strongly upcurved along the terior right and the anterior left cardinals deeply sul- anterior ventral margins, but the shells, if they occurred cate, the anterior right and posterior left cardinals thin within the same area and formation, would be difficult and laminar. Adductor scars elongated, placed well to separate. up under the dorsal margins. Margin of mantle at Distribution: North Carolina: Pliocene, Waccamaw forma tachment ragged. Pallial line simple, fairly close to tion, Walkers Bluff on the Cape Fear River, Bladen County; the base. Neills Eddy Landing on the Cape Fear River, Columbus County. Outside distribution: Pliocene, Waccamaw formation, Wac Dimensions of holotype: Height 18.0 millimeters, camaw River, S. C. Caloosahatchee marl, Calossahatchee width 19.1 millimeters, convexity 5.5 millimeters. Siver, Fla. Holotype, a right valve: U. S. Nat. Mus. 325556. Diplodonta leana Dall Type locality: Urbanna on the Rappahannock River, Middlesex 'County, Va. St. Marys formation. 1846. Psammocola lucinoides H. C. Lea, Am. Philos. Soc. Trans., new ser., vol. 9, p. 239, pi. 34, fig. 16. Not Diplodonta, The St. Marys subspecies differs from Diplodonta lucinoides Deshayes, 1824. leana from the Yorktown formation in the larger, heav 1863. Psammocola? htcinoides H. C. Lea. Conrad. Acad. Nat. ier, and relatively higher and less inflated shell. It Sci. Philadelphia Proc., for 1862, p. 573. closely resembles the Waccamaw and Caloosahatchee 1900. Diplodonta leana Dall, Wagner Free Inst. Sci. Trans., species, D. caloosaensis Dall, but it is broader and a vol. 3, pt. 5, p. 1187. little less produced anteriorly and more evenly rounded P. testa suborbiculari, pene aequilaterali, postic^ et antice posteriorly. rotundata convexa, tenui, striata; striis concentricis, minimis; natibus prominentibus, subrectis; valva sinistra dentibus duobus The subspecies has a fairly good representation at cardinalibus, quorum unus bifidus, lateralibus nullis. the single locality from which it has been reported. PART 1. PELECYPODA 81 Section PHLYCTIDERMA Ball Outside distribution: Pleistocene, Ashley River and Simmons Blur, Wadmalaw Sound, S. C. Recent, Tortugas to Texas and 1899. Phlyctiderma Ball, Jour, conchology, London, vol. 9, p. 244. south to Jamaica and the Antilles in less than 50 fathoms. Type by original designation: Diplodonta semiaspera Philippi. Superfamily Leptonacea Recent from Hatteras to Rio de Janeiro. Shell like Diplodonta but with the surface more or less punc Family Leptonidae tate or pustulate.—Ball, 1899. Genus ERYCINA Lamarck Diplodonta (Phlyctiderma) soror (C. B. Adams) 1805. Erycina Lamarck, Mus. histoire nat. Annales, vol. 6, p. 413. Plate 14, figures 42, 43 Type by subsequent designation (Stoliczka, Geol. Survey 1852. Lucina soror C. B. Adams, Contr. conchology, N.O. 12, p. 247. India, Mem., Palaeontologia Indica, Cretaceous fauna of south 1858. Lucina* Mawahensis Holmes, Post-Pleiocene fossils of ern India, vol. 3, p. 263, 1871) : Erycina pelludda Lamarck. South Carolina, p. 29, pi. 6, fig. 5. Calcaire grossier of the Paris Basin. 1900. Diplodonta soror O. B. Adams. Ball, Wagner Free Inst. S'ci. Trans., vol. 3, pt. 5, p. 1188. The earliest designation was probably that of Anton, Verzeichniss der Conchylien^ p. 6, 1839. However, the L. t. suborbiculari; margine superiore antice et postice declivi, inferiore antice subarcuatft ; cinereoalbidft; microscopice creber- species designated by Anton, Erycina elliptical Des- rime punctulata; striis concentricis exilissimis creberrimis; um- hayes, is a Diplodonta; and as the confusion resulting bonibus prominentibus; apicibus subobliquis; lunuia minutis- from the acceptance of E. elliptic^ as the type would be simft; limbo simplici; dentibus lateralibus obsoletis. Long. 19.6 very great, a request has been made to set aside the millim., alt. 18 millim., lat. 12.7 millim — C. B. Adams, 1852. rules so that E. pellucida may be retained as the Type locality: Kingston Harbor, Jamaica. Living. genotype of Eryaina. Shell thin, inflated, suborbicular, and approximately Shell small, thin, elongate-oval, usually subequilat- equilateral, but somewhat flattened or obscurely cari- eral. Surface usually smooth and sometimes with nate posteriorly. Umbones central, inconspicuous, the concentric or still more rarely with a radial sculpture. tips incurved and prosogyrate. Posterior dorsal mar External ligament feeble; internal ligament lodged in gin a little oblique and slightly depressed, broadly a triangular resilial pit behind the umbones and near rounded or obscurely truncate laterally. Anterior the dorsal margin. Cardinals minute, subumbonal, 1 dorsal margin continuous with the convex lateral mar or 2 in each valve; strong laminated laterals developed gin. Base line strongly arcuate. External surface both in front of and behind each umbo. Adductor shagreened by microscopic punctae, which are im impressions small, oval. Pallial line entire or slightly perfectly radial in arrangement and are largest and sinuated. most numerous on the posterior slope. Ligament The genus apparently both originates and culminates external, opisthodetic. Nymph short, inconspicuous; in the Eocene. In the Paris Basin alone 47 species outer margin delimited by a moderately deep groove. are known. In North America, although Erycina is Hinge normal, delicate; posterior cardinal of right most abundantly represented in the Gulf Eocene, it valve and anterior cardinal of left valve deeply sul- also occurs throughout the Tertiary section of the east cated; anterior cardinal of right valve and posterior coast. cardinal of left valve simple and laminar; hinge .Erycina carolinensis Dall strengthened by the grooving of the dorsal margins. Plate 14, figure 9 Adductor impressions usually irregular, subequal, submedian in position. Pallial line simple, rather 1900. Erycina carolinensis Ball, Wagner Free Inst. Sci. Trans., vol. 3, pt. 5, p. 1145, pi. 44, fig. 3. near the ventral margin. The figured left valve (U. S. Nat. Mus. 325555) Shell large for the genus, inequilateral, somewhat compressed, elongated, the anterior end produced, rounded, the posterior end from the Duplin marl at the Natural Well, N. C., shorter, downwardly arcuated; base nearly straight, slightly measures 12.3 milimeters in height and 12.7 millimeters insinuated near the middle, corresponding to a slight mesial in width. constriction of the shell; anterior dorsal margin nearly parallel Diplodonta soror is characterized by the more or less with the base; posterior declining to a rounded point at its pronounced posterior flattening and by the shagreened junction with .the base; beaks small, low, pointed; surface with rather strong, irregular, concentric incremental lines but very external surface. The single left valve from the Dup little radial striation; hinge normal, the lamellae rather long, lin marls near Magnolia is a little more elevated than and the hook (or cardinal) small; resiliary groove deep and the normal form but agrees perfectly in all other strong, elongated; interior of the valves smooth or faintly characters. The species has also been found in the radially striated toward the margins; adductor scars high up, Waccamaw formation. the anterior larger, the pallial line rather wide, somewhat irregular. Longitude 13.25, altitude 7, diameter 4 millimeters. Distribution: North Carolina: Miocene, Duplin marl, Natural This is the largest and apparently the most common species Well and 1^ mile north of Magnolia, Duplin County. Pliocene, of Erycina in the later Tertiary of the Carolinas. On occa Waccamaw formation, Neills Eddy Landing, 3 miles north of sional specimens a little faint radial striation may be observed Cronly, Columbus County. under the shelter of the concrntric sculpture, but many speci- 82 MOLLUSCA FROM MIOCENE AND LOWER PLIOCENE' OF VIRGINIA AND NORTH CAROLINA mens do not show it, and on none does it appear to cover the Genus BORNIA Pliilippi surface.—Ball, 1900. 1836. Bomia Philippi, Enumeratio molluscorum Siciliae, vol. The right valve (U. S. Nat. Mus. 115096), from Nat 1, p. 13. ural Well, Duplin County, N. C., is here designated the Type by subsequent designation (Stoliczka, Geol. Survey lectotype. The measurements are as follows: Height India, Mem,, Palaeontologia Indica, Cretaceous fauna of south 5.7 millimeters, width 9.0 millimeters, convexity 1.5 ern India, vol. 3, p. 266) : Bornia, corbuloides Philippi. Recent millimeters. The dimensions given by Dall are those in the Mediterranean. of the form from the Waccamaw formation of South The shell is moderately compressed, subtrigonal to Carolina, the type of a suspecies elongata. transversely elliptical and subequilateral. The surface The species varies rather widely in its relative pro may be smooth or feebly rippled and faintly striate portions, in the location of the umbones, and in the concentrically. There is a feeble external ligament and configuration of its posterior end. The Duplin shells a subumbonal resilium. The dentition in the right are generally higher than the Waccamaw forms, the valve includes an anterior and a more produced pos umbones are more nearly central, and the arch of the terior lamina; in the left, two short anterior lamellae posterior dorsal and lateral margins is more uniform. and a much longer posterior lamina. The pallial line The elongation of some of the later and more southern is simple. specimens is so pronounced that the differences are Bornia is recorded from the Eocene of the Paris recognized by a subspecific division. Basin and from the Tertiary of eastern North America Distribution: North Carolina: Miocene, Duplin marl, Natural and the Gulf of Mexico. The Recent species are Well and 1^ miles north of Magnolia, Duplin County. Pliocene, Waccamaw formation, Lake Waccamaw, Columbus County. restricted largely to the Mediterranean. Erycina carolinensis elongata Gardner, n. subsp. Bornia triangula Dall Plate 14, figures 2, 3, 4, 5,10 Plate 14, figure 1 1900. Erycina carolinensis Dall (part), Wagner Free Inst. Sci. Kellia triangula H. C. Lea, Label in coll. Acad. Nat. Sci. Trans., vol. 3, pt. 5, p. 1145, pi. 44, fig. 22. Philadelphia. 1900. Bornia triangula, n. sp.?, Dall, Wagner Free Inst. Sci. Shell large for the genus. Outline elongate-ovate, Trans., vol. 3, pt. 5, p. 1151. inequilateral. Umbones low, slightly posterior, proso- 1904. Bornia triangula Dall. Glenn, Maryland Geol. Survey, gyrate. Anterior dorsal margin rectilinear and par Miocene, p. 330, pi. 88, figs. 9a, 9b. allel with the horizontal base line; lateral margin This is the most common fossil species of our Tertiary. broadly rounded; posterior dorsal margin oblique, It occurs quite plentifully sometimes and is readily distin merging gradually into the posterior lateral, which is guished from B. mactroides, as a rule, by its shorter, more obscurely truncated at right angles to the base line. triangular, and less fiexuous shell. The outline is quite uniform as a whole and the shell almost always easily separated from Incremental sculpture uneven, obsolete on the umbones; B. mactroides, for which reason I have retained Lea's unpub faint, crowded radials similar to those developed in lished name, though I do not feel wholly confident that both Erycina kurtzia Dall but less distinct. these forms may not eventually prove to be extremes of a single Dimensions of holotype, a left valve: Height 7.5 species. millimeters, width 12.7 millimeters, convexity 4.0 Type locality: Petersburg, ya.—Dall, 1900. millimeters. Dimensions of paratypes, a right and a left valve of Holotype, a left valve: U. S. Nat. Mus. 325542. different individuals: Height 3.0 millimeters, width 3.3 Type locality: Neills Eddy Landing on the Cape millimeters. Fear River, Columbus County, N. C. Waccamaw Paratypes, a right valve and a left valve of different formation. individuals: U. S. Nat. Mus. 325547, from Yorktown, The subspecies elongata is separated from carolin York County, Va. Yorktown formation. ensis s. s. because of the relatively greater width, the Hinge concentrated; resilial pit moderately deep, more posterior umbones, and the more oblique posterior subumbonal; anterior lamella of right valve pocketlike, dorsal margin. The subspecies seems to be particularly thickening abruptly in front of the umbones, recurved characteristic of the later and more southern faunas. and coalescent with the dorsal margin directly beneath It has been recognize.d not only in the Waccamaw of the tips; posterior lamella subspinose medially; lamel both the Carolinas but in the Caloosahatchee marl of lae of left valve two, the one in front sharply bent and Florida as well. thickened at its umbonal end (thus simulating a true Distribution: North Carolina: Pliocene, Waccamaw forma cardinal), the one behind slightly diverging and re tion, Neills Eddy Landing, 3 miles north of Cronly, Columbus duced to a cardinallike 'protuberance directly beneath County. the umbo; posterior lamella of left valve not so heavy Outside distribution: Pliocene, Waccamaw formation, Wac camaw River, S. C. Caloosahatchee marl, Caloosahatchee as the'anterior, obscurely cuneiform, wedging out near River, Fla. the tips of the beaks. PART 1. PELECYPODA 83 Bornia triangula JL>all is characterized by an outline Bornia bladenensis is represented by a single right that roughly approximates a rather high isosceles valve that is apparently not full grown. The plication triangle, with the umbones at the apex, the ventral is so diagnostic, however, and so unlike any character margin at the base. The species varies somewhat in exhibited by any of the coexistent species that it seems general proportions and in the position and promi worth while to announce the form at once. nence of the umbones. The representatives from York- Dimensions of holotype: Height 3.9 millimeters, town are higher, as a rule, than those collected at either width 4.75 millimeters. Petersburg, Va., or Natural Well, N. C. The outline Holotype, a right valve: U. S. Nat. Mus. 325546. of the Yorktown representatives is more inequilateral, Type locality: Walkers Bluff, Bladen County, N. C. the anterior dorsal margin somewhat contracted in Waccamaw formation. front of the umbones, and the anterior slope percept Distribution: North Carolina: Pliocene, Waccamaw forma ibly steeper than the posterior. The valve is conse tion, Walkers Bluff, Bladen County. quently more narrow in front than behind, and the umbones are more conspicuous than in those forms that Family SPOETELLIDAE are not contracted anteriorly. The young of the Genus SPORTELLA Deshayes species are so unlike the adults that they would cer 1858. Sportella Deshayes, Description animaux sans vertebres tainly be considered distinct were they not found as Bassin de Paris, vol. 1, p. 593. sociated in an unbroken series. They are stout, convex, Type by original designation: Psammotea dubia Deshayes. suborbicular little shells with rude, unformed hinges Calcaire grossier of the Paris Basin. and heavy lamellae. Shell small, thin, transversely elongate, slightly con The representatives of the species in Virginia and North Carolina are not confusable with the broader, vex, subequilateral in the majority of species. Um bones low and inconspicuous. Neither lunule nor more angular B. mactroides of the Maryland fauna. escutcheon defined. Surface smooth or feebly undu B. rota of the Duplin and Waccamaw is smaller, more compressed, and more attentuated dorsally. lated by incrementals, occasionally sculptured with a submicroscopic radial striation. External ligament Distribution: Virginia: Miocene, Yorktown formation, York- seated on elongate nymphs; internal lodged in oblique, town and I1/! miles below Yorktown, York County; Petersburg, subumbonal resilial pit. Dentition of right valve con Dinwiddie County; Mr. Everet's farm near Benns Church, Isle of Wight County; 1% miles northeast of Suffolk and % mile sisting of a strong, often recurved, posterior cardinal below the Suffolk waterworks dam, Nansemond County. and a rudimentary anterior cardinal; hinge of left North Carolina: Miocene, Yorktown formation, 1% miles valve with two unequal, divergent cardinals, the an below Tar Ferry on Wiccacon Creek, Hertford County; Colerain terior of which is stronger. Adductor impressions Landing on the Chowan River, Bertie County; Wilson, Wilson oval, subequal. Pallial line entire, often punctate. County; Rock Landing on the Neuse River, Craven County. Duplin marl, Natural Well and 1% miles north of Magnolia, Inner margins smooth. Duplin County; Lumber ton (near the bottling works), Robeson This is a genus of small and inconspicuous bivalves County. Pliocene? Waccamaw formation, Walkers Bluff, Bladen that inhabited the near-shore waters of Europe and County; Neills Eddy Landing (3 miles north of Cronly) and America during Tertiary and Quaternary times. Lake Waccamaw, Columbus County. Outside distribution: Miocene, Duplin marl, Darlington, S. C. Sportella constricta (Conrad) Dall Pliocene, Caloosahatchee marl, Caloosahatchee River and Shell Plate 14, figures 19, 20 Creek, Fla. 1841. Amphidesma constricta Conrad, Am. Jour. Sci., 1st ser., Bornia bladenensis Gardner, n. sp. vol. 41, p. 347, pi. 2, fig. 15. 1843. Amphidesma constricta Conrad, Am. Assoc. Geologists Plate 14, figures 11, 12 and Naturalists, vol. 1, p. 110, pi. 5, fig. 15. 1845. Amphidesma constricta Conrad, Fossils of the medial Ter Shell thin, polished, strongly convex, oval, subequi- tiary of the United States, p. 76, pi. 43, fig. 10. lateral. Umbones slightly anterior, inflated, incurved, 1854. Syndosmya constricta, Conrad, Acad. Nat. Sci. Philadelphia prosogyrate at the tips, scarcely interrupting the low Proc., vol. 7, p. 29. arch of the similar dorsal margins; lateral margins 1863. Fabella, constricta Conrad, Acad. Nat. Sci. Philadelphia broadly and regularly curved; ventral margin straight Proc. for 1862, pp. 574, 586. [Monotype of Fabella.] 1889. Lepton (Fabella) constricta Conrad. Dall, U. S. Nat. medially, upcurved distally. Surface gently rippled Mus. Bull. 37, p. 48. by about a dozen feeble radial folds, strongest near the 1898. Sportella constricta Conrad. Dall, Wagner Free Inst. Sci. periphery, evanescing halfway to the umbones; external Trans., vol. 3, pt. 4, pi. 25, figs. 4, 4a. undulations reflected within. Hinge delicate. Eesili- 1900. Sportella constricta Conrad. Dall, idem, vol. 3, pt. 5, p. fer sublinear, oblique. Anterior lamella of right valve 1128. 1932. Sportella constricta (Conrad). Mansfield, Florida Geol. thickened beneath the umbo into a small but prominent Survey Bull. 8, p. 107, pi. 21, figs. 14, 18. cardinal hook; posterior lamella elongated, subspinose Oblong, oval, ventricose; basal margin opposite the apex a little behind the middle; left valve not known. slightly contracted; end margins rounded; beaks nearest the 84 MOLLUSCA FROM MIOCENE AND LOWER PLIOCENE OF VIRGINIA AND NORTH CAROLINA posterior extremity; fosset profound; cardinal teeth prominent, posterior cardinal rudimentary. Adductor impressions lateral teeth none.—Conrad, 1841. obscure, apparently rather near the ventral margin. Dimensions of figured specimens: Right valve, height Pallial line entire. 6.0 millimeters, width 9.0 millimeters. Left valve, Dimensions: Height 10.2 millimeters, width 14.7 mil height 5.7 millimeters, width 9.0 millimeters. limeters, convexity 3.5 millimeters. Figured specimens: U. S. Nat. Mus 155730, from the Holotype, a right valve: U. S. Nat. Mus. 325543. Caloosahatchee River, Fla. Type locality: iy2 miles below Tar Ferry, on Wic- Type locality: Natural Well, Duplin County, N. C. cacon Creek, Hertford County, N. C. Yorktown Duplin marl. formation. Shell heavy, slightly inequilateral, transversely oval Sportella calpix is most closely, allied to S. pelex to subquadrate. Umbones inconspicuous, prosogyrate, Dall, from the Yorktown of Virginia. The latter is, located a little behind the median line. Anterior end however, a much smaller, relatively higher shell with slightly contracted in front of the beaks; anterior a less produced and attenuated anterior end. The dorsal margin nearly rectilinear and subparallel to the obliquity of the anterior dorsal margin separates S. base; lateral margin broadly rounded. Posterior dor calpix at once from S. constricta (Conrad) and S. wac- sal margin slightly oblique and reflected; posterior end camawensis, whereas the dissimilarity of the dorsal a little shorter and more narrow than the anterior. margins separates it from the more nearly equilateral Surface irregularly wrinkled by the incrementals. S. petropolitana Dall. Hinge conspicuously robust. Ligamentary attachment Distribution: North Carolina: Miocene, Yorktown formation, opisthodetic, sublinear. Resilial pit oblique, deeply Tar Ferry on Wiccacon Creek (opposite Harrellsville) and l1/^ excavated. Right posterior and left anterior cardinals miles below Tar Ferry, Hertford County; % to % mile above stout and conical; right anterior and left posterior Edenhouse Point, Bertie County. Duplin marl, 1% miles north east of Fairmont, Robeson County. Pliocene, Waccamaw cardinals rudimentary; cardinal fossets correspond formation, Walkers Bluff, Baden County. ingly deep. Adductor scars obscure, set well up to ward the dorsal margin, the anterior a little higher Sportella gibberosa Gardner, n. sp. than the posterior. Pallial line entire. Plate 14, figures 6, 7 Sportella constricta (Conrad) differs from all its Shell small, heavy for its size, moderately inflated, congeners by its subquadrate outline and by the vigor transversely ovate, inequilateral. Umbones subcentral, of its hinge. . slightly posterior, prosogyrate. Anterior end con Distribution: North Carolina: Miocene, Duplin marl, Nat tracted in front of the umbones; anterior dorsal slope ural Well and 1% miles north of Magnolia, Duplin County. Plio rather gentle, merging gradually into the rounded lat cene, Waccamaw formation, Walkers Bluff on the Cape Fear River, Bladen County. eral margin. Posterior dorsal margin obscurely Outside distribution: Miocene, Choctawhatehee marl, north arched; lateral margin broadly rounded. Base line ern Florida. Pliocene, Waccamaw formation, Tillys Lake, straight. Incrementals distant and inconspicuous; Horry County1, S. C. Caloosahatchee marl, Caloosahatchee traces of a radial striation faintly discernible on both River and Shell Creek, Fla. the external and the internal surfaces. Hinge delicate. Sportella calpix Gardner, n. sp. Ligament groove minute, opisthodetic; resilial pit oblique, moderately deep. Only the right posterior and Plate 14, figures 30, 39 left anterior cardinals developed and these not promi Shell moder.ately convex in the umbonal region, com nently. Anterior adductor impression elongated; pos pressed ventrally, often with a very broad and shallow terior suborbicular, situated a little below the median medial depression. Outline transversely ovate, in horizontal. Pallial line entire. equilateral. Umbones a little posterior, prosogyrate. , Dimensions of cotypes: Right valve, height 3.2 milli Anterior end slightly contracted in front of the beaks; meters, width 4.5 millimeters. Left valve, height 3.3 anterior dorsal margin obliquely truncated, lateral millimeters, width 4.5 millimeters. margin evenly rounded. Posterior dorsal slope more Cotypes, a right and a left valve of different indi steep than the anterior, merging gradually into the viduals: U. S. Nat. Mus. 325544. broadly rounded lateral margin. Base horizontal. Type locality: Walkers Bluff on the Cape Fear Surface concentrically striated with submicroscopic in River, Bladen County, N. C. Waccamaw formation. crementals, most plainly visible toward the lateral The slight contraction in the basal margin of the margins; traces of a faint, distant, radial striation dis left valve of the type is an individual rather than a cernible on both the exterior and the interior of the specific character. This small form recalls in outline valve. Ligament opisthodetic, lodged in a deep groove. and dimensions. Mactra clathrodon H. C. Lea. Be Resilial pit oblique, profound. Posterior cardinal of cause of its minute size and the delicacy of the hinge, right valve stout, subtriangular; anterior cardinal rudi it was at first considered to be the young of an un- mentary ; anterior cardinal of left valve strong, conical; reported adult, but the relatively heavy shell and the PART 1. PELECYPODA 85 crowding of the incrementals toward the ventral mar 1900. Sportella compressa H. C. Lea. Dall, idem, vol. 3, pt 5, gin are evidences to the contrary. p. 1130. The vaulting of the dorsal margin behind the um- Shell very transverse, very inequilateral, subelliptical, com bones gives to the species a hunch-backed aspect that is pressed, posteriorly subtruncate, anteriorly rounded, thin, striate posteriorly and anteriorly; striae very small, concen characteristic. tric; basal margin straight; dorsal margin straight; beaks Distribution: North Carolina: Pliocene, Waccamaw forma somewhat acute, prominent; teeth 2, small, divergent. Diame tion, Walkers Bluff on the Cape Fear River, Bladen County; ter 0.10, length 0.12, breadth 0.25 inch. Neills Eddy Landing, 3 miles north of Cronly, Columbus County. The concentric lines of growth are very small. They are visible on the anterior and posterior portions of the shell. On Sportella waccamawensis Gardner, n. sp. the central part they are obsolete, leaving it smooth. The Plate 14, figures 21, 22 teeth are small and unusually divergent for a Petricola.—H. C. Lea, 1846. Shell of moderate size, rather compressed, especially toward the ventral margin; outline Roughly ovate, Figured specimen, a left' valve: Acad. Nat. Sci. Phil rather angular, inequilateral. Umbones moderately in adelphia 1596. flated, prosogyrate, subcentral, or slightly posterior. Type locality: Petersburg, Va. Yorktown formation. Anterior end contracted in front of the umbones; dorsal Sportella compressa (H. C. Lea) is separated from margin slightly excavated; lateral margin squarely /S. protexta (Conrad) by a heavier shell, by an elongate truncated. Posterior dorsal slope rather steep, merg and oval rather than a sublanceolate outline, and by the ing gradually into the evenly rounded, lateral margin. absence of punctae on the external surface. No other Base horizontal. Surface sculptured with unequal, of the coexistent Sportellas approaches it in the degree often exaggerated incrementals and with faint traces of transverse elongation. of rather distant radiating striations; interior of valve Distribution: Virginia: Miocene, Yorktown formation, Peters also faintly rayed. External ligament lodged in a burg, Dinwiddie County. groove behind the umbo; resilial pit deep and oblique. North Carolina : Pliocene, Waccamaw formation, (?) Walkers Bluff, Bladen County; Neills Eddy Landing, 3 miles north of Right posterior and left anterior cardinals stout; other Cronly, Columbus County. cardinals not developed; cardinal sockets moderately Outside distribution: Pliocene, Waccamaw formation, Tillys deep. Adductor impressions rather obscure, placed Lake, Horry County, S. C. Caloosaliatchee marl, Caloosa- about halfway between the umbones and the base; an hatchee River, Fla. Croatan sand, Slocums Creek, Craven terior elongated, posterior subcircular. Pallial line County, N. C. (Dall). entire. Family MONTACUTIDAE Dimensions of holotype: Height 8.2 millimeters, width 13.5 millimeters, convexity 2.0 millimeters. Genus MYSELIA Angas Holotype, a right valve: U. S. Nat. Mus. 325545. 1876 (July 24). Rochefortia Velain, Comptes rendus, p. 285 Type locality: Walkers Bluff on the Cape Fear (nomen ,nudum). River, Bladen County, N. C. Waccamaw formation. 1877 (Aug. 1, fide Iredale). Mysella Angas, Zool. Soc. London Sportella waccamwwensis differs from all its congen Proc., p. 176. ers by the configuration of the anterior part of its shell, 1878 (not earlier than Nov. 12, fide Iredale). Rochefortia outlined by the slightly excavated dorsal margin, the Velain, Archives de zoologie experimental et ge'ne'rale, horizontal ventral margin, and the lateral margin trun vol. 6, p. 132. cated at right angles to the base. The young are rela Type by monotypy: Rochefortia australis, Ve"lain. St. Paul tively higher and less angular, and thus approach S. Island, South Indian Ocean. pelex Dall and S. calpix. The form has been reported 1891. Mysella Angas. E. A. Smith, Annals and Mag. Nat. His from the Waccamaw formation only. tory, 6th ser., vol. 8, p. 235. 1899. Mysella Dall, U. S. Nat. Mus. Proc., vol. 21, pp. 876, 881. Distribution: North Carolina: Pliocene, Waccamaw forma 1900. Rochefortia Dall, Wagner Free Inst. Sci. Trans., vol. 3, tion, Walkers Bluff on the Cape Fear River, Bladen County; pt. 5, p. 1157. Neills Eddy Landing, 3 miles north of Cronly, Columbus 1924. Mysella Angas. Iredale, Linnean Soc. New South Wales County. Proc., vol. 49, p. 207. Sportella compressa (H. C. Lea) Dall Type by monotypy: Mysella anomala Angas. Recent off the southeastern Australian shores. Plate 14, figures 27-29 Dall, 1900J has given a comprehensive discussion of 1846. Petricola compressa. H. C. Lea, Am. Philos. Soc. Trans., 2d the group. He failed to recognize the nudity of Roche ser., vol. 9, p. 239, pi. 34, fig. 15. fortia Velain, 1876; and apparently the priority of 1863. Petricola compressa, H. C. Lea. Conrad, Acad. Nat. Sci. Philadelphia Proc. for 1862, p. 576. Mysella Angas has been established by Iredale. Many 1898. SporteUa compressa H. C. Lea. Dall, Wagner Free Inst. of the recent species of Rochefortia are commensal with Sci. Trans., vol. 3, pt. 4, pi. 25, fig. 3a. Crustacea. 86 MOLLUSCA FROM MIOCENE AND LOWER PLIOCENE OF VIRGINIA AND NORTH CAROLINA Mysella stantoni (Dall) Gardner Mysella bladenensis is allied to M. stantoni (Dall) and to M. velaini. It does not, however, exhibit the Plate 14, figure 8 peculiar oblique truncation of the posterior ventral 1900. Rochefortia stantoni Dall, Wagner Free Inst. Sci. Trans., margin that characterizes M. stantoni (Dall), and it vol. 3, pt. 5, p. 1160, pi. 43, fig. 11. differs furthermore in the similar anterior and posterior dental laminae. M. velaini is a less regular, more Shell minute, convex, elongate-ovate, quite inequilateral, the anterior end much longer; surface with faint incremental lines, elevated species. polished; dorsal margin arcuate in front, descending behind the Distribution: North Carolina : Pliocene, Waccamaw formation, umbo; ends rounded, an oblique nearly straight bit of margin Walkers Bluff, Bladen County. intervenes between the posterior rounded end and the areua'te base as if a little of the edge had been shaved off; beaks low, Mysella velaini Gardner, n. sp. hinge with small lamellar teeth, the anterior nearly twice as long as the posterior, resiliary notch small; adductor scars Plate, 14, figures 15, 16 high, rather large, and distinct; margin simple, entire. Longi Shell minute, moderately compressed, elongate-ovate, tude 3.6, altitude 2.4 [2.2], diameter 1.5 [0.8] millimeters— inequilateral. Umbones low, inconspicuous, rising only Dall, 1900. a little above the level of the dorsal margin, located Holotype, a right valve: U. S. Nat. Mus. 115102. about two-thirds of the distance toward the posterior Type locality: Natural Well, Duplin County, N. C. margin. Posterior end very short, faintly depressed, Duplin marl. broadly and evenly rounded; anterior end much pro This minute, ovate, inequilateral form is the most duced, the dorsal margin rudely parallel to the base, individual of any of the east coast Tertiary Mysellas. the lateral margin evenly rounded; base line horizontal It is characterized by a transversely elliptical outline medially. Incremental sculpture strong, irregular, and a simple laminar dentition. most conspicuous anteriorly. Resilifer concealed be The species was named in honor of Dr. T. W. Stan- neath the tip of the umbones. Dental laminae short, ton, who retained his interest in and his command of subequal, feeble but distinct, subspinose near their the Lower Cretaceous faunas through many years of ventral extremities. Adductor impressions and pallial duty in high administrative positions. line obscure. Dimensions of holotype: Height 3.0 millimeters, Distribution: Virginia: Miocene, Yorktown formation, Syca more on the Nottoway River, Southampton County. width 4.2 millimeters, convexity 0.9 millimeter. • North Carolina: Miocene, Duplin marl, Natural Well and 1% Holotype, a right valve: U. S. Nat. Mus. 325548. miles north of Magnolia, Duplin County. Pliocene, Waccamaw Type locality: Walkers Bluff on the Cape Fear River, formation, Neills Eddy Landing, 3 miles north of Cronly, Co Bladen County, N. C. Waccamaw formation. lumbus County; Wilmington, New Hanover County. This odd little ovate form is characterized by the Mysella bladenensis Gardner, n. sp. obliquely elliptical outline, the relatively strong incre mental sculpture, and the feeble dentition. It is more Plate 14, figures 17, 18 elevated and less regular than M. bladenensis, the only Shell thin, minute, moderately compressed, elongate- form that approaches it in general outline. It is named oval, slightly contracted anteriorly. Umbones low, al in honor of M. Velain, the author of the genus most level with the anterior dorsal margin, incurved, Rochefortia. placed about two-thirds of the distance back toward the Distribution: North Carolina: Pliocene, Waccamaw forma posterior margin. Anterior dorsal margin rectilinear, tion, Walkers Bluff, Bladen County; Neills Eddy Landing, 3 parallel with the horizontal base line; lateral margin miles north of Cronly, Columbus County. evenly rounded; posterior end very short, slightly con Mysella majorina Gardner, n. sp. tracted behind the umbones; rounded laterally. Incre mental sculpture strong, equally conspicuous on all Plate 14, figures 13, 14 parts of the external surface. Radial sculpture dis Shell moderately large for the genus; transversely cernible under high magnification, possibly adventitious ovate; moderately compressed, inequilateral. Umbones as in so many of the species of Leptonacea. Resilifer low and inconspicuous, a little behind the median hori concealed beneath the tip of the umbo. Dental lamellae zontal, slightly bulbous at their apices. Lunule and short, equal, divergent, subspinose near their ventral escutcheon not defined. Anterior end produced, the margins. Adductor impressions and pallial line dorsal slope very gentle, almost rectilinear; the lateral obscure. margin broadly rounded. Posterior end relatively Dimensions of holotype: Height 3.0 millimeters, short and narrow; the dorsal margin descending more width 4.5 millimeters, convexity 1.0 millimeter. rapidly posteriorly than anteriorly; the lateral margin Holotype, a right valve: U. S. Nat. Mus. 325550. obtusely pointed. Base line feebly arcuate. External Type locality: Walkers Bluff, Bladen County, N. C. surface polished, sculptured only with microscopically Waccamaw formation. fine and close concentric striations. Ligament entirely PART 1. PELECYPODA 87 internal, lodged in a subumbonal resilial pit concealed Aligena chowanensis Gardner, n. sp. beneath the apices of the umbones. Hinge lamellae of Plate 14, figures 31, 32 right valve short, equal, divergent, subspinose distally; margins of left valve on each side of the umbones Shell small, moderately convex, elevated, roughly beveled to fit into the sockets between the lamellae and trigonal, inequilateral. Umbones inflated, subcentral, the dorsal margins of the right valve. Interior of strongly prosogyrate. Dorsal and lateral areas not valve faintly radiate. Adductor muscle impressions differentiated. Anterior end contracted and slightly and pallial line obscure. excavated in front of the umbones; rounded and some Dimensions of cotypes: Right valve, height 2.7 milli what produced laterally. Posterior end obscurely con meters, width 4.0 millimeters, convexity 0.6 millimeter. vex, rounding rather abruptly into the feebly arcuated Left valve, height 2.7 millimeters, width 4.1 milli ventral margin. Surface sculptured with fine, irregu meters, convexity 0.5 millimeter. lar, discontinuous striations; resting stages conspicu Cotypes, a right and a left valve of different indi ous, occurring at fairly regular intervals, 4 in all. viduals : U. S. Nat. Mus. 325549. Ligament internal; resilifer narrow, obliquely elong Type locality: Neills Eddy Landing on the Cape ated, deeply submerged beneath the umbones. Cardinal Fear River, N. C. Waccamaw formation. broken away; scar, of moderate size, just below the tip Mysella majorina is conspicuous among its congeners of the beak. Adductor impressions and sinus obscure. for its narrow, obtusely pointed, posterior extremity. Dimensions of holotype: Height 4.7 millimeters, It is known only from the type locality. width 4.7 millimeters, convexity 1.5 millimeters. Distribution: North Carolina: Pliocene, Waccamaw forma Holotype, a right valve: U. S. Nat. Mus. 325551. tion* Neills Eddy Landing (3 miles north of Cronly) on the Type locality: The single right valve on which the Cape Fear River, Columbus County. species is founded was collected in the marls of the Yorktown formation at Colerain Landing, on the Genus ALIGENA H. C. Lea Chowan River, Bertie County, N. C. 1846. Aligema H. C. Lea, Am. Philos. Soc. Trans., 2d ser., vol. 9, The peculiar concavo-convex outline of the anterior p. 238. and posterior ends, the attenuated dorsal region and Type by subsequent designation (Dall, Wagner Free Inst. Sci. the strong resting stages are not displayed by any of Trans., vol. 3, pt. 5, p. 1175) : Aligena striata H. C. Lea. Mio the coexistent Aligenas and vaguely suggest some of cene (Yorktown) from Petersburg, Va. the small Phacoides, notably P. trisulcatus Conrad. Shell equivalve; subequilateral, closed posteriorly and an Distribution: North Carolina: Miocene, Yorktown formation, teriorly ; hinge with one cardinal tooth and a long shallow Colerain Landing, Bertie County. sulcation under the beaks. The cardinal tooth is, in general, rather small. The sulcus Aligena rhomboidea Gardner, n. sp. appears to have received the ligament. It commences at the beak and runs obliquely past the dorsal margin into the cavity Plate 14, figure 23 under the beak. As I possess only odd valves of both the fol lowing species, I am unable to determine whether the shell is Shell rather large for the genus, strongly convex, equivalve or not. * * * I have called the genus Aligena, slightly depressed posteriorly, inequilateral, roughly one of the surnames of Venus, from ite resemblance to Erycina, rhomboidal. Umbones placed a little behind the also an appellation of that goddess.—H. C. Lea, 1846. median line, inflated, feebly prosogyrate. Anterior Aligena is known by its rounded-trigonal convex dorsal margin rectilinear; subparallel with the base, shell, obliquely elongated resilifer, and single sub extending a little beyond it; lateral margin broadly umbonal cardinal. rounded. Posterior end shorter than anterior and The genus has representatives in the Tertiary de much narrower; posterior dorsal slope steep, roughly posits of the east coast and of the Paris and Vienna parallel with the anterior lateral margin. Surface Basins and still persists in the cooler waters of the badly worn; sculpture limited to incrementals that were Atlantic. probably rather strong. Ligament internal. Resilifer Two species were cited by Lea in his original de narrow, elongated, deeply submerged beneath the car scription of Aligena. The first, designated as the type dinal margin. Cardinal tooth solitary, a small, of the genus, is A. striata. The second, A. laevis (pi. rounded protuberance directly below the tip of the 14, figs. 24-26), differs from the first in the much more umbo. Interior polished. Adductor impressions and produced and less conical cardinal tooth and in the pallial line obscure. thickened, and, modified dorsal margins. Dall sug Dimensions of holotype: Height 7.8 millimeters, gested that it is "apparently a species of Fulcrella" but width 8.8 millimeters, convexity 2.3 millimeters. it is distinct from the American species assigned to Holotype, a left valve: U. S. Nat. Mus. 325552. that genus. Only the holotype, a right valve, has Type locality: Duplin marl at the Natural Well, been recorded. Duplin County, N. C. 88 MOLLUSCA FROM MIOCENE AND LOWER PLIOCENE OF VIRGINIA AND NORTH CAROLINA Aligena rhomboidea does not seem to be closely related pressed, attached by the lower left valve, which is to any of the coexistent Aligenas. It is larger than irregular in outline, moderately deep, and medially de any except the largest of the A. aequata; the rhom- pressed; upper right valve flattened except near the boidal outline is peculiar to the species, and the cardinal apex of the umbo, irregular in outline, obscurely bi- or tooth is relatively smaller than in any of its congeners. tri-lobate. Surface of lower valve sculptured with Only a single left valve was collected. about half a dozen overlapping lamellae, transversely puckered, the free edges occasionally flaring into sub- Distribution: North Carolina: Miocene, Duplin marl, Natural spinose processes, which occur most commonly along Well, Duplin County. the ridges that outline the medial depression and on Superfamily CHAMACEA the posterior slope; sculpture of upper valve much finer, the laminae sometimes breaking into free spines Family CHAMIDAE along the summits of the radial ridges and near the posterior margin, usually gathered into closely proxi The Chama group offers one of the best examples of mate and closely appressed tubuli. Ligament groove the effect of habitat on the outline of valves and on the narrow, moderately deep. Dental socket of left valve development of hinge dentition. True Chama is narrow, oblique, undercutting the dorsal margin; tooth attached by the left valve, Pseudochama by the right, laminar, slightly crescentic, transversely grooved dor- but in both genera the resulting form is the same—a sally; dental process of right valve rather slender, heavy, concave, often cornucopia-shaped attached valve sharp; dorsal margin grooved beneath the umbones to and a thinner, flatter free valve. The Mesozoic Rudi- correspond to the sulcations of the tooth of the left stids of all the sessile bivalves present the most striking valve. Adductor impressions elongate-oblong, sub- shell modifications, but the same tendency may be medial, the anterior terminating just in front of the observed to a lesser degree in the Ostreas. dental lamina. Pallial line simple. Inner margins finely and closely crenate. Genus CHAMA Linnaeus Chama striata Emmons is a smaller and more com 1758. Chama Linnaeus (part), Systema naturae, 10th ed., p. 601. pressed species than its less frequent congener, C. con-^ 1919. Chama Odhner, K. svenska vetensk. akacl. Handl., Band gregata Conrad. The medial depression of C. striata 59, Nr. 3, p. 75. is a diagnostic character; the lamellae on the left valve Type by subsequent designation (Schmidt, 'C. F., Versuch are fewer, and the spines are fewer and stronger than tiber die beste Einricht, etc., pp. 63, 177, 194, Gotha, 1818) : those of C. congregata. The right valve is more flat Chama lazarus Linnaeus. Recent in the Indian Ocean. tened than in C. congregata and the radial sculpture The apices are twisted to the right, and the left valve more delicate except for an occasional strongly de is attached to the substratum. veloped spine. In Florida C. striata has been reported only from the Cancellaria zone of the Choctawhatchee, Chama striata Emmons whereas C. congregata occurs not only in the Ccmcellaria Plate 13, figures 12-15 zone but also in the underlying Ecphora zone. C. con gregata has been reported by Olsson from the Gatun 1858. Chama striata Emmons, North Carolina Geol. Survey of Costa Rica. C. involuta Guppy of the upper Mio Kept, p. 288, fig. 211. 1863. Chama striata Emmons. Conrad, Acad. Nat. Sci. Phila cene mid-American fauna is a smaller shell with a delphia Proc. for 1862, p. 576. more highly inflated left valve and a more closely 1903. Chama striata Emmons. Dall, Wagner Free Inst. Sci. plicate sculpture. Trans., vol. 3, pt. 6, p. 1401. Distribution: Virginia: Miocene, Yorktown formation, Benns 1932. Chama striata Eminons. Mansfield, Florida Geol. Survey Church, Isle of Wight County. Bull. 8", p. 91, pi. 16, figs. 8,10. North Carolina: Miocene, Yorktown formation, Rock Land Shell small, ovate, rather thick for its size; lower valve dis ing, Craven County. Duplin marl, 2l/2 miles south of Clinton, tinctly striate. Usually found in the hollow or inside of the 4 miles south of Clinton, Sampson County; 3 miles northeast univalves.—Emmons, 1858. of Warsaw, Natural Well, 1% miles north of Magnolia, and Habitat, North Carolina. Frank Wilson's and W. H. Kornegay's marl pits (near Mag nolia), Duplin County; Lumber ton (near the bottling works), Right and left ^valves of different individuals from 2 miles below Lumberton, 4 to 5 miles below Lumberton, 1% the Waccamaw formation at Neills Eddy Landing on miles northeast of Fairmont (Ashpole), and at Fairmoint, Robe- the Cape Fear River, N. C., have been figured. The son County. Pliocene, Waccamaw formation, Lake Waccamaw, right valve (U. S. Nat. Mus. 325541) measures 17.0 Neills Eddy Landing, Columbus County; Wilmington, New millimeters in height and 18.5 millimeters in width. Hanover County. Outside distribution: Miocene, Choctawhatchee formation, The left valve (also U. S. Nat. Mus. 325541) measures northern Florida. Pliocene, Waccamaw formation, Tillys Lake, 24.0 millimeters both in height and in width. Horry County, S. C. Caloosahatchee marl, Caloosahatchee Shell inequivalve, inequilateral, small, rather com River and Shell Creek, Fla. PART 1. PELECYPObA 89 Genus FSEUDOCHAMA Odhner tooth, an irregular pit for the reception of the corre 1917. Pseudochama Odhner, K. svenska vetensk. akad. Handl., sponding process in the right valve. Muscle impres Band 52, No. 16, p. 30. sions much elongated, slightly reniform, the dorsal termination of the anterior adductor subumbonal; Type by monotypy: Chama cristella Lamarck. Recent from the Gulf of Siam to Java, the Moluccas, and Australia. posterior adductor less produced dorsally. Pallial line simple. Inner surface finely and irregularly crenate a The apices are twisted to the left, and it is the right short distance from the margin of the valve. valve that is attached to the substratum. The generic Pseudochama corticosa (Conrad) is conspicuous value of the sinistral twist is not recognized by among its congeners for its large size and sinistral beaks. Davies.43 Distribution: Virginia: Miocene, Yorktown formation, York- Pseudochama corticosa (Conrad) Gardner town, York County; near mouth of Baileys Creek, Prince George County; 3% miles north of Smithfield, Isle of Wight County. Plate 13, figures 5, 16, 28 North Carolina: Miocene, Yorktown formation, 1% miles above Murfreesboro, Hertford County; 6 miles west of Golds- 1833. Chama corticosa Conrad, Am. Jour. Sci., 1st ser., vol. 23, boro, Wayne County; Rock Landing, Craven County. Duplin p. 341. marl, Natural Well, 1% miles north of Magnolia, Duplin County; 1838. Chama corticosa Conrad, Fossils of the medial Tertiary Lumber ton (near the bottling works), Robeson County. of the United States, p. 32, pi. 17, fig. 3. Outside distribution: Miocene, Duplin marl, Darlington, Darl 1855. Chama corticosa Conrad. Tuomey and Holmes, Pleiocene ington County, S. C. fossils of South Carolina, p. 22, pi. 7, figs. 1-3. 1858. Chama corticosa Emmons, North Carolina Geol. Survey Superfamily CAKDIACEA Kept., p. 288, fig. 210. 1863. Chama corticosa Conrad, Acad. Nat. Sci. Philadelphia Family CARDJJIDAE Proc. for 1862, p. 576. 1903. Chama corticosa Conrad. Dall, Wagner Free Inst. Sci. Genus CARDIUM Linnaeus Trans., vol. 3, pt. 6, p. 1400. 1758. Cardium Linnaeus, Systema naturae, 10th ed., p. 678. Shell sinistral, with strong concentric undulated laminae 1799. Cardium Lamarck, Prodrome d'une nouvelle classification transversely striated; superior valve fiat; inner margin cren- des coquilles: Soc. d'histoire nat. Paris Mem., p. 86. ulated. Found with the preceding species [Chama congregata Conrad].—Conrad, 1833. Type by subsequent designation (Schmidt, C. F., Versuch iiber die beste Einricht, etc., pp. 53, 176, Gotha, 1818) : Cardium Type locality: James River near Smithfield, Isle of costatum Linnaeus. Recent in the Indo-Pacific. Wight County, Va. The type of the genus is a thin, gaping, highly in Illustrations of specimens from the Duplin marl at flated, transversely elongate shell, with narrow elevated Darlington, S. C., made by Tuomey and Holmes, have radials persistent to the margin and interlocking at the been reproduced. margin with the radials of the opposite valve. The Shell large, heavy, lamellose, attached by the strongly cardinals of the right valve are two prominent cusps convex right valve; upper (left) valve flat, disklike; united at the base and received between the anterior and obscure, submedial carina most clearly defined on the posterior cardinals of the left valve, one beneath the umbones, becoming evanescent ventrally; posterior other rather than side by side. Both the anterior and radial fold usually developed. Umbones very high and the posterior laterals are strongly developed in both prominent, twisted toward the left; right umbo per valves. forming at least one complete revolution; umbo of left Cardium s. s. is not recorded in the fossil state. valve less strongly gyrate; outline of interior of valve, exclusive of cardinal area, subcircular. Surface of Genus CERASTODERMA Mbrch both valves covered with overlapping concentric lamel 1853. Cerastoderma Morch, Catalogus conchyliorum quae reli- lae that are attached dorsally, the ventral edges more quit D. Alphonso d'Aguirra & Gadea Comes de Yoldi, flaring and more closely overlapping in the upper fasc. 2, p. 34. valve than in the lower; transverse striations irregular, 1930. Cerastoderma (Poll) Mo'rch. Stewart, Acad. Nat. Sci. most conspicuous on eroded surfaces and toward the Philadelphia Special Pub. 3, p. 259. ventral margin of the right valve. Ligament groove Type by subsequent designation (Von Martens, Zool. Rec. for inset, crescentic, broader and deeper in the right valve 1869, vol. 6, p. 586, 1870) : Cardium edule Linnaeus. Recent than in the left. Dental socket in right valve broad, along European shores from the ' North Atlantic to the transversely elongated, central in position, separated Mediterranean. from ligament groove by a shelly ridge and limited Valves closed; rotund, transversely or obliquely ventrally by a rude, horizontal, dental process; den ovate, cordate in outline. Anterior and posterior areas tition in left valve little more than a roughened inconspicuous or not defined. Kadial costae numerous, modification of the dorsal margin and, ventral to the elevated, smooth, granulated, or imbricated. Inter costal areas simple. Left cardinals anterior when 43 Davies, A. M., Tertiary faunas, vol. 1, p. 150, 1935. interlocked. 90 MOLLUSCA FROM MIOCENE AND LOWER PLIOCENE OF VIRGINIA AND NORTH CAROLINA Cerastoderma laqueatum (Conrad) Conrad posterior area and with fewer but broader radials. It occupies in the fauna of the Duplin and Waccamaw Plate 16, figure 4 much the same position that C. laqueatum (Conrad) 1831. Cardium laqueatum Conrad, Acad. Nat. Sci. Philadelphia does in the St. Marys. Jour., 1st ser., vol. 6, p. 258. C. laqueatum (Conrad) is represented in the Area 1938. Cardium laqueatum Conrad, Fossils of the medial Ter zone of the Choctawhatchee formation by Cardium tiary of the United States, p. 31, pi. 17, fig. 1. (Cerastoderma} laqueatum blountense Mansfield, 1932. 1839?. Car Mum ingens Wagner. Unpublished figure. The Floridian species is not so large as that from the 1863. Cardium (Cerastoderma) laqueatum Conrad, Acad. Nat. Sci. Philadelphia Proc. for 1862, p. 576. middle Atlantic slope, is less oblique, and differs in 1897. Cardium ingens Wagner. Dall, Wagner Free Inst. Sci. the details of the sculpture pattern. In these varia Trans., vol. 5, p. 10, pi. 3, fig. 2. tions it approaches Cerastoderma waltoniamwi, abund 1900. Cardium (Cerastoderma) laqueatum Conrad. Dall, idem, ant in the Shoal River formation of the Alum Bluff vol. 3, pt. 5, p. 1092. group. 1904. Cardium (Cerastoderma) laqueatum Conrad. Glenn, Maryland Geol. Survey, Miocene, p. 319, pi. 86, fig. 1. Distribution: Virginia: Miocene, St. Marys formation?, Nomini Cliffs, Westmorland County. St. Marys formation, Shell cordate, ventricose, thin, with about 33 subtriangular, half a mile below Bowlers Wharf, Essex County; Claremont transversely wrinkled ribs; umbones prominent; lunule not Wharf (lower bed), and old Claremont Wharf (lower bed), profoundly impressed and somewhat lanceolate; cardinal tooth Surry County. subulate. Outside distribution: Miocene, Hawthorn formation, Porters Cab[inet of the] Academy. Landing, Effinghani County, Ga. Choptank formation, Greens Inhabits—Fossil from Maryland. boro, Caroline County, Md.; Dover Bridge and Sand Hill, Talbot Length 1% inches; length and height nearly equal. The only County, Md.; Governor Kun, Flag Pond, and St. Leonards Creek, determinate fossil species of its genus yet discovered in this Calvert County, Md.; Jones Wharf, Turner, Pawpaw Point, and country; I found it only in the clay beds at St. Marys River, Cuckold Creek, St. Marys County, Md. St. Marys formation, and always in a state of decomposition, that rendered it im Cove Point, Calvert County, Md.; Langleys Bluff and St. Marys possible to obtain any but mutilated specimens.—Conrad, 1831. River, St. Marys County, Md. A left valve from the Choptank formation at Jones Cerastoderma acutilaqueatum (Conrad) Conrad Wharf on the Patuxent River, St. Marys County, Md., was figured by Glenn, and the illustration is repro Plate 16, figure 5 duced in this paper. The specimen is in the collection 1839. Cardium acutilaqueatum Conrad, Fossils of the medial of the Maryland Geological Survey, Johns Hopkins Tertiary of the United States, back cover of No. 1. University, Baltimore, Md. 1840. Cardium acutilaqueatum Conrad, idem, p. 34, pi. 18, fig. 2. 1863. Cardium (Cerastoderma) acutilaqueatum Conrad, Acad. Shell large; the height and width nearly equal; Nat. Sci. Philadelphia Proc. for 1862, p. 576. rounded and produced anteriorly, obliquely truncated 1900. Cardium (Cerastoderma) acutilaqueatum Conrad. Dall, posteriorly, slightly arcuate ventrally. Umbones in Wagner Free Inst. Sci. Trans., vol. 3, pt. 5, p. 1092. flated. Radial ribs generally rounded, less frequently Shell oblique, ovate, ventricose, rounded at base and posterior flat-topped or triangular, slightly wider than the inter- extremity; ribs about 36, subtriangular, narrow, prominent; radials, normally 28 to 32 in number, exclusive of the posterior margin very long, oblique, and subrectilinear; umbo 6 to 9 low, overturned ridges on the posterior area; very narrow, summit very prominent; margin profoundly crenate. Length 4 inches, height 4y2 inches. Locality, Yorktown, Va.— faint secondary radial striae sometimes visible on the Conrad, 1839. summits of the primaries; concentric sculpture of un- This species has been confounded with C. laqueatum, the ribs dulatory incrementals that are strongest near the pos of which, in immature specimens, resemble those of the present terior margin of the valves; ribs made up of hollow species in their subtriangular form; but the latter shell is cones, one within the other, -laid obliquely on the shell, proportionately more elevated, being higher than long, whilst the apices directed toward the umbones—a very weak the former is rather more in length than height.—Conrad, 1840. structure responsible for the decorticated condition in Conrad's illustration of his holotype, a right valve, which the valves of this species are usually found; has been reproduced. sculpture best preserved near the ventral margins; scars Cerastoderma acutilaqueatum weathers in much the left by the ribs in the form of pairs of elevated radiat same manner that Cerastoderma laqueatum does. It ing lines, each pair marking the lateral boundaries of is more widely distributed than the latter species, though a former rib. the geologic and geographic ranges of both are much Cerastoderma laqueatum (Conrad) is a relatively the same. The former tends, in a general way, to be lower, broader form than C. acutilaqueatum of the the more common and to occur at a slightly higher hori same author. The ribs are slightly fewer and are zon and in a more southern area. Dall reports the usually flat or rounded on the top rather than tri species from the upper bed at Alum Bluff, Liberty angular, as in the latter species. Dinocardium robus- County, Fla., an outcrop considered by Mansfield to be tum (Solander) is not quite so broad as C. laqueatum, a typical of the Ecphora zone of the Choctawhatchee for little more oblique, with a more strongly differentiated mation. PART 1. PELECYPODA 91 Distribution: Virginia: Miocene, Yorktown formation, York- Distribution: Virginia: Miocene, Yorktown formation, York- town, York County; a quarter of a mile south of the Smith- town, Bellefield, York County; l1/^ miles west of the mouth of field powerhouse, Isle of Wight County; a quarter to % mile Baileys Creek, Prince George County; * Smithfield and Zuni, below Sycamore, Southampton County; % mile north of Chuck- Isle of Wight County; Sycamore, 3 to 4 miles above the lower atuck, 2% miles northwest of Suffolk, 1 mile west of Suffolk, Seaboard Railway bridge, and % to % mile above the lower iy2 miles northeast of Suffolk, 1 mile northeast of Suffolk, Seaboard Railway bridge over the Meherrin River, Southampton and % mile below the Suffolk'waterworks dam, Nansemond County. County. North Carolina: Miocene, Yorktown formation, 1% miles North Carolina: Miocene, Yorktown formation, 2 miles below above Branches Bridge, 1 mile above Branches Bridge, and •Toddy Station, 2 miles southeast 'of Tugwell (on Jacobs Branches Bridge, Northampton County; Halifax (on Mr. Dur Branch), 3 miles south of Farmville, 2% miles north of Stand ham's farm), % mile above the Atlantic Coast Line Railway ard, 8 to 9 miles west of Greenville (on the east side of Pine- bridge and at Palmyra Bluff, Halifax County. log Branch), 9 to 10 miles south of Greenville, and 1 mile north Outside distribution: Miocene, Choctawhatchee formation, west of Galloway Crossroads, Pitt County; 1% miles north Alum Bluff (upper bed), Calhoun County, Fla. (?) Miocene, east of Chocowinity, Beaufort County, % mile east of Lizzie, Gay Head, Mass. (Dall). Greene County; Rock Landing, Craven County. Duplin marl, Natural Well, Duplin County. Genus TRACHYCARDIUM Morch Outside distribution: Miocene, Choctawhatchee formation, Alum Bluff (upper bed) (Dall), Calhoun County, Fla. 1853. Trachycardium Morch, Catalogus conchyliorum quae reli- quit D. Alphonso d'Aguirra et Gadea Comes de Yoldi, Cerastoderma virginianum (Conrad) Conrad fasc. 2, p. 34. Plate 16, figure 3 Type by subsequent designation (Von Martens, Zool. Rec. for 1869, vol. 6, p. 586, 1870) : Cardium isocardia Linnaeus. Re cent on the east coast from Hatteras to Trinidad; fossil in the 1839 (April). Cardium virginianum Conrad, Fossils of the medial Tertiary of the United States, back cover of No. 1. later Tertiary and Pleistocene. 1839 (December). Cardium quadrans Rogers and Rogers, Am. Valves closed, rotund, or ovate-cordate in outline; Philos. Soc. Trans., 2d ser., vol. 5, p. 375, pi. 30, fig. 1. ribs concentrically sculptured or granulose, many of 1840, Cardium virginianum Conrad, Fossils of the medial Ter them elaborately imbricated or tuberculate; left cardi tiary of the United States, p. 33, pi. 18, fig. 1. 1840. Cardium ingens Wagner. Conrad, idem, p. 33. Not C. nals anterior when interlocked. Ingens Wagner, 1839? 1863. Cardium (Cerastoderma) virginianum Conrad, Acad. Nat. Trachycardium isocardia (Linnaeus) Sci. Philadelphia Proc. for 1862, p. 576. Plate 15, figures 19, 20 ,1900. Cardium (Cerastoderma) virginianum Conrad. Dall, Wagner Free Inst. Sci. Trans., vol. 3, pt. 5, p. 1094. 1758. Cardium isocardia Linnaeus, Systema naturae, 10th ed., 1932. Cardium (Cerastoderma) virginianum Conrad. Mans p. 679. field, Florida Geol. Survey Bull. 8, p. Ill, pi. 17, fig. 6. 1782. Cardium isocardia Linnaeus. Chemnitz, Conchylien cabi net, vol. 6, p. 182, pi. 17, figs. 174-176. Shell very oblique, convex-depressed; ribs about 26, broad, 1845. Cardium isocardia Linnaeus. Reeve, Conchologia iconica, flat; interstices narrow and very shallow; summit narrow and vol. 2, Cardimm, pi. 17, fig. 84. not very prominent, oblique; anterior margin rectilinear, ex 1856. Cardium egmontianum Shuttleworth, Jour, conchyliologie, tremity angular; posterior extremity rounded; basal margin vol. 5, 2d ser., vol. 1, p. 172. very long, arcuated. Length about 4 inches. Locality, James 1858. Cardium isocardia Linnaeus. Holmes, Post-Pleiocene River, near Smithfield.—Conrad, 1839. fossils of South Carolina, p. 25, pi. 5, fig. 4. Conrad's illustration of his holotype, a right valve, 1875. fCardium eburniferum Guppy, Annals and Mag. Nat. His has been reproduced. tory, ser. 4, vol. 15, p. 51, pi. 7, fig. 3. 1900. Cardium (Trachycardium) isqcardia Conrad. Dall, Wag Cerastoderma virginianum (<3onrad) is an unusually ner Free Inst. Sci. Trans., vol. 3, pt 5, p. 1085. well characterized species. The diagnostic features are Cardium testa cordata ; sulcis squamis fornicatis imbricatis.— the rhomboidal outline; the low, flattened, posterior Linnaeus, 1758. umbones; the rectilinear anterior margin; the sharply Paired valves of a .Recent individual from the Flor differentiated posterior area; and the very low, broad, ida coast (U. S. Nat. Mus. 57147) have been figured. flat-topped ribs, often showing faint, secondary stria- The shell measures 47.5 millimeters in height and 37.5 tion. The posterior area is unsculptured except for millimeters in width. five to seven impressed lines, which become obsolete before reaching the margin. The concentric sculpture This, is the type of the subgenus and has about 27 to 33 ribs, with comparatively low and distant arcuate imbricating is similar to that of the other members of the subgenus. scales; the ribs are squarish and the interspaces channeled, Even the merest fragment may be determined if it the scales tend to be seated on the posterior side of the ribs; includes a bit of the hinge line or of the radial on the anterior face of the shell the imbrications are closer, sculpture. lower, and heavier, but these ornaments change their form very The species is limited in its known distribution to gradually from one end of the shell to the other. the Yorktown of southern Virginia and northern North Linn6 and the earlier writers confounded this shell with a similar form from the East Indies, which was afterwards Carolina, and to the Ecphora zone of the Choctawhat named C. squamosum by Gmelin. A specimen of the West chee formation of Florida (Mansfield, 1932). Indian shell was in the Linnaean cabinet and serves to hol 401033—43- MOLLUSCA FROM MIOCENE AND LOWER PLIOCENE OF VIRGINIA AND NORTH CAROLINA terior lateral is very feeble. The obscure radial sculp Type by subsequent designation (Schmidt, C. F., Versuch ture is most strongly indicated in the crenation of the iiber die beste Einricht, etc., pp. 51, 177, Gotha, 1818) : Tellina radiata Linnaeus. Recent in the West Indies. inner margins. Shell transversely ovate to ovate-trigonal in outline, Laevicardium sublineatum (Conrad) Conrad compressed; usually rostrate and flexed to the right posteriorly, and broadly depressed in front of the Plate 15, figures 11, 12, 15, 16 rostrum. Umbones low, subcentral or posterior, often 1841. Cardium sublineatum Conrad, Am. Jour. Sci., 1st ser., p. opisthogyrate. External surface rarely smooth; dom 347, pi. 2, fig. 13. inant sculpture concentric, regular, and generally in 1843. Cardium suNineatum Conrad, Assoc. Am. Geologists and cremental in character; radial ornamentation commonly Naturalists Proc. and Trans., p. 110, pi. 5, fig. 13. suggested by the color pattern and by the reinforcing 1845. Cardium sublineatum Conrad, Fossils of the medial Ter tiary of the United States, p. 66, pi. 37, fig. 4. internal rays, rarely by the sculpture; oblique sculpture 1856. Cardium sublineatum Conrad. Tuomey and Holmes, developed in one group. Ligament external, opistho- Pleiocene fossils of South Carolina, p. 64, pi. 19, fig. 3. detic. Two cardinals, one of them bifid, developed in 1863. Cardium (Laevicardium) sublineatum Conrad, Acad. Nat. each valve, interlocking in the closed valves so that Sci. Philadelphia Proc. for 1862, p. 576. the bifid teeth are flanked on either side by a simple 1900. Cardium (Laevicardium) sublineatum, Conrad. Dall, laminar tooth. Anterior and posterior laterals de Wagner Free Inst. Sci. Trans., vol. 3, pt. 5, p. 1111. 1906. Laevicardium sublineatum, Conrad. Bb'se, Inst. Geol. veloped in some groups in both valves; in others, Mexico Bol. 22, pp. 25, 28, 79, pi. 2, figs. 1-3; pi. 11, reduced to a single right anterior lateral. Sinus free fig. 4. or coalescent ventrally with the pallial line, often dis Obliquely obovate, thin, slightly ventricose, with obsolete crepant in the two valves, the dorsal margin of the radiating lines, most distinct near the ends; submargins of sinus commonly uniting the anterior and posterior anterior and posterior sides destitute of radiating lines; within adductors. striated; margin crenulated.—Conrad, 1841. The Tellinas are essentially a modern group, though Type locality: Wilmington, 1ST. C. Waccamaw they have their roots in the Mesozoic. formation. Dimensions of figured specimens: Eight valve, height Subgenus MOERELLA Fischer 28.7 millimeters, width 29.0 millimeters, convexity 8.7 1887. Hoerella Fischer, Manuel de conchyliologie et de paleon- millimeters. Left valve, height 26.0 millimeters, width tologie conchyliologique, p. 1147. 28.5 millimeters, convexity 8.0 millimeters. Type by monotypy: Tellina, donacina, Linnaeus. Recent off Figured specimens, a right and a left valve of dif the European coasts from the Hebrides to the Mediterranean. ferent individuals (U. S. Nat. Mus. 325559) from the Fossil in the Coralline Crag of England. Waccamaw formation at Neills Eddy Landing on the Shell rather small for the genus, transversely ovate, Cape Fear River, Columbus County, N. C. obscurely rostrate posteriorly. Sculpture dominantly The outer smooth and polished surface is readily re concentric, the Kecent species often rayed with colors. moved by erosion and reveals the radially striate, Umbones low, opisthogyrate. Lunule and escutcheon porcellanous layer beneath. extremely narrow, indicated but not well defined. Distribution: Virginia: Miocene, Yorktown formation, % Ligament external, opisthodetic. Two cardinal teeth mile north of Chuckatuck and 1^ miles northeast of Suffolk, in each valve, the anterior right and the posterior left Nansemond County. simple and laminar, the posterior right and the anterior North Carolina: Miocene, Yorktown formation, 14 to % mile above Edenhouse Point, Bertie County. Duplin marl, left stouter and bifid. True laterals not developed in Natural Well and at several neighboring localities, Duplin the left valve, though the edges are beveled to func County. Pliocene, Waccamaw formation, Walkers Bluff, tion as laterals and are received within the lateral Bladen County; Lake Waccamaw, Cronly (^ mile east of the sockets on the right valve; the anterior lateral more factories), and Neills Eddy Landing, Columbus County; Wil elevated and closer to the umbo than the posterior. Pal mington, New Hanover County. Outside distribution: Miocene, Duplin marl, Darlington, lial sinus confluent ventrally with the pallial line Darlington County, S. C.; Santa Rosa and Santa Maria Tetetla, throughout the greater part of its extent. V,era Cruz, Mexico. Waccamaw formation, Nixons, Tillys Lake, Most of the east coast Tertiary Tellinas, referred in and Todds Ferry, Horry County, S. C. earlier publications to Angulus, seem more closely allied to Moerella. Angulus is an Indo-Pacific group Superfamily TELLINACEA in which only a single lateral—the right anterior—is Family TELLINIDAE developed; it has not been recognized in the Miocene and lower Pliocene faunas of the east coast. Genus TELLINA (Linnaeus) Lamarck Tellina (Moerella) declivis Conrad 1758. Linnaeus, Systema naturae, 10th ed., p. 674. 1799. Lamarck, Prodrome d'une nouvelle classification des co- 1834. Tellina declivis Conrad, Acad. Nat. Sci. Philadelphia Jour., quilles, Soc. histoire nat. Paris Me"m., p. 84. 1st ser., vol. 7, p. 131. PART 1. PELECYPODA 95 1840. Tellina declivis Conrad, Fossils of the medial Tertiary of than T. producta Conrad, and the anterior dorsal mar the United States, p. 35, pi. 19, fig. 1. gin is generally at a low angle to the base instead of 1863. Tellina (Angulus) declivis Say. Conrad, Acad. Nat. Sci. parallel with it, as in the latter. It is more elongated, Philadelphia Proc. for 1862, p. 573. 1894. Tellina, (Angulus) declivis Say. Whitfield, U. S. Geol. however, than T. calpix, from the Yorktown of North Survey Mon. 24, p. 77, pi. 14, figs. 4-6. Carolina, an oval form with subcentral umbones and 1900. Tellina (Angulus) declivis Conrad. Dall, Wagner Free rounded dorsal margins nearly similar to one another. Inst Sci. Trans., vol. 3, pt. 5, p. 1029. T. macilenta Dall, of the Duplin fauna, is relatively 1904. Tellina (Angulus) declivis Conrad. Glenn, Maryland higher, with a much higher umbonal angle. T. sayi Geol. Survey, Miocene, p. 298, pi. 72, fig. 14. 1909. Tellina declivis Conrad. Grabau and Shinier, North Deshayes, of the Pliocene and Eecent, is closely allied American index fossils, vol. 1, p. 567, fig. 777a. and is its possible descendant. T. sayi, however, aver Shell somewhat elliptical, with the anterior [posterior] side ages a little smaller, is the more regular in outline, and short, and the margin obliquely truncated; posterior [anterior] is obliquely produced and truncated along its posterior end regularly rounded; beaks hardly prominent; lateral teeth margin. In T. declivis, there is a small contraction at distinct. the nymph; below it, the slightly flaring margin may Locality: Yorktown, Va. be very gently arched or rather obscurely truncated. It resembles in outline the Amphidesma subreflexa noMs; and might, viewing the exterior only, be mistaken for that shell.— The angle of the margin with the base is decidedly Conrad, 1834. higher than in T. sayi and often approaches a right Shell thin, fragile, compressed, inequilateral. Out angle. The dentition of T. sayi is usually a little line ovate-elongate. Umbones low, inconspicuous, stronger, and the dorsal margin of the pallial sinus opisthogyrate, situated about two-thirds of the distance seems a trifle higher. The two forms rarely occur toward the posterior margin. Anterior dorsal margin together, T. declivis being essentially a Miocene species produced, gently sloping into the rounded anterior end ; north of the Hatteras, whereas T. sayi is a post-Miocene posterior slightly contracted at the nymph, the contrac shell south of the Hatteras. The former, however, per tion most noticeable in the right valve; obscurely trun sists in much reduced numbers in the Caloosahatchee cate from the umbones to the base; ventral margin fauna. straight, ^usually at-a lo.w angle to the anterior dorsal Distribution: Virginia: Miocene, St. Marys formation, 1 to 2 margin. Surface feebly sculptured with concentric miles below Bowlers Wharf, Essex County; Union Mills, 2% groovings that are least faint anteriorly and near miles south of Farnham, Richmond County; Urba*ina, Middle sex County; Sunken Marsh Creek (lower bed), James River, the base, though obsolete on the umbones. Cardi Surry County. Yorktown formation, Yorktown, York County; nals normal in both valves, but rather small and rude. Petersburg, Dinwiddie County; 2 miles northwest of Smithfield; Anterior lateral of right valve strong, not in line with &y2 miles below Zuni, Isle of Wight County; % mile north of the anterior cardinal, but a little dorsal to it; posterior Chuckatuck, % mile east of Everets Post Office, 5% miles lateral short, low, and inconspicuous, located near the northwest of Suffolk, 2y2 miles northwest of Suffolk, 1% miles ventral terminal of the nymph; margin o.f valve slightly north of Suffolk, l 1^ miles north of Suffolk, iy2 miles northeast of Suffolk, 1 mile northeast of Suffolk, half a mile below the' contracted at this point, thus making a little V-shaped Suffolk waterworks dam, and 1 mile south of Deep Creek, groove for the reception of the feeble prominence on the Nansemond County. dorsal margin of the left valve. No true laterals de North Carolina : Miocene, Yorktown formation, Palmyra Bluff, veloped in left valve but dorsal margins modified to Halifax County; half a mile above Bells Bridge, Tar River, function as laterals. Slightly thickened anterior ray Edgeconibe County; Tar Ferry on Wiccacon Creek (opposite Harrellsville), 1% miles below Tar Ferry, and Mount Pleasant often visible internally. Muscle scars and pallial line Landing, Hertford County; % to % mile above Edenhouse and sinus usually obliterated. Anterior scar some Point, Bertie County. what elongated and very irregular; posterior semi- Outside distribution: Miocene, Calvert formation, Shiloh, elliptic. Sinus, a wavy line rising a little higher in Cumberland County, N. J.; Plum Point, Calvert County, Md. the right valve than in the left and reaching its max Choptank formation, Jones Wharf, St. Marys County, Md. Pliocene, Caloosahatchee marl, Shell Creek, Fla. imum at a point on a vertical with the umbones, then more gradually descending and falling only a little Tellina (Moerella) sayi (Deshayes ms.) Dall short of the anterior scar. Tellina declivis Conrad is one of the most abundant Plate 17, figure 4 representatives of the genus in the Tertiary of North 1822. Tellina polita Say, Acad. Nat. Sci. Philadelphia, 1st ser., Carolina and, more particularly, of Virginia along the vol. 2, p. 276. Not T. polita Poli, 1795, T. polita York River and in the vicinity of Suffolk, Nansemond Spengler, 1798, T. polita Pulteny, 1813, or T. polita County. Though inconstant in outline, the species has Sowerby, 1825. an individuality that makes it readily recognizable—a 1834. Tellina polita Say, Am. conchology, pt. 7, pi. 65, fig. 2. 1846. Tellina, polita Say. Hanley, Thesaurus conchyliorum, generally untidy appearance owing to the irregularity vol. 1, pt. 6, p. 282, pi. 57, fig. 60. of outline and to the nicked and ragged margins of the 1856. Tellina polita Say. Tuomey and Holmes, Pleiocene fos thin and fragile valves. It is less elongated anteriorly sils of South Carolina, p. 91, pi. 22, fig. 6. 96 MOLLUSCA FROM MIOCENE AND LOWER PLIOCENE OP VIRGINIA AND NORTH CAROLINA 1856. Tellina (Angulus) polita Say. H. and A. Adams, Genera noted the similarity of piesa to his subspecies, T. sayi Recent Mollusca, vol. 2, p. 398. deadenensis from the Area and Cancellaria zones of 1858. Angulus polita Say. Holmes, Post-Pleiocene fossils of the Choctawhatchee formation. The Recent species is South Carolina, p. 45, pi. 8, fig. 2. 1900. Tellina sayi Deshayes, ms., fide Dall. a little higher relatively than either of the fossil forms. 1900. Tellina (Angulus) sayi Deshayes. Dall, Wagner Free Distribution: North Carolina: Pliocene, Waccamaw forma Inst. Sci. Trans., vol. 3, pt. 5, p. 1034. tion, Walkers Bluff, Bladen County; Neills Eddy Landing, .3 miles north of Cronly, Columbus County. Shell transversely subtriangular, minutely wrinkled concen Outside distribution: Pliocene, Waccamaw formation, Wacca trically, white, immaculate; anterior [posterior] margin rather maw River, S. C. Caloosahatchee marl, Caloosahatchee River, shorter than the posterior [anterior] one, the hinge slope Fla. Croatan sand, Slocums Creek, Craven County, N. C. declining, in a very slightly arquated line to a subacute termi Pleistocene, Simmons Bluff, S. C.; Rose Bluff, St. Marys River, nation; basal margin nearly rectilinear from behind the Nassau County, Fla. Recent, North Carolina to Yucatan. middle to the anterior [posterior] termination; a lateral tooth behind [in front of] the primary teeth. Tellina (Moerella) dupliniana Dall Length two-fifths of an inch, breadth thirteen-twentieths of an inch. 1900. Tellina (Angulus) dupliniana Dall, Wagner Free Inst. Sci. Inhabits the southern coast. Trans., vol. 3, pt. 5, p. 1032, pi. 46, fig. 17. . Cabinet of the Academy and Philadelphia Museum. 1900. Tellina (Angulus) propetenella Dall, idem, vol. 3, pt. 5, p. Not unfrequent on the beach of South Carolina and east 1033, pi. 46, fig. 6. Florida.—Say, 1822. 1904. Tellina (Angulus) dupliniana Dall. Glenn, Maryland The well-known name of this species must be changed, as Geol. Survey, Miocene, p. 299, pi. 73, fig. 1. it had been used for a Tellina 3 or 4 times before Say so ap Shell small, solid, rather convex, inequilateral, dorsal margins plied it, and one of the prior attempts at least was made on rectilinear, diverging at an agle of about 108°, anterior end a species of Angulus. The name of Deshayes is suggested in longer, rounded evenly into the base, which is nearly parallel one of his manuscripts in my possession.—Dall, 1900. with the anterior dorsal margin; posterior end much shorter, A Recent left valve (U. S. Nat. Mus. 128444) from pointed, the terminal angle slightly decumbent and the basal margin in front of it slightly incurved; beaks incouhtileuous, off the coast of South Carolina has been figured. It hinge normal, the right adjacent lateral short and the anterior measures 10.0 millimeters in height and 17.4 millimeters hinge margin in front of it grooved for the edge of the Opposite in width. valve; middle of the disk smooth—the beaks, posterior dorsal Shell rather thin but solid, moderately compressed, area, and the portions of the disk near the basal margin more often slightly flexuous in front of the posterior fold. or less concentrically striated; interior with the pallial sinus rising to a small angle under the umbo, then descending in a Posterior end cuneate, the anterior rounded, the an somewhat wavy line to a point on the pallial line considerably terior dorsal margin gently sloping, as a rule, though short of the anterior adductor scar; in the left valve the sinus approaching a parallel with the straight base line. is not angulated above and extends somewhat nearer the Umbones low, inconspicuous, opisthogyrate, placed be adductor; the interior is marked with some faint radiations tween half and two-thirds of the distance toward the near the adductors, but no thickened ray appears. Longitude 12.5, altitude 8, diameter 4 millimeters. posterior margin. Posterior flexure feeble. Faint con There is some little difference in the proportional height in' centric groovings visible near the ventral margin, ob different individuals, in the amount of inflation, and in the solete in the umbonal region. Ligament external, opis- arcuation of the posterior dorsal margin; the posterior fold, or thodetic; nymphs elongate. Dentition similar to but ridge bounding the posterior dorsal area, is not strongly marked. slightly stronger than that of Tellina declivis—a simple Compared with T. tenella Verrill, this species is a heavier and higher shell, with the posterior end more^ pointed and decurved. and a bifid cardinal in both right and left valves, and a The dorsal margin of the right valve is not grooved in T. tenella, strong anterior and an inconspicuous posterior lateral and the adjacent lateral is longer than in T. dupliniana of the in the right valve only. Faint internal radiations but same size.—-Dall, 1900. no thickened fold. Muscle scars and pallial sinus ob Holotype: U. S. Nat. Mus. 115040. literated in the majority of individuals. Anterior Type locality: Magnolia, Duplin County, N. C. muscle impression irregular and somewhat elongated; Duplin marl. posterior semielliptical. Dorsal margin of pallial sinus T. dupliniana Dall is a compact and solid little marked by wavy line, which reaches its maximum ele species that displays a rather remarkable series of vation beneath the umbones, then descends more grad variations in the degree of convexity, posterior flexture, ually, almost but not quite reaching the anterior scar. and general form—particularly in respect to the in T. sayi Deshayes is identified with the Recent fauna clination of the anterior and dorsal margins to the and has only a meager representation in the North base and the outline of the posterior margin—and, to Carolina Pliocene. It is well characterized among its a limited extent, even in the dentition, notably in the Tertiary congeners by the moderately low height and prominence of the anterior right lateral. the obliquely produced and truncated posterior end. A constant peculiarity of the hinge separates the T. (Moerella) piesa Gardner, abundant and wide form from all the coexistent Tellina with which in some spread in the Shoal River formation of northern Flor of its various manifestations it might easily be con ida, is perhaps a precursal form. Mansfield, 1932, has fused. This is the position of the anterior right lat- PART 1. PELECYPODA 97 eral, which instead of being a little dorsal to the 1932. Tellina (Moerella) macilenta Dall. Mansfield, Florida cardinal, as in the majority of Moeretta, is in a direct Geol. Survey Bull. 8, p. 137, pi. 27, figs. 10-12. line with it. Shell solid, subtrigonal, moderately convex, equivalve; in T. propetenella Ball (U. S. Nat. Mus. 144850) is equilateral ; anterior end longer,< rounded, posterior roundly pointed near the base; beaks pointed, dorsal margins slightly synonymous with T. dupliniana. The forms separated arched; surface polished, faintly distantly concentrically stri under that name are slightly smaller than the average ated ; near the basal margin the striae become regular and dupliniana and are more uniform in outline, but they more sharp and conspicuous; posterior dorsal area nearly have no characters by which they can be distinguished smooth, posterior end not folded, but slightly flexed; hinge even subspecifically. Much more worthy of separation normal, adjacent lateral short, strong and prominent; pallial sinus somewhat arched above, long, wholly confluent below; are forms from Robeson County, most of which are interior more or less radially striate; in the' left valve the unusually high and heavy individuals, strongly flexed thickened rays inside the adductor scars are obvious. Longi posteriorly, with the posterior margin somewhat pro tude 16.5, altitude 10.5 [10.8], diameter 5.5 milometers. duced and with remarkably strong and prominent This form is not intimately related to any of the recent teeth. As these characters are exhibited in a greater species and is easily discriminated by its solid subtrigonal or less degree, both individually and collectively, at a valves, size, and shortness from any of the Miocene species.— Dall, 1900. number of widely separated localities, it has seemed unnecessary and undesirable to subdivide the species. Holotype> a right valve: U. S. Nat. Mus. 115045. Type locality: Natural Well, Duplin County, N. C. Distribution: Virginia: Miocene, Yorktown formation, York- town, and 1 mile below Yorktown, York County; 5% miles Duplin marl. northwest of Smithfield, and % mile northeast of Smithfield, Mansfield records the species from the Cancellaria Isle of Wight County: Sycamore, Southampton County; 1% zone of the Choctawhatchee formation. miles southeast of Reics Perry, 1% miles north of Suffolk, 1% Distribution: North Carolina: Miocene, Yorktown formation, miles north of Suffolk, l1/^ miles northeast of Suffolk, 1 mile 2^ miles northwest of Williamston (on Joseph Cherry's farm), northeast of Suffolk, and % mile below the Suffolk water Martin County; 1 mile east of Lizzie (on T. N. Lassiter's works dam, Nansemond County. farm), Greene County. Duplin marl, Natural Well, 1% miles North Carolina: M locene, Yorktown formation, Palmyra north of Magnolia, Duplin County; 2 mile^s below Lumberton Bluff, Halifax County; 2 miles west of Rocky Mount, 5 miles and 1% miles northeast of Pairmont (on Andrew Jones' farm), below New Bridge on the Tar River, Edgecombe County; Robeson County. Pliocene, Waccamaw formation, Walkers Jacobs Branch (2 miles southeast of Tugwell), 3 miles south Bluff, Bladen County. of Parmville, 8 to 9 riiles south of Greenvile, 9 to 10 miles south of Greenville, a ad 2 miles east of Grifton (on J. F. Tellina (Moerella?) verdevilla Gardner, n. sp. Brooks' land), Pitt County; 1 mile west of Wilson (in Hominy Swamp, on Prank Ba:'nes' land), Wilson County; 1% miles Plate 17, figures 6, 7 below Tar Perry, Wiccacon Creek, and 3 to 4 miles below Tar Ferry, Hertford Count 7; Colerain Landing and % to % mile Shell thin, ovate, subcuneate posteriorly, flexuous. above Edenhouse Point, Bertie County; Rock Landing, Craven Posterior fold indistinct, emphasized by depression in County. Duplin marl, 4 miles south of Clinton (on J. L. front of it. Umbones low, inconspicuous, slightly opis- Mathis' farm), Sampson County; Natural Well, l1/^ miles north thogyrate, posterior. Lunule narrow, elongated, clear of Magnolia, and the :narl pit of W. H. Kornegay near Mag ly delimited. Anterior dorsal margin gently sloping; nolia, Duplin County; 1 mile west of Lumberton (on the farm of Charles Rowland), Lumberton (near the bottling works), lateral margin broad, evenly rounded. 'Posterior end 2 miles below Lumberton, 4 to 5 miles below Lumberton, 4 miles obliquely truncated. Dorsal slope steep, margin ex northeast of Pairmont (on the farm of D. E. Lewis), and 1% panding slightly below the nymph. Base arcuate, miles northeast of Fairmont (on the farm of Andrew Jones), somewhat contracted posteriorly. Surface sculptured Robeson County. Pliocene, Wncoamaw formation, 4 miles south with microscopic concentric striations and stronger in- of Elizabethtown on i-Iammoml Creek (on the land of Mrs. Clark), and Walkers Bluff, Bladen County; Lake Waccamaw, crementals. Hinge characters of only the right valve Cronly (i£ mile east of the factories), and Neills Eddy Land known. Ligament external, opisthodetic; nymph sub- ing (3 miles north of Cronly), Columbus County; Wilmington, linear, a deep groove at its ventral margin. Anterior New Hanover County. cardinal short, laminar; posterior cardinal deeply sul- Outside distribution : Miocene, Calvert formation, Plum Point, cated; both the anterior and posterior laterals promi Gal vert County, Md. (Dall). Pliocene, Waccamaw formation, Tillys Lake. Waccamaw River, S. C. Caloosahatchee marl, nent, subspinose, separated from the margins by deep Caloosahatchee River, Fla. grooves. Traces of an inner posterior ray faintly vis ible in one of the two valves. Adductor impressions Tellina (Moerella) macilenta Ball very feeble. Pallial line indistinct. Sinus moderately Plate 17, figure 5 broad, the dorsal margin slightly bowed beneath the umbones, the ventral margin confluent with the pallial 1900. Tellina (Angulut) macilenta Dall, Wagner Free Inst. Sci. line, rather shallow for the genus, extending only about Trans., vol. 3, pt. 5, p. 1034, pi. 46, fig. 20. 1919. Tellina (Angulur.) macilenta Dall. Gardner and Aldrich, two-thirds of the distance toward the anterior margin. Acad. Nat. Sci. Philadelphia Proc., vol. 71, p. 19. Dimensions of holotype: Height 13.8 millimeters, (Check list of fossils frpm Muldrow Place, S. C.) width 20.0 millimeters, convexity 3.6 millimeters. Par- 98 MOLLUSCA FROM MIOCENE AND LOWER PLIOCENE OF VIRGINIA AND NORTH CAROLINA atype: Height 15.0 millimeters, width 21.0 millimeters. being more nearly equilateral and more rounded, both Holotype and paratype, both right valves: U. S. anteriorly and posteriorly. The outline suggests a Nat. Mus. 325596. miniature Macoma, but the development of laterals in Type locality: 6 miles below Greenville, Pitt County, the right valve throws it out of that genus. A knowl N. C. Yorktown formation. edge of the left valve is necessary for the assured Tellina verdevilla, n. sp., is sharply separated from placement of the species within the proper subgeneric all members of the Moerella group, which it most closely group. resembles in the external characters, by the strong pos Distribution: North Carolina: Miocene, Yorktown formation, terior lateral in the right valve. The outline recalls 3y2 miles below Palmyra Bluff, Halifax County; 8 to 9 miles Moerella madlenta Dall, but the hinge is less concen south of Greenville and 9 to 10 miles south of Greenville, Pitt trated and the anterior lateral more isolated. In most County. of the Moerellae the groove separating the anterior car Tellina (Subgenus uncertain) egena Conrad dinal and the dorsal margin is continuous with the lateral socket. In verdevllla the groove is extremely Plate 17, figure 1 shallow medially. 1834. Tellina egena Conrad, Acad. Nat. Sci. Philadelphia Jour., Distribution: North Carolina: Miocene, Yorktown formation, 1st ser., vol. 7, p. 131. 6 miles below Greenville, Pitt County. 1840. Tellina, egena Conrad, Fossils of the medial Tertiary of the United States, p. 35, pi. 19, fig. 2. Tellina (Moerella?) calpix Gardner, n. sp. 1900. Tellina (Peronidiaf) egena Conrad. Dall, Wagner Free Inst. Sci. Trans., vol. 3, pt. 5, p. 1029. Plate 17, figures 2, 3 Shell subtriangular, convex, with fine, crowded, concentric lines and obscure, radiating striae; anterior margin oblique, Shell thin, oval, rather compressed, slightly con rectilinear; extremity subangulated; dorsal margin but little tracted posteriorly, almost but not altogether equilat arcuated; lateral teeth none. Length, 2^ inches. eral. Umbones low, flattened, opisthogyrate, situated a Locality, James River, Va.—Conrad, 1834. little behind the median line. Both anterior and pob- It is strange that a form so conspicuously largo terior dorsal and distal margins rounded; the anterior should not have been recorded from some of the later end slightly broader, higher, and more evenly arched; collections. the posterior with a tendency toward an obscure trun- Dall referred T. egena to Peronidia, a group char catou: Base line gently arched. Posterior flexure acterized by the absence of laterals. The type has not indistinct. Concentric groovings discernible only on been examined. the anterior end and near the ventral margin. Valves faintly radiate within, but not noticeably thickened. Genus MACOMA leach Ligament external, attached to narrow, elongated nymphs. Dentition of right valve only known, similar 1819. Macoma Leach. Ross, John, A voyage of discovery made under the orders of the Admiralty in His Majesty's to that of Tellina, declivis Conrad; posterior bifid and ships Isabella and Alexander for the purpose of ex anterior simple cardinals rather slender. Anterior lat ploring Baffin's Bay and inquiring into the probability eral of moderate strength, situated a little dorsal to the of a northwest passage, App. 2, p. 62. anterior cardinal; posterior lateral low and small; 1819. Macoma Leach, Jour, physique, vol. 88, p. 465. lateral grooves extending for some distance toward the Type by monotypy: Macoma> tencra Leach = Tellina icalcarea base before becoming entirely obsolete. Posterior Gmelin. Recent in the North Atlantic and Arctic Oceans. muscle impression subcircular; anterior irregular, Outline transversely ovate or subtrigonal, strongly longer than broad. Pallial sinus very indistinct, more flexuous, as a rule, posteriorly. External surface regular than in most of the group, ascending from a smooth or feebly sculptured concentrically. Two di point about halfway down the anterior side of the vergent cardinals in each valve. Laterals absent. posterior adductor impression to a point underneath Pallial sinus often discrepant in the two valves, varying the umbones and level with the dorsal boundary of the widely within the limits of the genus. posterior scar, then descending gradually in a regular The genus is fairly common from the Miocene on line and just clearing the anterior adductor. and is represented in the Recent seas by about 100 Dimensions of holotype: Height, 8,0 millimeters, species. Though not restricted to the cooler waters, width 11.5 millimeters, convexity 2.0 millimeters. the typical members are characteristic of the higher Holotype a right valve: U. S. Nat. Mus. 325595. latitudes. Type locality: Eight to 9 miles south of Greenville, Pitt County, N C. Yorktown formation. Macoma virginiana (Conrad) Dall The shell is remarkable for its regularly rounded, Plate 17, figures 9, 10 oval form, its subcentral umbones, and the absence of 1840. Tellina lusoria Conrad, Fossils of the medial Tertiary of the posterior angulation. It is apparently most closely the United States, p. 35, pi. 19, figr 3. Not PsammoUaf related to T. declivis Conrad, from which it differs in lusoria Say, 1822. PART 1. PELECYPODA 99 1856. Tellina lusoria Conrad. Tuomey and Holmes, Pleiocene general aspect; in the right valve there is a tendency fossils of South Carolina, p. 89, pi. 22, fig. 5. toward a perceptible flare in the anterior dorsal mar 1858. Tellina lusoria, Emmons?, North Carolina Geol. Survey gin; in the left valve the anterior dorsal and ventral Kept., p. 297, f g. 225a. 1863. Tellina (Peronaederma) lusoria? Say. Conrad, Acad. margins are more nearly parallel. The species is well Nat. Sci. Philadelphia Proc. for 1862, p. 573. characterized by the nasute aspect of the posterior 1866. Macoma virgmiana Conrad, Am. Jour. Conchology, vol. 2, portion of the shell. This feature is absent in M. caro- p. 76. linensis Gardner and Aldrich, the closely related form 1900. Macoma virginiana Conrad. Dall, Wagner Free Inst. south of the Hatteras axis, for in the latter the pos Sci. Trans., vol. 3, pt. 5, p. 1048. terior dorsal margin declines at a uniform and rather Shell elliptical, with a distinct fold near the posterior ex steep angle, and the lateral margin is evenly rounded tremity ; posterior end reflected; posterior dorsal margin and merges gradually into the base line. straight, oblique, extremity truncated and much above the line Macoma virginiana Conrad is fairly common, par of the base; beaks nearest the posterior end; basal margin ticularly in the Yorktown formation of the State from very regularly arched; lateral teeth none. Locality, Yorktown, Va.—Conrad, 1840. which it takes its name. Mansfield has described a This species is extinct and may be distinguished from M. subspecies coensis from the Cancellarid zone of the lusoria, by being proportionally more elevated, rounded at base, Choctawhatchee formation, which differs both from and less compressed and reflexed anteriorly.—Conrad, 1866. M. virgmiana and from the subspecies conradi by the After repeated studies of the subject I have come to the more tapering posterior extremity. conclusion that Say's Psammo'bw, lusoria was probably based on a large specimen of the shell, which he afterwards described Distribution: Virginia: Miocene, St. Marys formation, 1 to 2 under the name of Tellina tenta. From that species the present miles below Bowlers Wharf, Essex County. Yorktown forma shell differs, as Conrad states it does from lusoria, by being tion, Yorktown, 1 mile below Yorktown, and 1% miles below higher, more arcuate below, and less compressed and flexuous Yorktown, York County; mouth of Baileys Creek, Prince behind; it also averages considerably larger. The pallial sinus George County; 7 to 7% miles below1 Zuni, 1% miles northeast is low, rather short, rounded in front, and about half confluent of Smithfield, and % mile northeast of Smithfield, Isle of with the pallial line below. There is some doubt as to whether Wight County; 1% miles southeast of Reiids Ferry, iy2 miles the shell figured by Emmons is the same, as he speaks especially north of Suffolk, 1% miles north of Suffolk, 1% miles north of sharp, elevated lines on the surface, which I have not east of Suffolk, 1 mile northeast of Suffolk, 1 mile east of observed on any of the Virginia shells.—Dall, 1900. Suffolk, and V2 mile below the Suffolk waterworks dam, Nanse- mond County. Shell thin, inflated, slightly inequivalve, the right Macoma virginiana conradi Dall valVe a trifle higher than the left, inequilateral, the Plate 17, figure 22 anterior end semielliptical, its dorsal margin subpar- allel to the base, and the lateral margin broadly and reg 1900. Macoma conradi Dall, Wagner Free Inst. Sci. Trans., vol. ularly rounded. Posterior end shorter, attenuated, 3, pt. 5, p. 1048, pi. 47, fig. 3. the dorsal margin slightly contracted beneath the um- Shell thin, inflated, ovate, broad and rounded in front, rapidly attenuated, roundly pointed and somewhat flexuous behind; bones, and the dorsal and ventral margins converging beaks low, pointed, near the posterior third; surface smooth or at a low angle, obscurely truncated distally. Umbones marked only with fine incremental lines; hinge normal, feeble, posterior, opisthogyrate. Surface feebly sculptured teeth small; adductor scars large, pallial sinus short, rounded, with incremental. Ligament external, opisthodetic, and curved (in the right valve) well backward below before seated, on a very narrow and rather elongated coalescing with the pallial line. Longitude 22 [21.7] altitude 14, diameter 7 millimeters. nymph. Hinge armature of right valve a rather stout, This is a shorter and broader and less flexuous shell than simple, anterior cardinal and a rather slender, bifid, If. virginiana Conrad, some of the varieties of which somewhat posterior cardinal. Left valve with a bifid anterior aproach it.—Dall, 1900. and a very slender, almost laminar, posterior car Holotype, a right valve: U. S. Nat. Mus. 144475. dinal. No laterals developed in either valve. In Type locality: Yorktown, Va. Yorktown formation. terior faintly striated radially. Anterior adductor The characters that separate the type of conradi scar irregularly elongated; the posterior, semiellip from M. virginiana s. s. are of degree rather than kind, tical. Pallial sinus broad, rounded, often slightly and an unbroken series connecting the two forms can be arched just beneath the umbones, extending about two- established. The individuals from the Carolinas that thirds of the distance across from the posterior to the have been referred to this species are, however, distinct, anterior margin. and the same diagnostics that are used to separate Dimensions of figured specimen: Height 12.3 milli virginiana s. s. and carolinensis—that is, the nasute meters, width 19.8 millimeters. posterior end and the broader but more shallow pallial Figured specimen, a right valve: U. S. Nat. Mus. sinus of the former—are shared by the subspecies as 325594, from 1 mile northeast of Suffolk, Va. York- well. town formation. Distribution: Virginia: Miocene, Yorktown formation, York- Though the inequality of the valves is very slight, town, York County; Exit, 1% miles northwest of Suffolk, and it is sufficient to make a noticeable difference in their 1 mile northeast of Suffolk, Nansemond County, 100 MOLLUSCA FROM MIOCENE AND LOWER PLIOCENE OF VIRGINIA AND NORTH CAROLINA North Carolina: Miocene, Yorktown formation, Colerain Dimensions of holotype: Height 28.0 millimeters, Landing on the Chowan River, Bertie County. width 34.3 millimeters, convexity 7.1 millimeters. Holotype, a right valve: U. S. Nat. Mus.-325592. Macoma carolinensis Gardner and Aldrich Type locality: Yorktown, York River, Va. York- 1919. Macoma carolinensis Gardner and Aldrich, Acad. Nat. Sci. town formation. Philadelphia Proc., p. 50, pi. 3, figs. 5-7. Macoma cookei is described from a single valve col Right valve, altitude 12.3 millimeters, latitude 18.2 milli lected at the type locality of the Yorktown formation. meters, semidiameter 4.3 millimeters. Left valve of another This relatively large and elevated shell has, however, individual, altitude 12.5 millimeters, latitude 19.5 millimeters, little but the generic characters in common with its small semidiameter 3.3 millimeters. and transversely elongated congeners. In outline and Type locality: Darlington, S. C. Duplin Formation. general aspect it most closely resembles M. baltMca Lin Macoma carolinensis is the analogue in the Neogene south of the Hatteras axis of M. virainiana and its subspecies conradi naeus of the Pleistocene and Recent faunas. The north of the axis. It is rather higher, less flexuous, and more Yorktown species is larger, however, and has a much nearly equilateral than either of the former, both by reason stronger dentition. of the more nearly central umbones and the greater similarity I have the pleasure of naming the form in honor of of the anterior and posterior extremities. The posterior dorsal Dr. Wythe Cooke, whose name has long been associated margin of If. carolinensis has a uniform, fairly steep slope, while that of M. virginiana is slightly contracted directly behind with the Lower Tertiary faunas of the Gulf region. the umbones, then obliquely produced at a very low angle. Distribution: Virginia: Miocene, Yorktown formation, York- The posterior lateral margin of the former is rounded into town, York County. the slightly upturned base; that of the latter, obscurely trun cated and its ventral margin more strongly recurved. The Family SEMELIDAE Ball pallial sinus in both species varies quite widely but that of carolinensis is, on the average, more profound and more The family is most readily separable from the Telli- strongly arched beneath the umbones. nidae by the presence of an internal resilium. The species is rare in the Duplin and Waccamaw formations of North and South Carolina.—Gardner and Aldrich, 1919. Genus SEMELE Schumacher Distribution: North Carolina: Miocene, Duplin marl, 2 miles below Lumberton, Robeson County. Pliocene, Waccamaw 1817. Semele Schumacher, Essai d'un nouveau systeme des formation, Mrs. Guion's marl pit, Cape Fear River, Bladen habitations des vers testaces, p. 165. County. Type by monotypy: Tellina fetlculata Spengler=TeMwa Outside distribution: Pliocene, Caloosahatchee marl, Caloosa- proflcua Pulteney. Pliocene of South Carolina and Florida and hatchee River, Fla. living from Virginia to Fernando de Moronha and east to Bermuda in less than 50 fathoms. Macoma cookei Gardner, n. sp. Shell oval or suborbicular, slightly inequivalve, Plate 17, figures 8, 11 usually more or less rostrate posteriorly. Umbones Shell relatively large, irregular in outline; rather subcentral, low, proximate, prosogyrate. Ligament thin, flexuous; anterior half of shell moderately in short, external; resilium strong, internal. Hinge arm flated, posterior somewhat depressed. Posterior fold ature consisting of 2 cardinals and 2 laterals in • each obscure, evanescent toward the ventral margin. Um valve, the laterals of the right valve usually stronger. bones set a little in front of the median line, rather Adductor impressions large, semielliptical. Pallial low and inconspicuous, their tips acute. Anterior end sinus profound. somewhat eccentric, slightly flarfng dorsally, obscurely The genus is represented in the Tertiary formations and obliquely truncated medially; strongly arcuate by some 30 species, many of them very attractive, and toward the ventral margin; posterior end somewhat in the Recent waters by about 60 species, most of them produced and attenuated. Surface sculptured with tropical. fine, irregular concentric striations. Ligament opistho- Section SEMELE s. s. detic; nymph narrow elongated, rather surprisingly Semele s. s. includes the relatively large members of robust. Hinge armature of right valve reduced to a the genus. The sculpture may be radial and concentric, couple of short, feeble cardinals, divergent beneath the reticulate, or undeveloped. The chondrophore is umbones. Muscle impressions irregular, distinct, the obliquely elongated, the laterals of the left valve are anterior submedial and rudely elongated, the posterior feeble but present, and the left posterior cardinal is roughly quadrate. Pallial sinus of right valve co- slender and laminar. alescent ventrally with pallial line, upcurved dorsally, its maximum elevation a little above the median Semele subovata (Say) Dall horizontal and directly beneath the umbones, its frontal margin overreaching the median vertical but falling 1824. Amphidesma subovatd Say, Acad. Nat. Sci. Philadelphia Jour., 1st ser., vol. 4, p. 152, pi. 10, fig. 10. short of the anterior adductor, Pallial line moderately 1840. Amphi&esma svlovata Say. Conrad, Fossils of the medial distinct, Tertiary of the United States, p. 36, PART 1. PELECYPODA 101 1854. Syndosmya subobliqua Conrad, Acad. Nat. Sci. Phila (upper bed), Surry County; Fergusons Wharf, % mile north delphia Proc., vol. 7, p. 29 (lapsus for subovata). east of Smithfield, Benns Church; 1,4 mile north of Chuckatuck, 1862. Abra ovalis Conrad, Acad. Nat. Sci. Philadelphia Proc. for 1% miles southeast of Reids Ferry, 6^ miles below Zuni 1862, p. 288. and 12 to 14 miles below Zuni, Isle of Wight County; Sycamore, 1863. Abra (AmpMdesma) subovata, Say. Conrad, idem, p. % to V2 mile below Sycamore, Maddelys Bluff, and % to % 574. mile above the lower Seaboard Railway bridge over the Meher- 1900. Semele subovata Conrad. Dall, Wagner Free Inst. Sci. rin River, Southampton County; \% miles northeast of Suffolk, Trans., vol. 3, pt. 5, p. 990. 1 mile northeast of Suffolk, 1 mile west of Suffolk, % mile below 1900. Semele bella Conrad. Dall, idem, vol. 3, pt. 5, p. 990. the Suffolk waterworks dam, and the drainage ditch of the Not Semele bella, Conrad, 1875. Norfolk & Western Railway just east of Jericho ditch, Nanse- 1904. Semele subovata (Say). Glenn, Maryland Geol. Survey, mond County. Miocene, p. 295, pi. 72, figs. 6, 8. North Carolina: Miocene, Yorktown formation, 1 mile above 1909. Semele subovata (Say). Grabau and Shimer, North Murfreesboro, Hertford County; % mile above Bells Bridge American index fossils, vol. 1, p. 568, fig. 780a. over the Tar River, and Swift Creek, Edgecombe County; 2 miles southeast of Tugwell, 9 to 10 miles south of Greenville, Shell transversely ovate-oval, with somewhat prominent Hardeeig Creek (S1/^ miles from' confluence with Tar River), and regular concentric striae. and 1 mile northwest of Galloway Crossroads, Pitt County; 2 Shell compressed; beaks rather before the middle, but little miles north of Lizzie and 4 miles east of Lizzie, Greene County; prominent; anterior submargin with an obsolete, obtuse undu Colerain Landing, Bertie County. Duplin marl,, 1^ miles lation ; lunule lanceolate; cardinal and lateral teeth prominent. northeast of Fairmont, Robeson County. Length seven-tenths of an inch, breadth less than 1 inch.— Outside distribution: Miocene, Galveston well (at 2,552 to Say, 1824. 2,600 feet), Texas. Calvert formation, Centerville and Church Type locality: Maryland. Hill, Queen Annes County, Md.; Fairhaven, Anne Arundel County, Md. Choptank formation, Governor Run, Calvert This is a common species of the Virginia Miocene, separable County, Md.; Greensboro, Caroline County, Md.; Cordova, Peach from the S. oarinata—which is almost equally common—by its Blossom Creek, and Dover Bridge, Talbot County, Md.; Jones more oval and thinner shell and finer, sharper, and closer con Wharf, St. Marys County, Md. centric sculpture. The posterior dorsal area is usually con spicuously sculptured, whereas in S. carmata the tendency of the Semele subovata alta Gardner, n. subsp. sculpture on this area is to become obsolete.—Dall, 1900. Plate 17, figures 16, 17 Say has confused the anterior and posterior portions of the valve. The beaks are subcentral or slightly pos Shell high, ovate to subtrigonal. Somewhat com terior, and the obtuse undulation is on the posterior pressed posteriorly. Produced, rounded, and slightly and not the anterior area. inflated anteriorly. Umbones placed a little behind The examination ef a long series of individuals from the median line. Anterior dorsal slope gentle, pos a number of localities in the Virginia and North Caro terior more pronounced, in certain individuals gently lina Miocene indicates that all the elongate-oval to sub- arched; anterior lateral margin evenly rounded. Base triangular Semeles ornamented solely with close line arcuate, posterior sinus shallow, often obsolete. concentric laminae of approximately equal strength are Concentric sculpture fine, close, and lirate, or lamellar. referable to this single species. The other characters are shared by all members of The three subspecies are based on variations in the the species. outline and in the number and character of the con Dimensions of holotype: Height 21.0 millimeters, centric laminae and on the persistence or nonpersistence width 26.3 millimeters, diameter 11.3 millimeters. of the sculpture across the posterior keel. Holotype (double valves) : U. S. Nat. Mus. 325582. Semele subovata (Say) is separated from S. carinata Type locality: 2 miles northeast of Lizzie, Greene (Conrad) by the absence of secondary concentric orna County, N. C. Yorktown formation. mentation; from 8. 'bellmtnata (Conrad) by the ab The subspecies is relatively higher than other mem sence of radial ornamentation. In weathered individ bers of the species, and its sculpture is finer, closer, and uals erosion has often acted on the striae differently, less commonly lirate. It has a tendency, furthermore, partly obliterating some; whereas others retain their toward a larger size and a more pronounced inflation original prominence and thus give to the form the of the anterior portion of the valves. aspect of a more distantly sculptured species. Distribution: Virginia: Miocene, St. Marys formation, Ur The resemblance to S. carinata (Conrad) is embar banna, Middlesex County. Yorktown formation, Yorktown, York rassingly close where faint traces of the lost lirations County; Zuni (near the pumping station) and 6% to 7 miles still persist. The original sculpture usually may be below Zuni, Isle of Wight County; iy2 miles north of Suffolk, 1% caught on the lateral margins, however, even though it miles northeast of Suffolk, and 1 mile northeast of Suffolk, is removed from the disk. Nansemond County. North Carolina: Miocene, Yorktown formation, Palmyra Bluff, Distribution: Virginia: Miocene, St. Marys formation, Union Halifax County; 1 mile northwest of Galloway Crossroads, Mill, 2y2 miles south of Farnham, Richmond County; Urbanna, Pitt County; 2 miles northeast of Lizzie, Greene County; Cole- Middlesex County. Yorktown formation, Yorktown, Bellefleld, rain Landing, Bertie County. Pliocene, Waccamaw formation, York County; Petersburg, Dinwiddie County; Claremont Wharf Wilmington, New Hanover County. 102 MOLLUSCA FROM MIOCENE AND LOWER PLIOCENE OF VIRGINIA AND NORTH CAROLINA Semele bellastriata (Conrad) Ball fathoms except off Hatteras, where it occurs in both shallow and deep water. Plate 17, figures 27, 28, 32, 33 Section SEMELINA Dall 1837. AmpMdesma bellastriata Conrad, Acad. Nat. Sci. Phila delphia Jour., 1st ser., vol 7, p. 239, pi. 20, fig. 4. 1900. Semelina Dall, Wagner Free Inst. Sci. Trans., vol. 3, pt. 5, 1845. AmpMdesma cancellata D'Orbigny. Sagra, Historia fisica p. 986. politica y natural de la Isla de Cuba, pt. 2, vol. 5, p. 297, pi. 25, figs. 42-44. Type by original designation: Semelina nuculoides Conrad. 1847. AmpMdesma cancellata D'Orbigny. Sagra (French ed.), Upper Miocene of Virginia and North Carolina, Pliocene (Ca Histore Physique, Politique et Naturelle de L'lle de loosahatchee) of Florida, Recent from Hatteras to the West Cuba, Mollusques, vol. 2, p. 241; Atlas, pi. 25, figs. 42-44. Indies. 1862. Semele nexilis Gould, Boston Soc. Nat. History Proc., Shell small, nuculiform; sculpture uniform, close, concentric; vol. 8, p. 281. chondrophore short; left valve without distinct laterals, the 1862. Semele nexilis Gould, Otia conchologica, p. 238. dorsal margins fitting above the laterals of the right valve; 1873.. Semele nexilis Gould. Tryon, American marine conchol- left posterior cardinal absent or obsolete, the anterior cardinal ogy, p. 155. bifid; otherwise as in Semele s. s. 1875. Abra l)ella Conrad. In Kerr, Geol. Survey North Caro The species of this section are very similar to one another lina, Kept, App. A., p. 19, pi. 3, fig. 4. and have extended from the Oligocene through all the Tertiary 1883. Semele nexilis Gould. Ball, U. S. Nat. Mus. Proc., vol 6, horizons to the present fauna. For this reason it seems worthy p. 338. of sectional rank. The characters by which the shell differs 1885. Semele lata C. B. Adams. Bush, Connecticut Acad. Arts from Semele proper are only such as are usually correlated and Sci. Trans., vol. 6, pt. 2, p. 476. with diminished size.—Dall, 1900. 1889. Semele cancellata D'Orbigny. U. S. Nat. Mus. Bull. 37, p. 62. An exceedingly thin and laminar left posterior car 1900. Semele bellastriata Conrad. Dall, Wagner Free Inst. Sci. dinal is developed in both the Alum Bluff species. In Trans., vol. 3, pt. 5, p. 993. most individuals it is broken, but in a few it is 1932. Semele bellastriata (Conrad)? Mansfield, Florida Geol. preserved entire. Survey Bull. 8, p. 145, pi. 32, fig. 3. Shell elliptical, compressed; anterior margin very regularly Semele (Semelina) nuculoides (Conrad) Dall rounded; posterior side with a slight fold; disk with numerous prominent, not very regular, concentric striae and obscure Plate 17, figures 18, 19, 20, 21 radiating lines, which are profound near the anterior and pos 1841. AmpMdesma nuculoides Conrad, Am. Jour. Sci., 1st ser., terior extremities; beaks rather nearer the posterior extremity; vol. 41, p. 347. lateral teeth prominent, distinct in both valves; margin entire. 1845. AmpMdesma nuculoides Conrad, Fossils of the medial Inhabits Mobile Point, Ala. Occurs sparingly in the Newer Tertiary of the United States, p. 73, pi. 41, fig. 6. Pliocene marl, near Newbern, N. C.—Conrad, 1837. 1863. Abra nuculoides Conrad, Acad. Nat. Sci. Philadelphia Proc. Mansfield reports the doubtful occurrence of the for 1862, p. 574. species in the Ecphora zone of the Choctawhatchee 1889. Semele nuculoides Conrad. Dall, U. S. Nat. Mus., Bull No. 37, p. 62. formation. 1900. Semele nuculoidea Conrad. Dall, Wagner Free Inst. Sci. The figured specimens are U. S. Nat. Mus. 325583, Trans., vol. 3, pt. 5, p. 994. from the Waccamaw formation at Neills Eddy Landing 1932. Semele (Semelina) nuculoides (Conrad). Mansfield, Flor on the Cape Fear River, Columbus County, N. C. The ida Geol. Survey Bull. 8, p. 146, pi. 30, fig. 9. dimensions of the right valve are height 13.2 milli Ovate, convex, with very regular minute concentric lines; meters, width 18.3 millimeters; of the left valve, height anterior extremity acutely rounded; beaks near the posterior 14.5 millimeters, width i9.0 millimeters. extremity; basal margin arcuate; lateral teeth obsolete.— Conrad, 1841. Abra bella of Conrad is a reticulately sculptured form synonymous with his AmpMdesma bellastriata Type locality: Wihnington, N. C. of 1837. The two varieties of Dall, duplinensis and The figured specimens are U. S. Nat. Mus. 325581, appresa, were founded on individuals from the North from the Waccamaw formation at Neills Eddy Land Carolina Duplin marl that exhibit no radial sculpture ing on the Cape Fear River, Columbus County, N. C. but show peculiarities in the concentric sculpture. The height of the right valve is 3.8 millimeters, the These same features are developed, though less com width 5.6 millimeters; the height of the left valve is monly, in the subovata of Virginia, and complete gra 4.0 millimeters, the width 5.6 millimeters. dations to the normal form occur in both States. Three valves of Semelina nuculoides are reported by k Mansfield from the Cancellaria zone of the Choctaw Distribution: North Carolina: Pliocene, New Bern, Craven hatchee formation. County? (Conrad). Waccamaw formation, Walkers Bluff, Bladen County; Cronly and Neills Eddy Landing (3 miles Distribution: Virginia: Miocene, Yorktown formation, York- north of Cronly), Columbus County, town, York County; 1 mile northeast of Suffolk, Nansemond Outside distribution: Pliocene, Waccamaw formation, Nixons County. and Tillys Lake, Horry County, S. C. Caloosahatchee marl, North Carolina: Miocene, Duplin marl, 4 miles south of Clin Caloosahatchee River and Shell Creek, Fla. Recent, Cape Hat- ton (on the farm of J. L. Mathis), Sampson County; Natural teras to Cape St. Roque and east to Bermuda in less than 50 Well, drainage ditch just east of railroad 1% miles north of PART 1. PELECYPODA 103 Magnolia, and W. H. Kornegay's marl pit near Magnolia, nearly parallel with the dorsal margin. Length half an inch. Duplin County. Pliocene, Waccamaw formation, Walkers Bluff, Locality, Suffolk, Va.—Conrad, 1834. Bladen County; Lake Waccamaw, Cronly, Neills Eddy Landing Shell elliptical; anterior side narrowed, produced, rounded (3 miles north of Cronly), Columbus County; Wilmington, New at tip, the dorsal line rectilinear; posterior side very short, Hanover County. with a rather acute fold, the extremity narrow, but obtuse; Outside distribution: Pliocene, Caloosahatchee marl, Caloosa- lateral teeth in the right valve; in the left, none. hatchee River, Fla. Recent, Cape Hatteras south to the West Locality, Yorjjtown, Va.—Conrad, 1840. Indies in both deep and shallow water. Dimensions of figured specimens: Right valve, height Genus ABBA (Leach ms.) Lamarck 5.6 millimeters, width 10.4 millimeters, convexity 1.8 millimeters; left valve, height 9.0 millimeters, width 1818. Abra, (Leach ms.) Lamarck, Histoire naturelle des ani- 15.6 millimeters, convexity 2.7 millimeters. maux sans vertebres, vol. 5, p. 492. Figured specimens: U. S. Nat. Mus. 325584, the Type by subsequent designation (Herrmannsen, Indicis gen- right and left valves of different individuals. erum Malacozoorum, vol. 1, p. 1, 1846: Mactra tennis Montagu. Locality of figured specimens: Yorktown formation Recent off the English and Irish coasts. at Colerain Landing, Chowan River, Bertie County, Most of the European conchologists, including N. C. Forbes, Hanley, Stoliczka, and Lamy, reject Abra in Mansfield 46 described a subspecies jacksonensis from favor of Syndosmya Eecluz, 1843. Lamarck, in listing the Ecphora zone of the Choctawhatchee formation. Leach's manuscript name, did not, to be sure, charac In his discussion of the subspecies he noted that Con terize the genus, but he gave a new name to a known rad in the first description of Amphulesma subreflexa, and recognizable shell, and, as Cossmann 45 pointed 1834, cited Suffolk, Va., as the type locality. In 1840 out, the genotype is beyond question. Whether or not he cited Yorktown. Mansfield remarked that he had Lamarck had it in his mind to create a new genus is not never found the species at Suffolk and never below the concern of nomenclature. the lower part of zone 2 of the Yorktown formation. Shell small, ovate to trigonal, or rudely quadrate Shell transversely elongate, strongly inequilateral, in outline; rather compressed, flexuous posteriorly. angulated posteriorly. Umbones low, flattened, opis- Umbones low, subcentral to posterior, prosogyrate. thogyrate, located about two-thirds of the distance back Outer surface smooth or finely sculptured concentri from the anterior end.. Anterior portion of shell cally. Internal ligament stronger than the external, horizontally produced, rounded laterally; posterior the chondrophore narrow but produced and deeply dorsal margin strongly oblique, rounding distally into inset beneath the umbones. Dentition delicate; nor a base line that is usually straight and subparallel to mally two short simple cardinals developed in each the anterior dorsal margin, though occasionally slightly valve and the modified dorsal margins of the left valve sinuous behind. Surface smooth, polished. Resilial received in the lateral sockets of the right; laterals pit deep, oblique, elongated, subparallel to the posterior commonly obsolete in the species of trigonal outline. dorsal margin. Lateral margins of right valve Pallial sinus deep, confluent ventrally with the pallial grooved to receive the modified dorsal margins of the line. left. Pallial sinus evenly rounded, extending forward The Eecent forms are relatively few but have a wide at least two-thirds of the distance toward the anterior geographic and bathymetric range. margin. The species varies rather widely in relative propor Abra subreflexa (Conrad) Conrad tions and in the configuration of the posterior margins. Plate 17, figures 23, 24, 30, 31 Its transversely elongate outline, however, sharply separates it from the associated Abra. 1834. Ampliidesmu subreflexa, Conrad, Acad. Nat. Sci. Phila Distribution: Virginia: Miocene, Yorktown formation, York- delphia Jour., 1st ser., vol. 7, p. 133. town, York County; Petersburg, Dinwiddie County; mouth of 1840. Amphidesma subreflexa, Conrad, Fossils of the medial Baileys Creek, Prince George County; Claremont Wharf (upper Tertiary of the United States, p. 37, pi. 19 (1st ed.), bed), and Sunken Marsh Creek (upper bed), Surry County; % fig. 6; (2d ed.), fig. 12. mtle northeast of Smithfield, Benns Church, and 12 to 14 1863. Abra subreflexa Conrad, Acad. Nat. Sci. Philadelphia Proc. miles below Zuni, Isle of Wight County; Sycamore, and % to % for 1862, p. 574. mile above the lower Seaboard Railway bridge, Southampton 1900, Abra, subreflewa, Conrad. Dall, Wagner Free Inst. Sci. County; 1% miles southeast of Reids Ferry, 2% miles north Trans., vol. 3, pt. 5, 997. west of Suffolk, 1% miles north of Suffolk, 1% miles northeast Shell somewhat elliptical, convex, anterior margin descend of Suffolk, 1 mile northeast of Suffolk, and the drainage ditch ing very obliquely and nearly rectilinearly from the beak; of the Norfolk & Western Railway just east of Jericho ditqh, extremity subreflected, obtusely pointed; posterior side elon Nansemond County. gated, margin rounded; anterior basal margin oblique and 46 Mansfield, W. C., Miocene pelecypods of the Choctawhatchee forma 45 Cossmann, A. E. M., and Peyrot, A., Conchologie n6og£nique de tion of Florida : Florida Geol. Survey Bull. 8, p. 148, pi. 32, figs. 11, 14, ]' Aquitaine, vol. 1, 215, 1909. 15,1932. 104 MOLLUSCA FROM MIOCENE AND LOWER PLIOCENE OF VIRGINIA AND NORTH CAROLINA North Carolina: Miocene, Yorktown formation, near Mur- anterior of which is slightly the stronger), and feebly freesboro, Tar Ferry on Wiccacon Creek (opposite Harrells- developed lateral grooves. In the left valve the an ville), 1% miles below Tar Ferry, 3 to 4 miles below Tar terior cardinal is fairly strong, ^but the posterior is Ferry, Dogwood Landing (on the Chowan River) and Mount Pleasant Landing, Hertford County; Colerain Landing, Mount almost obsolete; there are no distinct laterals, although Gould Landing, and % to % mile above Edenhouse Point, the dorsal margins are somewhat modified. The pal- Bertie County; Halifax on Quankey Creek (just below the lial sinus is deep and broad and evenly rounded. county bridge) and Palmyra Bluff, Halifax County; 3 miles The species is rare in Virginia but quite abundant west of Williamston and 2% miles northwest of Williamston in the post-Chesapeake formations of North Carolina. (on Joseph Cherry's farm), Martin County; % mile above Bells Bridge, Shiloh Mills, and Tarboro (on L. E. Fountain's farm), Mansfield reports a few young or fragmentary speci Edgecombe County; 8 to 9 miles southeast of Greenville and mens from the Cancellaria zone of the Choctawhatchee 9 to 10 miles south of Greenville, Pitt County. The species is formation. particularly abundant in the Yorktown of North Carolina. Distribution: Virginia: Miocene, Yorktown formation, 1% miles northeast of Suffolk and 1 mile northeast of Suffolk, Abra aequalis (Say) Holmes Nansemond County. Plate IT, figures 12-15 North Carolina: Miocene, Yorktown formation, Tar Ferry on Wiccacon Creek (opposite Harrellsville) and Mounf Pleasant 1822. Amphidesma aequaUs Say, Acad. Nat. Sci. Philadelphia Landing, Hertford County; Colerain Landing and % to % Jour., 1st ser., vol. 2, p. 307. mile above Edenhouse Point, Bertie County; 2% miles north 1830. Amphidesma aequalis Say, Am. conchology, facing pi. 28, west of Williamston (on Joseph Cherry's farm), Martin County; pi. 28 unnumbered lateral figures. 3 miles southwest of Frog Level (on J. A. Noble's branch), 8 1845. Amphidesma equalis Say. Conrad, Fossils of the medial to 9 miles southeast of Greenville, and 9 to 10 miles south Tertiary of the United States, p. 76, pi. 43, fig. 9. of Greenville, Pitt County; 1 mile west of Wilson, Wilson 1856. Amphidesma, equalis Conrad. Tuomey and Holmes, Pleio- County; 1 mile north of Castoria and 1 mile east of Lizzie cene fossils of South Carolina, p. 93, pi. 23, fig. 3. (on the farm of T. N. Lassiter), Greene County; Rock Land 1858. Abra aequalis Say. Holmes, Post-Pleiocene fossils of ing, Craven County. Duplin marl, drainage ditch just east of South Carolina, p. 50, pi. 8, fig. 7. Not Abra aequalis railroad 1% miles north of Magnolia, Duplin County; 2 miles Whitfield, U. S. Geol. Survey Mon. 24, p.' 80, pi. 14, below Lumberton, 4 to 5 miles below Lumberton, and 1% miles figs. 11-15, 1894. northeast of Fairmont, Robeson County. Pliocene, Waccamaw 1863. Abra equalis Say. Conrad, Acad. Nat. Sci. Philadelphia formation, Walkers Bluff, Bladen County; Lake Waccamaw, Proc. for 1862, p. 574. Cronly (% mile east of the factories), and Neills Eddy Landing 1867. Abra nuculiformis Conrad, Am. Jour.. Conchology, vol. 3, (3 miles north of Cronly), Columbus County. p. 14. Outside distribution: Miocene, Duplin marl, Darlington 1900. Abra aequalis Say. Dall, Wagner Free Inst. Sci. Trans., County, S. C. Choctawhatchee formation, northern Florida. vol. 3, pt. 5, p.« 998. Pliocene, Waccamaw formation, Tillys Lake, Horry County, 1932. Abra aequalis (Say)?. Mansfield, Florida Geol. Survey S. C. Caloosahatchee marl, Caloosahatchee River, Fla. Croatan Bull. 8, p. 148. sand, Slocums Creek and Mallisons, Craven County, N. C. Shell orbicular, slightly oblique, polished, white, with very Pleistocene, Dismal Swamp canal between posts 15 and 16, minute and numerous concentric wrinkles near the margin, Virginia; Simmons Bluff, S. C.; Kissimmee well (at a depth of which are obsolete, on the disk and umbo; lateral teeth none; 96 feet), Osceola County, Fla. Recent, Connecticut to the primary teeth two in the left valve and one in the other; Gulf of Mexico in 13 to 233 fathoms; occurs in both shallow interior ligament cavity subfusiform, as long as the exterior and deep water off Hatteras, elsewhere in shallow water only. ligament. Length two-fifths of an inch. Inhabits the southern coast.— Abra aequalis deltoidea Gardner, n. subsp. Say, 1822. This species varies a good deal in outline in the same lo Plate 17, figures 25, 26 cality, but southern specimens of the recent shell, especially those from Florida, have the anterior dorsal slope less rounded Shell convex, triangular; the three sides subequal, and the umbonal angle smaller than those from more northern suggesting the Greek delta; truncate posteriorly, sub- localities. The fossils are generally of this type rather than truncate anteriorly, evenly rounded toward the ventral like the more rounded northern recent specimens.—Dall, 1900. margin, which is straight or slightly arched. Sculp The figured specimens (U. S. Nat. Mus. 325585) ture limited to incrementals as in the typical Abra are from the Yorktown formation on the Chowan aj&qualis of Say. Hinge normal in the number and dis Eiver, one-half to three-fourths of a mile above Eden- position of the teeth but with the laterals of the right house Point, Bertie County, 1ST. C. The right valve valve more strongly developed. ' measures 10.6 millimeters in height and 12.0 milli Dimensions of cotypes: Eight valve, height 11.2 milli meters in width. The left valve of another individual meters, width 11.4 millimeters, convexity 3.0 milli measures 10.5 millimeters in height and 12.0 millimeters meters; left valve, height 11.1 millimeters, width 11.9 in width. millimeters, convexity 3.2 millimeters. The shell is subtriangular to obliquely orbicular in Cotypes, a right and a left valve of different individ outline and is, as a rule, somewhat warped posteriorly. uals : U. S. Nat. Mus. 325586. The umbories are central or slightly posterior. The Type locality: Two miles below Lumberton, Robeson dentition in the right valve consists of 2 cardinals (the County, N. C. Duplin marl. PART 1. PELECYPODA 105 The extremes of the subspecies seem quite distinct 1898. Donax emmonsi Dall, Wagner Free Inst. Sci. Trans., vol. from Abra aequalis s. s., but the connecting series de 3, pt. 4, pi. 28, fig. 16. 1900. Donax emmonsi Dall, idem, vol. 3, pt. '5, p. 967. termines the true relation. A. cequalis dettoidea is characterized by the approximately equilateral outline Shell triangular, rather abruptly truncate behind, and trav ersed by a ridge from the umbo to the base; surface marked by and relatively strong dentition, which is doubtless the obscure radiating lines; base crenulated. This small shell corollary of the heavier valves. The subspecies is best differs from the variabilis in its proportion; it is more tri developed in the Duplin marl of Robeson County in angular and is not produced so much in front.—Emmons, 1858. the vicinity of Lumberton, though it is known also from This species is more triangular than any of the recent forms the Waccamaw. of the coast, faintly radially striate, ventrally somewhat flexu ous, and with a sharply serrate margin. The teeth are normal Distribution: North Carolina: Miocene, Yorktown formation, and strong, especially the sockets for the laterals. Longitude 1 mile west of Wilson, Wilson County. Duplin marl, 2 miles 10 [10.2], altitude 7 [6.7], diameter 4 millimeters.—-Dall, 1900. below Lumberton and 4 to 5 miles below Lumberton, Robeson County. Pliocene, Waccamaw formation, Neills Eddy Landing, Holotype, a right valve: U. S. Nat. Mus. 108447. Columbus County. Type locality: Cape Fear River, near Cronly, N. C. Waccamaw formation. Family DONACIDAE Deshayes It is strange that, though Emmons described and figured this species, he suggested no name by which it Genus DONAX (Linnaeus) Lamarck should be called. 1758. Donax Linnaeus, Systema naturae, 10th ed., p. 682. Donax emmonsi Dall is separated from D. fossor Say 1799. Donax Lamarck, Prodrome d'une nouvelle classification by the relatively higher outline, the more ventricose des coquilles: Soc. histoire nat. Paris Mem., p. 85. valves,' the longer, more oblique, posterior dorsal 1847. Donax Gray, Zool. Soc. London Proc., pt. 15, p. 187. margin, and the anterostral depression with the re Type by subsequent designation (Schmidt, C. F., Versuch sulting contraction of the ventral margin. The species, iiber die beste Einricht, etc., pp. 55, 176, Gotha, 1818) : Donax exclusive of varietal forms, is rare and rather limited rugosa Linnaeus. Recent in the West Indies. in distribution. Shell rather solid, moderately inflated, of varying Distribution: Virginia: Miocene, Yorktown formation, York- dimensions, elongate-cuneate to trigonal to subcylin- town, York County; 1% miles south of Reids Ferry, Nansemond drical in outline. Umbones subcentral to posterior, County. opisthogyrate. Sculpture finely radial, often subcuta North Carolina: Miocene, Yorktown formation, Dogwood neous, sometimes punctate. Ligament both external Landing, Hertford County; 2% miles northwest of Williamston and internal; external ligament short, heavy, inset; (on the farm of Joseph Cherry), Martin County; 9 to 10 miles the resilium seated on short, usually excavated nymphs. south of Greenville, Pitt County. Duplin marl, Natural Well, Duplin County; 4 to 5 miles below Lumberton, Fairmont, 1% Dentition rather rude; normally two cardinals in each miles northeast of Fairmont, and 4 miles -northeast of Fair valve, one of them commonly bifid; laterals varying mont, Robeson County. Pliocene, Waccamaw formation, 4 miles widely in strength and relative position within the south of Elizabethtown (on Hammond Creek) and at Walkers genus. Pallial sinus deep, partly confluent ventrally Bluff, Bladen County; Neills Eddy Landing on the Cape Fear with the pallial line. Inner margins serrate. River (3 miles north of Cronly), Columbus County. The genus is remarkably uniform and well char Donax emmonsi preaequilibrata Gardner, n. subsp. acterized by its solid, rather pronounced cuneate and flexuous valves, opisthogyrate and usually posterior Plate 23, figures 3, 4 umbones, and serrated inner margins. The earliest Valves tumid, elongate-trigonal, rostrate posteriorly, known occurrence of the form in American waters is depressed in front of the rostrum; umbones posterior in the Oligocene. The approximately 100 living species to subcentral; anterior dorsal margin oblique, posterior inhabit the sandy beaches of warm and tropical seas. oblique or slightly hunched; base line feebly sinuated They are lovely little bivalves, ornamented with vari by the anterostral depression; basal serration sharp; colored rays on a dull gray or dun background. The hinge characters normal, varying somewhat with the "pampalone shells," as they are called along the Florida outline of the valves. coast, where they are particularly abundant, are used The subspecies includes a series of forms gradational to a considerable extent for food. between the inequilateral, cuneate, rather strongly ros trate, and sinuous Donax emmonsi Dall s.s. and the Donax emmonsi Dall more nearly equilateral and elongated D. aequilibrata Plate 23, figure 5 Dall, in which the posterior carination is feeble and ill defined and the ventral margin almost, or altogether, 1858. Donax Emmons, North Carolina Geol. Survey Kept., p. 298, straight. fig. 227 (cited by error as 226). 1863. Donax Emmons. Conrad, Acad. Nat. Sci. Philadelphia D. emmonsi preaequilibrata is mostly limited to the Proc. for 1862, p. 574. Duplin marl of Robeson County. Its development in 1892. Donax emmonsi Dall, Nautilus, vol. 5, p. 126. the environs of Lumberton and Fairmont suggests the 106 MOLLUSCA FROM MIOCENE AND LOWER PLIOCENE OF VIRGINIA AND NORTH CAROLINA immediate vicinity as the site of the evolution of the Dimensions of holotype: Height 3.6 millimeters, Pliocene D. aequilibrata from the earlier D. ertvtnonsi. width 5.2 millimeters, convexity 1.0 millimeter. One rarely finds a connecting series so complete be Holotype, a left valve: U. S. Nat. Mus. 325589. tween extremes so widely separated. Type locality: A quarter of a mile north of Chucka- Dimensions of holotype: Height 8.0 millimeters, tuck, Nansemond County, Va. Yorktown formation. width 14.4 millimeters, diameter of double valves 6.5 Although the species is described from a single left millimeters. valve, there should be no doubt about its determination, Holotype (double valves) : U. S. Nat. Mus. 325590. as it is well characterized by the compressed shell; by Type locality: 2 miles below Lumberton, Robeson the sharp, flattened, almost subterminal umbones; by County, N. C. Duplin marl. the absence of an acute posterior keel; the anterior Distribution: Virginia: Miocene, Yorktown formation, 1% truncation extending almost to the ventral margin; miles north of Suffolk, Nansemond County. and by the smooth, highly polished external surface. North Carolina : Miocene, Yorktown formation, Rock Landing, Donax chuckatuckensis is perhaps most nearly related Craven County. Duplin marl, Lumberton, 2 miles below Lum to D. fossor Say. The want of a sharp rostrum and berton, 4 to 5 miles below Lumberton, and 4 miles northeast the degree of truncation of the anterior margin will, of Fairmont, Robeson County. Pliocene, Waccamaw formation, however, preclude any confusion of the two forms. Walkers Bluff, Bladen County; Cronly, Columbus County. Distribution: Virginia: Miocene, Yorktown formation, a Don ax aequilibrata Dall quarter of a mile north of Chuckatuck, Nansemond County. Plate 17, figure 29 Donax fossor Say Plate 23, figures 1, 2, 10, 11 1892. Donax aequilibrata Dall, Nautilus, vol. 5, p. 126. 1898. Donax aequilibrata, Dall, Wagner Free Inst Sci. Trans., 1822. Donax fossor Say, Acad. Nat. Sci. Philadelphia Jour., 1st vol. 3, pt. 4, pi. 28, fig. 17. ser., vol. 2, p. 306. 1900. Donax aequilibrata Dall, idem, vol. 3, pt. 5, p. 968. 1849. Donax protracta Conrad, idem, 2d ser., vol. 1, p. 208, pi. Shell longer in proportion to its height than in any of our 39, fig. 8. (Senile stage.) Recent species, rounded in front, the posterior end rostrate and 1856. Donax variabilfe Tuomey and Holmes (not Say), Pleio- pointed; truncated area impressed, its borders not carinated cene fossils of South Carolina, p. 95, pi. 23, fig. 6. and ill defined, rostrum faintly grooved, the rest of the shell 1863. Donax variabilis Tuomey and Holmes?. Conrad, Acad, polished, with obsolete, impressed lines; inner margin denticu Nat. Sci. Philadelphia Proc. for 1862, p. 573. late; hinge teeth well developed, laterals strong and near the 1873. Donax fossor Say. Tryon, American marine conchology, cardinals; pallial sinus rounded and extending a little in front p. 153, pi. 27, figs. 376, 377. of the beaks; the latter are well defined, not prominent, and 1900. Donax fossor Say. Dall, Wagner Free Inst. Sci. Trans., nearly central. Longitude of shell 17 [17.9], altitude 8.9 [8.5], vol. 3, pt. 5, p. 967. diameter 6 millimeters.—Dall, 1892. 1932. Donax fossor Say. Mansfield, Florida Geol. Survey Bull. 8, p. 151, pi. 31, figs. 6, 7. Holotype, a right valve: U. S. Nat. Mus. 108450. Type locality: Mrs. Guion's marl bed, Cape Fear Shell subtriangular; anterior margin short and rounded; posterior hinge slope rectilinear; base very slightly prominent River, Columbus County, N. C. Waccamaw formation. beyond a regular curve at the middle; valves longitudinally Distribution: North Carolina: Pliocene, Waccamaw forma striated with numerous, equal, parallel, regular impressed lines, tion, Mrs. Guion's marl pit and Neills Eddy Landing, Columbus not visible to the unassisted eye, and obsolete on the posterior County. margin; basal edge within crenate; color pale livid, with two longitudinal whitish rays before the middle, both within and Donax chuckatuckensis Gardner, n. sp. without. Breadth from half an inch to three-fifths. Inhabits the coasts of New Jersey and Maryland.—Say, 1822. Plate 23, figure 6, 7 The figured specimens (U. S. Nat. Mus. 325587) are Shell small, remarkably compressed, cuneate. Um- from the Waccamaw formation 4 miles south of Eliza- bones acute, flattened, opisthogyrate, placed about two- bethtown, N. C. The right valve measures 3.3 milli thirds of the way back toward the posterior extremity. meters in height and 5.0 millimeters in width; the left Anterior dorsal margin produced and oblique; pos valve of another indiivdual measures 4.9 millimeters terior short and slightly rounded near the ventral in height and 9.0 millimeters in width. margin. Posterior keel rounded off. Base line feebly Say, in his description, has confused the anterior and arcuate, finely serrate within. Surface highly polished posterior portions of the shell. The species is char with a mircroscopic, subsurficial, radial lineation; hinge acterized by the posterior umbones; the rounded pos armature compact. Two- strong diverging cardinals in terior margin, the long, only slightly oblique, anterior the left valve, separated by a subumbonal, triangular dorsal margin; and the straight base line. The form pit; on either side of the cardinals is a less prominent is much less conspicuously cuneate than Donax ein- lateral, the posterior the stronger. Pallial sinus deep, monsi Dall, the umbones are set farther back, the pos indistinct. terior dorsal margin is rounded instead of angular, PART 1. PELECYPODA 107 and the prerostral area is not depressed sufficiently to- elongated parallel to the dorsal margin. The pallial sinuate the base. sinus is deep and its axis nearly horizontal. The Kecent representatives range from the West Indies north to New Jersey, the only east coast species Tagelus gibbus (Spengler) Dall of Donax to venture into the temperate seas. Plate 22, figures 1-4 Mansfield reports eight valves from one locality in 1685. Chama angustior, etc., Lister, Historiae conchyliorum, the Cancellaria zone of the Choctawllatchee formation, fig. 265. which "appear closely related to if not the same as the 1794. Solen gibbus Spengler, Skr. Naturhistorie-Selsk. Kiobeii- Recent species Donax fossor Say." havn, vol. 3, pt. 2, p. 104. D. fossor is strikingly similar in outline and orna 1795. Solen guineensis Chemnitz, Conchylien cabinet, vol. 11, p. 202, pi. 198, fig. 1937. mentation to Z>. transversa Deshayes, the type of Para- 1818. Solen caribo Inhabits the southern coast. Subgenus MACTROTOMA Dall Cabinet of the Academy and Philadelphia Museum.—Say, 1822. 1894. Mactrotoma Dall, Nautilus, vol. 8, p. 2(5. 1898. Mactrotoma Dall, Wagner Free Inst. Sci. Trans., vol. 3, A recent shell (U. S. Nat. Mus. 153356) from Smiths •pt. 4, p. 876. Island, Va., has been figured. The height is 7.5 milli meters, the width 35.5 millimeters. Type by original designation: Mactra fragilis Gfmelin. Recent Fragments of this species, showing the diagnostic on the east coast from Hatteras to Brazil. terminal cardinal and the narrow, elongated, adductor Anterior left lateral tooth bidentate, right ventral tooth tridentate.—Dall, 1894. muscle impression, have been found at a single locality Shell subequilateral, elongate; with a thin, silky epidermis, in the Waccamaw formation. Hitherto the form has posterior dorsal areas bordered by an impressed fasciole, over been known only from the Pleistocene of Simmons which the epidermis is darker colored and differently wrinkled; Bluff and from the Recent east coast faunas from beaks adjacent; pallial sinus large; valves convex, gaping Rhode Island to Georgia. markedly; ligament lanceolate; chondrophore large, shallow, The more anterior vertical cardinal, the absence of apically roofed; anterior laminae issuing from the dorsal sinus; cardinals prominent, thin, their posterior arms projecting over the horizontal cardinal, and the position of the anterior the chondrophore; each anterior arm attended by a high acces adductor impression—parallel rather than oblique to sory lamella in nearly the same plane, closely appressed in the the dorsal margin—will serve to separate this species right valve to the ventral lamina and in the left valve to the from the coexistent Ensis, which it closely resembles in anterior lateral, so that, to a cursory inspection, the lamina general aspect. appears tridentate and the tooth bidentate.—Dall, 1898. Distribution: North Carolina: Pliocene, Waccamaw forma Mactra (Mactrotoma) fragilis Gmelin tion, Walkers Bluff on the Cape Fear River, Bladen County. Outside distribution: Pleistocene, Simmons Bluff, S. C. Re Plate 18, figures 9-11, 13 cent, Rhode Island to Sarasota Bay, west Florida, and west to 1790. Mactra fragilis Gmelin, Systema naturae, vol. I, pt. 6. Texas in less than 50 fathoms. p. 3261. 1898. Mactra (Mactrotoma) fragilis Gmelin. Dall, Wagner Superfamily MACTRACEA Free Inst.. Sci. Trans., vol. 3, pt. 4, p. 894, pi. 27, figs. 1, 4, 8, 18. Family MACTRIDAE M. testa ovata tenui laevi pellucida planiuscula, vulva trans- 1917. Lamy, Revision des Mactridae vivants du Museum versim striata rugosaque, Chem. Conch. 6, t. 24, f. 235.— d'Histoire Naturelle de Paris, Jour, conchyliologie, vol. Gmelin, 1790. 63, pp. 173-275. This species, the type of the subgenus, is widely distributed 1918. Lamy, idem, pp. 291-411. and represented in eastern seas by very similar though gen erally smaller species. It was erroneousty referred to the Nicobar Islands by Chemnitz, but his figure enables us to Genus MACTRA Linnaeus correctly identify his species with the American shell.—Dall, 1898. 1766. Mactra Linnaeus, Systema naturae, 12th ed., p. 1125. 1799. Mactra, Lamarck, Prodrome d'une nouvelle classification Mactra fragilis s.s. has not been reported from beds des coquilles: Soc. histoire nat. Paris Mem., p. 85. older than the Caloosahatchee. The Recent species 1898. Mactra Dall, Wagner Free Inst. Sc}. Trans., vol. 3, pt. 4, ranges from Cape Hatteras, N.. C., to Rio de Janeiro. p. 874. It is cited for comparison with a possibly ancestral Type by subsequent designation (Anton, Verzeichniss der subspecies and Dall's excellent figures of the hinge Conchylien, p. 2, 1839) : Mactra stultorum Linnaeus. Recent on west European shores from Norway southward to the Medi plates have been reproduced. terranean and possibly to the Red Sea. Fossil in the Crag. Mactra (Mactrotoma) fragilis precursor Gardner, n. subsp. Within the family the best diagnostic of the genus Plate 18, figure 14 is the small shelly plate that separates the area of attachment of the internal ligament from that of the Shell oblong, oval, compressed; dorsal margins gently marginal external ligament. The plate is so thin and sloping, anterior lateral margin rounded, posterior so short that it is frequently lost in the fossil forms, obliquely truncated. Base line arcuate. Posterior and traces of its former existence are hard to find. area clearly differentiated, sculptured with 2 narrow Labiosa, a large thin shell reinforced by a concentric acute ribs, of which the dorsal is the stronger; obscure rippling, resembles Mactra in that the marginal and medial rib also present. Surface sculpture of very fine, internal ligaments are separated by a thin lamella. irregular, discontinuous concentric striae, which are The laterals of Labiosa, however, are rudimentary. more numerous on the anterior portion of the shell and The hinge of L. (Raeta) alta (Conrad), from the Mio terminate abruptly at the posterior keel. Hinge and cene of North Carolina, is figured (pi. 18, fig. 6) for pallial characters as in M. fragilis Gmelin, the type comparison with Mactra. of the genus. 401033—45 110 MOLLUSCA FROM MIOCENE AND LOWER PLIOCENE OF VIRGINIA AND NORTH CAROLINA Dimensions of holotype: Height 79.0 millimeters, satisfactory. Three of the species and one subspecies width 121.0 millimeters, convexity 20.0 millimeters. are small, heavy forms allied to similar Miocene species Holotype, a left valve: U. S. Nat. Mus. 325593. and possibly sufficiently removed from the subgenotype Type locality: Neills Eddy Landing, Columbus to receive a new sectional name. The other two Mio County, N. C. Waccamaw formation. cene forms that are referred to Mactromeris" are rela A complete series might prove the distinguishing tively large and thin, and seemingly they differ more characters of this Mactra to be only individual varia from the type of Hemimactra than Hemimactra differs tions from-^f. fragilis. As the species has never be from Spisula. fore been reported from so early a horizon, it seems batter to regard the relatively lower, more oblong out Subgenus HEMIMACTRA Swainson line and the more gently sloping dorsal margins oi 1840. Hemimactra Swainson, Treatise on malacology, this single, finely preserved, left valve as subspecific p. 369. rather than individual differences. M. (Mactrotoma] profragilis Gardner, from the Oak Type by monotypy: Mactra, gigantea Lamarck= Grove sand of Florida, is a smaller shell with more Mactra solidissima Chemnitz. Recent seas from Lab pointed umboiies and a more decided concentric stria- rador to North Carolina. tion. The three forms in question are, however, closely Swainson, in his original description of Hemimactra related. cited a second species, "Hemimactra grandis Swainson, Distribution: North Carolina: Pliocene, Waccamaw forma sp. nov.," but as his species was neither described nor tion, Neills Eddy Landing, Columbus County. figured the name seems to be nude. Many of the large, transversely elongated^ and rela Genus SPISUIA Gray tively thin species of Spisula are included under the 1837. Spisula Gray, Mag. Nat. History, new ser., vol. 1, p. 372. subgenus Hemimactra. 1898. Spisula, Gray. Dall, Wagner Free Inst. Sci. Trans., vol. 3, pt. 4, p. 878. Section HEMIMACTRA s. s. 1918. Spisula, Gray. Lamy, Jour, conchyliologie, vol. 63, p. 291. Laterals grooved; cardinals compressed; anterior arm Type by subsequent designation (Gray, Zool. Soc. London Proc., pt. 15, p. 185, 1817) ; Mactra, solida Linnaeus. Recent of right cardinal confluent with ventral lamina. on the west coast of Europe. Fossil in the Crag. Spisula (Hemimactra) rappahannockensis Gardner, n. sp. Shell often large and rather heavy, moderately in Plate 18, figure 2-4, 7 flated, subequilateral, ovate-trigonal in outline, slightly produced and obscurely ro&trate posteriorly. Umbones Shell elongate-trigonal. Umbones inflated, subcen prominent, subcentral. Surface smooth or increment- tral, prosogyrate at their tips. Anterior dorsal margin ally scultpured. Ligament inset, not cut off from the oblique, the lateral margin rounded. Posterior dorsal resilium by a shelly ridge. Hinge armature strong. margin more steeply sloping than the anterior, the Right anterior and posterior cardinals coalescent under lateral extremity rounded or vaguely truncated. Base the mnbones, the anterior arm near the dorsal margin, line straight or slightly sinuous towar,d the posterior the posterior bordering the chondophore and partly margin. Surface smooth except for incrementals. separating it from the socket in which the small, in Concrentric furrows often developed by weathering as verted V-shaped cardinal of the left valve is lodged. in Spisula confragosa Conrad. Chondrophore ob Strong lateral teeth, developed within the dorsal mar liquely triangular, cardinal teeth compressed. Lat gins of the left valve, received in the double sockets erals not very heavy, straight, transversely grooved, of the right; teeth and sockets both transversely stri lateral furrows of right valve also grooved. Muscle ated in most of the groups. Muscle scars large and impressions and pallial line distinct. Pallial sinus sunken in the heavier shells. Pallial sinus distinct, rounded, extending about two-thirds of the distance short, broadly U-shaped, nearly horizontal. from the posterior margin to the medial line of the The absence of a shelly lamina between the chondro- shell. phore and the ligament separates Spisula from Mactra. Dimensions: Holotype, height 21.0 millimeters, Furthermore, the laterals of Mactra are smooth or width 31.5 millimeters, convexity 7.3 millimeters; para- finely granular, but those of Spisula are as a rule type, height 15.0 millimeters, width 23.0 millimeters, transversely striated. convexity 5.3 millimeters. Two other valves: Height The genus extends well back into the Cretaceous, and, 19.2 and 20.4 millimeters, width 27.1 and 28.8 milli though not abundantly represented in Recent seas, it meters, convexity 6.8 and 6.5 millimeters. is of almost universal occurrence. Types: Holotype, a ris:ht valve, and left figured For the half dozen Miocene Spisulas considered in hinpre. TT. S. Nat. Mus. 325601; paratype, a left valve, this report, the superspecific groupings are far from U. S. Nat. Mus. 325600. PART 1. PELECYPODA 111 Type locality: Holotype, and left hinge, 1 to 2 miles Suffolk, Nansemond County, Va. Yorktown forma below Bowlers Wharf on the Kappahannock River, tion. Essex County, Va. St. Marys formation. These weather-beaten little forms are among the most Paratype, Union Mills, 2% miles south of Farnham, abundant of the smaller bivalves in the vicinity of Richmond County, Va. Yorktown. The young of S. rappahannockensis are higher and Distribution: Virginia: Miocene, St. Marys formation, Union more triangular than the adults. There is, in many of Mill, 2% miles south of Farnham, Richmond County. York- town formation, Yorktown, York County; % mile northeast the individuals, an ill-defined ridge extending from of Smithfield, Isle of Wight County; % mile north of Chuck- the umbo to the posterior end of the basal margin, a atuck, iy2 miles southeast of Reids Ferry, 1 mile northeast of ridge that becomes obsolete in the adults. The new Suffolk, 1 mile west of Suffolk, and % mile below the Suffolk species is separated from /$. confragosa Conrad and S. waterworks dam, Nansemond County. sub par His Conrad by the more gibbous umbones, the North Carolina: Miocene, Yorktown formation, 6 miles below Greenville, 8 to 9 miles south of Greenville, and 9 to 10 miles more gently sloping dorsal margins, and the tendency south of Greenville, Pitt County. toward a posterior truncation and sinuous base line. The species is exceedingly abundant at certain local Spisula (Hemimactra) modicella alta Gardner, n. subsp. ities along the Rappahannock River and the surround Plate 23, figures 16, 17 ing territory, notably near Bowlers Wharf and at Union Mill, 2% miles south of Farnham. The individ The subspecies resembles Spisula (Hemimactra) uals developed at the latter locality exhibit a decidedly modicella s. s. except in the notably greater height; more elongated outline than do those along the river. concomitant with this are the more oblique anterior and posterior dorsal margins. The general aspects of Distribution : Virginia: Miocene, St. Marys formation ?, Nom- ini*Cliffs, Westmoreland County. St. Marys formation; 2% the normal and of the varietal forms are therefore miles south of Farnham, Richmond County; 1 to 2 miles below quite dissimilar. Bowlers Wharf, Essex County; Urbanna Bluff, Middlesex The subspecies is best developed %at Rock Landing, County. on the Neuse River. At this locality it is one of the most conspicuous of the smaller bivalves and occupies Spisula (Hemimactra) modicella (Conrad) Meek a position in the fauna similar to that of S. 'modi Plate 23, figures 8, 9, 18, 19 cella s. s. in the Yorktown of Virginia. 1833. Mactra modicella, Conrad, Am. Jour. Sci., 1st ser., vol. 23, Dimensions of holotype: Height 13.2 millimeters, p. 340. width 18.0 millimeters, convexity 4.1 millimeters. 1838. Mactra modicella, Conrad, Fossils of the medial Tertiary Holotype, a right valve: U. S. Nat. Mus. 325599. • of the United States, p. 25, pi. 13, fig. 3. Type locality: Rock Landing, Craven County, N. C. 1863. Hemimactra modicella, Conrad, Acad. Nat. Sci. Philadel Yorktown formation. S. (Hemimactra) modicella alta phia Proc. for 1862, p. 572. 1898. Spisula modicella, Conrad. Dall, Wagner Free Inst. Sci. is a higher, cruder shell than S. (Hemimactra) craspe- Trans., vol. 3, pt. 4, p. 900. dota, an abundant species in the Shoal River formation. It is much less elongated transversely than the St. Shell subtriangular, compressed; posterior side shortest and abrupt or truncated at the extremity; fosset a little oblique, Marys form, S. rappahannockensis. triangular; lateral teeth strong. Length, three-fourths of an Distribution: Virginia: Miocene, Yorktown, formation, 1% inch. miles northeast of Smithfield, Isle of Wight County; ^4 mile Locality, Yorktown, Va.—Conrad, 1833. north of Chuckatuck, Nansemond County. North Carolina: Miocene, Yorktown formation, 3 miles south A small, heavy species, characterized by the flattened of Farmville, Pitt County; Colerain Landing, Bertie County; inequilateral valves, the produced anterior extremity, Rock Landing and 2 miles southwest of Maple Cypress, Craven the strongly grooved laterals, the conspicuous muscle County. Duplin marl, 4 miles northeast of Fairmont, Robeson impressions and pallial line. The form seems to be County. peculiarly susceptible to weathering forces, for all the Spisula (Hemimactra) similis (Say) Gardner individuals have a very much worn and battered aspect. It varies quite widely in relative proportions—so Plate 22, figures 6, 7 1822. Mactra similis Say, Acad. Nat. Sci. Philadelphia Jour., widely, indeed, that it has been thought wise to give 1st ser., vol. 2, p. 309. the higher forms subspecific rank. 1856. Mactra, similis Say. Tuomey and Holmes, Pleiocene Dimensions of figured specimens: Right valve, height ^ fossils of South Carolina, p. 97, pi. 23, fig. 8, 11.2 millimeters, width 15.0 millimeters, convexity 3.9 1856. Mactra, similis Say. Holmes, Post-Pleiocene fossils of millimeters. Immature left valve, height 7.9 milli South Carolina, p. 39, pi. 7, fig. 8. meters, width 11.7 millimeters, convexity 2.3 milli Shell subtrigonate, smooth, or very slightly wrinkled, white meters. on the disk or upon the umbones, and dirty light brownish colour on the margin; umbones nearly central; lateral teeth Figured specimens: U. S. Nat. Mus. 325598. strongly and regularly crenated on the side next the recipient Locality of figured specimens: One mile northeast of cavity. 112 MOLLUSCA FROM MIOCENE AND LOWER -PLIOCENE OF VIRGINIA AND NORTH CAROLINA Length l%o inches, nearly1; width 1% inches. appreciably, projected almost but not quite halfway Inhabits the coast of the United States. to the anterior margin. Cabinet of the Academy.—Say, 1822. Dimensions of holotype: Height 53.0 millimeters, The young of this species are very close to adult width 70.0 millimeters, diameter 28.0 millimeters. Spisula subparUis of Conrad. In the former, however, Holotype, paired valves: U. S. Nat. Mus. 498201. the shell is sub-ovate and rounded posteriorly; in the Type locality: iy2 - miles below Bowlers Wharf, latter, subtriangular and obliquely truncated poste Rappahannock River, Va. St. Marys formation. riorly. Spisula (Mactromeris) bowlerensis is most nearly re lated to S. (M.) duplinensis Dall. It is readily sep Distribution: North Carolina: Miocene, Duplin marl, 2 miles below Lumberton and 1% miles northeast of Fairmont, Robeson arable from the latter, however, by the higher and County. Pliocene, Waccamaw formation, Cronly, % mile east somewhat less inflated valves; by the more inequilateral of the factories, Columbus County. outline, which is consequent on the more pronounced Outside distribution: Pliocene, Waccamaw formation, Nixons excavation of the anterior dorsal slope of bowlerensis and Tilly Lake, Horry County, and Goose Creek, Berkeley and its slightly convex posterior dorsal margin; by the County, S. C. Pleistocene, Simmons Bluff, Abbapoola, and St. Andrews, S. C.; Orient, Hillsborough County, Fla.; Kissimee less smooth and polished external surface; atid by the well (at a depth of 96 feet), Osceola County, Fla. Recent, broader, nontapering pallial sinus. The new species is Massachusetts to Florida and the Gulf of Mexico. smaller and less inequilateral than S. delumbis Con rad, less strongly concave anteriorly, more gently slop Section MACTROMERIS Conrad ing and less strongly angulated posteriorly, and with a 1868 (January). Mactromeris Conrad, Am. Jour. Conchology deeper and less sharply ascending pallial sinus. /& for 1867, vol. 3, app., p. 45. valhosierr Gardner, from the Shoal River, is closely related, but the beaks and hinge plate of the older Type by subsequent designation (Dall, Wagner Free Inst. Sci. species are not so high and the posterior area is less Trane., vol. 3, pt. 4, p. 878, 1898) : Spi -ula ovalis Gould=Mactra polynyma Stimpson. Recent from Hudson Bay to Cape Ann, clearly defined. Mass. This interesting form, which seems to be intermediate between S. delumbis and S. duplinensis and yet distinct The section is characterized by smooth or feebly from both of them, is fairly abundant in the single granular laterals, noncompressed cardinals, and the area where it has been found—Bowlers Wharf, on isolation of the anterior arm of the right cardinal from the Rappahannock River. the ventral lamina. Distribution: Virginia: Miocene, St. Marys formation, Bowlers Spisula (Mactromeris) bowlerensis Gardner, n. sp. Wharf and 1 to % miles below Bowlers Wharf, Essex County. Plate 18, figures 1, 5 Spisula (Mactromeris) duplinensis Dall Shell rather large, thin, moderately inflated, rudely Plate 22, figure 10 trigonal, equivalve, inequilateral. Anterior end slightly 1898. Spisula, (Hemimactra) duplinensis Dall, Wagner Free excavated dorsally, rounded laterally. Posterior end Inst. Sci. Trans., vol. 3, pt. 4, p. 898, pi. 30, fig. 1. gently sloping, very slightly arched dorsally, obscurely Shell subovate, thin, moderately inflated; beaks subcentral, truncated laterally. Ventral margin straight medially, not prominent, adjacent; surface smooth except for incremental upturned before and behind. Anterior dorsal area lines, which are most prominent toward the ends; the middle of the valve is more or le§s polished, anterior end somewhat slightly impressed, not clearly delimited. Posterior shorter than the posterior, both moderately rounded; dorsal area including a smooth, somewhat depressed region slope nearly equal on both sides of the beak; dorsal areas next to the margins and in front of them, a narrow obscure, the posterior 'smoother and more impressed; hinge roughened wedge-shaped surface, the anterior bound much as in S. marylandica, but the pit larger and with a more ary of which is marked by an irregular pitted line1 projecting ventral margin; pallial sinus reaching forward more than half the length of the shell, pointed in front; basal margin extending from the umbo to the posterior ventral curved but not arcuate. Longitude 58, altitude 42, diameter margin. Umbones rather low and inconspicuous, prox 22 millimeters. imate, slightly prosogyrate. Surface irregularly fur This species at first sight looks very close to 8. marylandica rowed with growth lines and with a peculiar reticulate but has a longer pallial sinus, less prominent beaks, more wrinkling. Hinge armature strong and clean-cut. equal dorsal slopes, and less arcuate basal margin. The lateral laminae are finely granulated and not striated—which sep Chrqndrophore cuneate, expanding posteriorly. An arates it at once from the similis group—and the proportions terior arm of right cardinal coalescent with ventral are quite different from those of the young $. polynyma Stimp lamina. Inverted V-shaped cardinal of left valve com son of the same size. It is probably the shell referred to 8. pressed. Laterals short but prominent, their inner similis Say by Tuomey and Holmes 47 and Emmons. **.—Dall, surfaces granular. Muscle impressions distinct but 1898. not conspicuous. Pallial sinus of equal breadth 47 Tuomey and Holmes, Pleiocene fossils of South Carolina, p. 97, pi. 23, fig. 8, 1850. throughout its length, rounded in front, not ascending 48 Emmons, B., North Carolina Geol. Survey Kept., p. 298,1858. PART 1. PELECYPODA 113 Holotype, a right valve: U. S. Nat. Mus. 153T84. which crassidens is a young shell. Conrad, by the extraordi Type locality: Natural Well, Duplin County, N. C. nary carelessness which was norma]L to him, placed the tw» latter names under Mulinia, while congesta appears both as Duplin marl. , Hemimactra and as Standella in different places in the same Though the figure of Tuomey and Holmes is not list of Miocene fossils printed in 1863!—Dall, 1898. conclusive, the finding of indubitable specimens of Dimensions of figured specimens: U. S. Nat. Mus. S. similis in the t)uplin of Robeson County makes the 325602. right valve, height 15.5 millimeters, width 21.0 correctness of their determination plausible. millimeters, convexity 5.6 millimeters; left valve of Distribution : North Carolina "Chesapeake Miocene of Duplin another individual, height 15.3 millimeters, width 22.0 County, Willcox." millimeters, convexity 5.5 millimeters. U. S. Nat. Mus. Genus MULINIA Gray 325603. right valve, height 23.0 millimeters, width. 25.5 millimeters, convexity 9.5 millimeters; left valve of 1837. Mulinia Gray, Mag. Nat. History, new ser., vol. 1, p. 375. another individual, height 24.5 millimeters, width 26.5 1898. Mulinia Dall. Wagner Free Inst. Sci. Trans., vol. 3, pt. 4, millimeters, convexity 10.0 millimeters. p. 880. Locality of figured specimens: U. S. Nat. Mus. Type by subsequent designation (Herrmannsen, Indicis gen- 325602, Yorktown formation, 1 mile northeast of Suf erum Malacozoorum, vol. 2, p. 61, July 1847) : Mactra later alis folk, Nansemond County, Va.; U. S. Nat. Mus. 325603, Say. Recent from New Brunswick to Texas and the West Indies. Late Tertiary and Pleistocene. Yorktown formation, iy2 miles west of Smithfield, Isle of Wight County, Va. Shell with the ligament and resilium both enclosed in a single pit and invisible externally. Laterals subequal, moderately dis Mulinia cpngesta (Conrad) is one of the most easily tant ; teeth normal ; valves closing almost hermetically ; pallial recognized representatives of the pelecypod fauna of sinus short and small ; siphons short ; foot narrow, pointed. the east coast Miocene. It has been reported from the Widely distributed in estuaries of the tropics and temperate majority of North Carolina and Virginia localities at seas over most of the world. The most conspicuous species are which the fossiliferous Miocene occurs, and in number from South America. — Dall, 1898. of individuals it generally exceeds all other bivalves. Mulinia congesta (Conrad) Dall At some of the exposures in southern Virginia and northern North Carolina, on the Meherrin Eiver in Plate 23, figures 12-15, 21-24 Southampton County,-Va., for example, and in the 1833. Mactra congesta Conrad, Am.- Jour. Sci., 1st ser., vol. 23, vicinity of Murfreesbpro, Hertford County, N. C., the p. 340. marls are literally packed with this shell. The form 1838. Mactra congesta Conrad, Fossils of the medial Tertiary varies rather widely in .size and outline, though the of the United States, p. 27, pi. 15, fig. 2. 184J. Mactra crassidens Conrad, Am. Jour. Sci., 1st ser., vol. 41, characters are usually fairly constant at a single locality. p. 346, pi. 2, fig. 11. The majority of the forms from the Meherrin Kiver 1843. Mactra triquetra Conrad, Acad. Nat. Sci. Philadelphia outcrops correspond closely to the type of Conrad's Proc., vol. 1, p. 324. M. congesta. They are commonly smaller than those 1845. Mactra triquetra Conrad, Fossils of the medial Tertiary at Yorktown and are relatively lower with a more pro of the United States, p. 69, pi. 39, fig. 3. duced posterior margin and more proximate umbones. 1845. Mactra crassidens Conrad, idem, p. 69, pi. 39, fig. 5. 1856. Mactra congesta Conrad. Tuomey and Holmes, Pleiocene In the later Yorktown fauna, on the other hand, the spe fossils of South Carolina, p. 98, pi. 23, fig. 10. cies is of the larger, heavier, subequilateral, triangular 1863. Hemimactra congesta Conrad, Acad. Nat. Sci. Philadelphia type, and thus follows the line of Variation represented Proc. for 1862, p. 572. by M. triquetra Conrad. This variant is particularly 1863. Mulinia crassidens Conrad, idem, p. 573. abundant in the environs of Suffolk, Nansemond 1863. Mulinia triquetra Conrad, idem, p. 573. 1863. Standella congesta Conrad, idem, p. 573. , County, Va. Near Exit, in the same county, the shells 1894. Mactra (Mulinial) lateralis "Say". Whitfield, U. S. Geol. are remarkable for the preservation of the con Survey Mon. 24, p. 82, pi. 15, figs. 1-3. Not Mactra centric color markings. M. congesta of the Duplin lateralis Say, 1821. fauna is inconstant. Though often of medium size, in 1898. Mulinia congesta Conrad. Dall, Wagner Free Inst. Sci. dividuals from the vicinity of Clinton, Sampson Trans., vol. 3, pt. 4, p. 900. 1932 Mulinia congesta (Conrad). Mansfield, Florida Geol. County N. C., reach a height of 26.5 millimeters and a Survey Bull. 8, p. 154, pi. 32, figs. 1, 2, 5, 6. width of 35.0 millimeters, and near Lumberton, in Shell triangular, convex, thick ; posterior side cuneate, beaks Robeson County, N. C., they commonly measure 24 nearly central; lunule none; fosset small, circular, profound; to 26 millimeters in height, with a corresponding width lateral teeth thick. Length, 1 inch. of 34 to 34.5 millimeters. These large Duplin forms Locality: Suffolk, Va., where it is extremely abundant. A differ, however, from those of the Yorktown fauna in much smaller variety occurs at James River — generally shorter the produced posterior margin. The oval, elongate in proportion to the height, and with central beaks. Upper ma rine formation. — Conrad, 1833. forms were set aside by Dall under the manuscript This well-known and variable species is of wide distribu name elongata. They have been given subspecific rank, tion. Short, high specimens form the variety triquQtr^ Q£ for they are distinct and readily separable; though, on 114 MOLLUSCA FROM MIOCENE AND LOWER PLIOCENE OF VIRGINIA AND NORTH CAROLINA the other hand, they are connected with the normal Landing, 2 miles southeast of Hamilton Bluff (at old fort), representatives of the species by an unbroken grada- and 2% miles northwest of Williamston (on Joseph Cherry's farm), Martin County; 2 miles below Toddy Station, 2 miles tional series. southeast of Tugwell (on Jacobs Branch), 1*4 miles northeast Mulinia congest a (Conrad) is distinguished from the of Farmville, 3 miles south of Farmville, 2% miles north of later and much less abundant M. lateralis (Say) by Standard, near Standard, 8 miles southwest of Frog Level (on the heavier, usually larger shell and the more robust • J. A. Nobles branch), 8 to 9 miles west of Greenville (on the hinge. Both species vary widely in outline, but the east side of Pinelog Branch), 3 miles west of Greenville (on former is, for the most part, less triangular and more Schoolhouse Branch), Greenville (just east of the county bridge), 6% miles below Greenville (at Tafts Landing), 8 to 9 equilateral. miles southeast of Greenville, 1% miles west of Galloway Mansfield records M. congesta from each of the three Crossroads, and 9 to 10 miles south of Greenville, Pitt County; zones of the Choctawhatchee formation of Florida but 2% miles northwest of Chocowinity, and 1^ miles northeast "only one small valve has been collected from the Area of Chocowinity, Beaufort County; 2 miles southwest of Maple zone." He reported it to be one of the most common Cypress, Rock Landing, Craven County; 1 mile west of Wilson (in Hominy Swamp), 3 miles east-southeast of Wilson, 5 miles species in the Ecphora zone and observed that "the south of Wilson, and 7 miles southeast of Wilson, Wilson shells are larger, thicker, and have Stronger laterals in County; 6 miles west of Goldsboro, Wayne County; 1 mile the Ecphora zone than in the Cancellaria zone." north of Castoria, % mile east of Lizzie, 1 mile east of Lizzie, 4 miles east of Lizzie (on Dog Swamp), and 1% miles east of Distribution: Virginia: Miocene, Yorktown formation, York- Ormondsville, Greene County. Duplin marl, 3 miles south of town, York County; Lanexa (upper bed), New Kent County; Clinton (on Gum Chimney Branch), 4 miles south of Clinton, Petersburg, Dinwiddie County; 5 miles northeast of Smith- and 10 miles south of Clinton, Sampson County; 2 miles north field, 1% miles northeast of Smithfield, 2 miles west of Smith- east of Warsaw, Natural Well, drainage ditch just east of rail field, iy2 miles west of "Smithfield, and Benns Church, Isle of road, IT/2 miles north of Magnolia, and Magnolia (at Frank Wight County; 2% to 3 miles northwest of Zuni, 2 miles north Wilson's marl pit), Duplin County; 4 miles north of Lumberton west of Zuni, 1% miles above Zuni, 1 mile north of Zuni, % (on Berry Godwin's plantation), 1 mile west of Lumberton, mile north of Zuni, Zuni (near the pumping station), 6^ to 7 Lumberton (near the bottling works), 2 miles below Lumberton, miles below Zuni, 7 to 7^ miles below Zuni, and 8 to 8% 4 to 5 miles below Lumberton, Fairmont, 1% miles northeast miles below Zuni, Isle of Wight County; Hitchcock, Greensville of Fairmont, 4 miles northeast of Fairmont, and 2 miles north County; Sycamore ? Harcum's store, M to % mile below Syca west of Barnesville, Robeson County. Pliocene, Waccamaw for more, the lower Seaboard Railway bridge, and Maddelys mation, Walkers Bluff, Cape Fear River, Bladen County; Lake Bluff, Southampton County; 2 miles below South Quay; % Waccamaw, Columbus County; Wilmington (at the city rock mile north of Chuckatuck, Chuckatuck mill dam, Everets, quarry), New Hanover County. Exit, iy2 miles southeast of Reids Ferry, 1% miles north of Outside distribution: Miocene, Choctawhatchee formation, Suffolk, 1% miles north of Suffolk, 5y2 miles northwest of northern Florida. Choptank formation, (?) Atlantic City (well Suffolk, 2% miles northwest of Suffolk, !*,£ miles northwest of bore), N. J. Duplin marl, Muldrow Place, Sumter County, Suffolk, 1 mile west of Suffolk, 1% miles northeast of Suffolk. S. C.; Porters Landing on the Savannah River, Effingham 1 mile northeast of Suffolk, y2 mile below the Suffolk water County; Brunswick River bed, Brunswick, Glynn County, Ga. works dam, and the drainage ditch of the Norfolk & Western Pliocene, Caloosahatehee marl, Nashua, Putnam County, Fla.; Railway just east of Jericho ditch, Nansemond County. De Leon Springs, Volusia County, Fla. Croatan sand, Slocums North Carolina: Miocene, Yorljtown formation, 3 to 4 miles Creek and Mallisons, Craven County, N. C. below the lower Seaboard Railway bridge over the Meherrin River, 1% miles above Branches Bridge, 1 mile above Branches Mulinia congesta magnoliana (Dall) Gardner Bridge, Branches Bridge, and 1% miles below Branches Bridge, Northampton County; 2% miles northwest of Murfreesboro (at 1898. Spisula (Hemimactra?) magnoliana Dall, Wagner Free Watsons Mill on Kirbys Creek), 1% miles above Murfreesboro, Inst. Sci. Trans, vol. 3, pt. 4, p. 899, pi. 27, fig. 29. 1 mile above Murfreesboro, and near Murfreesboro, Hertford Shell small, equilateral, somewhat compressed, with small, County; Tar Ferry on Wiccacon Creek (opposite Harrellsville), little-elevated, pointed, adjacent beaks; surface smooth except 1% miles below Tar Ferry, 3 to 4 miles below Tar Ferry, for lines of growth and a feeble angulation extending back Dogwood Landing, and Mount Pleasant Landing on the Chowan ward from the umbo to the lower posterior margin; ends nearly River, Hertford County; Colerain Landing, Bertie County; equally rounded, the posterior slightly more pointed, the base 1 to 2 miles above the Atlantic Coast Line Railroad bridge, moderately and evenly curved; pallial sinus small, angular, very Halifax (at Quankey Creek, just below the county bridge), short; hinge normal, feeble, -with short granulose laterals. 1% miles northeast of Enfield, % mile west of Enfield, Palmyra Longitude 17, altitude 10, diameter 7 millimeters.—Dall, 1898. Bluff, and 3% miles below Palmyra Bluff, Halifax County; 1% miles east of Battleboro, 3 miles south of Battleboro, Holotype, a left valve: U. S. Nat. Mus. 115080. and 2 miles southeast of Sharpsburg, Nash County; 3% Type locality: Magnolia, Duplin County, N. C. miles northwest of Rocky Mount, 2 miles west of Rocky Mount, % mile northwest of the Rocky Mount waterworks, % In the unique valve that was taken as the type of mile north of the Rocky Mount waterworks, 6 to 7 miles below Spisula magnoliana Dall, the cardinal margin is broken Rocky Mount (at Capt. Turner Battle's), Compass Creek (at a away and the edges are so perfectly rounded by erosion point 1 mile from the confluence with the Tar), % mile north that all trace of the characteristic ligamentary attach of New Bridge, 5 miles below New Bridge, Swift Creek, 15% ment of Mwlinia has been obliterated and replaced by a miles above Bells Bridge, % mile above Bells Bridge, 100 yards below Bells Bridge, % mile below Bells Bridge, 1 mile below pseudospisuloid attachment. This fact was .brought Bells Bridge, Shiloh Mills, and 1 mile below old Sparta Bridge, out by the examination of fresh individuals in which Edgecombe County; Hamilton Bluff, ys mile below Hamilton the septum had been recently shipped away. PART 1. PELECYPODA 115 The subspecies is separated from M. congesta s. s. the hinge margin. Sinus evenly rounded, projected by the lower, more regularly oval and elongate valves, forward as far as the umbones. the less prominent umbones, and the short, rather Dimensions of holotype: Height 6.4 millimeters, heavy laterals. width 10.3 millimeters, convexity 1.7 millimeters. • Distribution: Virginia: Miocene, Yorktown formation, South Holotype, a right valve: U. S. Nat. Mus. 325591. Quay, Nansemond County. Type locality: 1 mile northeast of Suffolk, Nanse North Carolina: Miocene, Yorktown formation, S1/^ miles mond County, Va. Yorktown formation. below Palmyra Bluff, Halifax County; 8 to 9 miles south of This single valve, the only one* of the genus thus Greenville, Pitt County; 1 mile north of Castoria, Greene far reported from the east coast Miocene, has many County; Rock Landing, Craven County. Duplin marl, 10 miles 'south, of Clinton, Sampson County; Natural Well, Duplin characters hi common with Mesodesma deauratum County; 2 miles below Lumberton, Robeson County. Pliocene, Turton of the Pleistocene faunas of the North Atlantic Waccamaw formation, Walkers Bluff, Bladen County; Neills coast and may be the precursor of that species. The Eddy Landing, Columbus County. . umbones are more posterior than in the majority of Outside distribution: Miocene, Duplin marl, Brunswick River the Recent individuals; the hinge plate is set in the bed, Brunswick, Glynn County, Ga. plane of the dorsal margins rather than slightly ob Family MESODESMATIDAE lique to it, as in the M. deauratum of Turton; and the ventral laminae of the laterals and the anterior arm Genus MESODESMA Deshayes of the cardinals are less elevated. The species also 1831, Mesodesma Deshayes, Encyclopedie rfle'thodique, vers. suggests at first glance Spisula modicella Conrad. It vol. 2, p. 442. is, however, relatively lower, more inequilateral, with a Type by subsequent designation (Anton, Verzeichniss der much more deeply excavated resilial pit and shorter Conchylien, p. 3, Halle, 1839) : Mactra donacia Lamarck. Re and more narrow lateral grooves. cent off the coast of Chile. Distribution: Virginia: Miocene, Yorktown formation, 1 mile Shell heavy, compressed, donaciform or subtrigonal, northeast of Suffolk, Nansemond County. inequilateral. Umbones posterior. Ligament short, mostly internal. Hinge strong. Resilial pit deep. A Genus ERVILIA Turton single cardinal in each valve, that of the left usually 1822. Ervilia Turton, Conchylia insularum britannicarum: stronger and often bifid. Anterior and posterior sul- Dithyra, p. 55. cated laterals in the left valve received between the Type by monotypy: Mya nitens Montagu. Recent from the sulcated laminae of the right. Inner margin of valves Tortugas to the northern coast of South America. smooth. Muscle impressions deep. Pallial sinus well Shell small, oval to triangular. Umbones low, sub- defined, variable. central, slightly opisthogyrate. External ligament ob The genus is first recognized in the Eocene. The solete; internal, lodged in a small resilifer, situated Recent species are relatively few, but they are world between the anterior and posterior cardinals. Lateral wide in distribution. armature feeble; grooves developed in right valve; lat eral teeth of left usually replaced by modifications of Mesodesma spatha Gardner, n. sp. the dorsal margins. Pallial sinus well defined. ' . Plate 18, figures 8, 12 These lentil-shaped bivalves form an inconspicuous Shell small, compressed, ovate-oblong, strongly in factor in the marine faunas of the Tertiary and post- equilateral. Umbones very low and flattened, located Tertiary seas. The Recent forms are mostly tropical. about two-thirds of the distance back. Anterior por tion of shell slightly contracted, much produced, gently Ervilia lata Dall sloping dorsally, evenly rounded distally. Posterior Plate 23, figure 20 dorsal margin slightly hunched. Lateral margin sub- 1898. Ervilia lata Dall, Wagner Free Inst. Sci.- Trans., vol. 3, truncate. Base line nearly straight. Surface smooth pt. 4, p. 915, pi. 33, fig. 20. or marked with feeble incrementals. Hinge known 1932. Ervilia lata Dall. Mansfield, Florida Geol. Survey BulL 8, from right valve only; hinge plate heavy. Resilial p. 155, pi. 32, figs. 4, 7,10. pit large and deep, slightly oblique; limiting margins Small, very similar to E. concentrica, from which it differs raised. Lateral furrows narrow, deep, transversely by being broader between the beak and the basal margin, with the beaks slightly more equilateral and the dorsal margin grooved, the posterior decidedly shorter. Anterior behind the umbo usually more impressed; the surface is usually arm of cardinal in line with the anterior ventral lamina covered with concentric ridges, which are flattened and coarser but not confluent with it; posterior arm projecting al and less regular than those of E. concentrica; the hinge teeth most horizontally over the chondrophore. Lateral also are less strong than the latter species. Longitude 4.5 [5.2], sockets deep. Muscle impressions and pallial charac altitude 3.5 [3.6], diameter 2.2 millimeters. • This form on casual inspection would be referred to E. con- ters distinct. Anterior adductor scar pyriform; pos ce^trica as a mere variety, but when a large number of speci terior semielliptical. Pallial line rather distant from mens are examined and the characters above-mentioned seem 116 MOLLTJSCA FROM MIOCENE AND LOWER PLIOCENE OF VIRGINIA AND NORTH CAROLINA to be fairly constant, I believe it is best to recognize the Distribution: Virginia: Miocene, Yorktown formation, 1 mile average differences by a name than to overlook them by northeast of Suffolk, Nansemond County. consolidation with what I regard as probably a distinct North Carolina: Miocene, Dupljn marl, Frank Wilson's marl species.—Dall, 1898. pit near Magnolia, Duplin County. Pliocene, Waccamaw for Holotype, a right valve: U. S. Nat. Mus. 115054. mation, Neills Eddy Landing, Columbus County. Type locality: Natural Well, Duplin County, N. C. Superfamily VENERACEA Menke Duplin marl. Family PETRICOLIDAE D'OrMgny Distribution: Nortfl Carolina: Miocene, Duplin marl, 1% miles north of Magnolia and at Frank Wilson's marl'pit near Genus FETRICOLA Lamarck Magnolia, Duplin County. Pliocene, Waccamaw formation, 1801. Petricola Lamarck, Systeme des animaux sans vertebres, Cronly and Neills Eddy Landing 3 miles north of Cronly on p. 121. the Cape Fear River, Columbus County. Type by subsequent designation (Schmidt, C. F., Versuch Ervilia lata radiata Gardner, n. subsp. fiber die beste Einricht, etc., pp. 55, 176., Gotha, 1818) ; Venus Plate 23, figures 25, 29 lapicida Chemnitz. Found by Chemnitz in ballast of coral rock from the West Indies. Shell minute, oblong to subtriangular, slightly in Shell thin, oval or elongate, often irregular, gaping. equilateral. Umbones subcentral or a little in front Umbones anterior but not terminal. Lunule ill defined. of the medial line, opisthogyrate. Dorsal margins Sculpture dominantly radial and in the genotype di fairly steep; anterior lateral margin evenly rounded, varicate or zigzag. Inner margins smooth. Ligament posterior slightly produced and rounded. Base line external, attached to nymphs. Armature of right valve strongly arcuate, often slightly contracted posteriorly. usually consisting of two cardinals, the posterior of Surface sculptured with crowded concentric lirae, which is grooved or bifid; third rudimentary cardinal which vary rather widely in strength in different in rarely present; left valve furnished either with three dividuals, and on the posterior slope, with distinct divergent cardinals (the middle one bifid, the remain though submicroscopic radial striations. Ligament pit ing two simple) or with two divergent cardinals (a moderately large. Anterior cardinal of right valve simple posterior and a bifid anterior); laterals absent strong, the posterior obsolete. Anterior lateral groove in the normal adult. Pallial sinus narrow, as a rule, ill defined, posterior less feeble; dorsal edges of left and ascending, with considerable variation in depth. valve modified to function as laterals. Pallial sinus This is a nestling or burrowing genus, which exhibits rather deep, well rounded. the variability characteristic of dwellers in such a Dimensions of holotype: Height 2.6 millimeter's, habitat. width 4.0 millimeters, convexity 0.8 millimeter. Para- The group has been recognized from strata as early as type: Height 2.6 millimeters, width 4.2 millimeters. the Cretaceous; the Recent species, though numbering Holotype, a right valve, and paratype, a left valve: only about 25, are, owing in part to their habitat, widely U. S. Nat. Mus. 325597. distributed in the temperate and warm waters. Type locality: Neills Eddy Landing on the Cape Petricdla s.s. has not been recognized in the Miocene Fear River, Columbus County, N. C. Waccamaw or in the pre~Caloosahatchee Pliocene. Dall reports formation. the genotype from the Caloosahatchee marl. Possibly Ervilia lata radiata differs from E. lata s.s. by the the temperature of the water may have been the con lower, less triangular outline, by the tendency toward trolling factor that excluded it from the early Pliocene a less regular and less clearly defined concentric sculp of the Carolinas, although it is recorded in the Recent ture, and preeminently by the radial striations of the faunas from the coast of South Carolina. posterior keel. The subspecies is best developed at the type locality, Neills Eddy Landing, in the Wacca Subgenus RUPELLARIA Fleuriau-Bellevue maw, though it is present in the Yorktown and is 1802. Rupellaria, Fleuriau-Bellevue, Jour, physique, vol. 54, p. associated with E. lata Dall in the Duplin. The con 347; Soc. Philom. (Paris) Bull, des Sciences, 62, p. 106. centric and radial sculpture serve also to separate 1900. Rupellaria, Dall, Wagner Free Inst. Sci. Trans., vol. 3, the subspecies radiata from the coexistent E. polita pt. 5, p. 1058. Dall. Type by elimination: Venus lithophaga Retzius. Widely re Less than half a dozen valves of this small species ported but most 'common off the Atlantic coasts of France and were recovered by Mansfield from the Gancellaria zone Spain and in the western Mediterranean. of the Choctawhatchee formation in Florida. Fleuriau-Bellevue cited two species under his newly A closely related species, E. gabbi Woodring, is de described genus: the first a Venerupis, the second scribed by Woodring, 1925, from the Bowden of Venus lithophaga Retzius, which be'comes by elimina Jamaica. He differentiated it from the southeastern tion the type of the subgenus. .American species because it is less compressed and less Rupellaria is short and inflated in front, less inflated inequilateral. and attenuated behind. A radial sculpture is usually PART 1. PELECYPODA 117 developed over the entire shell but is stronger an Dimensions «f figured specimens: Eight valve (U. S. teriorly. The pallial sinus is broad and broadly Nat. Mus. 325562, from Palmyra Bluff on the Roanoke rounded. River, Halifax County, N. C.), height 13.5 millimeters, width 23.5 millimeters, convexity 5.5 millimeters.' Left Petricola (Rupellaria) grinnelli Olsson valve (U. S. Nat. Mus. 325561, from Wilmington, Plate 15, figures 13, 14, 18 N. C.), height, 16.0± millimeters, width 24.8 milli 1914. Petricola (Claudiconcha) grinnelli Olsson, Bull. Am. Pale meters, convexity 5.8 millimeters. ontology, vol. 5, No. 24, p. 16, pi. 4, figs. 7-10. P. grinnelti Olsson is characterized by the laminar Shell elongated, solid, often distorted; anterior end rounded; texture, the irregular Pleiorytis-likQ radials, distrib posterior end elongated, pointed; right valve slightly larger uted with approximate uniformity over the .entire ex and overlapping the left, especially on the posterior dorsal ternal surface, and the bizarre outline of the pallial margin^ surface sculpture of irregular radial striae, which as a rule are slightly larger and separated by wider interspaces line and sinus, which is due to the elevated position of on the anterior portion of the shell; striae more or less gran the adductors. Almost any of these characters alone ulated by concentric lines; hinge weak, with slender teeth, would suffice to differentiate the species. those in the specimens broken off but, judging from the stumps remaining, consisting of three cardinal teeth in each valve. Distribution: Virginia: Miocene, Yorktown formation, Belle- Type specimen : Length 22, height 13, thickness 12 millimeters. field on the York River, York County; Petersburg, Dinwiddie A large valve: Length 25, height 16, thickness 7 millimeters. County; 5 miles north of Smithfield on the James River, Isle of The subgenus Claudiconcha Fischer, as exemplified by P. Wight County; Suffolk, Nansemond County. monstrosa Gmelin, contains shells which have the right valve North Carolina: Miocene, Yorktown formation, Palmyra slightly larger and overlapping on the left. This species Bluff, Halifax County; 1% miles below Bells Bridge, Tar River, probably burrowed in the sand. The Miocene shell compares Edgecombe County. Pliocene, Waccamaw formation, Walkers well with the type form of this subgenus but possesses a much Bluff (?), Bladen County; Wilmington(?), New Hanover more degenerate hinge. County. Yorktown formation, .Tames River, 5 miles north of Smith- Subgenus PETRICOIARIA Stoliczka field; Bellefield.—Olsson, 1914. 1871. Petricolaria Stoliczka, India Geol. Survey Mem., Palae- The Chemnitz figures to which Gmelin refers in his ontologia Indica, Cretaceous fauna of southern India, citation of monstrosa indicate a shell unlike grinnelli. vol. 3, p. 139. Olsson's species, seems more properly referable to Type toy original designation: Petricola, pholadiformis Rupellaria. Lamarck. Recent from Prince Edward Island to the West The shell is built up of concentric layers, and the Indies and the Gulf of Mexico. successive laminae are often visible in cross section at In this the shell is very much elongated, subcylindrical, the the inner margins of the valves. The outline is sinus narrow and very deep; the hinge has 2 teeth in each strongly convex, oval, cylindrical, or trapezoidal. The valve, attached below the hinge area and curving upward; in dorsal margins are usually rectilinear, the anterior the right valve the anterior tooth is hooklike, the posterior sometimes flaring widely, the posterior parallel with much larger, broadly laminar and bipartite; in the left the anterior is very large and bipartite, its anterior portion almost the base. The lateral margins are evenly and similarly representing a separate hooklike tooth corresponding to the rounded or obscurely truncated at approximately the anterior tooth of the right valve; the posterior portion is thick same angle to the base. The umbones are inflated, and prominent and longitudinally grooved; besides this there incurved to the dorsal margins, their tips proximate is a small, sometimes obsolete, posterior cardinal tooth.— and prosogyrate, and located about one-third of the Stoliczka, 1870. distance back from the anterior margin. The surface Petricola (Petricolaria) pholadiformis Lamarck is sculptured with some 40 irregular radials, mostly equisize and equispaced but slightly more crowded pos 1818. Petricola pholadiformis Lamarck, Histoire naturelle des teriorly. The free edges of the concentric lamellae are animaux sans vertebres, vol. 5, p. 505. ruffled at the intersection with the ribs. The lunule is 1822. Petricola fornicata Say, ,Acad. Nat. Sci. Philadelphia Jour., 1st ser., vol. 2, p. 319. not defined. The ligament is external and seated on a 1832. Petricola pholadiformis Lamarck. Conrad, American very narrow nymph. The 2 right cardinals are proxi marine conchology, p. 37, pi. 7, fig. 3. mate, slender, conical, recurved, issuing from beneath 1834. Petricola pholadiformis Lamarck. Say, American conch the umbo. The dentition of the left valve is imper ology, pt. 6, pi. 60 (upper and lower figs.). fectly known. The anterior adductor impression is 1841. Petricola pholadiformis Lamarck. Gould, Invertebrata of Massachusetts, p. 63. oval, the posterior suborbicular, and both of them are 1854. Petricola pholadiformis Lamarck. Sowerby, Thesaurus set well up toward the dorsal margin. The pallial conchyliorum, pt. 15, p. 771, pi. 166, fig. 1. line and sinus are strongly marked. The sinus is very 1858. Petricola pholadiformis Lamarck. Holmes, Post-Pleiocene broad and somewhat oblique, the frontal margin fossils of South Carolina, p. 38, pi. 7, fig. 6. rounded and not far from the median vertical; the 1889. Petricola pholadiformis Lamarck. Dall, TJ. S. Nat. Mus. Bull. 37, p. 58, pi. 59, fig. 15; pi. 64, fig. 140a. ventral margin parallel to but not coalescent with the 1900. Petricola (Petricolaria) pholadiformis Lamarck. Dall, pallial line. Wagner Free liast. Sci. Trans., vol. 3, pt. 5, p. 1061. 118 MOLLUSCA FROM MIOCENE AND LOWER PLIOCENE OF VIRGINIA AND NORTH CAROLINA 1906. Petricola pholadiformis Lamarck. ClarE, Maryland Geol. of a stout, projecting, slightly recurved, anterior cardi Survey, Pliocene and Pleistocene, p. 201. nal, and a laminar, sulcated, posterior cardinal; in the P. testa transversim elongata; latere postico brevissimo, left valve 3 divergent teeth—the anterior cardinal sulcis longitudinalibus Inmelloso-dentatis utrinque radiato; simple, the middle cardinal feebly sulcated on the ven-- antico subglabro . . . Largeur, 46 millim.—Lamarck, 1818. tral surface, and the posterior cardinal simple and The species is characterized by a cylindrical outline, laminar. Anterior adductor muscle impressions sub- by a strong differentiation of the sculpture on the- an circular; the posterior semieHiptical. Sinus free, ex terior and posterior portions of the shell, and by the tending about half the distance toward the anterior relatively few but prominent denticulated radials on margin, rounded in front, its dorsal and ventral the anterior end. There are 3 cardinals in the left boundaries parallel. Pallial line usually indistinct. valve—the middle one sulcated, the anterior and Inner margins of valve often crenate, particularly in posterior ones simple. front. Distribution* Virginia: Miocene, Yorktown formation, York- Petricola carolinensis Conrad is separated from P. town, York County. pholadiformis Lamarck by the less strongly differenti North Carolina: Pliocene, Waccamaw formation, Walkers ated sculpture of the anterior and posterior areas. The Bluff, Bladen County; Neills Eddy Landing, 3 miles north of radials as a whole are more numerous and consequently Cronly, Columbus County. less prominent and distant. The concentric sculpture Outside distribution: Pleistocene, Sankaty Head (early fauna), Mass.; Wailes Bluff near Cornfield Harbor, St. Marys is laminar at its intersection with the radial, but the County, Md.; Eau Gallie, Brevard County, Fla. Recent, Prince edges are rarely free and vaulted as in P. pholadi Edward Island to Greytown, Nicaragua, in less than 50 fathoms; formis. P. carolinensis is most closely allied to the most abundant on sandy and muddy bottoms. Recent P. dactylus Sowerby, from which it differs in. being constantly more elongated and cylindrical. The Petricola (Petricolaria) carolinensis Conrad general characters of the sculpture are very similar. 1856. Petricola pholadiformis Tuomey and Holmes, Pleiocene The Tertiary species is on the whole rather rare, though fossils of South Carolina, p. 87, pi. 21, fig. 5. Not in the Duplin marl, in Robeson County, well preserved P. pholadiformis Lamarck, 1818. individuals have been collected in considerable 1863. Petricola carolinensis Conrad, Acad. Nat. Sci. Philadel phia Proc. for 1862, p. 576. (New name for P. numbers. pholadiformis Tucmey and Holmes.) Distribution: North Carolina: Miocene, Yorktown formation, 1900. Petricola (Petricolaria) carolinensis Conrad. Ball, Wag 2% miles northwest of Williamston (on the farm of Joseph ner Free Inst. Sci. Trans., vol. 3, pt. 5, p. 1060. Cherry), Martin County. Duplin marl, 2 miles below Lum Shell elongated, cylindrical, buccal side very short, radiately ber ton, 1% miles northeast of Fairmont (on the farm of [costate] and striate; ribs lamellar; anal side much elongated, Andrew Jones), and at Fairmont, Robeson County. radiately striate; lunule ovate. . . . The shell is ovate-cylin Outside distribution: Pliocene, Waccamaw formation, Goose drical, equivalve, but very unequilateral; the buccal side is Creek and Pee Dee River, S. C. rounded and covered with irregular lamellar and somewhat toothed ribs; anal side covered with radiating irregular raised Genus PLEIORYTIS Conrad lines. The lunule is defined by the termination of the lines 1862. Pleiorytis, Conrad, Acad. Nat. Sci. Philadelphia Proc. of growth.—Tuomey and Holmes, 1856. for 1862, p. 286. Locality: Pee Dee and Smiths, Goose Creek, S. C. 1936. Pleiorytis Conrad. Gardner, Florida Dept. Cons. Geol. Bull. 14, p. 39. ' Valves gaping, strongly convex, elongate-ovate, very Type by monotypy: Pleiorytis ovata Conrad (Days Point, inequilateral. Anterior end short and evenly rounded; James River, Va.) = Petricola centenaria Conrad, 1833. Mid posterior, alar, produced, tapering gradually to the dle and upper Miocene of the middle and south Atlantic acutely rounded extremity. Umbones tumid, proxi Coastal Plain. mate, prosogyrate, located about one-fifth of the dis Equivalve, ovate or oval, with radiating striae, gaping pos tance back from the anterior margin. Radial sculpture teriorly; hinge of right valve with 2 widely diverging teeth; on the anterior part of the shell coarse and distant, the left valve with 1 direct, thick, triangular, bifid tooth under posterior • of the primary radials originating at the the apex, and an oblique compressed tooth posteriorly; sinus of pallial impression extending beyond the middle of the valves; umbones and reaching the ventral margin a little in muscular impressions large. (Miocene.)—Conrad, 1862. front of the median line; remainder of shell covered with fine and uniform radiating striae, some 50 to 70 Conrad placed this genus under the family Petri- in number. Concentric lines inconsequential except on colidae. the anterior end, where they tend to become scabrous The group of Pleiorytis centenaria Conrad has a at the intersection with the prominent radials. Lun limited geographic and stratigraphic range, and per ule delimited by the anterior radial. Escutcheon not haps for that reason its dissimilarity to the type of defined. Ligament external; nymphs elongated, lentic Asaphis (Venus deflorata Linnaeus from the Ba ular in the closed valves, with a deep groove at their hamas) was not noted by Ball and others in assigning ventral margins. Armature in right valve consisting centenaria to Asaphis. In Asaphis, as in many of the PART 1. PELECYPODA 119 tellinids, the tips of the umbones are bent inward and 1932. -Asaphis centenaria (Conrad). Mansfield, Florida Geol. very slightly backward, and no trace of a lunular spur Survey Bull. 8, p. 149^ pi. 31, fig. 4. appears across the cardinals. In Pleiorytis, as in Shell solid, ovate, distorted more or less by the irregularities Petricola and other venerids, the umbones are decidedly of its situs; posterior end blunt, longer; anterior end shorter, rounded; sculpture of fine, nearly uniform, radial, rounded prosogyrate, and the lunular spur is more or less de threads with wider interspaces, crossed by fine, rounded, veloped. In AsapMs the bifid cardinal of the right slightly elevated incremental lines; beak moderately elevated; valve is produced and oblique; in Fleiorytis it is short hinge short, with (in the left valve) 1 strong, apically grooved and nearly vertical. In Asaphis, in the left valve, the cardinal between 2 simple narrow diverging teeth; ligament- dorsal margin is tabulated in front of the bifid cardi ary nymph short, strong, deeply grooved; basal margin feebly crenulated by the external sculpture; pallial sinus wide, shal nal; in Pleiorytis there is a well-developed laminar, low; altitude 20 [20.5], latitude 23 [22.5]; semidiameter 7 left anterior cardinal. millimeters. The general relations of Pleiorytis were properly Only 1 valve of this species was obtained by Professor Harris, indicated by Conrad, and though possibly it should be in whose honor it is named.—Dall, 1900. given only subgeneric rank under Petricola, the habits Holotype of P. harrisii Dall, a left valve: U. S. Nat. of the animal are not those of typical Petricola, the shell Mus. 145020. is not adjusted to a boring habitat, and the consequent Type locality: Bellefield.Bluff, 4^/2 miles above York- differences may be recognized generically. The genus town, Va. Yorktown formation. may then be described as follows: Mansfield was the first to suggest that Petricola Shell of moderate dimensions, rather thin, slightly harrisii Dall should fall into the synonymy of "Asa- gaping; transversely elongate, moderately inflated. phis" centenaria Conrad. Umbones anterior, not conspicuously prominent, the tips proximate and prosogyrate. Lunule and es Family COOPERE1LIDAE cutcheon not developed. Posterior area flattened but Genus COOPEREILA Carpenter not rostrate. Ligament strong, external. A slender 1864. Cooperella Carpenter, British Assoc. Advancement Sci. spur from the lunular region carried across the Kept, for 1863, p. 639. cardinals. Teeth short, built up from a narrow 1900. Cooperella Carpenter. Dall, Wagner Free Inst. Sci. Trans., hinge plate; a laminar anterior and bifid medial vol. 3, pt. 5, p. 1061. cardinal in the right valve, the posterior cardinal Type by monotypy: Cooperella scintilloeformis Carpenter= almost or entirely obsolete; a laminar anterior, Oedalia subdiaphana Carpenter. Recent on the Pacific coast between Vancouver and Todos Santos Bay. bifid medial, and laminar posterior cardinal in the left valve. Laterals not developed. Adductor scars New subgenus of Oedalia. Cartilage semi-internal; only 1 tooth bifid.—Carpenter, 1864. large, the pallial sinus broad and deep, not confluent Shell small, thin, smooth, or concentrically striate or un ventrally with the pallial line. Inner edges of the dulate, equivalve, nearly equilateral, with entire margins; liga valves simple or faintly rayed but not crenate. ment long, feeble, profuse, amphidetic; resilium short, stout, The group is particularly characteristic of the mid opisthodetic, immersed behind the cardinals on an oblique thick dle and upper Miocene of the eastern seaboard of the ening of the hingeplate, not excavated to form a pit or pro duced into a chondrophore; hingeplate narrow, carrying two United States. right and three left subumbonal, divaricating, short, cardinal Petricola (Rupellaria) harrisii Dall has a hinge teeth, of which the left central tooth is always, and the others identical with that of Pleiorytis centenaria and may, frequently, bifid; laterals none; muscular impressions small, as indicated by Mansfield,49 be nothing more than a oval; pallial line narrow with an ample sinus.—Dall, 1900. much-warped individual of that species. Warping is This small genus has a very interesting distribution. not common in the group, but it is present to a con Only a few species of Cooperella s. s. have been recog siderable degree in a few individuals. Petricola nized—a single species from the east coast Tertiary; (Petricolaria) calvertensis Dall is-similar in sculpture the others, including the genotype, from the Pleistocene but it more cylindrical and, though the hinge is rather and Recent of the west coast. Woodring, 1925, de badly broken, does not seem to have the hinge plate so scribed a species from the Bowden, but he referred it well developed as that of Pleiorytis. to a new subgenus Cooperellopsis. , Pleiorytis centenaria (Conrad) Conrad? Cooperella carpenter! Dall Plate 15, figure 17 Plate 14, figures 44, 47 1833. Petricola centenaria Conrad?, Am. Jour. Sci., 1st ser., 1900. Cooperella carpenteri Dall, Wagner Free Inst. Sci. Trans., vol. 23, p. 341. vol. 3, pt. 5, p. 1063. 1863. Pliorytis centenaria Conrad?, Acad. Nat. Sci. Philadel 1900. Diplodonta yorJcensis Dall, idem, vol. 3, pt. 5, p. 1185, phia Proc. for 1862, vol. 14, p. 576. pi. 43, fig. 5. 1900. Petricola (Rupellaria) harrisii Dall, Wagner Free Inst. 1903. Cooperella carpenteri Dall, idem, vol. 3, pt. 6, pi. 49, fig. 8. Sci. Trans., vol. 3, pt. 5, p. 1060, pi. 43, fig. 1. Shell smooth or slightly concentrically undulate, and with 49 Mansfield, W. C., Florida Geol. Survey Bull. 8, p. 149, 1932, faint incremental lines; oval, nearly equilateral, the beaks mod- 120 MOLLTJSCA FROM MIOCENE AND LOWER PLIOCENE OF VIRGINIA AND NORTH CAROLINA erately elevated; hinge delicate, hingeplate narrow, excavated; is a flat concentric lamination, least feeble toward the pallial sinus deep but only moderately high; base arcuate, ends lateral margins. The ligament is deeply inset and rounded. Longitude 14 [12.5], altitude 11.5 [10.0], diameter produced about half the length of the dorsal margin. 7.50 millimeters.—Dall, 1900. The anterior and middle cardinals of the right valve Holotype, a right valve: U. S. Nat. Mus. 153714. are short and laminar with parallel proximate faces. Type locality: Petersburg, Va. Yorktown for The posterior cardinal is produced and bifid. -In the mation. left valve the anterior cardinal is short and laminar Both the cardinals in the right valve show a tendency to fit between the opposing faces of the anterior and toward a sulcated ventral margin. In the left valve middle cardinals of the right valve, the middle left the middle cardinal is strongly bifid, the posterior one cardinal is relatively heavy, and the posterior cardinal simple and laminar, and the anterior cardinal usually is thin and not very prominent. There is a short simple but sometimes feebly sulcated iii the adult. The dental process by way of an anterior lateral in the regularly transverse-oval and convex valves, the pecul left valve and, in the right valve, a corresponding iar depression of the hinge behind the umbones, and the socket placed near the ventral extremity of the lunule. dentition characterize this small form, which in out The pallial line is rather distant from the smooth inner ward semblance recalls some of the smaller and more margins, and the sinus is almost horizontally directed convex of the Diplodontas. and acutely rounded at the extremity. Dall described, under the name of Diplodonta york- The genus has been reported from the Wangaloa ensis^ a shell apparently identical with his Cooperella beds, Palaeocene of New Zealand, but some doubt has carpenteri. been cast by Stewart, 1930, on its occurrence at so The species has been reported from a number of lo early a time. In Europe the earliest records of the calities and is particularly abundant in the Yorktown genus, according to Cossmann and Peyrot, are in the formation in the vicinity of Suffolk. Aquitanian, and in the Coastal Plain deposits of this Distribution: Virginia: Miocene, Yorktown formation, York- country the Miocene marks the first recorded appear town, York County; Petersburg, Dinwiddie County; Cobham ance of the group. Marwick 50 noted that the left Wharf (upper bed) on the James River, Surry County; 12 to anterior lateral is merely the isolated extension of the 14 miles below Zuni, Blackwater River, Benns Church, Isle of anterior cardinal and does not arise independently of Wight County; Sycamore on the Nottoway River and % to % mile above the lower Seaboard Railway bridge over the Me- the cardinal, as in Macrocdllista and Callocardia. herrin River, Southampton County; 5% miles northwest of Suffolk, 2% miles northwest of Suffolk, 1% miles north of Subgenus DOSINIDIA Dall Suffolk, 1% miles northeast of Suffolk, 1 mile northeast of Suffolk, and % mile below the Suffolk waterworks dam, Nanse- 1902. Dosinidia Dall, U. S. Nat. Mus. Proc., vol. 26, p. 347. mond County. Type by original designation: Venus concentrica Born. Re North Carolina: Miocene, Yorktown formation, % mile above cent from the Florida Keys to Rio de Janeiro. Bells Bridge, Tar River, Edgecombe County; Dogwood Landing, Valves suborbicular, subcompressed, white, with a sculpture Hertford County. Duplin marl, Natural Well, Duplin County of concentric grooving, never lamellose; -furnished with an (Dall). obvious periostracum;, lunule small, impressed; escutcheon absent; pallial sinus ample, ascending, angular in front; pos Family VENEKIDAE terior cardinals serrate or corrugated in the nepionic young, smooth in the adult. Subfamily DOSINIINAE This group is confined to the tropical and warmer temperate seas of America.—Dall, 1902. Genus DO SIN IA Spopoli Dosinia (Dosinidia) acetabulum (Conrad) Conrad 1777. Dosinia Scopoli, Introductio ad Historiam naturalem, sistens genera Lapidum, Plantarum et Animalium, Plate 11, figure 4 hactenus detecta, caracteribus essentialibus donata, in tribis divisa, subinde ad leges Naturae, p. 399. 1832. Artemis acetabulum Conrad, Fossil shells of the Tertiary formations of North America, p. 20, pi. 6, fig. 1. Type by tautonomy: Chama dosin Adanson = Dosinia afri- 1834. Cytherea obovata Conrad, Acad. Nat. Sci. Philadelphia cana Hanley. Recent off the coast of Senegal and adjacent Jour., vol. 7, p. 132 (young shell). waters. 1838. Cytherea obovata Conrad, Fossils of the medial Tertiary of the United States, p. 14, pi. 8, fig. 4. The outline of the paired valves of Dosinia recalls 1838. Artemis acetabulum Conrad, idem, p. 29, pi. 16, fig. 1. that of some of the discoidal lucinoids. The beaks are 1863. Dosinia acetabulum Conrad, Acad. Nat. Sci. Philadelphia prominent and the prodissoconch is, in many species, Proc. for 1862, p. 575. unusually conspicuous. The lunule is small, sunken, 1863. Dione obovata Conrad, idem, p. 575. and outlined by a deeply impressed line. In the type 1870. Dosinia obovata Conrad, Am. Jour. Conchology, vol. 6, p. 77. Not D. obovata Conrad. Bush, Connecticut section, the escutcheon is clearly indicated both by the Acad. Sci. Trans., vol. 6, pt. 2, p. 477, 1885. contour and by the sculpture, and it extends the length of the posterior dorsal margin. Tlje usual sculpture *° Marwick, J., New Zealand Inst. Trans., vol. 57, p. 580, 1927. 1. PELECYPODA 1894. Dosinia acetabuT\um Conrad. Whitfield, U. S. Geol. Sur lenticular, the upper end, at .the ventral extremity of vey Mon. 24, p. 73, pi. 13, fig. 2. the lunule, the lower at, or a trifle above, the median 1903. Dosinia (Dosinidia) acetabulum Conrad. Ball, Wagner horizontal; posterior adductor scar relatively wider Free Inst. Sci. Trans., vol. 3, pt. 6, p. 1230. 1904. Dosinia acetabulum Conrad. Glenn, Maryland Geol. Sur and submedial in position. Pallial line moderately vey, Miocene, p. 315, pi. 83, fig. 1; pi. 84, fig. 1. distant from the base. Sinus sharply ascending, 1906. Dosinia acetabulum Conrad? Bose, Inst. geol. Mexico pointed in front. Young relatively higher than the Bol. 22, p. 81, pi. 11, figs. 7, 12. adults, the umbones more prominent; the concentric 1922. Dosinia acetabulum Conrad. Olsson, Bull. Am. Paleon sculpture stronger and more regular, and the posterior tology, vol. 9, No. 39, p. 231, pi. 31, fig. 1. 1926. Dosinia (Dosinidia) acetabulum (Conrad). Palmer, cardinal transversely grooved. Palaeontographica Americana, vol. 1, No. 5, p. 63, pi. Dosinia acetabulitm is one of the most widely dis 19, figs. 1-3, 6-7, 9. tributed, abundant, and conspicuous bivalves in the 1932. Dosinia (Dosinidia) acetabulum (Conrad). Mansfield, east coast Miocene. The shell substance crumbles read Florida Geol. Survey Bull. 8, p. 116, pi. 24, fig. 1. ily so that the external surface is often badly decorti Lentiform, with numerous concentric striae, which are rather cated. The characters are so distinctive, however, that sharp and elevated on the anterior and posterior sides; cardinal the species may be confidently determined even from fosset large, oblong, profound; with age, almost obliterating fragments. The only coexistent representative of the the posterior tooth; right valve with 3 teeth, the posterior one long and sulcated longitudinally; 2 anterior teeth approximate; genus—D. elegans Conrad—is a somewhat smaller, left valve with 4 teeth, 3 of them distant; the anterior tooth thinner, more compressed shell with a more pronounced somewhat pyramidal and entering a groove formed by 2 slight and regular concentric sculpture. elevations in the opposite valve. Mrs. K. V. W. Palmer has noted an increase in the Type localities: St. Marys River and Easton, Md.; James size of the specimens in the later formations. The River, near Smithfield, and Suffolk, Va. Upper Tertiary.— Conrad, 1832. prominence of the beaks and the strength and regu larity of the concentric sculpture in juvenile specimens Conrad's original figures are reproduced. is so marked that it is not surprising they, were de Shell large, heavy, crumbly, moderately compressed, scribed by Conrad as a distinct species. Mansfield re prolately discoidal. Umbones subcentral, flattened, ports the rare occurrence of D. acetabulum s. s. from oblique, strongly prosogyrate. Lunule impressed, cor both the Ecphora and the Cancellaria zones of the date in the double valves, clearly delimited by an in Choctawhatchee formation, and a variety, D. acetdb- cised line. Escutcheon absent. Surface covered with ulum ~blountana, from the Area zone. The mid-Ameri a dark brown or rufous periostracum, which is some can shells described by Bose, 1906, and by Toula, 1909, times well preserved even in the Chesapeake Miocene may be referable to D. delicatissima Brown and Pilsbry, forms; surface beneath concentrically sulcated with 1913, from the Gatun formation. somewhat irregular grooves, which are strongest and Distribution: Virginia: Miocene, St. Marys formation?, most regular near the dorsal magins and tend to be Nomini Cliffs, Westmoreland County. St. Marys formation, 1 come obsolete on the central portion of the disk. Liga to 2 miles below Bowlers Wharf, Essex County; 2y2 miles ment very strong; nymph elongated, roughly sickle- south of Farnham, Richmond County; a quarter of a mile shaped, limited dorsally by a very sharp and deep below Jones Point and Urbanna, Middlesex County. York- groove; resilial pit deep, oblong, subumbonal, often town formation, 3 miles northeast of Walkerton, King and Queen County; Lanexa (upper bed), New Kent County; York- enlarged by decay in senile individuals so that it en town, York County; mouth of Baileys Creek, Prince George croaches to a considerable extent on the posterior County; Lieutenant Run, Petersburg, Dinwiddie County; cardinal. Hinge plate broad and heavy; armature of Sunken Marsh Creek (upper bed), Surry County; 5 miles north right valve consisting of a simple anterior and a medial east of Smithfield, 2 miles northwest of Smithfield, 1% miles cardinal, their inner surfaces flattened and proximate ; northwest of Smithfield, 1% miles west of Smithfield, Zuni (near the pumping station), 6% to 7 miles below Zuni, and 12 ancl of a single obliquely elongated, rather distant, bifid, to 14 miles below Zuni, Isle of Wight County; Hitchcock, posterior cardinal; groove for reception of anterior Greensville County; 3 to 4 miles above the lower Seaboard lateral of left valve shallow; posterior lateral absent; Railway bridge, and % to % mile above the lower Seaboard hinge margin just behind posterior cardinal sharply Railway bridge, Southampton County; 1 mile east of Everets pinched; armature of left valve consisting of three Post Office, Exit, 5% miles northwest of Suffolk, 2% miles divergent cardinals, the anterior and the posterior card northwest of Suffolk, 1% miles north of Suffolk, 1% miles north of Suffolk, 1 mile west of Suffolk, !*/£ miles northeast of Suffolk, inal simple and moderately elongated, the middle tooth 1 mile northeast of Suffolk, and half a mile below the Suffolk broader and somewhat undulated or grooved; anterior waterworks dam, Nansemond County. lateral a small, rounded prominence placed near the North Carolina: Miocene, Yorktown formation, 1% to 2 miles ventral margin of the lunule. Adductor impressions abpve Branches Bridge over the Meherrin River, 1 mile above and pallial line distinct, the area of the adherent Branches Bridge, Branches Bridge, and 1% mile below Branches Bridge, Northampton County; 2% miles north mantle usually somewhat roughened, the rest of the west of Murfreesboro, 1% miles above Murfreesboro, and interior often polished. Anterior muscle scar rudely near Murfreesboro, Hertford County; Halifax (at Quankey 122 MOLLUSCA FROM MIOCENE AND LOWER PLIOCENE OF VIRGINIA AND NORTH CAROLINA Creek, just below the county bridge) and at Palmyra Bluff, margin; posterior hinge margin elongated, slightly convex, ob Halifax County; 2 miles west of Rocky Mount, % mile above lique; lunule cordate, deeply impressed. Height 2% inches, Bells Bridge over the Tar River, % mile below Bells Bridge, 1 length 2% inches. mile below Bells Bridge, I1/! miles below Bells Bridge, Shiloh Locality, Neuse River, below New Bern, N. C. Miocene. Mills, and 1 mile below old Sparta Bridge, Edgecombe County, This beautiful shell is allied to A. concentrica but is readily 2 miles southeast of Tugwell (on Jacobs Branch), 3 miles distinguished by its stronger, remoter stria, by its convexity south of Farmville, 3 miles southwest of Frog Level (on J. A. of disk and its more robust anterior cardinal teeth; the pos Noble's branch), 8 to 9 miles west of Greenville (on the east terior teeth are less oblique, forming a wider space between side of Pinelog* Branch), l 1/^ miles west of Greenville (on them and the anterior teeth. The posterior hinge margin is Schoolhouse Branch), Greenville (just east of the county not so elongated, in proportion as in the concentrica.—Conrad, bridge), 6 miles below Greenville, 6% miles below Greenville 1844. (at Tafts Landing), 8 to 9 miles southeast of Greenville, IVa The figured right valve, U. S. Nat. Mus. 497065 from miles west of Galloway Crossroads, 9 to 10 miles south of Greenville (on Fred Haddock's farm), 1 mile northwest of the Caloosahatchee Pliocene at Shell Creek, DeSoto Galloway Crossroads, and % mile north of Grimesland, Pitt County, Fla., measures 61 millimeters in height and 68 County; 2y2 miles northwest of Chocowinity, Beaufort County; millimeters in width. half a mile east of Lizzie (on David Summeril's farm), Greene Dosinia elegans Conrad resembles his D. acetabulum County. i in the major features. It runs a little smaller than Outside distribution: Miocene, Santa Maria Tetetla, Vera the latter, is somewhat more compressed and more Cruz, Mexico. Calvert formation, Atlantic City (well bore), N. J.; Reeds, Queen Annes County, Md,; Lyons Creek, Anne uniformly rotund; the valves are thinner and less fri Arundel County, Md.; Whites Landing, Prince Georges County, able, the concentric sculpture is stronger and much Md.; Plum Point and Chesapeake Beach, Calvert County, more regular, and, though more elevated near the Md. Choptank formation, Greensboro, Caroline County, dorsal margins, it is always persistent and moderately Md.; Cordova, Peach Blossom Creek, Dover Bridge, and prominent over the entire surface. The hinge is less Trappe Landing, Talbot County, Md.; Sand Hill, Dorchester County, Md.; Governor Run, Flag Pond, and St. Leonard Creek, heavy and rude than in D. acetabulum, and the teeth, Calvert County, Md.; Turner, Jones Wharf, and Pawpaw Point, though similar and similarly arranged, are more St. Marys County, Md. St. Marys formation, Cove Point, Cal sharply cut. D. discus Reeve, of the post-Miocene vert County, Md.; St. Marys River and Langleys Bluff, St. faunas, is even smaller, thinner, and more compressed Marys County, Md. than Z>. elegans, and it has a finer, closer, less conspicu Dosinia (Dosinidia) elegans (Conrad) Conrad ous concentric sculpture. In all the young of this section the outline is more Plate 11, figure 1 elevated, and the umbones are more prominent than 1685. Pectunculus albidus, etc., Lister, pi. 288, fig. 124. 1838. Artemis elegans Conrad, Fossils of the medial Tertiary in the adults. of the United States, p. 30. D. elegans Conrad, though never so abundant, occu 1844. Artemis elegans Conrad, Acad. Nat. Sci. Philadelphia pies in the Tertiary faunas south of the Hatteras axis Proc., vol. 1, p. 325. a position analagous to that of D. acetabulum north 1846. Artemis elegans Conrad, Am. Jour. Sci., 2d ser., vol. 2, of the axis. p. 393. 1850. Artemis concentrica Reeve, Conchologia iconica, vol. 6, Distribution: North Carolina: Miocene, Duplin marl, 4 miles pi. 2, fig. 8. Not Venus concentrica Born, 1780. north of Lumberton (on the land of Charles Rowland), Lum- 1856. Venus concentrica Gmelin. Tuomey and Holmes, Pleio- berton (near the bottling works), 2 miles below Lumberton, cene fossils of South Carolina, p. 82, pi. 21, fig. 7. and 4 to 5 miles below Lumberton, Robeson County. Pliocene, 1858. Artemes transversus Emmons, North Carolina Geol. Sur Waccamaw formation, Walkers Bluff on the Cape Fear River, vey Rept, p. 295, figs. 223, 224. Bladen County; Neills Eddy Landing, 3 miles north of Cronly, 1863. Dosinia elegans Conrad, Acad. Nat. Sci. Philadelphia Proc. Columbus County. for 1862, p. 575. . Outside distribution: Miocene, Santa Maria Tetetla, Vera 1863. Dosinia, intermedia Conrad, idem, p. 575. Cruz, Mexico. Duplin marl, Sumter district, S. C. Pliocene, 1889., Dosinia elegans Conrad. Dall, U. S. Nat. Mus. Bull. 37, Waccamaw formation, Tillys Lake and Todds Ferry, Horry p. 56. County, S. C. Caloosahatchee marl, half a mile above the 1903. Dosinia (Dosinidia) elegans Conrad. Dall, Wagner Free Atlantic Coast Line Railroad bridge, Putnam County, Fla. Inst. Sci. Trans., vol. 3, pt. 6, p. 1231. Caloosahatchee River, Snell Creek, and Alligator Creek, Fla. 1906. Dosinia elegans Conrad? Bose, Inst. geol. Mexico Bol. Pleistocene, North Creek near Osprey, Manatee County, Fla.; 22, p. 80, pi. 11, fig. 6. Labelle, Hendry County, Fla.; Fort Lauderdale, Broward 1926. Dosinia (Dosinidia) elegans (Conrad). Palmer, Palae- County, Fla.; Torch Key, Fla. Recent, Hateras to Aspinwall in • ontographica Americana, vol. 1, No. 5, p. 62, pi. 18, less than 50 fathoms. figs. 3, 4, 8, 9; pi. 20, fig. 2. Subfamily MERETRICIITAE This shell is nearly related to A. concentrica but is much larger and has the concentric lines more remote and deeply Genus MACROCALLISTA Meek impressed.—Conrad, 1838. Lentiform, regularly convex, with strongly marked, rather 1876. Macrocallista Meek, Rept. U. S. Geol. Survey of the distant, impressed, concentric lines; on the posterior side these Territories, vol. 9, p. 179. are closely arranged and profound, forming prominent recurved Type by monotypy: Venus gigantea Gmelin=Fen«s nimbosa lines, which become acute or lamelliform toward the posterior Solander, Pliocene and Pleistocene of the Carolinas and Florida. PART 1. PELECYPODA 123 Recent from North Carolina to the Gulf of Mexico. former and higher than the latter; the umbones are The group was isolated by Meek as a subgenus of Callista. between a quarter and a third of the length behind the The solid shell, transversely ovate outline, and highly anterior margin; the posterior dorsal margin, is less polished surface characterize the genus. The well- oblique than in M. aTbaria but never so nearly recti defined lunule, indistinct escutcheon, and distinct pal- linear as in M. nimbosa (Solander); the ligainentary lial sinus are group characters. The dental formula nymph is between a third and half the length of the is similar to that of Oallocardia. There are three cardi dorsal margin; the hinge armature is less rude than nals in each valve—the anterior and middle cardinals that of M. aTbaria, and less sharp than that of M. short and not very heavy, the posterior cardinal lam nimbosa. The shell is never conspicuously thickened inar and produced. The anterior left lateral is slightly within, though it is rarely so delicate as in the Recent elongated and prominent and received in a deep double form. The distribution in time and space, as well as socket of the right valve. The Recent species has a the shell characters of M. reposta, are intermediate. periostracum and a radial color pattern similar to that M. albaria is most closely identified with the Chesa common among the Tellinas. peake Miocene faunas north of the Hatteras axis; The group is distinguished among the venerids by M. nimbosa, with the Caloosahatchee and Recent the sleek outline, the highly polished shell, the broad faunas south of the Hatteras axis; M. reposta, with and broadly rounded sinus almost horizontally directed'. the Duplin fauna of southern North Carolina. The Callocardia is more chalky, higher and more inflated, species is abundant only along the Lumber River in and has a less broad, obliquely directed sinus. Robeson County. Macrocallista is known from the earliest Tertiary. A closely related form is cited by Mansfield, 1932, It includes a considerable number of large and -attrac from the Cancellaria zone of the Choctawhatch.ee tive Tertiary and Quaternary species, inhabitants formation of Florida. chiefly of the warmer seas. Distribution: Virginia: Miocene, Yorktown formation, Suf folk, Nansemond County (Conrad). Macrocallista reposta (Conrad) Dall - North Carolina: Miocene, Yorktown formation, Colerain Landing (?) and % to % mile above Edenhouse Point (?), Plate 19, figures 1-3, 5 Bertie County. The young forms obtained at these two York- 1834. Cytherea reposta Conrad, Acad. Nat. Sci. Philadelphia town localities are probably, though not certainly, referable to Jour., 1st ser., vol. 7, p. 132. Macrocallista reposta. Duplin marl, 2% miles south of 1834. Cytherea pandata Conrad?, idem, 1st ser., vol. 7, p. 132 Clinton and 4 miles south of Clinton, Sampson County; Nat (young shell). ural Well, ll/2 miles north of Magnolia, and the marl pits of 1858. Cytherea reposta Emmons, North Carolina Geol. Survey Frank Wilson and W. H. Kornegay, Duplin County; 4 miles Kept., p. 294, fig. 223a. Not C. reposta Emmons, 1858. north of Lumberton, 2 miles below Lumberton, 4 to 5 miles 1863. Dione reposta Conrad, Acad. Nat. Sci. Philadelphia Proc. below Lumberton, and 1% miles northeast of Fairmont (on the for 1862, p. 575. land of Andrew Jones). Pliocene, Waccamaw formation, 4 1903. Macrocallista reposta Conrad. Dall, Wagner Free Inst. miles south of Elizabethtown (on Hammond Creek) and Walk Sci. Trans., vol. 3, pt. 6, p. 1252. ers Bluff (on the Cape Fear River), Bladen County; Neills 1926., Callista (Callista) reposta (Conrad). Palmer, Palaeon- Eddy Landing (3 miles north of Cronly), Columbus County; tographica Americana, vol. 1, no. 5, p. 82, pi. 13, figs. Wilmington, New Hanover County. 5, 10. Subgenus COSTACALIISTA Palmer Shell large, ovate, moderately thick, and convex; beaks prominent; dorsal margin depressed, slightly arcuated; pos 1926. Costacallista Palmer, Palaeontographica Americana, vol. terior extremity obtusely rounded; lunule large, lanceolate, v 1, No. 5, pp. 73, 84. defined by a slightly impressed line; 2 anterior cardinal teeth Type by original designation: Venus erycina Linnaeus. united above; posterior cardinal tooth laminar, slightly promi Recent in the Indo-Pacific. nent; anterior tooth thick, subpyramidal. Length 5 inches, height 3% inches. The subgenus is characterized by strong, flat, con Locality, Suffolk, Va.—Conrad, 1834. centric ribbing. The outline of the shell is higher in . Dimensions of figured specimens: Right valve (U. S. proportion to its width than that of most of the Nat. Mus. 325577), height 42.5 millimeters, width 62.8 Macrocallistas. millimeters; left valve (U. S. Nat. Mus. 325575), height Macrocallista (Costacallista) emmonsi Gardner, n. sp. 50.0 millimeters, width 85.0± millimeters. Locality of figured specimens: Right valve, 4 to 5 Plate 19, figures 6, 9 miles below Lumberton, Robeson County, N. C.; left Shell rather heavy, of moderate size and moderately valve, 2 miles below Lumberton, Robeson County, compressed, transversely ovate in outline. Umbones N. C. Duplin marl. rather low, not very conspicuous, prosogyrate, placed Macrocallista reposta (Conrad) is intermediate in within the anterior third. Lunule narrow, lanceolate, its characters between M. cUbaria (Say) and M. nim- outlined by an impressed line. Escutcheon suggested ~bosa (Solander). It is relatively lower than the but not defined by the evanescence of the sculpture to- 124 MOLLUSCA FROM MIOCENE AND LOWER PLIOCENE OF VIRGINIA AND NORTH CAROLINA ward the posterior margin. Anterior lateral margin the genus; angular and sharply defined to almost broadly rounded. Posterior lateral margin rounded obsolete. Inner margins of valves entire. above into the gently convex dorsal margin and below The group is first recognized in the Eocene, since into the ventral. Base arcuate. Surface sculptured when it has formed a fairly conspicuous and widely with 35 to 40 deep concentric furrows, linear in the distributed factor in the molluscan faunas of the umbonal region, much wider toward the ventral warmer seas. margin. Ligament marginal, opisthodetic, lodged in Subgenus AGRIOPOMA Ball a moderately deep groove, extending almost halfway down the dorsal slope. Hinge plate heavy; hinge of 1902. Agriopoma DaU, U. S. Nat. Mus. Proc., vol. 24, p. 509. only right valve known. Cardinal teeth 3 in number— Type by monotypy: Cytherea texasiana Dall. Recent in the the anterior and middle cardinals moderately heavy, Gulf of Mexico. simple, cuneate, convergent beneath the tips of the The subgenus as separated by Dall is characterized umbones; posterior cardinal laminar, much elongated; by the heavy chalky shell, the less involute umbones, anterior lateral short, conical, not far removed from and especially by the deep and angular pallial sinus. the umbones. Adductor scars quite large and distinct, the anterior placed a little higher than the posterior. Callocardia (Agriopoma) sayana (Conrad) Dall Pallial sinus very broad, obtuse, only slightly ascend Plate 19, figure 33 ing, produced almost to the median vertical. Inner 1824. Cytherea, convex® Say, Acad. Nat. Sci. Philadelphia margins smooth. Jour., 1st ser., vol. 4, p. 149, pi. 12, fig. 3. Not C. con- Dimensions of holotype: Height 43.0 millimeters, vexa Brongniart, 1822. width 56.5 millimeters, convexity 12.5 millimeters. 1833. Cytherea sayana Conrad, Am. Jour. Sci., 1st ser., vol. 23, Holotype: U. S. Nat. Mus. 107834. p. 345. Type locality: Natural Well (?), Duplin County, 1838. Cytherea sayana Conrad, Fossils of the medial Tertiary of the United States, p. 13, pi. 7, fig. 3. N. C. 1852. Venus.' sayana, Conrad. D'Oibigny, Prodrome palSonto- • A single valve of this large and conspicuous species logie, vol. 3, p. 108, No. 2011. was found among Emmons' duplicates. As nothing 1854. Meretrix sayana Conrad,. Acad. Nat. Sci. Philadelphia of the kind has been reported from any of the other Proc., vol. 7, p. 30. numerous collections made from the Duplin County 1856. Venus sayana D'Orbigny. Tuomey and Holmes, Pleio- cene fossils of South Carolina, p. 83, pi. 21, fig. 9. marls, Dall suggested that it might be a European shell 1858. CytJierea (misprint for Cytherea) sayana Emmons, North that was, through some error, passing for an east coast Carolina Geol. Survey Kept., p. 294, fig. 221. Tertiary fossil. Curiously enough, 2 immature left 1863. Dione sayana Conrad, Acad. Nat. Sci. Philadelphia Proc. valves have been found in the Yorktown materials, for 1862, p. 575. and, though quite young, they are apparently identical 1869. Caryatis plionema Conrad, Am. Jour. Conchology, vol. 4, p. 278, pi. 20, fig. 3. with the form in Emmons' collection. Further evi 1873. Callista convexa Say. Tryon, American marine conchol- dence of the American origin of the valve in question ogy, p. 161. is offered by the character of the iron stains and of the 1894. Dione sayana Conrad. Whitfield, U. S. Geol. Survey matrix still clinging to the shell. Mon. 24, p. 75, pi. 12, fig. 1. 1903. Callocardia (Agriopoma) sayana Conrad. Dall, Wagner Distribution: Virginia: Miocene, Yorktown formation, York- Free Inst. Sci. Trans., vol. 3, pt. 6, p. 1261, pi. 54, fig. 16. town, York County (young shells). 1904. Callocardia (Agriopoma) sayana (Conrad). Glenn, Mary North Carolina: Miocene, Duplin marl, Natural Well(?), land Geol. Survey, Miocene, p. 313, pi. 73, figs. 13, 14. Duplin County. 1926. Pitaria (Pitaria) sayana (Conrad). Palmer, Palaeonto- graphica Americana, vol. 1, No. 5, p. 20, pi. 4, figs. 2, Genus CALLOCARDIA A. Adams 5, 12, 14, 15, 18; pi. 5, figs. 11, 15, 19, 27, 28. 1864. Callocardia A. Adams, Annals and Mag. Nat. History, Shell subcordate; elevated convex, concentrically wrinkled, inequilateral; posterior tooth and fosset not striated; edge not 3d ser., vol. 13, p. 307. crenated; umbo rather prominent; lunule dilated, cordate, Type by monotypy: Callocardia guttata A. Adams. Recent marked by a simple line. in the China Sea. Length liV inch[es], breadth more than lA inch[es].—Say, Shell ovate to subtriangular. Umbones anterior, in 1824. volute. Lunule circumscribed by a faintly incised line. Type locality: Maryland. Escutcheon not delimited. Ligament external, lodged Shell porcellanous, thin in the young, moderately in a deep groove. Nymphs prominent. Exterior heavy in adults, massive in the senile forms. Outline sculpture concentric. Three rather discrepant cardi subtrigonal to ovate, inequilateral, strongly inflated in nals in each valve, commonly bifid or cuspid. Two the umbonal region. Umbones gibbose, rather promi lateral lamellae in right valve, which receive between nent, incurved, strongly prosogyrate, placed about two- them the anterior lateral tooth of the left valve. thirds of the way over toward the anterior margin. Pallial sinus varying widely within the limits of Lunule cordate, defined by an incised line. Escutcheon PART 1. PELECYPODA 125 absent. In the young, anterior end oblique in the lunu- established in the young forms, and even the sinus lar region; in the adult, somewhat produced and convex varies within narrow limits. Linsley's species is cer jn front of the lunule; in senile individuals, inclined tainly not present in the adult state in the material at toward a uniformly steep slope from the umbones to hand or in any of the available reference collections. the ventral margin. Posterior dorsal and lateral mar The only young Callocardia not readily reconcilable gins not differentiated, gently arcuate from the um with C. sayana (Conrad) is a single half-grown rotund bones to the base. Ventral margin much more strongly valve from the Yorktown formation, 1 mile east of arched in the young than in the adult. Surface con- Lizzie, in Greene County, N. C. It is probable, how 'centrically wrinkled with fine, close, discontinuous ever, that this is the young of an undescribed form or of striae. Ligament marginal, opisthodetic; nymph sub- C. castoriana rather than of C. morrhuana (Linsley). linear, extending a little more than a third of the way Distribution: Virginia: Miocene, St. Marys formation, 1 to to the base; groove behind it deep. Hinge plate heavy. 2 miles below Bowlers Wharf, % mile below Jones Point, Essex Three cardinals developed in each valve. In the right County. Yorktown formation, 3 miles northeast of Walker- valve the anterior and posterior cardinals are united be ton, King and Queen County. Yorktown and Bellefield, York County; Petersburg, Dinwiddie County; 5 miles northeast of neath the tips of the beaks—the former simple and Smithfleld, 2 miles northwest of Smithfieid, 1% miles west of laminar, the latter obliquely produced and longitudi Smithfleld, Zuni (near the pumping station) ? Isle of Wight nally sulcated—and the middle cardinal is an isolated County; % mile north of Chuckatuck, y± mile east of Everets denticle within the A formed by the union of the two Post Office, 5% miles northwest of Suffolk, 2% miles northwest distal teeth. Pit for reception of anterior lateral of of Suffolk, 1 mile west of Suffolk, 1% miles north of Suffolk, li/4 miles north of Suffolk, iy2 miles east of Suffolk, 1 mile left valve deep. Anterior and middle cardinals of left northeast of Suffolk, and % mile below the Suffolk waterworks valve united to form a A-shaped tooth, the an dam, Nansemond County. The species is exceedingly abundant terior arm being the thinner and more laminar; pos in the environs of Suffolk. terior cardinal slender, obliquely produced; anterior North Carolina: Miocene, Yorktown formation, Halifax (on lateral strong, subconical. Adductor muscle impres Quankey Creek, just below the county bridge) and Palmyra Bluff, Roanoke River, Halifax County; 2% miles northwest sions subequal, roughly semielliptical. Pallial line dis of Williamston (on Joseph Cherry's farm) and 3 miles west tinct, sinus short, moderately broad, both the dorsal of Williamston, Martin County; 15^ miles above Bells Bridge, and ventral margins usually ascending rather steeply. % mile above Bells Bridge, Tar River, and Shiloh Mills, Edge- Dimensions of figured specimen: Height 40.0 milli combe County; 2 miles southeast of Tugwell (on Jacobs meters, width 45.0 millimeters. Branch), 2y3 miles north of Standard, 3 miles southwest of Frog Level (on J. A. Noble's branch), 8 to 9 miles west of Figured specimen: U. S. Nat. Mus. 143732. Greenville (on the east side of Pinelog Branch), 2 miles west Locality of figured specimen: Choptank River, a of Greenville, 1% miles west of Greenville (on Schoolhouse quarter to half a'mile below Barkers Landing, Talbot Branch), 6% miles below Greenville (at Tafts Landing), 8 to 9- County, Md. Choptank formation. miles southeast of Greenville, 1^ miles west of Galloway Callocardia sayana exhibits the amount of mutation Crossroads, Hardees Creek (3y2 miles from its confluence with the Tar River), 1 mile northwest of Galloway Crossroads, to be expected of a widely distributed species, but the '% mile north of Grimesland, Pitt County; 2% miles north confusion in the literature and collections is due to dif west of Chocowinity, Beaufort County; 1 mile west of Wilson ferences in age characters rather than in latitude. (at Hominy Swamp, on the land of Frank Barnes), Wilson The species, though strongly inflated in the umbonal County; % mile east of Lizzie (on the land of David Sum region, is distinctly flattened toward the ventral mar mer il), Greene County; Tar Ferry, 1% miles below Tar Ferry, Wiccacon Creek (opposite Harrellsville), and Mount Pleasant gin so that in the young the shell is relatively more Landing, Hertford County; Colerain Landing and % to % convex and rotund than in the adult, the umbones are mile above Edenhouse Point, Bertie County. Duplin marl, 2 relatively higher and more prominent, and the base is miles below Lumberton, Fairmont (Ashpole), and 1% miles more strongly arcuate. Oaryatis plionema Conrad is northeast of Fairmont (on the property of Andrew Jones), described from a senile individual. Many forms de Robeson County. Pliocene, Waccamaw formation, 4 miles south of Elizabethtown (on Hammond Creek) and Walkers Bluff (on termined as Callocardia qubnasuta (Conrad) are young the Cape Fear River), Bladen County; Neills Eddy Landing (3 sayana in which the anterior margin is more produced miles north of Cronly), Columbus County; and Wilmington, than in the adults. They are not, however, rostrate as New Hanover County. in the true C. subnasuta, and the valves are less elongated Outside distribution: Miocene, Calvert formation, Atlantic transversely and the umbones higher and more inflated. City (well bore), N. J. Choptank formation, Peach Blossom Creek, and Choptank River, one-fourth to one-half mile below The young of the species have also been confused in Barkers Landing, Talbot County, Md.; Jones Wharf, Patuxent both the reference collections and the check lists with River, St. Marys County, Md. St. Marys formation, Cove Point, the Recent Callocardia morrkuana (Linsley), a rela Calvert County, Md.; St. Marys River, St. Marys County, Md. tively lower, less trigonal species most readily separable Duplin marl, Darlington, Darlington County, S. C. Pliocene, from G. sayana by the deeper pallial sinus in which the Waccamaw formation. Nixons and Tillys Lake, Horry County, S. C. Caloosahatehee marl. Kissimmee well (at a depth of dorsal margin is approximately horizontal rather than 150 feet), Osceola County, Fla.; Caloosahatchee River and Alli obliquely ascending. The outline of the shell is not gator Creek, Fla. Croatan sand, Slocums Creek, Craven County, 401033—43———9 126 MOLLUSCA FROM MIOCENE AND LOWER PLIOCENE OF VIRGINIA AND NORTH CAROLINA N. C. Pleistocene, Wailes Bluff near Cornfield Harbor, St. the danger of its later proving to be identical with an Marys County, Md. (Dall) ; Orient, Hillsborough County, Fla.; earlier species seems negligible. The single right valve Kissimmee well (at a depth of 96 feet), Osceola County, Fla.; was collected by Dr. Harvey Bassler from the vicinity Labelle, Hendry County, Fla. of Castoria, in Greene County. Callocardia (Agriopoma) castoriana Gardner, n. sp. Distribution: North Carolina: Miocene, Yorktown formation, 1 mile north of Castoria, Greene County. Plate 19, figures 28, 29 Shell rather large for the genus, moderately inflated, Callocardia (Agriopoma) chioneformis Gardner, n. sp. transversely oblong to subquadrate, inequilateral. Um- Plate 19, figures 7, 8 bones not prominent, anterior, between two-thirds and Shell heavy, moderately inflated. Outline chione- three-fourths of the distance over toward the anterior form, trigonal, inequilateral, a shallow depression in margin; tips incurved, prosogyrate. Lunule rather front of the obscure posterior carina. Umbones not narrow, much elongated, about three-fourths the length very prominent, their tips flattened, rather strongly of the anterior end. Escutcheon absent; posterior sub- incurved and prosogyrate. Lunule wide, cordate, de margin obscurely carinated. Anterior slope very steep, fined by an incised line. Escutcheon absent. Anterior uniform, the dorsal and lateral margins not differenti end oblique in the lunular area, bowed outward in front ated; posterior dorsal margin gently arcuate, lateral of the lunule; posterior end a gentle and uniform arch margin squarely truncate. Base line straight medially, from the umbones to the basal margin. Base line strongly upcurved distally. Surface sculptured with straight posteriorly or slightly sinuated by the pos crowded, discontinuous, concentric wrinkles. Ligament terior fold, strongly upcurved anteriorly. Surface external, opisthodetic; nymph abdut half as long as the closely and strongly wrinkled concentrically. Liga dorsal margin, slender, sickle-shaped, limited on the ment external, nymph elongated, sublinear, narrower outer margin by a deep groove. Hinge plate wide and than the groove behind it. Hinge armature complex. heavy. Three discrete cardinals in the right valve, Three cardinals in the right valve, the anterior and the anterior cardinal thin and laminar, the posterior posterior uniting to form an open U, the anterior one heavy, longitudinally sulcate, the middle one a sim simple and laminar, the posterio.r obliquely elongated, ple ridge with a flattened anterior surface, a little ven slender, and sulcate longitudinally; the middle cardi tral to the other two cardinals; pit for reception of nal isolated, flattened on its anterior surface; pit for lateral of left valve small but profound; armature of reception of lateral of left valve deep. Anterior and left valve not definitely known. Adductor impressions middle cardinals of left valve united beneath the tips subequal, semielliptical, submedial in position. Sinus of the umbones to form a A, the. anterior arm the short, broad, pointed in front, its dorsal margin ap more laminar; posterior cardinal oblique, very slender proximately horizontal. and longitudinally sulcate; anterior lateral subconical, Dimensions of holotype: Height 39.0 millimeters, prominent. Adductor impressions rather small, sub- width 49.0 millimeters, convexity 14.2 millimeters. equal, the anterior somewhat more elongated, median Holotype, a right valve: U. S. Nat. Mus. 325563. in position, broadly lenticular and placed not far from Type locality: 1 mile north of Castoria, Greene the ventral margin. Pallial line rather near the base. County, N. C. Yorktown formation. Sinus broad, obtusely pointed in front, gently ascend The species is more regularly oblong or quadrate ing, but falling short of both the median horizontal than any of the closely related forms. The young of and the vertical. / G. morrhuana (Linsley) sometimes approach it closely Dimensions of holotype, a left valve: Height 26.5 in outline, though the adults are constantly more trig millimeters, width 31.0 millimeters, convexity 9.4 onal. Both Linsley's species and the C. say ana of millimeters. Conrad have a cordate rather than a lanceolate lunule Dimensions of paratype, a right valve: Height 17.5 and both have the umbonal ends of the anterior and millimeters, width 20.5 millimeters, convexity 6.2 posterior right cardinals united to form a rather dis millimeters. tinct U; in C. castoriana they are discrete. The hinge Holotype and paratype, U. S. Nat. Mus. 325564. plate of the new species is more strongly angulated and Locality for both holotype and paratype: Wilming- wider anteriorly, and the space between the margin of ton, N. C. Waccamaw formation. the anterior lateral pit and the margin of the hinge Three valves of this well-characterized species were plate is broader and flatter than in any of the coexistent collected by Dr. T. W. Stanton at Wilmington. It species. The sinus is similar to that of C. morrhuana, stands apart from all the coexistent Callocardia by probably its nearest of kin. reason of its chionelike outline and the posterior de It is always unsatisfactory to describe a new species pression which, though shallow, persists from the um of a variable genus from a single valve, but in this bones to the base. The lunule is wider and less case the diagnostic characters are so distinctive that elongated than that of C. ^sayana (Conrad), and the PART 1. PELECYPODA 127 concentric wrinkling of the external surface somewhat 1863. Dione (Chamelea). cortinaria Rogers. Conrad, Acad. Nat. stronger. Sci. Philadelphia for' 1862, p. 575. 1903. CMone cortinaria Rogers. Dall, Wagner Free Inst. Sci- Distribution: North Carolina: Pliocene, Waccamaw forma Trans., vol. 3, pt. 6, p. 1292. tion, Wilmington, New Hanover County. 1926. CMone (CMone) cortinaria (Rogers). Palmer, Palaeon- tographica Americana, vol. 1, No. 5, p. 142, pi. 38, figs. Subfamily VENERJNAE 4, 11,13; pi. 40, figs. 8, 37. 1932. Chione (CMone) cortinaria (Rogers). Mansfield, Florida Genus CHIONE Von Miihlfeld Geol. Survey Bull. 8, p. 125, pi. 23, fig. 8. 1811. CMone Megerle von Muhlfeld, Entwurf eines neuen Sys Shell suflbcordate, inflated, with very regular, concentric, tem der Schalthiergehause, Magazin der Gesellschaft closely approximate, and very prominent imbricated ridges, naturforschender Freunde zu Berlin, 5ter Jahrg., p. 51. which incline toward the beak, except the portion opposite the Type by subsequent designation (Gray, Zool. Soc. London anterior, basal, and posterior margins, where they decline Proc., pt. 15, p. 183, 1847) : Venus dysera Chemnitz=Venus outward toward the margin; beaks moderately prominent, cancellata Linnaeus. Recent from North Carolina to Brazil. about twice as far from the anterior as the posterior end; two 'anterior cardinal teeth, closely approximate above, second one Ohione includes the solid trigonal venerids of me of the left valve thick and subbifid; lunule wide, cordate; basal dium size and convexity characterized most obviously margin crenate within; posterior margin short, straight, and by strong, often crude, concentric ribs or lamellae, with especially at the lunule finely crenate. Length 1 inch, height or without free upturned margins. A radial sculpture 0.9 inch. Locality, Williamsburg. Miocene. This beautiful shell is indicated in the flutting of the free edges of the con rarely shows the concentric ridges perfect, from their promi centric lamellae and in a radial grooving, in some nence and thinness.—W. B. and H. D. Rogers, 1837. groups restricted to the ventral surfaces of the con Dimensions of figured specimen, a left valve (U. S. centric ribs or, in some concentrically laminated Nat. Mus. 146126) from the Yorktown formation at groups, cancellating the disk. The lunule and escutch Grove Wharf, James River, Va.: Height 23.5 milli eon are sharply set off by both the sculpture and the meters, width 26.5 millimeters. contour of the shell. The ligament is marginal and Three discrete, divergent cardinals in each valve; deeply inset behind the beaks. There are three cardi the anterior cardinal of the right valve simple and nals radiating fanlike in each valve, the medial and laminar; the medial cardinal short, rather slender and posterior cardinals in many groups grooved or bifid. feebly bifid; the posterior cardinal elongated parallel True laterals are not developed. The muscle scars and to the dorsal margin and longitudinally sulcated. The the pallial line are distinct; the sinus is shallow and anterior cardinal of the left valve is simple and lami trigonal. The inner anterior and ventral margins are nar ; the central cardinal stout and bifid; the posterior strongly crenate. cardinal laminar and elongated parallel to the dorsal True CMone has not been certainly recognized in margin. the southeastern United States below the Chickasawhay CMone cortinaria has been confused with C. cribraria formation. Since the time of that formation CMone (Conrad), though the two species are distinct when rapidly increased in prominence, and in the upper seen together. C. cribraria is the heavier, more convex lower and in the middle Miocene of the mid-Americas shell; the concentric lamellae in C. cribraria seldom it was ubiquitous and exceedingly abundant. exceed 30, whereas in C. cortinaria they usually num Submenus CHIONE s. s. ber between 40 and 45; the lamellae of C. cortinaria are lower, the flutings less conspicuous and abruptly Type by subsequent designation (Gray, Zool. Soc. London, evanescent near the free edge, and ordinarily they are Proc., pt. 15, p. 183, 1847) : Venus dysera Chemnitz=Fewts so closely Oppressed dorsally that the interlamellar cancellata Linnaeus. Recent from North Carolina to Brazil. spaces are not visible as in C. cribraria; as might be CMone (CMone} is characterized by a sculpture of surmised, the dentition of the inner margins of C. regularly spaced, free-edged, concentric lamellae super cribraria is more coarse and obvious than in the more imposed upon a radially lirate surface. The lamellae finely laminated cortinaria. are commonly frilled in harmony with the radial lira- CMone cortinaria (Rogers and Rogers) seems to tions, and the inner margins of the valves are crenate. have a limited distribution, though its near relative is both widespread and abundant. Chione (Chione) cortinaria (Rogers and Rogers) Dall Mansfield regarded cortinaria as one of the diag Plate 19, figure 4 nostic fossils of zone 1 of the Yorktown formation and as a precursal form of cribraria. He reports corti 1837. Venous cortinaria W. B. and H. D. Rogers, Am. Philos. Soc. Trans., new ser., vol. 5, p. 333. naria from Florida, in the Ecphora zone of the 1838. Venus cortinaria, Rogers. Conrad,, Fossils of the medial Choctawhatchee formation. Tertiary of the United States, p. 11, pi. 8, fig. 1. Distribution: Virginia: Miocene, Yorktown formation, Grove 1839. Venus cortinaria W. B. Rogers and H. D. Rogers, Am. Wharf on the James River, Surry County; Williamsburg, Philos. Soc. Trans., new ser., vol. 6, pi. 26, fig. 7. James City County (Rogers and Rogers). 128 MOLLUSCA FROM MIOCENE AND LOWER PLIOCENE OF VIRGINIA AND NORTH CAROLINA Outside distribution: Miocene, Chqctawhatchee formation, and their free edges much less strongly recurved and Jackson Bluff (southeast of Tallahassee), Leon County, Fla. less dorsally appressed. Unlike the slightly earlier C. cortinaria, C. cribraria is a widely distributed, Chione (Chione) cribraria (Conrad) Ball abundantly represented species at many localities in 1843. Venus cribraria Conrad, Acad. Nat. Sci. Philadelphia the east coast Tertiary deposits. Proc., vol. 1, p. 310. 1845. Venus cribraria Conrad, Fossils of the medial Tertiary Distribution: Virginia: Miocene, Yorktown formation 12 to of the United States, p. 67, pi. 38, fig. 2. 14 miles below Zuni, Isle of Wight County; ^4 mile north of 1858. Venus cribrari[a] Conrad. Emmons, North Carolina Geol. Chuckatuck, Nansemond County. Survey Rept, p. 293, fig. 218. North Carolina: Miocene, Yorktown formation, Wilson, 1863. Dione (Chamelea) cribraria Conrad, Acad. Nat. Sci. Wilson County; Colerain Landing and % to % mile above Eden- Philadelphia Proc. for 1862, p. 575. house Point, Bertie County; Rock Landing, Craven County. 1903. Chione cribraria Conrad. Dall, Wagner Free Inst. Sci. Duplin marl, Natural Well, 1% miles north of Magnolia, and the Trans., vol. 3, pt. 6, p. 1292. marl pits of Frank Wilson and W. H. Kornegay, Duplin 1926. Chione (Chione) cribraria (Conrad). Palmer, Palaeon- County; 2 miles below Lumberton, Robeson County. Pliocene, tographica Americana, vol. 1, no. 5, p. 142, pi. 38, figs. Waccamaw formation, Walkers Bluff, Bladen County; Lake 1, 8, 9 ; pi. 39, figs. 3, 24. Waccamaw, Cronly (% mile east of the factories), and Neills Eddy Landing (3 miles north of Cronly), Columbus County; Subtrigonal, slightly ventricose, with about 25 concentric Wilmington, New Hanover County. elevated recurved lamelliform ribs, on the inferior side of which Outside distribution: Pliocene, Waccamaw formation, Nixons are elevated transverse lines; lunule cordate, laminated, suture and Tillys Lake, Horry County, S. C. profound; inner margin profoundly creunulated. Length 1% inch[es], height 1% [inches] nearly. Section TIMOCLEA Brown Locality: Wilmington, N. C.; Neuse River below New Bern, N, C.—Conrad, 1843. 1827. Timoclea Thomas Brown, Illustrations of the conchology of Great Britain and Ireland, pi. 19, fig. 11. , Shell rather large, heavy, and convex for the genus. Outline subtrigonal, inequilateral. Umbones moder Type by monotypy: Venus ovata Pennant. Recent along the western shores of Europe from Scandinavia southward and ately prominent, prosogyrate, about twice as far from in the Mediterranean. the posterior as from the anterior end. Lunule short, The section is characterized by relatively strong cordate, defined by a deeply incised line which dissects the concentric lamellae. Escutcheon indicated by the radial and relatively weak concentric sculpture. abrupt cessation of the concentric sculpture. Anterior Chione (Chione) grus (Holmes) Dall end bowed outward in front of the lunule. Posterior dorsal margin oblique or slightly gibbous; posterior Plate 19, figures 12, 13, 20, 21 lateral margin obscurely truncate. Base line strongly 1854. Venus parva G. B. Sowerby, Thesaurus conchyliorum, upturned anteriorly. Concentric lamellae on external pt. 14, p. 787, pi. 168, figs. 227, 228. Not V. parva surface 25 to 30 or even more in unusually large forms, James Sowerby, 1829. elevated, rising 1 to iy2 millimeters above the surface 1858. Tapes grus Holmes, Post-Pliocene fossils of South Caro lina, p. 37, pi. 7, fig. 5. of the valve and approximately at right angles to it 1860. Venus trapezoidalis Kurtz, Catalogue of Recent marine except near the escutcheon, where they flare rather shells of North and South Carolina, p. 5. widely and are often slightly inclined toward the 1867. Chione parva G. B. Sowerby. Romer, Malakozool. ,Blatter, base; transverse flutings strong, sometimes evanescent vol. 14, p. 60. just at the free margin, altogether absent on the lunular 1889. Ven\ws pygmaea Lamarck (part). Dall, U. S. Nat. Mus. Bull. 37, p. 54. lamellae. Ligament inset; nymph linear. Hinge plate 1903. Chione (Timoclea) grus Holmes. Dall, Wagner Free sinuous ventrally. Three divergent cardinals in each Inst. Sci. Trans., vol. 3, pt. 6, p. 1299. valve; the anterior and central cardinals of the right 1926. Chione (Chione) grus (Holmes). Palmer, Palaeonto- valve slender, simple, proximate; the posterior cardinal graphica Americana, vol. 1, No. 5, p. 156, pi. 40, figs. longitudinally sulcate, obliquely elongated parallel 13, 18, 21. 1932. Chione (Timoclea) grus (Holmes). Mansfield, Florida to the dorsal margin. Anterior cardinal of left valve Geol. Survey Bull, 8, p. 131, pi. 26, fig. 2. simple, slender, and laminar, the middle cardinal stout and bifid, the posterior laminar, parallel to the dorsal Shell small, convex, transversely oblong, subrhomboidal, in equilateral, with 25 or 26 ribs; ribs radiating and interrupted margin. Adductor impressions obscure, subequal, the by distinct overlapping zones of increase, which give the shell posterior slightly more rotund. Pallial sinus short, a laminated, or squamose appearance; umbones anterior; dorsal linguiform, the dorsal margin almost horizontal. In margin thick, rectilinear, or very slightly curved, without ribs, ner margins crenate. squamose; posterior margin subtruncated, anterior margin Chione cribraria (Conrad) is heavier than C. corti- shorter, regularly rounded; pallial margin crenated; pallial naria, and the crenulations of the inner margins of sinus deep; muscular impressions large.—Holmes, 1858. the valves are coarser and deeper; the concentric lamel Type locality: Simmons Bluff. .Pleistocene. lae of the former are fewer and consequently less Dimensions of figured specimens, a right and a left crowded; they are more strongly fluted transversely valve, U. S. Nat. Mus. 325565, from the Waccamaw PART 1. PELECYPODA 129 formation at Neills Eddy Landing on the Cape Fear Chamelea is characterized by the narrow, close, con River, N. C.: Right valve, height 6.8 millimeters, width centric lamellae and the absence of radial sculpture. 9.5 millimeters, > convexity 2.6 meters. Left valve, The cardinals are entire. height 5.0 millimeters, width 7.5 millimeters, convexity 2.2 millimeters. Chione (Chamelea) dalli Olsson The species varies in relative proportions and the Plate 19, figures 10, 11 outline may be rhomboidal, trapezoidal, or transversely 1914. CMone dalli Olsson, Bull. Am. Paleontology, vol. 5, No. 24, oblong. The lunule is short, cordate, clearly defined p. 19, pi. 3, figs. 7-9. and sculptured with microscopic radials; the escutch 1926. CMone (CMone) dalli Olsson. Palmer, Paleontographica eon is smooth or laminated by the concentric sculpture. Americana, vol. 1, No. 5, p. 162, pi. 41, figs.-l, 2, 6. The number of riblets usually exceeds 26 and those Shell ovate to triangular, slightly convex, very solid; beaks on the anterior half of the shell are medially bifur prominent, approximate, subacute; lunule lanceolate, defined cated. The relative prominence of the concentric by an impressed line, smooth or with lines of growth; es sculpture is a variable factor. The overlapping lami cutcheon long and narrow, smooth; surface of shell with thick, flattened, concentric lamellae, fairly regularly arranged on the nae number about 30 in a normal individual and are umbo, later becoming irregular and coalescing toward the basal strongest on the posterior slope, where the edges are margin; no radial sculpture present; hinge fairly heavy, with usually free and minutely ruffled on overriding the 3 cardinal teeth in each valve; pallial sinus merely a small radials. The nymph is short and not very prominent; notch; margin minutely crenulated. the dentition normal, concentrated; 3 simple, discrete Type: Length 23, height 20, thickness 6 millimeters. Larger shell: Length 25, height 21, thickness 6 millimeters. cardinals are arranged f anlike under the umbo of each On page 1290 Dall, in his Tertiary geology of Florida, vol valve. ume 3, part 6, briefly describes without naming a CMone from This small recticulate species has a meager repre Petersburg, Va., which appears to belong to this species. This sentation in the Yorktown and Duplin formations but, species bears some resemblance to C. cortinaria Wagner [Rog ers] but may be distinguished by its irregular concentric lamel in the Waccamaw formation particularly at Neills lae and the entire absence of the radial sculpture. At Clare- Eddy Landing, it is abundant. mont Wharf the species occurs in blue clays of the St. Marys Mansfield reports the species from a number of lo formation, accompanied by several unusual species. Area vir- calities in his Cancellaria zone at the top of the Choc- giniae Wagner is very common here, and a small triangular tawhatchee formation in Florida. Olsson, 1922, re Olycymeris .like Pectunculus virginiae Wagner showing rela tionship with O. subovata, Say, of whch it is probably a ports a varietal form from the Gatun stage in Costa mutation. Rica. It is common in the Floridian Pliocene and St. Marys formation; James River at Claremont Wharf, Va.— occurs in the Recent shallow-water faunas from North Olsson, 1914. Carolina to Yucatan. Shell rather small, heavy, rounded-trigonal, moder Distribution: Virginia: Miocene, Yorktown formation, York- ately compressed, inequilateral. Umbones low, placed town, York County; 1% miles northeast of Suffolk, 1 mile near the anterior third, the apices acute and proso- northeast of Suffolk, and y2 mile below the Suffolk waterworks gyrate. Lunule rather small, smooth, narrow cordate, dam, Nansemond County. defined by a strongly incised line. Escutcheon moder North Carolina: Miocene, Yorktown formation, Rock Land ing, Neuse River, Craven County. Duplin marl, Natural Well ately broad, sharply delimited by the angulation of the and 1% miles north of Magnolia, Duplin County; 2 miles below valve and the abrupt discontinuance of the concentric Lumberton, Robeson County. Pliocene, Waccamaw formation, sculpture. Anterior end somewhat expanded in front Walkers Bluff on the Cape Fear River, Bladen County; Neills of the lunule, rounding broadly and evenly into the Eddy Landing (3 miles north of Cronly), Columbus County; base line. Posterior dorsal margin obliquely produced Wilmington, New Hanover County. Outside 'distribution: Miocene, Choctawhatchee formation, with a suggestion of gibbosity near the umbones. Pos Jackson Bluff, Ochlockonee River, Leon County, Fla. Pliocene, terior lateral margin obscurely truncate. Base line Waccamaw formation, Tillys Lake, Horry County, S. C. Caloo- gently arched. Sculpture of many unequal irregular sahatchee marl, Caloosahatchee River and Shell Creek, Fla. lamellae attached ventrally, and their dorsal margins Pleistocene, Simmons Bluff, S. C.; Kissimmee well (at a depth somewhat fused with the surface or with each other of 96 feet), Osceola County, Fla.; Eau Gallic, Brevard County, posteriorly, usually free and overlapping anteriorly; Fla.; 1 mile southwest of Daytona, Volusia County, Fla. Re cent, Hatteras to Yucatan in 12 to 63 fathoms. no trace of radial sculpture discernible. Ligament ex ternal, inserted on a linear nymph. Hinge plate Section CHAMELEA Morch slightly sinuous. Right valve furnished with 3 discrete 1853. Chamelea Morch, Catalogus conchyliorum, quae reliquit cardinals, the anterior cardinal simple and laminar, D. Alphonso d'Aguirra & Gadea Comes de Yoldi, fasc. the middle cardinal moderately compressed, grooved 2, p. 23. longitudinally with a shallow sulcus; posterior cardinal slender, obliquely elongate, longitudinally sulcate. Type by subsequent designation (Bucquoy, Dautzenberg, and Dollfus, Mollusques marins du Roussillon, vol. 2, p. 355, 1893) : Cardinals of left valve also 3 in number, the anterior Venus gallina Linnaeus. Recent in the Mediterranean. simple and slender, the middle cardinal cuneiform, the 130 MOLLUSCA FROM MIOCENE AND LOWER PLIOCENE OF VIRGINIA AND NORTH CAROLINA posterior sublaminar, slightly convex. Adductor Breadth about 3 inches. Inhabits the coast of the United States. muscle impressions clearly defined, submedial, the an Cabinet of the Academy and Philadelphia Museum, and Mr. terior roughly semielliptical, the posterior subrotund. Wm. Hyde's collection.—Say, 1822. Pedal muscle impression a small dent just dorsal to the A Recent shell, U. S. Nat. Mus. 46867, from the east anterior adductor and concealed by the hinge plate. oast of Florida, has been figured. The height is 60.0 Inner margins very finely crenate. millimeters, the width 76.0 millimeters. Dimensions of figured topotypes (U. S. Nat. Mus. The shell is less heavy and oblique than in the sub- 325529) : Eight valve, height 20.0 millimeters, width genotype, V. mercenaria s. s., the posterior dorsal slope 22.3 millimeters, convexity 5.8 millimeters. Left valve, is less steep, and the posterior end is consequently height 19.5 millimeters, width 21.0 millimeters, con broader. The zigzag color pattern is, however, the vexity 6.4 millimeters. only sure diagnostic, and as this is rarely preserved Type locality: Claremont Wharf, Surry County, Va. in the fossil forms the subspecific determinations are Chione dalli is separated from G. latilirata> (Con exceedingly dubious. rad)—the only other species exhibiting low, dorsally appressed, concentric ribs—by the thinner shell, usually Distribution: Virginia: Miocene, Yorktown formation, York- smaller size, and the much more numerous and less town, York County; Claremont Wharf (upper bed) on the James River, Surry County. prominent costals; in Conrad's form, the ribs may Outside distribution: Pleistocene, Simmons Bluff, S. C. Re number as few as 5 but never higher than 12; in C. cent, Massachusetts to Georgia in less than 50 fathoms. dalli they may number as high as 25 and never fewer than 15, and they have, naturally, a concomitant differ Venus (Mercenaria) campechiensis rileyi Conrad ence in breadth and spacing. 1838. Venus rileyi Conrad, Fossils of the medial Tertiary of the United States, p. 9, pi. 6, fig. 1. Distribution: Virginia: Miocene, St. Marys formation, Clare 1856. Venus rileyi Conrad. Tuomey and Holmes, Pleiocene mont Wharf (lower bed) on the James River, Surry County. fossils of South Carolina, p. 78, pi. 21, fig. 8. 1858. Venus rileyi Emmons, North Carolina Geol. Survey Rept., Genus VENTTS Linnaeus p. 292. 1863. Mercenaria rileyi Conrad, Acad. Nat. Sci. Philadelphia 1758. Venus Linnaeus, Systema naturae, 10th ed., p. 684. Proc. for 1862, vol. 14, p. 574. Type by subsequent designation (Gray, Zool. Soc. London 1903. Venus tridacnoides var. rileyi Conrad. Dall, Wagner Proc., pt. 15, p. 183, 1847) : Venus verrucosa Linna'eus. Recent Free Inst. Sci. Trans., vol. 3, pt. 6, p. 1311. along European shores from southern England to northern 1904 Venus rileyi Conrad. Glenn, Maryland Geol. Survey, Mio Africa and the Mediterranean. cene, p. 304, pi. 76, figs. 4, 5. 1926. Venus tridacnoides (Lamarck) (part). Palmer, Palae Venus (Venus) is not represented in the Tertiary or ontographica Americana, vol. 1, No. 5, p. 191, pi. 33, Recent east coast faunas. figs. 1, 3. 1932. Venous tridacnoides rileyi Conrad. Mansfield, Florida Submenus MERCENARIA Schumacner Geol. Survey Bull. 8, p. 133, pi. 28, fig. 3. 1817. Mercenaria Schumacher, Essai d'un nouveau systdme des Shell obliquely ovate, slightly ventricose, thick, very inequi habitations des vers testaces, p. 135. lateral ; disks with small, crowded, reflected, concentric ribs; anterior side narrowed; umbo very oblique, prominent; pos Type by monotypy: Venus violacea Schumacher="Fewws mer terior margin arcuate; inner margin deeply crenulated. cenaria Linnaeus. Gulf of St. Lawrence to Florida and the Locality, Yorktown, Va. Gulf of Mexico. This shell has probably been confounded with V. tridacnoides, but it is much thinner, not undulate on the disk, and the Venus (Mercenaria) mercenaria notata Say cardinal teeth are much less robust. Its narrowed and com pressed anterior side will distinguish it from the other fossil Plate 21, figure 10 species, and its ribs from the recent V. mercenaria. Young 1822. Venus notata Say, Acad. Nat. Sci. Philadelphia Jour., shells are compressed or plano-convex. The disks are generally 1st ser., vol. 2, p. 271. worn, showing the radiating striae common to all these large 1858. Mercenaria, notata Say. Holmes, Post-Pleiocene fossils fossil species when the surface becomes decomposed. It is of South Carolina, p. 34, pi. 6, fig. 13. named in compliment to my scientific friend, Dr. William 1870. Venus notata Say. Gould, Invertebrata of Massachusetts Riley, of Baltimore.—Conrad, 1838. p. 135, fig. 446. Shell only moderately heavy, transversely oval or 1903. Venus mercenaria var. notata Say. Dall, Wagner Free ovate to subquadrate in outline. Umbones rather low Inst. Sci. Trans., vol. 3, pt. 6, p. 1312. 1926. Venus mercenaria notata Say. Palmer, Palaeontographica and not very prominent, their tips acute and pros- Americana, vol. ], No. 5, p. 186, pi. 32, fig. 5. sogyrate, situated as a rule within the anterior third. Lunule narrow, cordate, varying with the outline of Shell obtusely rounded before, and with a slight undulation on the anterior margin; disk nearly destitute of the elevated the shell, delimited posteriorly by a sharply, incised concentric striae, which mark the borders of the shell, and line which dissects the concentric lamellae; lunular distinguished by rufous zigzag transverse lines; within yellow sculpture (similar (to that of the disk. Escutcheon ish white. slightly narrower and more laminar in the right valve PART 1. PELECYPODA 131 than in the left valve, elongate-cuneate or scimitar- 95.0 millimeters, 83.5 millimeters; convexity 24.0 milli shaped; defined by both the angulation of the valve meters, 24.5 millimeters. and the partial obsolescence of the surface sculpture, The James River race as a whole, and particularly which, however, is manifested at least by vigorous the Smithfield forms, are small, relatively thin, and incrementals. Anterior end bowed out in front of the ovate in outline, with the concentric lamellae usually lunule, rounding broadly and evenly into the base; eroded except toward the basal margin. Measurements posterior dorsal margin subrectilinear, oblique, or of typical individuals from the James River are as slightly gibbous. Posterior lateral margin broadly follows: Height 65.0 millimeters, 60.0 millimeters; rounded, obtusely pointed or obscurely truncated. width 90.0 millimeters, 73.0 millimeters; convexity 22.0 Base line approximately horizontal or gently arcuate. millimeters, 18.0 millimeters. Along the Meherrin and Sculpture of thin, sharp, concentric lamellae, erect Nottoway Rivers the subspecies is characteristically or with a dorsal inclination, so crowded in perfect represented by large, notably thin, and elevated shells, individuals that the surface of the shell is visible only often posteriorly produced and obtusely pointed. The near the umbones, uniform in strength from the lunule dimensions of two perfect individuals are as follows: to the anterior margin of the escutcheon; concentric Height 91.0 millimeters, 93.0 millimeters; width 127.0 lamellae eroded in the great majority of individuals, millimeters, 123.0 millimeters; diameter 53.0 milli revealing a pronounced subsurficial radial sculpture. meters, 51.5 millimeters. These dimensions suggest the Ligament powerful, opisthodetic, seated on a corre Suffolk race, but the shells are larger and relatively spondingly heavy nymph. Dentition normal in pat higher, with a more oblique posterior dorsal margin tern but heavy. Adductor muscle scars very large, and a lateral margin more often bluntly pointed rather deeply impressed. Pedal scar, a dent beneath the ante than subtruncate. There is a tendency toward a sim rior cardinal. Pallial line distinct, the sinus short, ilar, though less extreme development in the representa acutely angular. Inner surface thickened over the area tives from the Roanoke and Tar Rivers in Edgecombe of the adherent mantel. Inner margins finely crenate. County, although along the lower course of the Tar Venus (M ercenaria) campechiensis rileyi is incon River in Pitt County, where the form is unusually abun stant in sculpture, the outline of the lunule and escutch dant, the valves are, generally, smaller and relatively eon, and the outline and equipment of the hinge plate. heavier, with a more persistent sculpture. In all the These characters vary not only concomitantly but inde Yorktown localities in southern Virginia and north of pendently as well. The group in each formation, how- the Hatteras axis in North Carolina the transition to ever, presents a similar general effect. This is most the moderately large and moderately heavy, subtrigonal strikingly exemplified in the Waccamaw where it is so F. campechiensis s. s. is very easy and frequently accom distinctive that, given an intergrading series of some plished. South of the Hatteras axis, however, the group twenty-odd forms with typical end members, one can assumes quite a different aspect. F. campechiensis is place the group vertically, and often horizontally, with represented in the Waccamaw by the ponderous sub a fair degree of assurance. species carolinensis Conrad, but even in the Duplin the The most serviceable characters in isolating the sub representatives of the subspecies rileyi have taken on the species rileyi have proved to be the oval, ovate, or peculiarities of the group, and the small, thin, trans subquadrate outline, which is never conspicuously tri versely oval, peripheral forms exhibit the close, crowded, gonal or circular; the moderately light shells; the often dorsally inclined concentric lamellae, which is rather compressed valves; and the low, anterior characteristic of their massive kindred, a significant umbones. fact in the consideration of the probable line of descent In the Yorktown formation, from which Conrad's of carolinensis. type was derived, the subspecies rileyi is relatively Mansfield records the species from the Ecphora zone small and heavy and is ovate to subquadrate in outline. of the Choctawhatchee formation. Along the Nansemond River, in the environs of Suffolk, Distribution: Virginia: Miocene, Yorktown formation, York- a larger, lighter, often posteriorly produced form is town, York County; mouth of Baileys Creek, Prince George County; Lieutenant Run near Petersburg, Dinwiddie County; very common. Measurements of valves typical of this Grove Wharf and Schmidts Bluff (8% miles below Claremont locality are as follows: Height 107.0 millimeters, 86.5 Wharf), Surry County; 1% miles northeast of Smithfield, % millimeters; width 144.0 millimeters, 116.5 millimeters; mile northeast of Smithfield, Fergusons Wharf, Benns Church, convexity 28.5 millimeters, 27.0 millimeters. The sub 1^ miles above Zuni, and 8 to 8^ miles below Zuni on the Blackwater River, Isle of Wight County; Hitchcock, Greens- species rileyi is exceedingly abundant on the Chowan ville County; Sycamore on the Nottoway River, % to % mile River, and pairs of valves with the crowded, concentric, below Sycamore, 3 to 4 miles above the lower Seaboard Railway lamellar sculpture perfectly preserved are far from bridge, % to % mile above the lower Seaboard Railway bridge, and jMaddelys Bluff on the Meherrin River, Southampton rare. Dimensions of typical individuals are as fol County; Exit, 5 miles northeast of Suffolk, 1% miles northwest lows : Height 67.0 millimeters, 68.5. millimeters; width of Suffolk, 1% miles north of Suffolk, 1% miles northeast of 132 MOLLUSCA FROM MIOCENE AND LOWER PLIOCENE OF VIRGINIA A.ND NORTH CAROLINA Suffolk, 1 mile northeast of Suffolk, y2 mile below the Suffolk 119.0 millimeters, width 153.0 millimeters, convexity waterworks dam, and the drainage ditch just east of Jericho 45.0 millimeters. ditch, Nansemond County. Shell ovate to subtriangular, very large, and ponder North Carolina: Miocene, Yorktown formation, 2% miles northwest of Murfreesboro (at Watsons Mill on Kirbys Creek), ous. Posterior dorsal margin often slightly gibbous. Tar Ferry on Wiccacon Creek (opposite Harrellsville), 1% Lunule cordate, delimited by a deep linear groove, lam miles below Tar Ferry, 3 to 4 miles below Tar Ferry, and inated. Escutcheon less sharply defined, narrower and Dogwood Landing on the Chowan River, Hertford County; Cole- more strongly laminated in the right valve than in the rain Landing, Mount Gould Landing, and % to % mile above left. Surface sculptured with thin, sharp lamellae that EdenhouFe Point on the Chowan River, Bertie County; Halifax (on Mr. Durham's property), % mile above the Atlantic Coast number 2 or 3 to the millimeter, except on the umbones; Line Railroad bridge, and at Palmyra Bluff, Halifax County; often dorsally appressed on the disk, most elevated Hamilton Bluff, 2 miles southeast of Hamilton Bluff, 4 miles near the lunule. Ligamental and hinge areas extremely northwest of Williamston, and 2% miles northwest of Williams- heavy but otherwise normal for the species. Adductor ton (on Joseph Cherry's property), Martin County; 1 mile below scars indicative of the powerful muscles necessary to. Bells Bridge, Shiloh Mills, Tarboro (at L. E. Fountain's farm), and 1 mile below old Sparta Bridge over the Tar River, Edge- control so weighty a shell. Pallial line and sinus dis combe County; 2 miles below Toddy Station, 4 miles east of tinct, often thrown into prominence by the thickening Farmville (on the east side of Pinelog Branch), 2% miles of the interior of the shell over the area of the adherent north of Standard, 8 to 9 miles west of Greenville, 2 miles west mantle. of Greenville, iy2 miles west of Greenville (on Schoolhouse The measurements of 3 characteristic valves are as Branch), Pitt County; Greenville (just east of the county bridge), 6 miles below Greenville, 6% miles below Greenville follows: Height 140.0 millimeters, 120.0 millimeters, (at Tafts Landing), 9 to 10 miles south of Greenville, 1 mile 130.0 millimeters; width 182.0 millimeters, 150.0 milli northwest of Galloway Crossroads, and % mile north of Grimes- meters, 160.0 millimeters; and convexity 50.0 mill- land, Pitt County; 2% miles northwest of Chocowinity and meters, 43.0 millimeters, 41.0 millimeters. 1% miles northeast of Chocowinity, Beaufort County; 1 mile Venus (Mercenaria) campechiensis carolinensis Con north of Castoria, % mile east of Lizzie (on David Summeril's rad is second in bulk only to V. campechiensis tridac- property), and 4 miles east of Lizzie (in Dog Swamp, on the property of O. W. Frizzelle), Greene County; Rock Landing on noides Lamarck. Although not approaching the lat the Neuse River, Craven County. Duplin marl, 3 miles south ter in the degree of deformity, some individuals in the of Clinton (on Gum Chimney Branch, on the property of collection exhibit not only a decided interior thickening Hugh Moore), Sampson County; Natural Well and 1% miles but the base line is rippled by a'radial undulation sim north of Magnolia, Duplin County; Lumberton (near the ilar to that of tridacnoides. By a decrease in size, bottling works) and 1% miles northeast of Fairmont (on the property of Andrew Jones), Robeson County. Pliocene, Wacca- weight, relative altitude, and prominence of the um maw formation, 4 miles south of Clarkton, Bladen County; bones V. carolinensis merges gradually into the ubiqui Donahues Landing, 48 miles above Wilmington, 4 miles south tous V. rileyi, its probable ancestor. of Elizabeth town (on Hammond Creek, on the property of Mrs. Mansfield reports the species from the Oancellaria Clark), Bladen County; Walkers Bluff on the Cape Fear zone of the Choctawhatchee formation. River, Bladen County; Lake Waccamaw and Neills Eddy Land ing (3 miles north of Cronly), Columbus County; Wilmington Distribution: North Carolina: Pliocene, Waccamaw forma (at the city rock quarry), New Hanover County. tion, 4 miles south of Elizabethtown (on Hammond Creek) and at Walkers Bluff (on the Cape Fear River), Bladen Venus (Mercenaria) campechiensis carolinensis Conrad County; Neills Eddy Landing (3 miles north of Cronly), Plate 20, figures 1, 2 Columbus County. Venus (Mercenaria) campechiensis tridacnoides (Lamarck) 1875. Mercenaria carolinensis Conrad. Kerr, North Carolina Conrad Geol. Survey Rept, vol. 1, App. A, p. 20. 1903. Venus campechiensis Gmelin (part). Dall, Wagner Free Plate 21, figure 11 Inst. Sci. Trans., vol. 3, pt. 6, p. 1315. 1685. —— Lister, Historiae sive Synopsis Methodicae Conchy- 1926. Venus ea-mpccMensis carolinensis (Conrad). Palmer, liorum, pi. 499, fig. 53. Palaeontographica Americana, vol. 1, No. 5, p. 190. 1818. Cyprina tridacnoides Lamarck, Histoire naturelle des 1932. Venus campechiensis carolinensis (Conrad). Mansfield, animaux sans vertebres, vol. 5, p. 558. Florida Geol. Survey Bull. 8, p. 132, pi. 28, fig. 4. 1824. Venus deformis Say, Acad. Nat. Sci. Philadelphia. Jour., Shell subtriangular, elongated, very inequilateral, slightly 1st ser., vol. 4, p. 148, pi. 12, figs. 2, 2a. ventricose, disk with coarse, flattened, uneven, imbricated ridges 1838. Venus tridacnoides Conrad, Fossils of the medial Tertiary on the middle and posterior side, the lines disposed to be ra of the United States, p. 10, pi. 7, fig. 2. mose ; on the anterior side and posterior slope they are sharp, 1856. Venus tridacnoides Conrad. Tuomey and Holmes, Pleio- prominent, rugose, imbricated lines; lunule large, cordate. cene fossils of South Carolina, p. 85, pi. 22, fig. 1. Length 5 inches, height 4 inches. 1858. Venus tridacnoides Conrad. Emmons, North Carolina 'Locality, Cape Fear River.—Conrad, 1875. Waccamaw for Geol. Survey Rept., p. 292. mation. 1858. Venus difformis Say. Emmons, idem. 1863. Mercenaria tridacnoides Lamarck. Conrad, Acad. Nat. Dimensions of figured specimen, a left valve, U. S. Sci. Philadelphia Proc. for 1862, p. 574. Nat. Mus. 325573, from the Waccamaw formation at 1867. Heroenaria percrassa Conrad, Am. Jour. Conchology, vol. Walkers Bluff on the Cape Fear Eiver, N. C.: Height 3, p. 13. PART 1. PELECYPODA 133 1869. Mercenaria percrassa Conrad, idem, vol. 4, p. 278, pi. 19, and abnormal types are coexistent at many localities fig. 1. would suggest a pathologic state that is due to some 1903. Venus tridacnoides Lamarck. Dall, Wagner Free Inst. organism. A general condition such as the mechanical Sci. Trans., vol. 3, pt. 6, p. 1310. 1926. Venus tridacnoides (Lamarck) (part). Palmer, Palaeon- or chemical constitution of the sea water or the features tographica Americana, vol. 1, No. 5, p. 191, pi. 33, fig. 6. of the food supply would be fairly constant at a given C. testa transversim ovata, corrugata; striis verticalibus; locality and would probably affect all individuals alike. limbo superiore undatim plicato. Distribution: Virginia: Miocene, Yorktown formation, York- Mon cabinet. List. Conch, t. 499. f. 53. town, York County; mouth of Baileys Creek, Prince George Habite . . . Fossile d'ltalie. Largeur, 11 centimetres. Co- County; Petersburg, Dinwiddie County; Fergusons Wharf, quille singulie"re; grande, plissee, en son limbe, comme dans Grove Wharf on the James River, Surry County; Benns Church, les tridacnes, ayant dans les interstices de ses sillons des stries iy2 miles above Zuni and 12 to 14 miles above Zuni on the verticales.—Lamarck, 1818. Blackwater River, Isle of Wight County; Sycamore, % to % Type locality not known but certainly not "Italie." mile below Sycamore on the Nottoway River, % to> i% mile above the lower Seaboard Railway bridge, and at Maddelys Shell subcordate, with transverse wrinkles, which are distant Bluff on the Meherrin River, Southampton County. and regular on the umbones, and much crowded on the basal North Carolina: Miocene, Yorktown formation, 1% to 2 miles half; several very obtuse longitudinal undulations, of which above Branches Bridge, Northampton County; 1% miles that on the middle is more profound; basal margin deeply above Murfreesboro on the Meherrin River, Hertford County; undulated in compliance with the undulations of the disk; Halifax (on Mr. Durham's farm % mile above the Atlantic within crenate on the edge; anterior margin flattened and Coast Line Railroad bridge), Halifax County; 4 miles north simply wrinkled. west of Williamston, Martin County; 15% miles above Bells Length nearly 5, breadth 6 inches. Smallest specimen, 3.7 Bridge, and % mile above Bells Bridge over the Tar River, inches long and 4% inches wide. Edgecombe County; 3 miles west of Greenville, Pitt County. • This extraordinary shell has so unusual an appearance, that I should almost have been disposed to regard a single specimen Venus (Mercenaria) berryi Gardner, n. sp. as a monstrosity. The examination of several individuals Plate 21, figures 1-6 proves that the species varies somewhat in form and in the locality of the undulations.—Say, 1824. Shell small, rather light, moderately inflated, ovate The deformity of this shell is sometimes so great to subtrigonal externally, ovate to subquadrate inter that a valve 107.5 millimeters in width will have a nally. Umbones rather plump but not very promi maximum thickness of 33.70 millimeters. The outline nent; the apices acute and prosogyrate, a distance of is variable, as Say has noted, and the undulations are about one-third the width back from the anterior mar inconstant in both their strength and their position. gin. Lunule rather narrow, conspicuously cordate, The lunule varies with the outline; the escutcheon is outlined posteriorly by a deeply impressed groove that moderately broad; the nymph is heavy and the groove dissects the sculpture. Escutcheon lanceolate, wider, deep enough to seat a ligament adequate to hold the and less strongly laminated in the left valve than massive valves; the rugose area is broadly lenticular in the right. Anterior margin bowed out in front and strongly marked. The hinge plate and dentition of the lunule. Posterior dorsal margin gently de are robust; the anterior cardinal of the right valve is clining or slightly gibbous. Lateral margin broadly simple, the middle and posterior cardinals are bifid; rounded, as a rule. Ventral margin gently arcuate, the anterior and middle cardinals of the left valve are more strongly upcurved in front than behind. Sculp bifid, the posterior is simple and somewhat laminar. ture unusually variable in detail but uniform in general The muscle impressions and pallial characters are aspect; concentric lamellae 45 to 65 in number, erect thrown into prominence by the thickening of the shell on the posterior and, particularly, on the anterior mar over the area of the adherent mantle. The adductor gin, the free edges frequently crenulated; laminae scars are very large, the anterior adductor semiellipti- closely appressed dorsally on the medial portion of the cal, the posterior, subcircular. The pallial line is mod disk, and often fused either with the surface or with erately distant from the hinge margin; the sinus is short one another; sculpture on the disk thus developed into and triangular. The crenulations of the inner margins low, flat, unequal areas, formed by the fusion of 2 to 8 are rather finer than one might expect in such ponderous lamellae, separated from one another by narrow chan valves. nels that occasionally bear 1 to 2 linear lirations. Neither the abnormal thickening nor the undulations Eadial sculpture discernible only on eroded surfaces. are developed in the young forms, which are indis Ligament area moderately wide, approximately half tinguishable from the young of Venus campechiensis the posterior dorsal margin in length; ligament rileyi, and the adults exhibit varying degree of thick mounted on rather vigorous nymphs, the outer margin ness and undulation from the normal subspecific form inset in a deep groove that obliquely undercuts the to the incongruously ponderous individuals that have dorsal margin of the valve. Rugose area narrow, elon attracted the attention of conchologists since the time gate. Three discrete cardinals in each valve, spreading of the prebinomial Lister. The fact that the normal fanlike from beneath the tips of the umbones. An- 134 MOLLUSCA FROM MIOCENE AND LOWER PLIOCENE OF VIRGINIA AND NORTH CAROLINA terior cardinal of right valve compressed; middle car uate School, Johns Hopkins University, who, though dinal robust, feebly bifid; posterior cardinal more com best known as an administrator and as a notable con pressed and elongate and more deeply sulcate longitu tributor to knowledge of the Tertiary floras, has done dinally. Anterior cardinal of left valve moderately much to advance the knowledge of the faunas as well. compressed-cuneiform but more elevated than either of Distribution: Virginia: Miocene, St. Marys formation,, 1 to 2 the other 2, feebly depressed medially; middle cardinal miles below Bowlers Wharf and 2% to 3 miles below Bowlers robust, rudely sulcate, but distinctly less elevated than Wharf on the Rappahannock River, Essex County. the tooth in front of it; posterior cardinal exceedingly Venus (Mercenaria) plena inflata Dall thin and elongate, partially fused with the rugose area behind it; lateral margin in right valve grooved for the Plate 21, figure 9 reception of the beveled edge of the escutcheon of the 1903. Venus plena var. inflata Dall, Wagner Free Inst. Sci. left valve. Adductor muscle scars of moderate size, Trans., vol. 3, pt. 6, p. 1310. submedial in position, distinct but not strikingly prom A variety which may be called inflata is more trigonal and inent. Pallial line moderately distant from the ventral measures 60 millimeters long, 55 [51.0] millimeters high, and margin. Pallial sinus short, not attaining the median 36 [20.5] millimeters in diameter [convexity of single valve]. vertical, its dorsal margin approximately horizontal, It is from Bellefield, York River, Va.—Dall, 1903. the terminal angle not far from 45°. Inner margins Holotype, a right valve: U. S. Nat. Mus. No. 163419. finely and evenly crenate. Type locality: Bellefield, York River, Va. York- Dimensions of holotype (paired valves) : Height 57.0 town formation. millimeters, width 62.5 millimeters, diameter 37.6 milli Shell heavy, elevated, trigonal, inflated in the um- meters. Dimensions of adult paratype, a right valve: bonal region. Umbones gibbous, involute, prosogyrate, Height 46.5 millimeters, width 54.0 millimeters, con fully three-fourths of the way over toward the anterior vexity 10.6 millimeters. Dimensions of adolescent par margin. Lunule broadly cordate, laminated, bounded atype, height 8.0 millimeters, width 8.5 millimeters. by a deeply incised line that dissects the concentric Holotype (paired valves) and adult paratype, a right sculpture. Escutcheon rather obscure, feebly laminar. valve: U. S. Nat. Mus. 325574. Anterior margin convex in front of the lunule. Pos Adolescent paratype, a right valve: U. S. Nat. Mus. terior dorsal margin obliquely produced or somewhat 325576. gibbous; posterior lateral margin subtruncate. Base Locality of types: Holotype and adult paratype, 2% line straight, upcurved anteriorly. Surface covered to 3 miles below Bowlers Wharf, Essex County, Va. with thick, heavy lamellae, closely crowded together. St. Marys formation. Adolescent paratype, 1 to 2 Ligamentary nymph rather slender; groove behind it miles below Bowlers Wharf, Essex County, Va. St. deep. Dentition normal, three discrete cardinals in Marys formation. each valve, fanlike in their arrangement; anterior Venus (Mercenaria) berryi stands so far apart from cardinal in both valves simple; middle cardinal in both the described Tertiary species of the middle Atlantic valves bifid; posterior cardinal bifid in the right, coast that its affinities are somewhat in doubt. The simple in the left; rugose area rather narrow. Ad more regularly sculptured forms suggest a subdued ductor impressions distinct; semielliptical. Pallial type of V. ducatelli Conrad, on which the concentric line rather distant from the margin. Sinus short, lamellae are developed in greater numbers and less triangular. conspicuously than in the normal form. The phenom The subspecies is heterodox only in the outline. enon of the fusion of the lamellae, is however, quite Distribution: Virginia: Miocene, Yorktown formation, Belle- unknown in Conrad's form, and when the fusion tends field, York County. toward the somewhat strongly marked obsolescence of the entire surface sculpture on the disk, the species Venus (Mercenaria) plena nucea Dall Plate 21, figures 7, 8 approaches some of the manifestations of V. mercenaria > Linneaus. The general contour of the shell, however, 1903. Venus plena var. nucea Dall, Wagner Free Inst. Sci. and the distribution are much more suggestive of V. Trans., vol. 3, pt. 6, p. 1310. ducatelli Conrad than of V. mercenaries,. Another form which I found mixed with the type at the same The young shells are rotund little valves sculptured locality [Bellefield, York River, Va.] and at first thought might be distinct, is rounded, subtruncate behind, very thick for its with equisize, equispaced, relatively distant, concentric size, the surface slightly undulate and with the lamellation lamellae, which are uniform in strength and character obsolete. It may take the name of variety nucea. It meas over the entire surface of the shell. So individual is ures: Length [width] 33, height 29 [30.0], and diameter 16 the species in the young stage that it recalls on first millimeters [convexity 11.0 millimeters].—Dall, 1903. examination an unusually rotund Chione. Holotype, a right valve: U. S. Nat. MUS. 163418. I have the pleasure of naming the species in honor Shell heavy, rude, rounded, roughly quadrate or trig of Dr. E. W. Berry, the former dean of the Undergrad onal, inflated in the umbonal region, often flattening PART 1. PELECYPODA 135 rather abruptly toward the umbones. Umbones 1932. Gemma magna Dall. Mansfield, Florida State Geol. Sur strongly anterior, sometimes not more than a fifth of vey Bull. 8, p. 134, pi. 27, figs. 1, 2. the way back from the anterior margin, involute, Shell trigonal, moderately convex, the anterior end slightly prosogyrate. Lunule cordate or oblong, sharply de shorter, rounded; the posterior end longer, more pointed; fined, laminated. Escutcheon lanceolate, laminar, beaks high, pointed; lunule [s]lightly flattened, bounded by an incised line often feeble, lanceolate, about half as long as rather obscure. Anterior end very short; slightly the anterior dorsal slope; escutcheon not defined; surface sculp arcuate in front of the lunule, in some individuals tured with numerous regular, even, concentric sulci, with sloping uniformly from the umbones to the base at wider smooth interspaces; hinge normal, well developed, es an angle not exceeding 10° or 12° off the vertical. Pos pecially the long lateral laminae, the cardinals entire; basal terior dorsal margin oblique or somewhat gibbous, margin crenulate, pallial sinus small, angular. Length 7, height broadly truncated laterally. Base line straight or 6, dimeter 4 millimeters. gently arcuate. Hinge characters normal for the G. magna+attains a larger size than any of the later repre sentatives of the genus. It resembles G. var. purpurea of the species. Muscle impressions and pallial line empha recent fauna in its sculpture, but relatively is much less sized by a thickening of the shell over the surface of inflated.—Dall, 1903. attachment of the mantle. The measured and figured specimen, which may be The subspecies is remarkable for its small, rude, considered the lectotype, is U. S. Nat. Mus. 115174. It stunted valves, which strongly suggest a pathologic is a right valve. Mounted on the same card with it condition. o and bearing the same Museum number is a second right Distribution: Virginia: Miocene, Yorktown formation, Belle- valve and two left valves. field, York County. Type locality: Natural Well, Duplin County, N. C. Subfamily GEMMINAE Duplin formation. Gemma magna Dall in the broader sense is a protean This group includes small species of Veneridae, which are species and one of the most prolific of the smaller bi characterized by viviparity and carry the young for a con valves. Were it not for the wealth of material, the siderable period, like Sphaeri\um, within the perivisceral cham ber. They have, as a rule, purple and white coloration, if differences between the peripheral members would be any, and a smooth or concentrically striated surface. They regarded as specific; but with a complete series of live in sand or mud in moderate depths of water on both intergrading individuals it is impossible to establish coasts of North America and have not been identified from anything more than subspecific variations. The York- any other region.—Dall,51 1903. town formation has two common subspecies, one notably small, high, and moderately heavy, with a Genus GEMMA Deshayes rather delicate hinge (subspecies virginiana) ; the other 1853. Gemma, Deshayes, Catalogue of the Conchifera of the characterized by a relatively large, rather thin, com British Museum, pt. 1, p. 112. pressed, and rounded, but usually inequilateral shell Type by tautonomy and monotypy: Venus gemma Totten. with umbones of little prominence and a moderately Recent from Labrador to North Carolina. robust hinge (subspecies majorina). In the Duplin, Gemma includes a group of small venerids roughly the species is fairly large, though smaller, relatively resembling in outline a 60° segment of a circle. A more strongly inflated, higher and more angular than large, rather obscurely defined lunule is developed but the subspecies majorina, but lower, more inequilateral, no escutcheon. The surface is concentrically wrinkled, and decidedly larger than the subspecies virginiana. and the inner margins of the valves are radially Gemma magna is, however, more unstable in the Duplin crenate. The hinge armature is restricted to three car than in any of the other formations, and it exhibits, dinals in each valve, unequal in size and diverging even at the type locality (the Natural Well), a be fanlike from beneath the tips of the umbones. The wildering range in. outline, degree of compression, and pallial sinus is short and steeply ascending. sculpture. The individual selected as the type is high, The genus has been an inconspicuous element in the trigonal, approximately equilateral, and closely and faunas of the east coast and Gulf since the middle regularly sulcated concentrically. From this charac Eocene. There is no record o.f it in either the Tertiary teristic type, the form may merge into a lower, less or the Recent European seas. angular, more compressed, a~nd more inequilateral phase. Variations in the strength of the sculpture bear Gemma magna Dall no relation, apparently, to the variations in outline. The prodissoconch and frequently the entire umbonal 1903. Gemma magna Dall, Wagner Free Inst. Sci. Trans., vol. region are destitute of sculpture, and occasionally, 3, pt. 6, p. 1330, pi. 57, fig 4. 1926. Gemma magna Dall. Palmer, Palaeontographica Ameri though more rarely than in the succeeding Waccamaw, cana, vol. 1, No. 5, p. 206, pi. 43, fig. 22. the entire valve is smooth (subspecies insulcata) • G. magna s.s. reaches distinctly greater dimensions in 61 Dall, W. H., Wagner Free Inst. Sci. Trans., vol. 3, pt. 4, p. 1329, 1903. Robeson County than in Duplin County and is usually 136 MOLLUSCA FROM MIOCENE AND LOWER PLIOCENE OF VIRGINIA AND NORTH CAROLINA more inequilateral in the former. The Waccamaw The most constant difference between the subspecies race is less differentiated than the Yorktown race and and G. magna s.s is the smaller size and less robust is hardly more than a collection of miniatures of Dup- hinge of the former. The greater degree of inflation lin forms. Both the high trigonal, inflated, equilateral and the higher and more nearly equilateral outline type and the lower, ovate, more compressed, inequi separate virginiana from the coexistent subspecies ma- lateral type are present together with the intergrading jorina. G. magna virginiana follows the tendency that individuals. The tendency toward a smooth surface seems to be general among the Tertiary Gemmas of is much stronger than in Miocene forms, a rather per presenting an unsculptured as well as a sculptured verse phase in the development of the species, since the phase. All the other characters remain constant, how juvenile valve is smooth, and, with the rise in the strati- ever, and the transition between the smooth form and graphic column, one might reasonably expect an evolu the evenly sulcated type is freely demonstrated in the tion toward a constantly and regularly sulcated type material at hand. rather than away from it. Distribution: Virginia: Miocene, Yorktown formation, York- Distribution: North Carolina: Miocene, Yorktown formation, town, York County (both smooth and sulcate races) ; 1% miles 3 miles south of Farmville, Pitt County; Colerain Landing on southeast of Reids Ferry (both smooth and sulcate races); 1 the Chowan River, Bertie County. Duplin marl, Natural Well, mile north of Suffolk (sulcate race only), Nansemond County. 1% miles north of Magnolia, and W. H. Kornegay's marl pit, North Carolina: Miocene, Yorktown formation, half a mile Duplin County; 4 miles north of Lumberton (on the Berry above Bells Bridge over the Tar River, Edgecombe County; Godwin plantation), 2 miles below Lumberton, 4 to 5 miles Tar Ferry on Wiccacon Creek (opposite Harrellsville), Hert below Lumberton, and 1% miles northeast of Fairmont (on ford County; Colerain Landing (smooth type only) and % to the property of Andrew Jones), Robeson County. Pliocene, % mile above Edenhouse Point on the Chowan River (smooth Waccamaw formation, 4 miles south of Elizabeth town (on Ham- type only), Bertie County; Rock Landing on the Neuse River mond Creek, on the property of Mrs. Clark) and Walkers (both smooth and sulcate types), Craven County. Bluff (on the Cape Fear River), Bladen County; Neills Eddy Landing (3 miles north of Cronly), and Lake Waccamaw, Gemma magna majorina Gardner, n. subsp. Columbus County; Wilmington (at the city rock quarry), New Plate 19, figures 19, 27 Handver County. Shell large for both the genus and the species; mod Outside distribution: Pliocene, Waccamaw formation, Todds Ferry on the Waccamaw River, Horry County, S. C. Caloosa- erately compressed. Outline ovate to subtrigonal, in hatchee marl, Nashua, Putnam County, Fla.; Caloosahatchee equilateral. Umbones flattened, inconspicuous, erect River, Alligator Creek, and Shell Creek, Fla. or slightly prosogyrate, often rather bulbous at their tips, placed a little in front of the median horizontal. Gemma magna virginiana Dall Lunule indicated merely by the cessation of the con Plate 19, figures 15-18, 25, 26 centric sculpture. Escutcheon not defined. Dorsal and lateral margins not differentiated; anterior slope 1903. Gemma magna var. virginiana Dall, Wagner Free Inst. Sci. Trans., vol. 3, pt. 6, p. 1330. shorter and consequently steeper than the posterior. 1926. Gemma magna virginiana Dall. Palmer, Palaeonto- Base line evenly and rather strongly arched. Surface graphica Americana, vol. 1, No. 5, p. 206. normally sculptured with 30 to 40 fine, regular, con Shell smaller, shorter, more delicate. Length 3.8, height 3.6, tinuous, concentric striae; occasional resting stages diameter 1.6 millimeters. present. Ligament external, opisthodetic; nymph From the Miocene of Yorktown, Va., in the middle portion short, sublinear; groove behind it narrow. Hinge con of the series; Harris. centrated; middle cardinal of right valve stout, tri This form is the earliest Gemma now known, and if I felt sure that it was adult I should separate it specifically from G. angular ; cardinal behind it more slender; that in front magna, which appears in the uppermost Miocene just before of it a thin lamina often worn or broken away; anterior the opening of the Pliocene epoch. It closely resembles the and middle cardinals in left valve cuneate, the anterior, young of the G. magna, and perhaps larger specimens may the more slender and produced, separated from the hereafter turn up.—Dall, 1903. medial cardinal by a deep, triangular, subumbonal Dimensions of figured cotypes: Eight valves, height socket; posterior cardinal of left valve thin and lami 3.4 millimeters, width 3.5 millimeters; height 3.2 milli nar; posterior dorsal margin of right valve and an meters, width 3.3 millimeters. Left valves, height 3.7 terior dorsal margin of left valve sulcated to receive millimeters, width 4.1 millimeters; height 3.0 milli the slightly modified corresponding margins of the meters, width 3.2 millimeters. opposite valves. Adductor impressions small, the an Dimensions of figured topotype, a left valve: Height terior impression somewhat oblong and submedial, the 3.3 millimeters, width 3.6 millimeters. posterior relatively broader and a little lower. Pallial Cotypes, 2 right and 3 left valves: U. S. Nat. Mus. line obscure, rather distant. Pallial sinus short, lin- 144633. guiform, and sharply ascending; inner margins usually Topotypes, a right and a left valve: U. S- Nat. Mus. crenate. 325571. Dimensions of cotypes: Eight valve, height 5.6 milli Type locality: Yorktown, Va. Yorktown formation. meters, width 6.6 millimeters, convexity 1.4 millimeters. PART 1. PELECYPODA 137 Left valve, height 6.6 millimeters, width 7.3 milli pressions obscure but apparently normal for the species. meters, convexity 1.5 milliireters. Pallial sinus short, very sharply ascending, somewhat Cotypes, the right and left valves of different indi- linguif orm. Inner margins finely crenate. diduals: U. S. Nat. Mus. 325566. Dimensions: Holotype, height 4.5 millimeters, width Type locality: One mile east of Lizzie, Greene 5.2 millimeters, convexity 1.5 millimeters; paratype, County, N. C. Yorktown formation. height 3.4 millimeters, width 4.1 millimeters. Gemma magna majorina is notably larger than G. Holotype, a right valve, U. S. Nat. Mus. 325567; magnet s. s., more compressed, less trigonal, with more paratype, a left valve, U. S. Nat. Mus. 325570. rounded margins, a relatively thinner shell, and a less Type localities: Holotype, Neills Eddy Landing, Co robust hinge. lumbus County, N. C.; paratype, Walkers Bluff, Bladen Distribution: Virginia: Miocene, Yorktown formation, 1 mile County, N. C. Waccamaw formation. northeast of Suffolk, and % mile below the Suffolk water The diagnostic character for the separation of G. works, Nansemond County. magna insulcata from the G. magna s.s. is the absence North Carolina: Miocene, Yorktown formation, Halifax and of a well-defined concentric sculpture. In many of Palmyra Bluff on the Roanoke River, Halifax County; Hamil ton Bluff, a % mile below Hamilton Landing, 3 miles west of the forms the sculpture is not assumed until the in Williamston, and 2% miles northwest of Williamston (on the dividual has attained a width of three millimeters, so property of Joseph Cherry), Martin County; 3 miles west of that adults with smooth uinbonal areas are quite com Rocky Mount, Bdgecombe County; 2 miles below Toddy Sta mon. It is rather unexpected that the tendency toward tion, 2 miles southeast of Tugwell (on Jacobs Branch), 3 a smooth shell, apparently a reversion to type, should miles southwest of Frog Level (on J. A. Noble's branch), 8 to 9 miles southeast of Greenville, 9 to 10 miles south of Green be most strongly marked in the Waccamaw (Pliocene). ville, and 2 miles east of Grifton (on J. F. Brooks' property), Distribution: North Carolina: Miocene, Duplin marl, 2 miles Pitt County; 2% miles northwest of Chocowinity, Beaufort below Lumberton and 4 to 5 miles below Lumberton, Robeson County; 2 miles southwest of Maple Cypress (on the Neuse County. Pliocene, Waccamaw formation, Walkers Bluff on River), Craven County; 1 mile west of Wilson (in Hominy the Cape Fear River, Bladen County; Cronly (% mile east of Swamp, on the property of Frank Barnes) (smooth race as the factories) and Neills Eddy Landing (3 miles of Cronly). well as sulcated), Wilson County; 1 mile north of Castoria Columbus County. and 1 mile east of Lizzie (both smooth and sulcate races), Greene -County; Tar Ferry and 1% miles below Tar Ferry Gemma cravenensis Gardner, n. sp. on Wiccacon Creek (opposite Harrellsville), Hertford County; % to % mile above Edenhouse Point on the Chowan River, Plate 19, figures 23, 24 Bertie County. Shell rather large for the genus, thin, compressed, Gemma magna insulcata Gardner, n. subsp. suboval in outline, .slightly inequilateral. Anterior Plate 19, figures 14, 22 dorsal margin a little shorter than the posterior, and consequently a little less gently sloping; lateral margins Shell trigonal or approximately so. Valves evenly broadly and evenly rounded; base line straight medi inflated. Apical angle not far from 60°; posterior ally, upcurved distally. Umbones low, rather flat, and margin often a little more produced and pointed than not at all conspicuous; apices obtuse and turned toward the anterior; base line arcuate, more strongly up- each other. Lunule merely suggested, not defined. curved, as a rule, before than behind. Umbones Escutcheon absent. Surface smooth or feebly sulcated inconspicuous, the apices obtuse, directed toward one an toward the margins by the growth lines. Ligament other. Lunule and escutcheon not differentiated. Sur external, opisthodetic, seated on a very narrow, but face smooth except for incrementals, which may assume rather robust nymph. Hinge normal but expanding a certain regularity toward the ventral margin. Liga with the dorsal margins, and less concentrated than in ment opisthodetic, mounted upon a sublinear nymph. the more trigonal races. Armature in the right valve Three cardinals in the right valve but only one of consisting of a very thin laminar anterior cardinal, a them at all obvious; anterior cardinal very thin and sturdy, triangular, subumbonal middle cardinal, and a laminar, often broken away; posterior cardinal only a compressed and obliquely produced posterior cardinal. little less slender but decidedly more elongate; middle Three cardinals present in the left valve as well, the cardinal stout and trigonal; three cardinals of left anterior cardinal only a little less robust and a little valve less discrepant in strength than those of right; more compressed than the middle, and separated from anterior cardinal much compressed and rather short; it by the deep, subumbonal socket; the posterior cardi middle cardinal narrowly cuneiform, posteriorly di nal thin, laminar, oblique, but not produced; right rected ; posterior cardinal merely a thin lamina, which anterior and left posterior dorsal margins feebly sul is rarely preserved in perfection; posterior dorsal mar cated and the opposing margins beveled. Muscle im gin of right valve and anterior dorsal margin of left pressions small, slightly below the median horizontal, valve sulcated to receive the slightly modified corre the anterior renif orm, and more regular in outline than sponding margins of the opposite valve. Adductor im the posterior. Pallial line rather distant. Pallial 138 MOLLUSCA FROM MIOCENE AND LOWER PLIOCENE OF VIRGINIA AND NORTH CAROLINA sinus broad and shallow. Inner margins faintly Distribution: North Carolina: Miocene, Yorktown formation, crenate. 8 to 9 miles southeast of Greenville, Pitt County. Dimensions of holotype: Height 3.7 millimeters, Superfamily MYACEA width 4.6 millimeters, convexity 0.9 millimeters. Holotype, the right and left valves of a single in Family MYACIDAE dividual : U. S. Nat. Mus. 325569. Type locality: Rock Landing on the Neuse Eiver, Genus MYA Linnaeus Craven County. Yorktowii formation. 1758. Mya Linnaeus, Systema naturae, 10th ed., p. 670. Gemma cravenensis is most closely allied to G. magna majorina. It is, however, much thinner, more com Type by subsequent designation (Schumacher, Bssai d'un nouveau systeme des habitations des vers testacSs, p. 116) : pressed, and more oval, with a fanlike divergence of Mya truncata Linnaeus. Recent in the estuaries and coastal the cardinals that isolates it readily even among the waters of the British Isles. Found in the fossil state as early protean representatives of G. magna. as the Coralline Crag. Distribution: North Carolina: Miocene, Yorktown formation, Shell oblong or rhomboidal, only slightly inequi- Rock Landing on the Neuse River, Craven County. valve, gaping at both extremities. Outer surface in- Gemma verdevilla Gardner, n. sp. crementally wrinkled. Umbones low, proximate. Ligament attached to a projecting chondrophore in the Plate 19, figures 31, 32 left valve and, in the right valve, to an inverted liga Shell minute, but rather heavy, subcircular, subequi- ment pit directly beneath the umbo. No development lateral. Posterior end more evenly arcuate than the of either a cardinal or a lateral dentition. Adductor anterior, which is obscurely truncate dorsally. Base scars subequal. Pallial sinus deep. line evenly rounded. Umbones, rather inflated but not Davies 52 has given an interesting series of diagram conspicuous. Apices obtuse, facing one another. matic sections showing the change in the position of Lunule faintly suggested but not defined. Escutcheon the resilium and resilifer from the strongly inequivalve absent. Surface very feebly and somewhat irregularly Corbulas, in which the attachment areas of the right sculptured by the incrementals. Ligament external, and left valves are diagonally opposed, to that of Mya, opisthodetic, seated on linear nymphs. Hinge delicate, in which the valves are approximately equal in size but concentrated. Right valve armed with a very thin, the chondrophore of the left valve projects beneath the laminar, anterior cardinal; a robust, cuneiform, middle resilial pit of the right, so that the opposing attachment cardinal; and a compressed, obliquely produced, pos faces are almost directly one above the other. terior cardinal. Left valve with subequal anterior, The genus is known from the Tertiary to the present and middle cardinals, the anterior a little the more day. The Recent species are largely confined to the compressed, the two separated by a deep, triangular, northern hemisphere and, though few in number, are subumbonal socket; posterior cardinal imperfect in the prolific in individuals. type but oblique and probably much compressed. Feeble lateral ridges developed on the anterior margin Mya arenaria Linnaeus of the right valve and the posterior margin of the left, / with corresponding grooves in the posterior margin of Plate 22, figure 8 the right valve and the anterior margin of the left. 1758. Mya, arenaria, Linnaeus, Systema naturae, 10th ed., p. 670. Muscle impressions small, a little below the median 1822. Mya acuta Say, Acad. Nat. Sci. Philadelphia Jour., 1st horizontal, the anterior minutely reinform and more ser., vol. 2, p. 313. regular in outline than the posterior. Pallial line 1822. Mya mercenaria Say, idem. 1841. Mya, arenaria Linnaeus. Gould, Invertebrata of Massa rather distant. Sinus broad and very shallow. Inner chusetts, p. 40. margins faintly radiate but not crenate. 1845. Mya, corpulenta Conrad, Fossils of the medial Tertiary Dimensions of holotype: Height 2.6 millimeters, of the United States, p. 68, pi. 39, fig. 1. width 2.6 millimeters, diameter 1.3 millimeters. 1858. Mya arenaria Linnaeus. Holmes, Post-Pleiocene fossils Holotype, the right and left valves of a single indi of South Carolina, p. 55, pi. 8, fig: 15. 1863. Mya corpulenta Conrad, Acad. Nat. Sci. Philadelphia vidual : U. S. Nat. Mus. 325568. Proc. for 1862, p. 572. Type locality: Eight to 9 miles southeast of Green 1889. Mya arenaria Linnaeus. Dall, U. S. Nat. Mus. Bull. 37, ville, Pitt County, N. C. Yorktowii formation. p. 70, pi. 49, fig 9; pi 55, fig 2; pi. 69, fig. 2. Gemma verdevilla is smaller than any of the associ 1898. Mya. arenaria Linnaeus. Dall, Wagner Free Inst. Sci. ated Gemmas, is more inflated, and is more rotund in Trans. vol. 3, pt. 4, p. 857. 1906. Mya arenaria Linnaeus. Clark, Maryland Geol. Survey, outline, with less angular umbones and a broader, more Pliocene and Pleistocene, p. 194, pi. 53, figs. 5, 6; pi. shallow, pallial sinus. The species is known only from 54, figs. 1-4. the two valves, which belong apparently to the same individual. 52 Davies, A. M., Tertiary faunas, vol. 1, p. 203, fig. 282, 1935. PART 1. PELECYPODA 139 1908. Mya arenaria Linnaeus. Rogers, Shell book, p. 324, pi. reason for rejecting it, Aloidis Von Miihlfeld becomes facing 323, fig. 7. an exact synonym of Corbula s. s. M. testa ovata postice rotundata, cardinis dente antrorsum Topotypes in the Academy of Natural Sciences, Phil porrecto rotundato denticuloque lateral!. adelphia, are between 15 and 20 millimeters high and Habitat in O. Europae septentrionalis sub arena, foraminibus 25 millimeters wide. The posterior keel is very sharp duobus detegenda.—Linnaeus, 1758. and is defined anteriorly by a deep sulcus, which per-> Mya, arenaria varies in the outline of the posterior sists from the nepionic shell to the margin. Both portion of the valves from the evenly rounded forms valves are coarsely rugose, the sculpture on the right to the distinctly angular. This, the soft-shell or sand valve being heavier than on the left. Radial sculpture clam of the fish market, is a common inhabitant of the is absent on the conch. The tips of the umbones are northern Atlantic and Arctic waters on both American conspicuously capped by the nepionic valves, which and European shores. Though most abundant on the differ from the adult to a remarkable degree. They gravelly mud flats of the New England coast, it is found are nearly equivalve, compressed, acutely rostrate, pos as far south as South Carolina and as far north as teriorly, and similarly sculptured with concentric rugae, Greenland, and though originally introduced accident which strengthen toward the ventral margin. There ally with seed oysters, it is now well established in the are no east American shells sufficiently close to the large waters of San Francisco Bay. coarse Senegalese shell to suggest the representation of dark's figure of a left valve from the Pleistocene the 0. sulcata group in east American waters either in at Wailes Bluff, Md., is reproduced. The species, Tertiary or in Recent times. though not abundant, may be found frequently in the red Miocene cliffs along the York River, while the Subgenus CARYOCORBULA Gardner waters at the base of the cliffs serve as a home for its 1926. Caryocorbula Gardner, Nautilus, vol. 40, p. 46. living representatives. Cuneocorbula Dall and authors, not Cuneocorbula Coss- mann, 1886. Distribution: Virginia: Miocene, Yorktown formation, York- town, York County. Type by original designation: Corbula alabamiensis Isaac Lea. North Carolina: Pliocene, Waccamaw formation, Lake Wac- Claiborne (Eocene) of the east coast and Gulf region from camaw and Neills Eddy Landing, Columbus County. South Carolina to the Rio Grande. Outside distribution: Pleistocene, Point Shirley and Sankaty Shell small or of moderate dimensions; acutely keeled Head, Mass.; Wailes Bluff and Cornfield Harbor, St. Marys County, Md.; Simmons Bluff and Abbapoola, S. C. Recent, posteriorly. Slightly inequivalve; right valve a little Arctic Ocean to North Carolina and possibly to Miami, Fla., larger and a little higher relatively than the left. in water up to 40 fathoms; also on Scandinavian coasts in Both valves concentrically rugose, the sculpture on the the low-tide area. right valve in some species stronger and more regular than on the left; a microscopically fine radial linea- Family CORBULIDAE tion developed in some of the later species, particularly Genus CORBULA Bruguiere on the posterior keel. Ligament, dental, muscle, and 1797. Corbula Bruguiere, Tableau encyclopedique et me"thodique sinal characters similar to those of Corbula, s.s. des trois regnes de la nature, vers, coquilles, mollusques, Caryocorbula includes most of the American species et polipiers, pi. 230, figs, la-c; 3a-c; 4a-d; 5a-c; 6a-b. formerly assigned to Cuneocorbula. Caryocorbula dif (Figures only, no text.) fers from the Paris Basin group in that the shell is 1799. Corbula, Lamarck, Prodrome d'une nouvelle classification less trigonal, not so produced posteriorly, usually heav des coquilles, Soc. histoire nat. Paris m£m., p. 89. (No species cited.) ier, unirostrate rather than birostrate, and more 1801. Corbula Lamarck, Systeme des animaux sans vertebres, strongly sculptured. Caryocorbula is abundantly rep p. 137. resented in the Tertiary and Pleistocene deposits of the 1811. Aloidls Megerle von Miihlfeld, Entwurf eines neuen 'Sys east coast and Gulf and in the Recent east American tem der Schalthiergehause, Magazin der Gesellschaft waters. naturforschende Freunde, 5ter Jahrg., p. 67. Type by monotypy: Corbula guineensis Von Miihlfeld=C'or- Corbula (Caryocorbula) conradi Gardner, n. sp. bula sulcata Lamarck. Plate 23, figures 27, 28 Type by subsequent designation (Schmidt, C. F., Versuch uber die beste Einricht, etc., pp. 57, 177, Gotha, 1818: Corbula Shell inequivalve, right valve commonly overlapping sulcata Lamarck. Recent off the coast of Senegal. the left, inequilateral, moderately heavy and convex, In the earlier reports, I have followed the type desig strongly rostrate. Umbones low, the left umbo a little nation of Children, 1822, Corbula nucleus Lamarck= the higher. Base line of right valve arcuate, slightly G. gibba (Olivi). G. sulcata Lamarck served as the sinuous posteriorly; that of the left slightly oblique, type of the subgenus Aloidis. If Schmidt's designa ascending a little in front of the rostrum. Sculpture tion be accepted, and there seems to be no adequate of fine, mostly continuous and equidistant, concentric 140 MOLLUSCA FROM MIOCENE AND LOWER PLIOCENE OF VIRGINIA AND NORTH CAROLINA lirae, which persist across the keel with little change 2 miles west of Greenville, and 6% miles below Greenville (at in character; submicroscopic, radial striations also vis Tafts Landing), Pitt County; Rock Landing, Craven County. ible in well-preserved specimens, more distinct as a rule Corbula (Caryocorbula) conradi retusa Gardner, n. subsp. on the le|t valve. Ligament internal, seated on a proc ess of the posterior dorsal margin of the left valve. Plate 23, figures 33, 34 Cardinal socket deep. Cardinal tooth stout, recurved, Shell rather small, subtrigonal, inequivalve. Inequi placed beneath the right umbo; resilial pit behind it lateral, rostrate posteriorly. Umbones flattened, in moderately excavated. Muscle impressions and-pallial curved, prosogyrate. Base line of right valve strongly line indistinct. arcuate; that of left slightly oblique. Concentric Dimensions of holotype (paired valves) : Height 6.7 sculpture of rather coarse lirae, 20 to 25 in the type; millimeters, width 11.0 millimeters, diameter 4.7 milli approximately equisize and equidistant; on the an meters. terior slope becoming discontinuous toward the medial Holotype, paired valves: U. S. Nat. Mus. 325605. portion of the valve, and on the posterior portion and Type locality: 15l/2 miles above Bells Bridge on keel often obsolete; radial striae faintly visible over the the Tar Eiver, Edgecombe County, S. C. Yorktown entire shell. Hinge normal. formation. ( Dimensions of holotype: Height 5.0 millimeters, The species suggests Corbula inaequalis Say in the width 7.7 millimeters, diameter 3.3 millimeters. general outline of the valves. It is not, however, so Holotype, paired valves: U. S. Nat. Mus. 325604. large or so heavy as the latter. The most conspicuous Type locality: Half to three-quarters of a mile below difference is in the concentric sculpture, which is closer, Edenhouse Point, Bertie County, N. C. Yorktown finer, and more regular than that of G. inaequalis and fo.rmation. approaches that of C. cuneata Say, a relatively low The subspecies retusa is a little smaller and notice species that is characterized by the straight base line ably higher than Corbula conradi s. s. The most con of the right valve. The new species differs, further stant difference, however, is in the concentric sculpture, more, from both G. inaequalis Say and C. cuneata Say which, instead of being approximately uniform over in the possession of a delicate radial sculpture that is the entire valve as in G. conradi s. s., becomes irregular less pronounced than, but similar in character to, that medially and evanescent posteriorly. These characters exhibited by C. barrattiana C. B. Adams and C. swifti- are shared by G. inaequalis Say, and the resemblance ana C. B. Adams. G. dominicensis Gabb is not rela between the subspecies retusa and the young of the tively so high and is larger. coexistent inaequalis is often disconcerting. The deli G. conradi is quite widely distributed and fairly cate radial sculpture will serve to determine the form, abundant in the Miocene and Pliocene of Virginia and if the individuals are fresh. If this diagnostic feature North Carolina, where it has doubtless been confused has been lost through erosion, there is an aspect of with its notoriously variable congener, G. inaequalis, regularity and clean definition of sculpture on the an and possibly with the much less common G. cuneata. terior part of the shell that will serve to separate a Distribution: Virginia: Miocene, St. Marys formation?, No- series, though it may be of little value in the determi mini Cliffs, Westmoreland County. St. Marys formation, 2% nation of single individuals. The type was taken from miles south of Farnham, Richmond County; Urbanna, Middle the Yorktown sands of the Chowan Eiver, half to sex County. Yorktown formation, 4 miles northwest of Walk- three-quarters of a mile above Edenhouse Point. The erton and 3 miles northeast of Walkerton, King and Queen County; Yorktown, York County; Petersburg, Dinwiddie subspecies is quite common at a number of localities County; % mile northeast of Smithfleld, 12 to 14 miles be along the Chowan, but it is rare in the Duplin. low Zuni, Isle of Wight County; Sycamore, and % to % mile Distribution: Virginia: Miocene, Yorktown formation, Exit, below Sycamore, Southampton County; 1% miles southeast of Nansemond County. Reids Ferry, 1% miles north of Suffolk, 1 mile northeast of North Carolina: Miocene, Yorktown formation, 7 miles south Suffolk, 1 mile west of Suffolk, and y2 mile below the Suffolk east of Wilson, Wilson County; 6% miles below Greenville (at waterworks dam, Nansemond County. Tafts Landing), Pitt County; 2 miles southwest of Maple North Carolina: Miocene, Yorktown formation, Watsons Mill Cypress, Craven County; Dogwood Landing and Mount Pleas on Kirbys Creek, 2% miles northwest of Murfreesboro, Tar ant Landing, Hertford County; Colerain Landing and half to Ferry, and 3 to 4 miles below Tar Ferry, Wiccacon Creek three-quarters of a mile above Edenhouse Point, Bertie County. (opposite Harrellsville), Hertford County; Halifax, Halifax Duplin marl, Natural Well and 1% miles above Magnolia, County; 2% miles northwest of Williamston (on Joseph Duplin County. Cherry's farm), Martin County; Swift Creek, 15% miles above Bells Bridge, % mile above Bells Bridge, Tar River, and Corbula (Caryocorbula?) scutata Gardner, n. sp. at Shiloh Mills, Edgecombe County; 7 miles southeast of Wil son, Wilson County; 1 mile north of Castoria, % mile east of Plate 23, figures 26, 30-32 Lizzie (on David Summeril's farm), and 4 miles east of Lizzie (in Dog Swamp, on O. W. Frizzelle's farm), Greene County; Shell heavy, subtriangular to subtrapezoidal; both 1% miles northeast of Farmville, 3 miles south of Farmville, right and left valves strongly convex, the former a PLATES 1-23 145 401033—43——11 PLATE 1 FIGURES 1-2. Nucula proxima Say (p. 19). 1. Exterior of right valve; height 4.0 millimeters; width 4.5 millimeters. (After Clark.) 2. Interior of same valve. (After Clark.) FIGURE 3. Nucula diaphana H. C. Lea (p. 20). Interior of left valve (Acad. Nat. Sci. Philadelphia 1591); height 2.5 millimeters; width 3.1 millimeters. FIGURES 4-5. Nucula proxima Say (p. 19). 4. Interior of left valve; height 3.9 millimeters; width 4.7 millimeters. (After Clark.) 5. Exterior of same valve. (After Clark.) FIGURE 6. Glycymeris tumulus (Conrad) (p. 27). Interior of left valve (U. S. Nat. Mus. 325483) from Nomini Cliffs, Westmoreland County, Va.; height 44.5 millimeters; width 44.7 millimeters. FIGURES 7-8. Brachidontes (Ischadium) recurvus (Rafinesque) (p. 29). 7. Exterior of right valve; height 18.0 millimeters; width 30.0 millimeters. (After Clark.) 8. Interior of left valve; height 13.3 millimeters; width 22.5 millimeters. (After Clark.) FIGURE 9. Nucula diaphana H. C. Lea (p. 20). Exterior of left valve (Acad. Nat. Sci. Philadelphia 1591); height 2.1 millimeters; width, 2.7 millimeters. FIGURE 10. Yoldia laevis (Say) (p. 21). Exterior of right valve and interior of left valve; height 13.0 ± millimeters width 26.0 ± millimeters. (After Say.) FIGURE 11. Glycymeris laevis (Tuomey and Holmes) (p. 26). Exterior of left, and interior, hinge and teeth of right valve; height 30.0 ± millimeters; width 31.0 ± millimeters. (After Tuomey and Holmes.) FIGURES 12-15. Glycymeris tumulus (Conrad) (p. 27). 12. Exterior of left valve (U. S. Nat. Mus. 325483) from Nomini Cliffs, Westmoreland County, Va.; height 44.5 millimeters; width 44.7 millimeters. 13. Exterior of juvenile (U. S. Nat. Mus. 325483); height 7.8 millimeters; width 7.3 millimeters. 14. Interior of same valve figured to show early dentition. 15. Profile of closed valves from front (U. S. Nat. Mus. 325483); greatest convexity 27.0 millimeters. FIGURES 16-21. Glycymeris americana (Defrance) (p. 27). 16. Hinge of left valve (U. S. Nat. Mus. 325482), Neills Eddy Landing, Cape Fear River, N. C.; natural size, figured to show partial encroachment of ligament area on dental series. 17. Hinge of left valve (U. S. Nat. Mus. 325482); natural size, figured to show further encroachment of ligament area on dental series. 18. Exterior of juvenile (U. S. Nat. Mus. 325482); height 11.5 millimeters; width 11.7 millimeters. 19. Interior of same juvenile figured to show dentition. 20. Exterior of left valve (U. S. Nat. Mus. 325482); height 85.5 millimeters; width 84.0 millimeters. 21. Interior of same valve. 146 GEOLOGICAL SURVEY PROFESSIONAL PAPER 199 PLATE 1 21 20 PELECYPODS. GEOLOGICAL SURVEY PROFESSIONAL PAPER 199 PLATE 2 PELECYPODS. PLATE 2 FIGURE 1. Barbatia (Granoarca) propatula (Conrad) (p. 22). Exterior of right valve and hinge of left valve; height 57.0 ± millimeter width 100.0 ± millimeter. (After Conrad.) FIGURE 2. Anadara (Cunearca) scalaris (Conrad) (p. 26). Exterior of left valve and hinge of right valve; height 54.0 ± millimeter; width 64.0 ± millimeter. (After Tuomey and Holmes.) FIGURE 3. Glycymeris duplinensis Ball (p. 27). Interior of holotype, a left valve (U. S. Nat. Mus. 114941); height 10.0 millimeters; width 9.0 millimeters. (After Ball.) FIGURE 4. Anadara lienosa (Say) (p. 23). Interior of right valve (U. S. Nat. Mus. 325428); height 69.0 millimeters; width 117.0 millimeters. FIGURE 5. Anadara protracta (Rogers and Rogers) (p. 24). Interior of right valve; height 40.0 ± millimeters; width 86.0 ± milli meters. (After Rogers and Rogers.) FIGURE 6. Anadara carolinensis (Wagner) (p. 25). Interior of right valve (Wagner Free Inst. Sci. Philadelphia); height 55.0 milli meters; width 56.0 millimeters. (After Ball.) FIGURE 7. Anadara lienosa (Say) (p. 23). Exterior of right valve (U. S. Nat. Mus. 325428), from Wilmington, N. C.; height 69.0 millimeters; width 117.0 millimeters. 147 PLATE 3 FIGURE 1. Anadara magnoliana Gardner, n. sp. (p. 25). Exterior of holotype, a right valve (U. S. Nat. Mus. 325486), from Natural Well, Duplin County, N. C.; height 34.3 millimeters; width 46.7 millimeters. FIGURE 2. Anadara callicestosa (Ball) (p. 24). Detail of sculpture of holotype. (After Dall.) FIGURE 3. Anadara protracta (Rogers and Rogers) (p. 24). Exterior of right valve; height 40.0 ± millimeters; width 86.0 ± milli meters. (After Rogers and Rogers.) FIGURE 4. Anadara magnoliana Gardner, n. sp. (p. 25). Interior of holotype. FIGURE 5. Anadara magnoliana Gardner, n. sp. (p. 25). Detail of sculpture of holotype. FIGURE 6. Anadara callicestosa (Dall) (p. 24). Exterior of holotype, a left valve (U. S. Nat. Mus. 146264); height 27.0 millimeters; width 32.0 millimeters. (After Dall.) FIGURE 7. Anadara magnoliana Gardner, n. sp. (p. 25). Interior of right valve (U. S. Nat.Mus. 325487); height 31.0 millimeters; width 39.0 millimeters. FIGURE 8. Anadara callicestosa wilsoni Gardner, n. subsp. (p. 24). Detail of sculpture of holotype. FIGURE 9. Anadara callicestosa wilsoni Gardner, n. subsp. (p. 24). Exterior of holotype, a left valve (II. S. Nat. Mus. 325488); height 30.6 millimeters; width 34.3 millimeters. FIGURES 10-11. Pododesmus (Moniaf) philippi Gardner, n. sp. (p. 41). 10. Interior of holotype, a left valve (II. S. Nat. Mus. 325497); height 35.7 millimeters; width 36.0 millimeters. 11. Detail of sculpture of holotype. FIGURE 12. Anadara callicestosa wilsoni Gardner, n. subsp. (p. 24). Interior of holotype. FIGURE 13. Pododesmus (Monial) philippi Gardner, n. sp. (p. 41). Exterior of holotype. FIGURES 14—16. Crenella precursor Gardner, n. sp. (p. 30). 14. Hinge of holotype, X 6. 15. Exterior of holotype, a right valve (U. S. Nat. Mus. 325498); height 7.6 millimeters; width 6.4 millimeters. 16. Interior of holotype. FIGURE 17. Ostrea waccamawensis Gardner, n. sp. (p. 41). Exterior of holotype, a left valve (II. S. Nat. Mus. 497063); height 68.0 millimeters; width 57.0 millimeters. 148 GEOLOGICAL SURVEY PEOFESSIONAL PAPER 199 PLATE 3 13 17 PELECYPODS. GEOLOGICAL SURVEY PROFESSIONAL PAPER 199 PLATE 4 PELECYPODS. PLATE 4 FIGURE 1. Chlamys (Lyropecten) jeffersonia septenaria (Say) (p. 34). Exterior of left valve; height 70.0 millimeters; width 70.0 millimeters. (After Say.) FIGURE 2. Chlamys (Lyropecteri) jeffersonia (Say) (p. 32). Exterior of left valve; "length 5.3 inches; breadth 5.7 inches." (After Say.) FIGURE 3. Chlamys (Placopecten) virginiana (Conrad) (p. 38). Exterior of holotype, a right valve (Acad. Nat. Sci. Philadelphia 1620); height 57.8 millimeters; width 58.8 millimeters. FIGURE 4. Pecten (Euvola) raveneli Ball (p. 30). Exterior of holotype, a right valve (U. S. Nat. Mus. 107750); height 42.0 milli meters; width 47.0 millimeters. (After Ball.) FIGURE 5. Chlamys (Lyropecten) madisonia (Say) (p. 32). Exterior of left valve (U. S. Nat. Mus. 325490); height 117.0 millimeters; width 126.0 millimeters. 149 PLATE 5 FIGURES 1-2. Chlamys decemnaria (Conrad) (p. 31). 1. Exterior of left valve (U. S. Nat. Mus. 325496); height 18.0 millimeters; width 15.7 millimeters. 2. Exterior of left valve (U. S. Nat. Mus. 325495); height 27.3 millimeters; width 25.0 millimeters. FIGURE 3. Pecten sp. cf. P. (Plagioctenium) gibbus (Linnaeus), s. 1. (p. 31). Exterior of right valve (U. S. Nat. Mus. 146256); height 43.0 millimeters; width 44.0 millimeters. FIGURE 4. Chlamys (Placopecleri) marylandica (Wagner) (p. 38). Exterior of left valve (U. S. Nat. Mus. 145991); height 67.5 milli meters; width 66.0 millimeters. FIGURE 5. Glycymeris duplinensis Ball (p. 27). Exterior of holotype, a left valve (U. S. Nat. Mus. 114941); height 10.0 millimeters; width 9.0 millimeters. (After Ball.) FIGURES 6-7. Chlamys decemnaria (Conrad) (p. 31). 6. Exterior of right valve (U. S. Nat. Mus. 325495); height 27.3 millimeters; width 25.0 millimeters. 7. Exterior of right valve (U. S. Nat. Mus. 325494); height 43.0 millimeters; width 42.0 millimeters. 150 GEOLOGICAL SURVEY PROFESSIONAL PAPER 199 PLATE 5 GEOLOGICAL SURVEY PROFESSIONAL PAPER 199 PLATE 6 PELECYPODS. PLATE 6 FIGURE 1. Chlamys (Placopecten) clintonia (Say) (p. 37). Exterior of left valve; height 100.0+ millimeters; width 104.0 millimeters (After Glenn.) FIGURES 2-3. Chlamys (Placopecten) marylandica (Wagner) (p. 38). 2. Exterior of right valve (U. S. Nat. Mus. 143966); height 53.5 millimeters; width 47.0+ millimeters. 3. Exterior of left valve (U. S. Nat. Mus. 145991); height 81 millimeters; width 70 millimeters. FIGURE 4. Chlamys (Placopecten) clintonia (Say) (p. 37). Exterior of left valve; "length 4 inches; breadth rather more." (After Say.) FIGURE 5. Chlamys (Lyropecten}\ peedeensis (Tuomey and [Holmes) (p. 35). Detail of sculpture. (After Tuomey and Holmes.) FIGURES 6-8. Chlamys (Lyropecten) ernestsmithi (Tucker) (p. 34). 6. Detail of sculpture. 7. Exterior of right valve (U. S. Nat. Mus. 325492); height 70.0 millimeters; width 67.0 millimeters. 8. Exterior of left valve (U. S. Nat. Mus. 325492); height 101.5 millimeters; width 100.0 millimeters. 151 PLATE 7 FIGURE 1. Chlamys (Aequipecteri) eborea (Conrad) (p. 36). Exterior of right valve (double valves); height 83.0±millimeters; width 90.0 ± millimeters. (After Tuomey and Holmes.) FIGURES 2-4. Chlamys (Aequipecteri) comparilis (Tuomey and Holmes) (p. 37). 2. Exterior of right valve of holotype (double valves); height 65.0±millimeters; width 65.0±millimeters. (After Tuomey and Holmes.) 3. Detail of sculpture and of ventral margin of holotype. (After Tuomey and Holmes.) , 4. Profile of double valves of holotype; convexity 29.0 ± millimeters. (After Tuomey and Holmes.) FIGURES 5—6. Chlamys (Aequipecteri) eborea (Conrad) (p. 36). 5. Profile of double valves; convexity 23.0± millimeters. (After Tuomey and Holmes.) 6. Detail of sculpture and of ventral margin. (After Tuomey and Holmes.) FIGURE 7. Chlamys (Aequipecteri) comparilis (Tuomey and Holmes) (p. 37). Exterior of left valve of holotype(?). (After Tuomey and Holmes.) FIGURE 8. Chlamys (Aequipecteri) eborea (Conrad) (p. 36). Exterior of left valve. (After Tuomey and Holmes.) 152 GEOLOGICAL SURVEY PROFESSIONAL PAPER 199 PL4TE 7 PELECYPODS. GEOLOGICAL SURVEY PROFESSIONAL PAPER 199 PLATE 8 PELECYPODS. PLATE 8 FIGURES 1—2. Amusium mortoni (Ravenel) (p. 39). 1. Interior of right valve; height 178 millimeters; width 195 millimeters. (After Tuomey and Holmes.) 2. Profile of double valves; convexity 31 millimeters. (After Tuomey and Holmes.) 153 401033—43———12 PLATE 9 FIGURE 1. Chlamys (Lyropecteri) planicosta Gardner, n. sp. (p. 34). Exterior of right valve (U. S. Nat. Mus. 325493); height 111.0 millimeters; width 118.0± millimeters. FIGURES 2-6. Coralliophaga? microreticulata Gardner (p. 66). Cotypes (U. S. Nat. Mus. 325560). 2. Cluster of burrows showing openings at smaller ends, X 3. 3. Fragment of ventral portion of shell, X2. 4. Fragment of anterior portion of right valve, X 2. 5. Fragment of anterior portion of left valve, X 2. 6. Cluster of burrows, natural size. FIGURE 7. Chlamys (Lyropecteri) madisonia (Say) (p. 32). Exterior of right valve (U. S. Nat. Mus. 325490); height 117.0 milli meters; width 131.0 millimeters. 154 GEOLOGICAL SURVEY PROFESSIONAL PAPER 199 PLATE 9 PELECYPODS. GEOLOGICAL SURVEY PROFESSIONAL PAPER 199 PLATE 10 25 -.. J'KLECYPODS. PLATE 10 FIGURES 1-2. Thracia maddelysensis Gardner, n. sp. (p. 44). 1. Exterior of holotype, a right valve (U. S. Nat. Mus. 325508); height 4.0 millimeters; width 5.0 millimeters. 2. Interior of holotype. FIGURE 3. Periploma (Cochlodesma) antiqua Conrad (p. 42). Interior of right valve of holotype and exterior of left valve; height 39.0+_ millimeters; width 52.5 +_ millimeters. (After Conrad.) FIGURE 4. Thracia conradi Couthouy (p. 43). Exterior of left valve and overtopping margin of right; height 74.0 millimeters; width 90.0 ± millimeters. (After Gould, 1870, and Ball, 1889.) FIGURES 5-10. Thracia transversa H. C. Lea (p. 43). 5. Interior of right valve (Acad. Nat. Sci. Philadelphia 1585); height 1.8+ millimeters; width 2.6± millimeters. 6. Interior of right valve (U. S. Nat. Mus. 325509); height 4.8± millimeters; width 7.3 millimeters. 7. Exterior of same right valve. 8. Interior of left valve (U. S. Nat. Mus. 325509); height 5.1± millimeters; width 7.9 millimeters. 9. Exterior of same left valve. 10. Interior of right vplve (Acad. Nat. Sci. Philadelphia 1585); height 1.8± millimeters; width 2.6± millimeters. FIGURE 11. Verticordia (Trigonulina) chowanensis Gardner, n. sp. (p. 51). Interior of holotype, a right valve (U. S. Nat. Mus. 325507); height 5.1 millimeters; width 5.6 millimeters. FIGURES 12-13. Verticordia (Trigonulina) rogersi Gardner, n. sp. (p. 50). 12. Interior of holotype, a right valve (U. S. Nat. Mus. 325506); height 2.5 millimeters; width 2.8 millimeters. 13. Exterior of right valve of holotype. FIGURE 14. Verticordia (Trigonulina) emmonsii Conrad (p. 50). Exterior of right valve (U. S. Nat. Mus. 145332); height 6.0 milli meters; width 6.8 millimeters. FIGURE 15. Verticordia (Trigonulina) chowanensis Gardner, n. sp. (p. 51). Exterior of holotype shown in figure 11. FIGURE 16. Pandora (Kennerlia) arenosa Conrad (p. 45). Interior of left valve of topotype (U. S. Nat. Mus. 325505); height 8.0 millimeters; width 14.5 millimeters. FIGURES 17-18. Pandora (Clidiophora) crassidens Conrad (p. 46). 17. Interior of right valve from Cove Point, St. Marys River, Md., slightly enlarged. (After Glenn.) 18. Exterior of left valve from Cove Point, St. Marys River, Md., slightly enlarged. (After Glenn.) FIGURES 19-20. Pandora (Kennerlia) arenosa Conrad (p. 45). 19. Exterior of topotype (U. S. Nat. Mus. 325505), a right valve, the margin of the slightly larger left valve visible dorsally and ventrally; height of double valves 8.5 millimeters; width 16.6 millimeters. 20. Exterior of double valves from left. FIGURE 21. Pandora (Kennerlia) dalli Gardner, n. sp. (p. 45). Interior of holotype, a left valve (U. S. Nat. Mus. 325503); height 11.1 millimeters; width 19.8 millimeters. FIGURES 22-23. Pandora (Kennerlia) naviculoides Gardner, n. sp. (p. 46). 22. Interior of holotype, a left valve (U. S. Nat. Mus. 325504); height 8.9 millimeters; width 16.6 millimeters. 23. Exterior of holotype. FIGURE 24. Pandora (Kennerlia) dalli Gardner, n. sp. (p. 45). Exterior of holotype. FIGURE 25. Pandora (Clidiophora) crassidens majorina Gardner, n. subsp. (p. 47). Interior of paratype, a left valve (U. S. Xat. Mus. 325500); height 25.0± millimeters; width 35.0± millimeters. P'IGURE 26. Pandora (Kennerlia) dalli Gardner, n. sp. (p. 45). Interior of paratype (U. S. Nat. Mus. 325503); height 10.2 millimeters; width 18.8 millimeters. FIGURE 27. Pandora (Clidiophora) luomeyi Gardner and Aldrich (p. 48). Exterior of holotype, a left valve (U. S. Nat. Mus. 325502); height 9.5 millimeters; width 21.0 millimeters; convexity 2.0 millimeters. FIGURE 28. Pandora (Clidiophora} crassidens majorina Gardner, n. subsp. (p. 47). Exterior of holotype, a left value (U. S. Nat. Mus. 325501); height 37.8 millimeters; width 59.6 millimeters. 155 PLATE 11 FIGURE 1. Dosinia (Dosinidia) elegans Conrad (p. 122). Exterior of right valve (U. S. Nat. Mus. 497065) from Shell Creek, De Soto County, Fla.; height 61.0 millimeters; width 68.0 millimeters. FIGURES 2-3. Pandora (Clidiophora) prodromes Gardner and Aldrich (p. 48). Holotype, the two valves of a single individual (U. S. Nat. Mus. 325499) from Yorktown, Va.; height 21.0 millimeters; width 33.0 millimeters. 2. Exterior of left valve. (After Gardner and Aldrich.) 3. Interior of right valve. (After Gardner and Aldrich.) FIGURE 4. Dosinia (Dosinidia) acetabulum Conrad (p. 120). Exterior of right valve and hinge of left valve of holotype. (After Conrad.) FIGURE 5. Isocardia fraterna Carolina Ball (p. 67). Exterior of specimen, a right valve (U. S. Nat. Mus. 325558) from Delaware, Nottoway River, Va.; height 71.0 millimeters; width 73.0 millimeters; semidiameter 25.0 millimeters. FIGURE 6. Plica'ula marginata Say (p. 40). Interior of right valve from the Darlington district, S. C.; height 34.0± millimeters; width 30.0 ± millimeters. (After Tuomey and Holmes.) FIGUP.E 7. Pandora (Clidiophora) trilineata Say (p. 49). Exterior of left valve (U. S. Nat. Mus. 61028), Recent in Tampa Bay, Fla.; height 8.0 millimeters; width 20.0 millimeters; diameter 2.0 millimeters. (After Dall.) FIGURE 8. Plicatula marginata Say (p. 40). Interior of left valve from the Darlington district, S. C.; height 34.0± millimeters; width 30.0 millimeters. (After Tuomey and Holmes.) FIGURES 9-10. Pandora (Clidiophora) tuomeyi Gardner and Aldrich (p. 48). 9. Interior of holotype, a left valve (U. S. Nat. Mus. 325502) from Walkers Bluff, Bladen County, N. C.; height 9.5 milli meters: width 21.0 millimeters. (After Gardner and Aldrich.) 10. Interior of paratype, a right valve (U. S. Nat. Mus. 325502) from Walkers Bluff, Bladen County, N. C.; height 11.0 milli meters. (After Gardner and Aldrich.) FIGURES 11-12. Pandora (Clidiophora) prodromes Gardner and Aldrich (p. 48). 11. Interior of left valve of holotype shown in figure 2. (After Gardner and Aldrich.) 12. Exterior of right valve of holotype shown in figure 3. (After Gardner and Aldrich.) FIGURES 13—14. Plicatula marginata Say (p. 40). 13. Ventral margin of paired valves from Darlington district, S. C. (After Tuomey and Holmes.) 14. Exterior of left (?) valve from the Darlington district, S. C.; height 29.0 ± millimeters; width 33.0± millimeters. (After Tuomey and Holmes.) FIGURE 15. Isocardia fraterna Say (p. 67). Exterior of right valve and hinge of right valve. (After Say.) 156 GEOLOGICAL SURVEY PROFESSIONAL PAPEE 199 PLATE 11 12 PELECYPODS. GEOLOGICAL SURVEY - PROFESSIONAL PAPER 199 PLATE 12 41 PLATE 12 FIGURES 1-4. Astarte symmetrica Conrad (p. 51). Topotvpes, a right and a left valve of different individuals (U. S. Nat. Mus. 325516) from Yorktowri, Va. 1. Exterior of right valve; height 16.9 millimeters; width 17.7 millimeters. 2. Interior of left valve; height 17.0 millimeters; width 17.5 millimeters. 3. Interior of right valve shown in figure 1. 4. Exterior of left valve shown in figure 2. FIGURES 5-8. Astarte exaltata Conrad (p. 52). A right and a left valve of different individuals (U. S. Nat. Mus. 325519) from the mouth of Baileys Creek, James River, Va. 5. Interior of left valve; height 16.0 millimeters; width 17.0 millimeters. 6. Exterior of left valve shown in figure 5. 7. Exterior of right valve; height 19.0 millimeters; width 18.8 millimeters. 8. Interior of right valve shown in figure 7. FIGURES 9-10. Astarte roanokensis Gardner, n. sp. (p. 53). Two cotypes, a right and a left valve of different individuals (U. S. Nat. Mus. 325523) from Halifax, N. C. 9. Interior of left cotype; height 24.2 millimeters; width 23.9 millimeters. 10. Exterior of right cotype; height 24.4 millimeters; width 23.9 millimeters. FIGURES 11-12. Astarte hertfordensis Gardner, n. sp. (p. 53). Holotype, the right and left valves of a single individual (U. 8. Nat. 325526) from Murfreesboro, Hertford County, N. ~C. 11. Interior of left valve of holotype; height 23.0 millimeters; width 25.7 millimeters. 12. Exterior of right valve of holotype. FIGURES 13-14. Astarte arata Conrad (p. 55). 13. Exterior of right valve (U. S. Nat. Mus. 325517) from Halifax, N. C., height 21.5 millimeters; width 21.0 millimeters. 14. Exterior of left valve (U. S. Nat. Mus. 325517) from Halifax, N. C.; height 20.0 millimeters; width 21.0 millimeters. FIGURE 15. Astarte coheni Conrad (p. 53). Exterior of right valve; height 18.0± millimeters; width 18.5± millimeters. (After Conrad.) FIGURES 16-17. Astarte stephensoni Gardner, ri. sp. (p. 54). Holotype, a left valve (U. S. Nat. Mus. 325528) from Halifax, N. C.; height 22.7 millimeters; width 24.2 millimeters; convexity 6.3 millimeters. 16. Exterior of holotype. 17. Interior of holotype. FIGURE 18. Astarte hertfordensis meherrinensis Gardner, n. subsp. (p. 54). Exterior of holotype, a right valve (U. S. Nat. Mus. 325531); height 23.0 millimeters; width 24.8 millimeters. FIGURES 19-20. Astarte (Ashtarotha) rappahannockensis Gardner, n. p. (p. 56). Holotype, aright valve (U. S. Nat. Mus. 325527) from Urbanna, Va.; height 25.8 millimeters; width 28.6 millimeters. 19. Exterior of holotype. 20. Interior of holotype. FIGURE 21. Astarte hertfordensis Gardner, n. sp. (p. 53). Holotype (U. S. Nat. Mus. 325526) from Murfreesboro, N. C. Double valves viewed from the front; diameter 14.4 millimeters. FIGURE 22. Astarte (Ashtarotha) griftonensis Gardner, ri. sp. (p. 57). Exterior of holotype, a left valve (U. S. Nat. Mus. 325524) from 2 miles east of Grifton, Pitt County, N. C.; height 23.8 millimeters; width 27.0 millimeters. FIGURES 23-24. Astarte berryi Gardner, n. sp. (p. 56). Holotype, a left valve (U. S. Nat. Mus. 325533) from 2J4 miles northwest of Chocowinity, Beaufort County, N. C.; height 25.0 millimeters; width 27.2 millimeters. 23. Interior of holotype. 24. Exterior of holotype. FIGURE 25. Astarte (Ashtarotha) undulata Say (p. 57). Exterior of right valve (U. S. Nat. Mus. 325521) from 1% miles northeast of Chocowinity, N. C.; height 25.0 millimeters; width 28.5 millimeters. FIGURES 26-27. Astarte (Ashtarotha) undulata vaginulata Dall (p. 58). Lectotype, a right valve (U. S. Nat. Mus. 146121) from Grove Wharf, James River, Va.; height 22.4 millimeters; width 27.5 millimeters. 26. Exterior of lectotype. 27. Interior of lectotype. FIGURE 28. Astarte (Ashtarotha) griftonensis Gardner, ri. sp. (p. 57). Interior of holotype shown in figure 22. FIGURES 29-30. Astarte (Ashtarotha) undulata deltoidea Gardner, n. subsp. (p. 59). Holotype, a right valve (U. S. Nat. Mus. 325525) from 7 to 7}£ miles below Zuni, Isle of Wight County, Va.; height 23.5 millimeters; width 24.7 millimeters. 29. Interior of holotype. 30. Exterior of holotype. FIGURE 31. Astarte (Ashtarotha) undulata Say (p. 57). Exterior of left valve (U. S. Nat. Mus. 325520) from Murfreesboro, N. C.; height 20.8 millimeters; width 24.0 millimeters. FIGURES 32-34. Astarte (Ashtarotha) concentrica Conrad (p. 59). Figured specimens (U. S. Nat. Mus. 325518) from Colerairi Land ing, Chowan River, N. C. 32. Interior of right valve; height 21.2 millimeters; width 25.0 millimeters. 33. Exterior of right valve shown in figure 32. 34. Interior of left valve; height 22.3 millimeters: width 28.0 millimeters. FIGURES 35-36. Astarte (Ashtarotha) undulata deltoidea Gardner, ri. subsp. (p. 59). Paratype, a right valve (U. S. Nat. Mus. 325532) from Zuni, Isle of Wight County, Va.; height 22.5 millimeters; width 19.0±millimeters. 35. Interior of paratype. 36. Exterior of paratype. FIGURE 37. Astarte (Ashtarotha) concentrica conradi Gardner, n. subsp. (p. 60). Interior of cotype, a right valve (U. S. Nat. Mus. 325530) from 4 to 5 miles below Lumberton, Robeson County, N. C.; height 15.7millimeters; width 19.0 millimeters. FIGURES 38-39. Astarte (Ashtarotha) concentrica bella Conrad (p. 60). Left valve (U. S. Nat. Mus. 325522) from Lieutenant Run, Petersburg, Va.; height 25.7 millimeters; width 29.0 millimeters. 38. Interior of left valve. 39. Exterior of left valve. FIGURE 40. Astarte (Ashtarotha) concentrica Conrad (p. 59). Exterior of left valve shown in figure 34. FIGURE 41. Astarte (Ashtarotha) concentrica conradi Gardner, n. subsp. (p. 60). Exterior of cotype, a left valve (U. S. Nat. Mus. 325530) from 4 to 5 miles below Lumberton, Robeson County. N. C.; height 16.8 millimeters; width 21.3 millimeters. 157 PLATE 13 FIGURES 1-4. Glans (Pleuromeris) tridentata decemcostata Conrad (p. 71). Double valves arid the right and left valves of other individuals (U. S. Nat. Mus. 325572) from 2 miles below Lumberton, Robeson County, N. C. 1. Exterior of double valves viewed from left; height 6.8 millimeters; width 7.8 millimeters. 2. Interior of right valve; height 6.8 millimeters; width 8.0 millimeters. 3. Interior of left valve; height 6.7 millimeters; width 7.7 millimeters. 4. Double valves viewed from front; diameter 5.2 millimeters. FIGURE 5. Pseudochama corticosa (Conrad) (p. 89). Double valves viewed from left. (After Tuomey and Holmes.) FIGURES 6-9. Glans (Pteromeris) perplana (Conrad) (p. 72). Right arid left valves of different individuals (U. S. Nat. Mus. 325512) from Neills Eddy Landing, Cape Fear River, N. C. 6. Exterior of left valve; height 8.0 millimeters; width 7.8 millimeters. 7. Interior of left valve shown in figure 6. 8. Interior of right valve; height 7.5 millimeters; width 7.9 millimeters. 9. Exterior of right valve shown in'figure 8. FIGURES 10-11. Crassinella dupliniana Dall (p. 64). Holotype, double valves (U. S. Nat. Mus. 114922) from Natural Well, Duplin County, N. C.; height 3.1 millimeters; width 3.2 millimeters. 10. Exterior of left valve. (After Dall.) 11. Interior of right valve. (After Dall.) FIGURES 12-15. Chama striata Emmons (p. 88). Right and left valves of different individuals (U. S. Nat. Mus. 325541) from Neills Eddy Landing, Cape Fear River, N. C. 12. Exterior of left valve; height 24.0 millimeters; width 24.0 millimeters. 13. Interior of right valve; height 17.0 millimeters; width 18.5 millimeters. 14. Exterior of right valve shown in figure 13. 15. Interior of left valve shown in figure 12. FIGURE 16. Pseudochama corticosa (Conrad) (p. 89). Interior of right valve. (After Tuomey and Holmes.) FIGURE 17. Phacoides (Cardiolucina) postalveatus Gardner, n. sp. (p. 77). Exterior of holotype, a left valve (U. S. Nat. Mus. 325539) from Yorktown, Va.; height 3.3 millimeters; width 3.4 millimeters. FIGURE 18. Crassinella nansemondensis Gardner, n. sp. (p. 64). Interior of paratype (U. S. Nat. Mus. 325515), from \% miles southeast of Reids Ferry, Nansemond County, Va.; height 2.7 millimeters; width 3.1 millimeters. FIGURES 19-22. Glans (Pteromeris) perplana abbreviate (Conrad) (p. 72). A right and a left valve (U. S. Nat. Mus. 325513) from Magnolia, N. C. 19. Interior of right valve; height 5.3 millimeters; width 5.0 millimeters. 20. Exterior of right valve. 21. Exterior of left valve; height 3.1 millimeters; width 3.2 millimeters. 22. Interior of left valve. FIGURES 23-24. Phacoides (Lucinisca) cribrarius (Say) (p. 77). A left valve (U. S. Nat. Mus. 325535) from Yorktown, Va.; height 10.0 millimeters; width 10.6 millimeters. 23. Interior of left valve, X 2. 24. Exterior of left valve, X 2. FIGURES 25-26. Phacoides (Cardiolucina) trisulcatus multistriatus (Conrad) (p. 76). A left valve (U. S. Nat. Mus. 325538) from city rock quarry, Wilmington, N. C.; height 5.8 millimeters; width 6.3 millimeters. 25. Interior of left valve. 26. Exterior of left valve. FIGURE 27. Crassinella nansemondensis Gardner, n. sp. (p. 64). Interior of holotype (U. S. Nat. Mus. 325514) half a mile below the Suffolk dam, Nansemond County, Va.; height 3.3 millimeters; width 3.5 millimeters. FIGURE 28. Pseudochama corticosa (Conrad) (p. 89). Profile of double valves from front. (After Tuomey and Holmes.) FIGURES 29-30. Phacoides (Lucinisca) cribrarius (Say) (p. 77). A right valve (U. S. Nat. Mus. 525536) fiom 5 miles northeast of Smithfield, Va.; height 12.8 millimeters; width 12.9 millimeters. 29. Exterior of right valve, X 2. 30. Interior of right valve, X 2. FIGURES 31-32. Ctena microimbricata Gardner, n. sp. (p. 75). Holotype, a right valve (U. S. Nat. Mus. 325540) from Natural Well, Duplin County, N. C.; height 9.8 millimeters; width 11.2 millimeters. 31. Detail of sculpture of holotype, X 10. 32. Exterior of holotype. FIGURE 33. Ctena speciosa (Rogers arid Rogers) (p. 75). Exterior of right valve (U. S. Nat. Mus. 145067) from Bellefield, York River, Va.; height 14.1 millimeters; width 16.4 millimeters. FIGURES 34-37. Phacoides (Parvilucina) multilineatus (Tuomey and Holmes) Dall (p. 78). A right and a left valve of different indi viduals (U. S. Nat. Mus. 325537) from Neills Eddy Landing, Cape Fear River, N. C. 34. Interior of left valve; height 7.5 millimeters; width 7.3 millimeters. 35. Interior of right valve; height 6.5 millimeters; width 6.6 millimeters. 36. Exterior of right valve shown in figure 35. 37. Exterior of left valve shown in figure 34. 158 GEOLOGICAL SURVEY PROFESSIONAL PAPER 199 PLATE 13 34 PELECYPODS. GEOLOGICAL SURVEY PROFESSIONAL TAPER 199 PLATE 14 47 PELECYPODS FIGURE 1. Erycina carolinensis elongata Gardner, n. subsp. (p. 82). Interior of holotype, a left valve (U. S. Nat. Mus. 325542) from Neills Eddy Landing. Cape Fear River, N. C.; height 7.5 millimeters; width 12.7 millimeters. FIGURES 2-5. Bornia triangula Dall (p. 82). 2. Hinge of holotype, a right valve (Acad. Nat. Sci. Philadelphia 1597) from Petersburg, Va., X 12. 3. Interior of paratype, a left valve (U. S. Nat. Mus. 325547) from Yorktowri, York River, Va.; height 3.0 millimeters; width 3.3 millimeters. 4. Interior of holotype, a right valve (Acad. Nat. Sci. Philadelphia 1597) from Petersburg, Va., X 4. 5. Exterior of holotype shown in figure 4, X 4. FIGURES 6-7. Sportella gibberosa Gardner, n. sp. (p. 84). Cotypes, a right and a left valve of different individuals (U. S. Nat. Mus. 325544) from Walkers Bluff, Cape Fear River, Bladen County, N. C. 6. Exterior of right valve; height 3.2 millimeters; width 4.5 millimeters. 7. Interior of left valve; height 3.3 millimeters; width 4.5 millimeters. FIGURE 8. Mysella stantoni (Dall) (p. 86). Interior of holotype, a right valve (U. 8. Nat. Mus. 115102) from Natural Well, Dupliii County, N. C.; height 2.2 millimeters; width 3.6 millimeters. (After Dall.) FIGURE 9. Erycina carolinensis Dall (p. 81). Interior of lectotype, a right valve (U. S. Nat. Mus. 115096) from Natural Well, Duplin County. -N. C.; height 5.7 millimeters; width 9.0 millimeters. (After Dall.) FIGURE 10. Bornia triangula Dall (p. 82). Interior of paratype, a right valve (U. S. Nat. Mus. 325547) from Yorktown, York County, Va.; height 3.0 millimeters; width 3.3 millimeters. FIGURES 11-12. Bornia bladenensis Gardner, n. sp. (p. 83). Holotype, a right valve (U. S. Nat. Mus. 325546) from Walkers Bluff, Bladen County, N. C.; height 3.9 millimeters; width 4.75 millimeters. 11. Interior of holotype. 12. Exterior of holotype. FIGURES 13-14. Mysella majorina Gardner, n. sp. (p. 86). Two cotypes, the right arid left valves of different individuals (U. S. Nat. Mus. 325549) from Neills Eddy Landing, Cape Fear River, N. C. 13. Interior of right valve; height 2.7 millimeters; width 4.0 millimeters. 14. Exterior of left valve; height 2.7 millimeters; width 4.1 millimeters. FIGURES 15-16. Mysella velaini Gardner, n. sp. (p. 86). Holotype, a right valve (U. S. Nat. Mus. 325548) from Walkers Bluff, Bladen County, N. C.; height 3.0 millimeters; width 4.2 millimeters. 15. Exterior of holotype. 16. Interior of holotype. FIGURES 17-18. Mysella bladenensis Gardner, n. sp. (p. 86). Holotype, a right valve (U. S. Nat. Mus. 325550) from Walkers Bluff, Bladen County, N. C.; height 3.0 millimeters; width 4.5 millimeters. 17. Interior of holotype. 18. Exterior of holotype. FIGURES 19-20. Sportella constricta (Conrad) (p. 83). A right and a left valve of different individuals (U. S. Nat. Mus. 155730) from the Caloosahatchee River, Fla. 19. Interior of right valve; height 6.0 millimeters; width 9.0 millimeters. 20. Interior of left valve; height 5.7 millimeters; width 9.0 millimeters. FIGURES 21-22. Sportella waccamawensis Gardner, n. sp. (p. 85). Holotype, a right valve (U. S. Nat. Mus. 325545) from Walkers Bluff, Cape Fear River, N. C.; height 8.2 millimeters; width 13.5 millimeters. 21. Exterior of holotype. 22. Interior of holotype. FIGURE 23. Aligena rhomboidea Gardner, n. sp. (p. 87). Interior of holotype, a left valve (U. S. Nat. Mus. 325552) from Natural Well, Duplin County, N. C.; height 7.8 millimeters; width 8.8 millimeters. FIGURES 24-26. Aligena laevis H. C. Lea (p. 87). A right valve (Acad. Nat. Sci. Philadelphia 1582). 24. Interior of right valve, X 4. 25. Exterior of right valve, X 4. 26. Hinge of right valve, X 12. FIGURES 27-29. Sportella compressa (H. C. Lea) (p. 85). A left valve (Acad. Nat. Sci. Philadelphia 1596). 27. Interior of left valve, X 4. 28. Exterior of left valve, X 4. 29. Hinge of left valve, X 12. FIGURE 30. Sportella calpix Gardner, n. sp. (p. 84). Interior of holotype, a right valve (U. S. Nat. Mus. 325543) from \% miles below Tar Ferry, Hertford County, N. C.; height 10.2 millimeters; width 14.7 millimeters. FIGURES 31-32. Aligena chowanensis Gardner, n. sp. (p. 87). Holotype, a right valve (U. S. Nat. Mus. 325551) from Colerain Landing, Bertie County, N. C.; height 4.7 millimeters; width 4.7 millimeters. 31. Exterior of holotype. 32. Interior of holotype. FIGURES 33-36. Incertae sedis. (p. 74). Two valves of a single individual (U. S. Nat. Mus. 325557) from Suffolk, Va.; height 1.7 millimeters; width 1.8 millimeters. 33. Interior of left valve, X 12. 34. Exterior of left valve, X 5. 35. Exterior of right valve, X 5. 36. Interior of right valve, X 12. FIGURES 37-38. Diplodonta leana eoleana Gardner, n. subsp. (p. 80). Holotype, a right valve (U. S. Nat. Mus. 325556) from Urbanna, Rappahannock River, Va.; height 18.0 millimeters; width 19.1 millimeters. 37. Exterior of right valve. 38. Interior of right valve. FIGURE 39. Sportella calpix Gardner, n. sp. (p. 84). Exterior of holotype shown in figure 30. FIGURES 40-41. Diplodonta caloosaensis Dall. (p. 80). Figured specimen, a left valve (U. S. Nat. Mus. 325553) Neills Eddy Landing, Cape Fear River, N. C.; height 20.6 millimeters; width 22.3 millimeters; convexity 6.5 millimeters. 40. Profile of figured specimen. 41. Exterior of figured specimen. FIGURES 42-43. Diplodonta (Phlyctiderma) soror (C. B. Adams) (p. 81). A left valve (U. S. Nat. Mus. 325555) from Natural Well, N. C.; height 12.3 millimeters; width 12.7 millimeters. 42. Exterior of left valve. 43. Interior of left valve. FIGURE 44. Cooperella carpenteri Dall (p. 119). Interior of holotype of "Diplodonta yorkensis" Dall, a left valve (U. S. Nat. Mus. 144548) from Yorktown, Va.; height 8.7 millimeters; width 10.9 millimeters. (After Dall.) FIGURE 45. Crassinella lunulata harrisi Gardner, ri. subsp. (p. 63). Exterior of left valve of holotype (U. S. Nat. Mus. 1630) from Yorktown, Va.; height 5.1 millimeters; width 5.2 millimeters. (After Dall.) FIGURE 46. Erycinella ovalis Conrad (p. 73). Drawings of hinge. (After Dall.) FIGURE 47. Cooperella carpenteri Dall. (p. 119). Interior of right valve (U. S.-Nat. Mus. 155714) from Petersburg, Va., X3 (After Dall.) 159 PLATE 15 FIGURES 1-2. Euloxa latisulcata Conrad (p. 65). Left valve (U. S. Nat. Mus. 214407) from the lower layer at old Claremont Wharf, James River, Va.; height 20.0 millimeters; width 23.4 millimeters. 1. Exterior of left valve X 2. 2. Interior of left valve, X 2. FIGURES 3-4. Ccrbicula densata (Conrad) (p. 65). Right valve (U. S. Nat. Mus. 325534) from Wilmington, N. C.; height 29.0 milli meters; width 31.8 millimeters. 3. Interior of right valve. 4. Exterior of right valve. FIGURES 5-6. Carditamera arata verdevilla Gardner n. subsp. (p. 69). Holotype, a right valve (U. S. Nat. Mus. 325511) from 8 to 9 miles south of Greenville, Pitt County, N. C.; height 22.3 millimeters; width 46.0 millimeters; convexity 10.0 millimeters. 5. Exterior of holotype. 6. Interior of holotype. FIGURES 7-8. Corbicula densata (Conrad) (p. 65). Left valve (U. S. Nat. Mus. 325534) from Wilmington, N. C.; height 26.3 milli meters; width 29.3 millimeters; convexity 9.5 millimeters. 7. Interior of left valve. 8. Exterior of left valve. FIGURES 9-10. Carditamera columbiana Gardner, n. sp. (p. 69). Holotype, a right valve (U. S. Nat. Mus. 325510) from Neills Eddy Landing, Cape Fear River, N. C.; height 27.5 millimeters; width 37.0 millimeters. 9. Exterior of holotype. 10. Interior of holotype. FIGURES 11-12. Laevicardium sublineatum Conrad (p. 94). Left valve (U. S. Nat. Mus. 325559) from Neills Eddy Landing, Cape Fear River, N. C.; height 26.0 millimeters; width 28.5 millimeters. 11. Interior view of left valve. 12. Exterior of left valve. FIGURES 13-14. Petricola (Rupellaria) grinnelli Olsson (p. 117). Right valve (U. S. Nat. Mus. 325562) from Palmyra Bluff, Halifax County, N. C.; height 13.5 millimeters; width 23.5 millimeters. 13. Exterior of right valve, X 2. 14. Interior of right valve, X 2. FIGURES 15-16. Laevicardium sublineatum Conrad (p. 94). (U. S. Nat. Mus. 325559) from Neills Eddy Landing, Cape Fear River, N. C.; height 28.7 millimeters; width 29.0 millimeters. 15. Interior of right valve. 16. Exterior of right valve. FIGURE 17. Pleiorytis centenaria Conrad? (p. 119). Exterior of holotype of Petricola (Rupellaria) harrisii Dall (U. S. Nat. Mus. 145020) from Bellefield, York River, Va.; height 20.5 millimeters; width 22.5 millimeters. (After Dall.) FIGURE 18. Petricola (Rupellaria) grinnelli Olsson (p. 117). Interior of left valve (U. S. Nat. Mus. 325561) from Wilmington, N. C.; height 16.0± millimeters; width 24.8 millimeters, X 2. FIGURES 19-20. Trachycardium isocardia (Linnaeus) (p. 91). Paired (U. S. Nat. Mus. 57147), Recent from the coast of Florida; height 47.5 millimeters; width 37.5 millimeters. 19. Exterior of left valve. 20. Interior of right valve. FIGURE 21. Trachycardium muricatum (Linnaeus) (p. 92). Exterior of left valve (Wagner Free Inst. Sci.) from Cape Fear River, N. C.; height 80 millimeters; width 80 millimeters. 160 GEOLOGICAL SURVEY PROFESSIONAL PAPER 199 PLATE 15 19 PELECYPODS. GEOLOGICAL SURVEY PROFESSIONAL PAPER 199 PLATE 16 PELECYPODS PLATE 16 FIGUEES 1-2. Isocardia fraterna glenni Gardner, n. subsp. (p. 68). 1. Interior of paratype, a left valve (Maryland Geol. Survey, Baltimore, Md., collection) from Jones Wharf, St. Marys County, Md ; height 53.3 millimeters; width 67.1 millimeters. (After Glenn.) 2. Exterior of holotype, a right valve (Maryland Geol. Survey, Baltimore, Md., collection)-from Jones Wharf, St. Marys County, Md.; height 59.0 millimeters; width 73.0 millimeters. (After Glenn.) FIGURE 3. Cerastoderma virginianum (Conrad) (p. 91). Exterior of holotype, a right valve from the. James River near Smithfield, Va.; "length about 4 inches." (After Conrad.) FIGURE 4. Cerastoderma laqueatum (Conrad) (p. 90). Exterior of left valve (Maryland Geol. Survey, Baltimore, Md., collection from Jones Wharf, St. Marys County, Md. X %• (After Glenn.) FIGURE 5. Cerastoderma acutilaqueatum (Conrad) (p. 90). Exterior of holotype, a right valve from Yorktown, Va.; "length 4 inches; height 4^ inches." (After Conrad.) 161 401033-43——13 PLATE IT FIGURE 1. Tellina egena Conrad (p. 98). Exterior of holotype, a right valve from the James River near Smithfield, Va. X 1. (After Conrad.) FIGURES 2-3. Tellina (Moerella?) calpix Gardner, n. sp. (p. 98). Holotype, a right valve (U. S. Nat. Mus. 325595) from 8 to 9 miles south of Greenville, Pitt County, N. C.; height 8.0 millimeters; width 11.5 millimeters. 2. Interior of holotype, X 4. 3. Exterior of holotype, X 4. FIGURE 4. Tellina (Moerella) sayi (Deshayes ms.) Ball (p. 95). Exterior of left valve (U. S. Nat. Mus. 128444), Recent off the coast of South Carolina; height 10.0 millimeters; width 17.4 millimeters. FIGURE 5. Tellina (Moerella) macilenta Ball (p. 97). Exterior of holotype, a right valve (U. S. Nat. Mus. 115045) from Natural Well, Duplin County, N. C.; height 10.8 millimeters; width 16.5 millimeters. (After Ball.) FIGURES 6-7. Tellina (Moerella?) verdevilla Gardner, n. sp. (p. 97). 6. Interior of paratype, a right valve (U. S. Nat. Mus. 325596) from 6 miles below Greenville, Pitt County, N. C.; height 15.0 millimeters; width 21.0 millimeters. 7. Exterior of holotype, a right valve (U. S. Nat. Mus. 325596) from 6 miles below Greenville, Pitt County, N. C.; height 13.8 millimeters; width 20.0 millimeters. FIGURE 8. Macoma cookei Gardner, n. sp. (p. 100). Interior of holotype, a right valve (U. S. Nat. Mus. 325592) from Yorktown; York River, Va.; height 28.0 millimeters: width 34.3 millimeters. FIGURES 9-10. Macoma virginiana (Conrad) (p. 98). A right valve (U. S. Nat. Mus. 325594) from 1 mile northeast of Suffolk, Va., height 12.3 millimeters; width 19.8 millimeters. 9. Exterior, X 2. 10. Interior, X 2. FIGURE 11. Macoma cookei Gardner, n. sp. (p. 100). Exterior of holotype. FIGURES 12-15. Abra aequalis (Say) (p. 104). A right and a left valve of different individuals (U. S. Nat. Mus. 325585) from half to three-quarters of a mile above Edenhouse Point, Chowan River, N. C. 12. Exterior of left valve; height 10.5 millimeters; width 12.0 millimeters. 13. Interior of left valve shown in figure 12. 14. Interior of right valve; height 10.6 millimeters; width 12.0 millimeters. 15. Exterior of right valve shown in figure 14. FIGURES 16-17. Semele subovata alia Gardner n. subsp. (p. 101). Holotype, the right and left valves of a single individual (U. S. Nat. Mus. 325582) from 2 miles northeast of Lizzie, Greene County, N. C.; height 21.0 millimeters; width 26.3 mill imeters. 16. Interior of right valve of holotype, X 2. 17. Exterior of left valve of holotype, X 2. FIGURES 18-21. Semele (Semelina) nuculoides (Conrad) Dall (p. 102). The right and left valves of different individuals (U. S. Nat. Mus. 325581) from Neills Eddy Landing, Cape Fear River, N. C. 18. Exterior of left vialve; height 4.0 millimeters; width 5.6 millimeters. 19. Interior of left valve shown in figure 18. 20. Interior of right valve; height 3.8 millimeters; width 5.6 millimeters. 21. Exterior of right valve shown in figure 20. FIGURE 22. Macoma virginiana conradi Dall (p. 99). Exterior of holotype, a right valve (U.'S. Nat. Mus. 144475) from Yorktcwn, York River, Va.; height 14.0 millimeters; width 21.7 millimeters. (After Dall.) FIGURES 23-24. Abra subreflexa Conrad (p. 103). 23. Interior of right valve (U. S. Nat. Mus. 325584) from Colerain Landing, Chowan River, N. C.; height 5.6 millimeters; width 10.4 millimeters. 24. Exterior of right valve shown in figure 23. FIGURES 25-26. Abra aequalis deUoidea Gardner, n. subsp. (p. 104). Cotypes, a right and a left valve of different individuals (U. S. Nat. Mus. 325586) from 2 miles below Lumberton, Robeson County, N. C. 25. Interior of right valve; height 11.2 millimeters; width 11.4 millimeters. 26. Exterior of left valve; height 11.1 millimeters; width 11.9 millimeters. FIGURES 27-28. Semele bellastriata (Conrad) (p. 102). 27. Interior of right valve (U. S. Nat. Mus. 325583) from Neills Eddy Landing, Cape Fear River, N. C.; height 13.2 millimeters; width 18.3 millimeters. 28. Exterior of right valve shown in figure 27. FIGURE 29. Donax aequilibrata Dall (p. 106). Exterior of holotype, a right valve (U. S. Nat. Mus. 108450) from Mrs. Guion's marl pit, Cape Fear River, near Cronly, N. C.; height 8.5 millimeters; width 17.9 millimeters. (After Dall.) FIGURES 30-31. Abra subreflexa Conrad (p. 103). 30. Interior of left valve (U. S. Nat. Mus. 325584) from Colerain Landing, Chowan River, N. C.; height 9.0 millimeters; width 15.6 millimeters. 31. Exterior of left valve shown in figure 30. FIGURES 32-33. Semele bellastriata (Conrad) (p. 102). 32. Interior of left valve (U. S. Nat. Mus. 325583) from Neills Eddy Landing, Cape Fear River, N. C.; height 14.5 millimeters; width 19.0 millimeters. 33. Exterior of left valve shown in figure 32. 162 GEOLOGICAL SURVEY PROFESSIONAL PAPER 199 PLATE 17 29 31 32 PELECYPODS GEOLOGICAL SUEVET PKOFESSIONAL PAPER 199 PLATE 18 PLATE 18 FIGURE 1. Spisula (Mactromeris) bowlerensis Gardner, n. sp. (p. 112). Holotype, the right and left valves of a single individual (U. S. Nat. Mus. 498201) from 1% miles below Bowlers Wharf, Rappahannock River, Va.; height 53.0 millimeters; width 70.0 millimeters. Interior of left valve of holotype. FIGURES 2-4. Spisula (Hemimactra) rappahannockensis Gardner, n. sp. (p. 110). 2. Exterior of holotype, a right valve (U. S. Nat. Mus. 325601) from 1 to 2 miles below Bowlers Wharf, Rappahannock River, Va.; height 21.0 millimeters; width 31.5 millimeters. 3. Exterior of paratype, a left valve (U. S. Nat. Mus. 325600) from Union Mills, 1% miles south of Farnham, Richmond County, Va.; height 15.0 millimeters; width 23.0 millimeters. 4. Interior of holotype shown in figure 2. FIGURE 5. Spisula (Mactromeris) bowlerensis Gardner, n. sp. (p. 112). Exterior of right valve of holotype the left valve of which is shown in figure 1. FIGURE 6. Labiosa (Raeta) alta (Conrad) (p. 109). Hinge plate of left valve: a, anterior lamina; b, cardinal tooth with one arm pro jecting over the chondrophore; c, ligament scar with septum below it; /, anterior lamina. (After Ball.) FIGURE 7. Spisula (Hemimactra) rappahannockensis Gardner, n. sp. (p. 110). Hinge plate of a left valve (U. S. Nat. Mus. 325601) from 1 to 2 miles below Bowlers Wharf, Rappahannock River, Va., X 3. FIGURE 8. Mesodesma spatha Gardner, n. sp. (p. 115). Hinge of holotype, a right valve (U. S. Nat. Mus. 325591) from 1 mile north east of Suffolk, Va., X 10. FIGURES 9-11. Mactra (Mactrotoma) fragilis Gmelin (p. 109). 9. Hinge plate of left valve: a, Posterior lamina; b, ligamentary scar with septum below it; c, spur, roofin the pit; d, cardinal tooth with e, accessory lamella, and /, anterior lamina. (After Dall.) 10. Right valve from below, showing the profile of the hinge teeth: a, Anterior ventral lamina, and b, anterior dorsal lamina; c, accessory lamella of right cardinal tooth, d, anterior arm, and e, posterior arm of same; the space between the teeth a, c, d, e, and the edge of the chondrophore is the ventral sinus, that between a and b is the anterior sinus; /, septum between the ligament (attached to the shell at g) and the resilium; h and i, ventral and dorsal posterior laminae, respectively. (After Dall.) 11. Hinge plate of right valve: a, Anterior dorsal lamina; b, accessory lamella of right cardinal, c, anterior arm (i, posterior arm) of same; d, septum between the resilium and ligament; e, ligamentary scar; /, anterior ventral lamina. (After Dall.) FIGURE 12. Mesodesma spatha Gardner, n. sp. (p. 115). Interior of holotype, a right valve (U. S. Nat. Mus. 325591) from 1 mile northeast of Suffolk, Va.; height 6.4 millimeters; width 10.3 millimeters. FIGURE 13. Mactra (Mactrotoma) fragilis Gmelin (p. 109). Profile of hinge plate of left valve: a, Anterior lamina; b, accessory lamella; c, cardinal tooth; d, septum; e, posterior lamina. FIGURE 14. Mactra (Mactrotoma) fragilis precursor Gardner, n. subsp. (p. 109). Holotype, a left valve (U. S. Nat. Mus. 325593) from Neills Eddy Landing, Cape Fear River, N. C.; height 79.0 millimeters; width 121.0 millimeters. 163 PLATE 19 FIGUEES 1-2. Macrocallista reposta (Conrad) (p. 123). A left valve (U. S. Nat. Mus. 325575) from 2 miles below Lumberton, Robeson County, N, C.; height 50.0 millimeters; width 85.0 ± millimeters. 1. Interior of left valve. 2. Exterior of left valve. FiGtiKE 3. Macrocallista reposta (Conrad) (p. 123). Interior of right valve (U. S. Nat. Mus. 325577) from 4 to 5 miles below Lumber- ton, Robeson County, N. C.; height 42.5 millimeters; width 62.8 millimeters. FIGUKE 4. Chione (Chione) cortinaria (Rogers and Rogers) (p. 127). Exterior of left valve (U. S. Nat. Mus. 146126) from Grove Wharf, James River, Va.; height 23.5 millimeters; width 26.5 millimeters X 1}£. FIGURE 5. Macrocallista reposta (Conrad) (p. 123). Exterior of right valve shown in figure 3. FIGURE 6. Macrocallista (Coslacallista') emmonsi Gardner, n. sp. (p. 123). Interior of holotype, a left valve (U. S. Nat. Mus. 107834 from Natural Well(?), Duplin County, N. C.; height 43.0 millimeters; width 56.5 millimeters. FIGURES 7-8. Callocardia (Agriopoma) chioneformis Gardner, n. sp. (p. 126). 7. Paratype, a right valve (U. S. Nat. Mus. 325564) from Wilmington, N. C.; height 17.5 millimeters; width 20.5 millimeters X l>i 8. Holotype, a left valve (U. S. Nat. Mus. 325564), from Wilmington, N. C.; height 26.5 millimeters; width 31.0 millimeters. FIGURE 9. Macrocallista (Costacallista) emmonsi Gardner, n. sp. (p. 123). Exterior of holotype shown in figure 6. FIGURES 10-11. Chione (Chamelea) cialli Olsson (p. 129). Topotypes, a right and a left valve (U. S. Nat. Mus. 325529) from lower layer at Claremont Wharf, James River, Va. 10. Interior of right valve; height 20.0 millimeters; width 22.3 millimeters. 11. Exterior of left valve; height 19.5 millimeters; width 21.0 millimeters. FIGURES 12-13. Chione (Chione} grus (Holmes) (p. 128). A right and a left valve (U. S. Nat. Mus. 325565) from Neills Eddy Landing, Cape Fear River, N. C. 12. Exterior of right valve; height 6.8 millimeters; width 9.5 millimeters. 13. Exterior of left valve of another individual; height 5.0 millimeters; width 7.5 millimeters. FIGURE 14. Gemma magna insulcata Gardner, n. subsp. (p. 137). Exterior of paratype, a left valve (U. S. Nat. Mus. 325570) from Walkers Bluff, Cape Fear River, N. C.; height 3.4 millimeters; width 4.1 millimeters. FIGURES 15-17. Gemma magna virginiana Dall (p. 136). Cotypes, a right and a left valve of different individuals (U. S. Nat. Mus. 144633) from Yorktown, Va. 15. Interior of right cotype; height 3.4 millimeters: width 3.5 millimeters. 16. Exterior of right cotype shown in figure 15. 17. Interior of left cotype; height 3.7 millimeters; width 4.1 millimeters. FIGURE 18. Gemma magna virginiana Dall (p. 136). Interior of topotype, a left valve (U. S. Nat. Mus. 325571) from Yorktown, Va.; height 3.3 millimeters; width 3.6 millimeters. FIGURE 19. Gemma magna majorina Gardner, n. subsp. (p. 136). Exterior of right cotype (U. S. Nat. Mus. 325566) from 1 mile east of Lizzie, Greene County, N. C.; height 5.6 millimeters: width 6.6 millimeters. FIGURES 20-21. Chione (Chione) grus (Holmes) (p. 128). 20. Interior of right valve shown in figure 12. 21. Interior of left valve shown in figure 13. FIGURE 22. Gemma magna insulcata Gardner, n. subsp. (p. 137). Interior of holotype, a right valve (U. S. Nat. Mus. 325567) from Neills Eddy Landing, Cape Fear River, N. C.; height 4.5 millimeters; width 5.2 millimeters. FIGURES 23-24. Gemma cravenensis Gardner, n. sp. (p. 137). Holotype, the right and left valves of a single individual (U. S. Nat. Mus. 325569) from Rock Landing, Craven County, N. C.; height 3.7 millimeters; width 4.6 millimeters. 23. Interior of right valve, X 4. 24. Exterior of left valve, X 4. FIGURE 25-26. Gemma magna virginiana Dall (p. 136). 25. Interior of cotype, a left valve (U. S. Nat. Mus. 144633) from Yorktown, Va.; height 3.0 millimeters; width 3.2 millimeters. 26. Interior of cotype, aright valve (U. S. Nat. Mus. 144633) from Yorktown, Va.; height 3.2 millimeters; width3.3 millimeters. FIGURE 27. Gemma magna mojorina Gardner, n. subsp. (p. 136). Interior of left cotype (U. S. Nat. Mus. 325566) from 1 mile east of Lizzie, Greene County, N. C.; height 6.6 millimeters; width 7.3 millimeters. FIGURES 28-29. Callocardia (Agriopoma) castoriana Gardner, n. sp. (p. 126). Holotype, a right valve (U. S. Nat. Mus. 325563) from 1 mile north of Castoria, Greene County, N. C.; height 39.0 millimeters; width 49.0 millimeters; convexity 14.2 millimeters. 28. Profile of holotype from front. 29. Interior of holotype. FIGURE 30. Crassinella lunulata (Conrad) (p. 62). Exterior of a left valve (U. S. Nat. Mus. 6123) from Natural Well, Duplin County, N. C.; height 5.9 millimeters; width 6.7 millimeters. (After Dall.) FIGURES 31-32 Gemma verdevilla Gardner, n. sp. (p. 138). Holotype, the right and left valves of a single individual (U. S. Nat. Mus. 325568) from 8 to 9 miles southeast of Greenville, Pitt County, N. C.; height 2.6 millimeters; width 2.6 millimeters. 31. Interior of right valve, X 4. 32. Exterior of left valve, X 4. FIGURE 33. Callocardia (Agriopoma) sayana (Conrad) (p. 124). Interior of a left valve (U. S. Nat. Mus. 143732) from the Chop- tank River, a quarter to half a mile below Barkers Landing, Talbot County, Md.; height 40.0 millimeters; width 45.0 millimeters. (After Dall.) 164 GEOLOGICAL SURVEY PEOFESSIONAL PAPER 199 PLATE 19 33 PELECYPODS. GEOLOGICAL SURVEY PROFESSIONAL PAPEE 199 PLATE 20 PELECYPODS. PLATE 20 FIGURES 1-2. Venus (Mercenarid) campechiensis carolinensis Conrad (p. 132). A left valve (U. S. Nat. Mus. 325573) from Walkers Bluff, Cape Fear River, N. C.; height 119.0 millimeters; width 153.0 millimeters. 1. Interior of left valve, X 0.95. 2. Exterior of left valve, X 0.95. 165 PLATE 21 FIGURES 1-3. Venus (Mercenaries) berryi Gardner, n. sp. (p. 133). Holotype, the right and left valves of a single individual (U. S. Nat. Mus. 325574) from 2}£ to 3 miles below Bowlers Wharf, Va.; height 57.0 millimeters; width 62.5 millimeters; diameter 37.6 millimeters. 1. Interior of left valve. 2. Dorsal view of double valves. 3. Interior of right valve. FIGURES 4-6. Venus (Mercenaries) berryi Gardner, n. sp. (p. 133). 4. Exterior of adult paratype, a right valve (U. S. Nat. Mus. 325574) from 2}£ to 3 miles below Bowlers Wharf, Va.; figured to show fusing of concentric lamellae; height 46.5 millimeters; width 54.0 millimeters. 5. Exterior of adolescent paratype, a right valve (U. S. Nat. Mus. 325576) from 1 to 2 miles below Bowlers Wharf, Essex County, Va.; height 8.0 millimeters; width 8.5 millimeters. 6. Exterior of left valve of holotype shown in figure 1. FIGURES 7-8. Venus (Mercenaria) plena nucea Ball (p. 134). Holotype, a right valve (U. S. Nat. Mus. 163418) from Bellefield, York River, Va.; height 30.0 millimeters; width 33.0 millimeters. 7. Exterior of holotype. 8. Interior of holotype. FIGURE 9. Venus (Mercenaria) plena inflala Ball (p. 134). Exterior of holotype, a right valve (U. S. Nat. Mus. 163419) from Belle- field, York River, Va.; height 51.0 millimeters; width 60.0 millimeters. FIGURE 10. Venus (Mercenaria) mercenaria notata Say (p. 130). Exterior of left valve (U. S. Nat. Mus. 46867), Recent on the east coast of Florida; height 60.0 millimeters; width 76.0 millimeters. % FIGURE 11. Venus (Mercenaria) campechiensis tridacnoides (Lamarck) (p. 132). Profile of double valves from the Wagner Free Institute of Science of Philadelphia; diameter 100.0 millimeters. 166 GEOLOGICAL SURVEY PROFESSIONAL PAPER 199 PLATE 21 10 11 PELECYPODS. GEOLOGICAL SURVEY PKOFESSIONAL PAPER 169 PLATE 22 PLATE 22 FIGURES 1-4. Tagelus gibbus (Spengler) (p. 107). 1. Exterior of left valve from Wailes Bluff (near Cornfield Harbor), St. Marys County, Md. (After Clark.) 2. Exterior of right valve from Wailes Bluff (near Cornfield Harbor), St. Marys County, Md. (After Clark.) 3. Interior of left valve shown in figure 1. (After Clark.) 4. Interior of right valve shown in figure 2. (After Clark.) FIGURE 5. Tagelus gibbus carolinensis (Conrad) (p. 108). Exterior of left valve (U. S. Nat. Mus. 145293) from Wilmington, N. C.; height 23.0 millimeters; width 69 millimeters. FIGURES 6-7. Spisula (Hemimactra) similis (Say) (p. 111). A Recent shell is figured (U. S. Nat. Mus. 95569). 6. Interior of left valve X 1. 7. Exterior of right valve X 1. FIGURE 8. Mya arenaria Linnaeus (p. 138). Interior of left valve from Wailes Bluff (near Cornfield Harbor), St. Marys County Md., X 5/6. (After Clark.) FIGURE 9. Barnea (Scobinopholas) arcuata (Conrad) (p. 141). Exterior of right valve and hinge of left valve of holotype from Suf folk, Va. (After Conrad.) FIGURE 10. Spisula (Mactromeris) duplinensis Dall (p. 112). Interior of holotype, a right valve (U. S. Nat. Mus. 153784) from Natural Well, Duplin County, N. C.; height 42.0± millimeters; width 58.0± millimeters. (After Dall.) 167 PLATE 23 FIGURES 1-2. Donax fossor Say (p. 106). 1. Exterior of left valve (U. S. Nat. Mus. 325587) from 4 miles south of Elizabethtown, 1ST. C.; height 4.9 millimeters; width 9.0 millimeters. 2. Exterior of right valve (U. S. Nat. Mus. 325587) from 4 miles south of Elizabethtown, N. C.; height 3.3 millimeters; width 5.0 millimeters. FIGURES 3-4. Donax emmonsi preaeqmlibrata Gardner, n. subsp. (p. 105). Holotype, the righ! and left valves of a single individual (U. S. Nat. Mus. 325590) from 2 miles below Lumberton, Robeson County, N. C.; height 8.0 millimeters; width 14.4 millimeters. 3. Interior of left valve of holotype, X 3. 4. Exterior of right valve of holotype, X 3. FIGURE 5. Donax emmonsi Dall (p. 105). Exterior of holotype, a right valve (U. S. Nat. Mus. 108447) from Mrs. Guion's marl- pit near Cronly, Cape Fear River, N. C.; height 6.7 millimeters; width 10.2 millimeters. (After Dall.) FIGURES 6-7. Donax chuckatuckensis Gardner, n. sp. (p. 106). 6. Exterior of holotype, a left valve (U. S. Nat. Mus. 325589) from a quarter of a mile north of Chuckatuck, Nansemond County Va.; height 3.6 millimeters; width 6.2 millimeters. 7. Interior of holotype, X 3. FIGURES 8-9. Spisula (Hemimactra) modicdla (Conrad) (p. 111). 8. Interior of immature left valve (U. S. Nat. Mus. 325598) from 1 mile northeast of Suffolk, Va.; height 7.9 millimeters; width 11.7 millimeters. 9. Exterior of valve shown in figure 8. FIGURES 10-11. Donax fossor Say (p. 106). 10. Interior of valve shown in figure 1. 11. Interior of valve shown in figure 2. FIGURES 12-15. Mulinia congesta (Conrad) (p. 113). The right and left valves of two individuals (U. S. Nat. Mus. 325602) from 1 mile northeast of Suffolk, Va. 12. Exterior of left valve; height 15.3 millimeters; width 22.0 millimeters. 13. Interior of left valve shown in figure 12. 14. Interior of right valve; height 15.5 millimeters; width 21.0 millimeters. 15. Exterior of right valve shown in figure 14. FIGURES lfr-17. Spisvla (Hemimactra) modicella alta Gardner, n. subsp. (p. 111). 16. Exterior of holotype, a right valve (U. S. Nat. Mus. 325599) from Rock Landing, N. C.; height 13.2 millimeters; width 18.0 millimeters. 17. Interior of holotype. FIGURES 18-19. Spisula (Hemimactra') modicella (Conrad) (p. 111). 18. Interior of a right valve (U. S. Nat. Mus. 325598) from 1 mile northeast of Suffolk, Va.; height 11.2 millimeters; width 15.0 millimeters, X 2. 19. Exterior of right valve shown in figure 18. FIGURE 20. Erv^lia lata Dall (p. 115). Interior of holotype, a right valve (U. S. Nat. Mus. 115054) from Natural Well, Duplin County, N. C.; height 3.6 millimeters; width 5.2 millimeters. (After Dall.) FIGURES 21-24. Mulinia congesla (Conrad) (p. 113). A right and a left valve of different individuals (U. S. Nal. Mus. 325603) from \ l/i miles west of Smithfield, Va. 21. Exterior of left valve; height 24.5 millimeters; width 26.5 millimeters. 22. Interior of left valve shown in figure 21. 23. Interior of right valve; height 23.0 millimeters; width 25.5 millimeters. 24. Exterior of right valve shown in figure 23. FIGURE 25. Ermlia lata radiata Gardner, n. subsp. (p. 116). Interior of holotype, a right valve (U. S. Nat. Mus. 325597) from Neills Eddy Landing, Cape Fear River, N. C.; height 2.6 millimeters; width 4.0 millimeters. FIGURE 26. Corbula (Caryocorbula?) scutata Gardner, n. sp. (p. 140). Exterior of right valve of holotype, (U. S. Nat. Mus. 497058) from Shell Creek, De Soto County, Fla.; height 6.4 millimeters; width 9.0 millimeters X 3. FIGURES 27-28. Corbula (Caryocorbula) conradi Gardner, n. sp. (p. 139). Holotype, the right and left valves of the same individual (U. S. Nat. Mus. 325605) from 15}£ miles above Bells Bridge, Edgecombe County, N. C.; height of closed valves 6.7 millimeters; width 11.0 millimeters. 27. Exterior of left valve, X 3. 28. Exterior of right valve, X 3. FIGURE 29. Ervilia lata radiata Gardner, n. subsp. (p. 116). Exterior of paratype, a left valve (U. S. Nat. Mus. 325597) from Neills Eddy Landing, Cape Fear River, N. C.; height 2.6 millimeters; width 4.2 millimeters. FIGURES 30-32. Corbula (Caryocorbula?) scutata Gardner, n. sp. (p. 140). 30. Interior of right valve of holotype shown in figure 26. 31. Interior of left valve of holotype shown in figure 26. 32. Double valves of holotype shown in figure 26 viewed from the rear, diameter, 5.7 millimeters. FIGURES 33-34. Corbula (Caryocorbula) conradi retusa Gardner, n. subsp. (p. 140). Holotype, the right and left valves of a single individual (U. S. Nat. Mus. 325604) from half to three-quarters of a mile below Edenhouse Point, Bertie County, N. C.; height 5.0 millimeters; width 7.7 millimeters. 33. Exterior of right valve, X 4. 34. Exterior of left valve, X 4. FIGURE 35. Kuphus calamus (H. C. Lea) (p. 143). Fragment of tube (U. S. Nat. Mus. 325608) from Baileys Creek, James River, Va.; outside diameter of tube 11.6 millimeters; inside diameter of tube 7.0 millimeters. FIGURES 36-37. Zirfaea rhomboidea (H. C. Lea) (p. 142). 36. Exterior of left valve of holotype (Acad. Nat. Sci., Philadelphia 1583), X 6. 37. Interior of right valve of holotype, X 6. FIGURE 38. Martesia cuneiformis (Say) (p. 143). Exterior of left valve (U. S. Nat. Mus. 46850), Recent from the east coast of Florida, height 9.6 millimeters; width 17.5 millimeters,X2. FIGURE 39. Isocardia fraterna Carolina Dall (p. 67). Interior of paratype (U. S. Nat. Mus. 146166) from Grove Wharf, James River, Va.; height 67.0 millimeters; width 84.0 millimeters; convexity 28.5 millimeters. (After Dall.) FIGURE 40. Solen viridis Say (p. 108). Interior of double valves of specimen (U. S. Nat. Mus. 153356), Recent from Smiths Island. Va.; height 7.5 millimeters; width 35.5 millimeters,X2 168 PROFESSIONAL PAPER 199 PLATE 23 35 PELECYPODS. INDEX Page abbreviata, Cardita______71 anodonta, Pbacoides——————————————————'.——————————— 9 Qlans (Pteromeris) perplana-——____.______72-73, pi. 13 Phacoides (Pseudomiltha)______————————————————.— 6 Pteromeris perplana______^______15 anomala, Mysella__—————————————————————————————— - 85 Venericardia perplana______._____ 9 Anomia aculeata_——————————————————————————————— 41 Abra.-.——-———...... —...———————__._.__...._.... 103-105 zealandiea._..-.-.--————_————————————..———*————-. 41 aeqnalls-.———.————..——._.___.____...... 16,104, pi. 17 antiqua, Anatina-——————————————— ——— ————————————,—— 42 deltoidea——.____—..____•—-___..___..... 16,104-105, pi. 17 Periploma.-—————————————————————————————————— . 42 bella...... __....______._ 102 Periploma (Cochtodesma).__—_„.——__————————————.. 42 nuculiformis______104 antiquata, Area-.———,—————— ——————————————————————— ---- , 23 nuculoides-.—-———_—__—„__..______...______102 antiquatum, Cochlodesma.-————————.—————————— -——————-— 42 ovalis-..—_____..__—______101 atata, Astarte..--—-—_...... —..__....._....—.... 9,11,14,55-56,pi. 12 subreflexa-—...... !...—...... _—————————- 16,103-104, pi. 17 Cardita——————————————————————————— 9,10 (Amphidesma) subovata-———.-——————__—______101 Carditamera_ ———————————————————————————————. 15 Abstract._—.....——__„______.______1 Cypricardia.------——————.——.——-———— — —-—. .. 6S acetabulum, Artemis. ______120 Area__.______-_____———————————————__ 22 Doslnia——...——._—___..____.__:__.—...... —.. 10,120 antiquata..— ———————————— —————————— ——— _--... ————.. 23 Dosinla (Dosinidia).____...... ____.__._____ 7,15,120-122, pi. 11 callicestosa-..-- —————————— —————————————— — —— ----—— 24 Acteocina_..__..„—_—______8 carolinensis-————————————————1———————————-——————— 25 canalieulata._——-._.....______.______12 glycymeris--..—————— ———————————————————————————— 26 Actinobolus tridentata,______. 70 hians- —______-___----__——,———————————-——-__ 22 aculeata, Anomia__.___...______.__.__.. 41 idonea- —------—————-————————-—————-—————..— 6,7,13 acuminata, Pholas———...——...... __—______.__ 141 improcera------— —— —— --- —— — — --————————-———————— 8,12 acuta, Mya.______138, pi. 22 incongrua__——— —— ———— ------—————,———- ——— —— 26 Nuculana.-.______9,12 lienosa-_————————————————————————————...————— 24, acutilaqueatum, Cardlum_.______10,90 noae__ ——.- — —— ------————— —————— ————..-—-——.. — -. 22 Cardium (Cerastoderma)-—______15,90 nucleus.——— ———————————————————— ————... —— —— - 19. Cerastoderma--______—______90-91, pi. 16 propatula_.- ———————————————————————— ————— - — —— 22 adamsi, Seila._.______8,12 protraeta---————————————————————————'—'———————— 24 advcrsarius, Conus..———..—..__——___—______8 scalaris.-- ———— ————————————————————————————— — 26 aequalis, Abra___„___.___.______16,104, pi. 17 staminea.---- ——————————————————— -——— ————— -.-- 5. Amphidesma———————————————_—__—___.„._____ 104 virginiae_.. —— ---.—————.. —————— — — ——— -- —— ------7,13 aequilibrata, Donax...... ———_——__...______„ 106,pi. 17 sp--_.———————————————————————————————————————— 6 Aequipecten.—__—_._.______35-37 (Aaadara) callicestosa.-.___.____—__——__.-.______24 africana, Dosinia--——...—————————_——_—..._„______120 lienosa__.._—————.————.—————————————..—__ 23 Agriopoma---.~__——_—___—______,______124-127 (Anomalocardia) protraeta—_...——————.———_—______24 alabamicnsis, Corbula______.,______139 (Barbatia) centenaria———__—————————————..—------___ 6 albidus, Pectunculus————————.——__—__...___——__.-__ 122 (Cunearca) scalaris__.____———.-————————..———.....___ 26, Alectrionperalta--..——.__.______13 (Noetia)incUe———————————————-—- — — - 9,10,13 Allgena-—->—..——----—---——————————— —— ————— 87-88 (Scapharea) scalaris———————————————————————-----___ 14 chowanettsis—_—..__.______...___.. 15,87, pi 14 lienosa__.___——————————————————.——_.___ 14 rhomboidea.__——_—___.______15,87-88, pi. 14 eallieestosa--.--_——.————— ————————————..-.-_... 14 striata_____—___.______87 earolinensis——————————————————————————_„___ 14 alta, Semele subovata______16,101, pi. 17 (Striarca) centenaria--. —— -—————_——————————______9,10 Spisula (Hemimactra) modicella..——————„...... :.-—.„ 16, 111, pi. 23 arctica, Yoldia.— ——— ———— „——————————————————-——__ 21 alticostnta, Turritella-_-__...______.______-__—.___ 9,10,11 arcuata, Barnea (Scobina)——————————————————————————_ 141 altilis, Ptycbosalpinx--_____-______.____ 10 Barnea (Scobinopholas)-——------——...... —. J——_ 16,141-142,pi. 22 americana, Glycymeris.-l—.—.....——.._—..__....__— 10,13,27-28,pi. 1 arcuata, Pholas __„._.————————————————————— '-...... _ 141 americanus. Pectunculus.-_..___—___.______27 arenaria, Mya...... — ,--.....— ———————————— 138-139,pi. 22 Americardia.———————-———...——-._—______..,__-.--. • 93 arenosa, Pandora___—„——. ————.———————————_____ 45 Amphidesma aequalis..--__....__...__.______104 Pandora (Kennerlia)______———..———...——__..__.. 14,46,pi. 10 bellastriata.—...... _....._....__.___.__...... - 102, pi. 17 Artemes transversus—————————————————————————— '.. ,___ 122 cancellata_____.______,______,___- 102 Artemis acetabulum—. __——__—————————————______120 constricta____-____.___.______- 83 concentrica._————————————... ——————————— ------___ 122 nuculoides-.__—___.._._„___...______102 elegans-..——...——...... ——.——.-. ———-——...——————...... 123 subovata---______.____. 100 Asapbis centenaria,------— — —'-———————————————_.___ 119 subreflexa----_-.—————__—.....—___....__..—....—. 103 Ashtarotha.___———-———————————————————————„„__ 56 Amusium.-.-____-____.___—______.______39 Astarte______.__.-———-———————————————————_____ 51-61 mortoni..-______.______39, pi. 8 arata..- ———— ————————————————.. ———_ 9,11,14,55-56 Anachis milleri.___.___.___...__..______12 beTla.—— ——————————————————————..... 61 Anadara..—_____—.__—.„_—__——__.____.___.__ 23-26 1 berryi——— - ——-——-————————————— 12,14,56,pl. 12 eallicestosa....—____.______24, pi. 3 coheni—_-„--—------— ---———————-----———.——... 9,53,pi. 12 callicestosa wilsoni-——...———..—-.-.._———_—.._——.- 24-25, pi. 3 compsonema- _ -____——__...——————..——__—______61 carolinensis______25-26, pi. 2 concentrica...... ___-___.„"—.-———__.___...___.'..'__ 59,61. lienosa..------„———.——-----——.———_-——__„.. —. 23-24,pi.2 bella-.-.....- ————— ——— ———————————— ———— 60-61 magnoliana.___-__...____-___—__-____..___- 25, pi. 3 exaltata.———————————————————— 6,7,9,14,52, pi. ^12. protraeta--.______-______24, pis. 2,3 hertfordensis...-.—.----- — -——--———————— 11,14,53,54, pi. 12 (Cunearca) scalaris————————————————————-—————— 26, pi. 2 llneolata—____._____...-___—______61 Anatina antiqua-__—.__——„...———.——__,—__—--_—— 42 lunulata_.--...._-----_.....———.——..__—______62 leana,.--——-.-————————————————.—————-———-——— 42 obruta—___———————_—————-•—————_.'..——'__'.__ 5 Angulus polita.___..___—__—_.....___....__—-.__—— 96 hertfordensis meherrinensis__—___—___.______14,54, pi. 12 angustior, Cbama...-———_——_——....———..———...——„——— 107 aff. A. obruta—______.______6 401033—43———14 170 INDEX Page Page Astarte—Continued. Calvert formation, description of—————————————————————— 4-5, fig. 1 perplana.—.———.——_.__.....——....—...... —...... 7,13 fossilsin.———————————————————————————————1——— 5 roanokensis-_.<.__...... _.__„—..._____...__..... 14,53. pi. 12 campechiensis, Venus..————————1————————————————————— 132 stephensoni______14,54-55, pi. 12 canah'culata, Acteocina..——.———.—————————————————————— 12 symmetrica....__.....—.___...——_....____ 10,13,14,51-52, pi. 12 canaliculatum, Busycon———————————————————————————— 12 undulata—______57 canaliferum, Fulgur canaliculatum.-.-—————.———————.—————— 8 vaginulata___.______._-______58 cancellata, Amphidesma———————————————————————————— 102 viclna————.....———..____...______52 Semele——————.———.....—————-———————————————— 102 (Ashtarotha) concentrica. —.___._-...... --.-.._ 10,12,14,59-60,pi. 12 Venus..———————————————————————————————————— 127 concentrica bella__•______14,60,pl. 12 candidus, Pholas—_.—————————————————————————————r 141 conradi.—...—...... _...... 14,60, pi. 12 cardiiformis, Verticordia.——————————————————————-—————— 60 griftonensis——————____—.____.___.___...... 14,57, pi. 12 Gardiolucina———————————————————————————————————— 76-77 rappahannoekensis______'.______.. 14,56-57, pi. 12 Cardita abbreviata_.——————————————.——1——-—-————— 71 undulata_...... __...... _„...... —...... 9,14,57-58, pi. 12 arata--—————————————-—————————-—————— 9,10 deltoidea.__...___..__...... 6,7,9,11,14,59, pi. 12 verdevilla——.—————————.—————————————————... 9 vaginulata—_____.__.______...._ 6,7,9,14,58-59, pi. 12 perplana...—————————————————————————————————— 71 Astrangia lineata______.______9 tridentata.——.————.——————————————..... —— 70,71 athleta, Chione_.....______._..._.______...... _...--.. 6 (Venerieardia> tridentata-___————————————————————— 70 attenuatum, Dentalium...,______7,11 Carditamera—...... ——.——..——...—.—.———————....——— 68-69 australis, Rochefortia______85 arata.._——————————————-—————————————i————— 15 columbiana..-.—. —... —— — - ———— — - —— — —— — ————— -- 15 verdevilla—..—...__...„.___——__.—....—__._ 15,69, pi. 15 Barbatia______'_ ____ 22-23 ' columbiana-.————.——_——-———————————————— 69, pi. 15 (Granoarca) propatula______.______22-23, pi. 2 Cardium..._...... ——...... ——.....———————————.» 89 Barnea...... ______.___...... I...... _ 141-142 aeutilaqueatum_—————————————————————————————— 10,90 spinosa...... _....__....__..._,______.____...... 141 costatum-———..—————————————————————————————— 89 (Scobina) arcuata______141 eburniferum————————————————————————————————— 91 (Scobinopholas) arcuata...... x..._____..__...... 16,141-142, pi. 22 edule._—————————————————-————————————,-———— 89 bella, Abra..______102 egmontianum..._——————————————————————————.—— 91 Astarte_.______61 europaeum.....——————————————————————————————— 93 concentrica.-__...... __——______.____..__.. 60-61 floridanum...————————————————————————————————— 92 (Ashtarotha) concentrica.....-.---.-._____...... _... 14,59,60, pi. 12 graniferum—.———————————————————————————————— 93 Marginella..______8,12 humanum——————————————————————————————————— 67 Semele..______L...... _____ 101 ingens-——-—————————————-——————————————————— 90 beltestriata, Amphidesma...... -...—-.—...... __ 102, pi. 17 isocardia.——————————————————————————————————— 91 ", 8emele—...... 16,102, pi. 17 laqueatum———————————————————————————.——————— 90 berryi, Astarte-...... ———————————————————— 12,14,56, pi. 12 medium..——————————————————————————————————— 93 . Venus (Mercenaria).._._...... _...... __..._ 15,133-134, pi. 21 muricatum————————————————————————————————— 92 bertiensis. Pecten eboreus____ .______. ______12 norvegicum—————————————————————————————————— 93 bicarinata, Pandora (Kennerlia)______._..._...... _...... 45 quadrans. —————————————.——- ———.—————————————— 91 bilirata, Pandora._._.___.._____...... I...... _.._ 45 quadrigenerium. -.. —— ————... ———————————————,...... 92 hladenensis, Bornia______.-____-..___..._ 15,83, pi. 14 sublineatum..———————————————————————————„.„——— 94 Mysolla—_-_-______.______.____.______..____._.__'___ 15,86, pi. 14 taenioplcura————————————————————————————————— 13 Bornia.—...... __....___.______._..___...... ___ 82 venustuni——J————.——...- ————. — — ——————————— 93 bladenensis...... ______...... _._._.__...._ 15,83, pi. 14 virginianum___...——————————————..—.——————————— 7,9,10,91 corbuloides..____.______._.__..".....__..___...__ 82 sp.——————————————————————————————————————— 5 triangula—__._...... 15,82-83, pi. 14 (Cerastoderma) aeutilaqueatum..————————————————————— 15,90 bowlerensLs, Spisula (Mactromeris)- ______16,112, pi. 18 laqueatum_———————————————————————————— 1... 90 Brachidontes.__.______.______....._._____ 29-30 virginianum.—————————————————————————————— 15,91 (Ischadium), recurvus.______._____._____ 29-30, pi. 1 (Fragum) medium.——————————————————————————1—— 93 Brachydontes hamatus.______....___ 29 (Laevicardium) sublineatum.-.—————„_——————.—————— 15,94 Bucardia fraterna______. 67 (Trachycardium) emmonsii—.———————————————,——————— 92 Bulliopsis quadrata______6 isocardia—__———————————————————————— 15,91 Busycon canaliculatum__.______12 muricatum...————————————....—————————————— 92 coronatum__...______..______13 cariboea, Siliquaria.- — ————————————————————————— ———— 107 rugosum...... _...... —..._..__...... _....___ 13 cariboeus, Cultellus..————...... ——————....— ..T....— 107,108 maximum fllosum.______1 _____i_____ 13 Planopaea]————————————————————————————————— 107 Solecurtus——....——————.——————————————————————— 107 Solen——————————————————————————— 107 Cadulus thallus.- ______9 carinata, Turritella plebeia.——————————————————————————— 7,13 Caecum stevensoni.. ______10 Carolina, Isocardia.-—————————————————————————'—————, 67 calamus, Kuphus ______6,9,10,16,143-144, pi. 23 Isocardia fraterna—————————————————. 9,11,15,67-68, pis. 11,23 Teredo-.-.--...——. __ .... __ ...... '...... 143 North, Miocene stratigraphy of, summary of__————————————— 2. calcarca, Tellina __ .. ______98 Pliocene stratigraphy of, summary of—————————————————— 2-3 calliccstosa, Anadara ______> 24, pi. 3 carolinense, Dentalium.".———————————————...——————————— 13 Area... ______24 carolinensis, Anadara.————————————————-—————————— 25-26, pi. 2 (Anadara) __ .... . __ .... — ___ . _ .... _____ . __ 24 Area—__-__..——-————-—————————-—-—-———— 26 (Scapharca) — - . ______.. 14 (Scapharca)__————————————————————————————— 14 Scapharca (Scapharea) . ^ ______. 24 Eontia..———...—-————.———-———.———-—————.——.— 12 Calliostoma humile. 13 Erycina——————...—.....—————————————— 15,81-82, pi. 14 mitehellL.- 9 Macorna_—————————————————————————————————— 100 phllanthropum..— —— ... ___ ....._ — __ .... — .._...._ _ ... ___ ~ 9,10 Mercenaria——————————————————.————-————-———--• 132 " virglhicum.. — _. ______. _ . __ . __ ...."____ ... _ ... 10 Modiola————————————————————————————— 29 Callista convexa ______. ______... 124 Pandora———————————————————————————————————— 46 (Callista) reposta—— ._——.—...... __ . __ ... . ____ ... .. 123 Petricola.------——...... ————————————— 118 CaHocardia.— ————.———.. __ . _ . ___ ...... ______124-127 (Petricolaria)_.__——__-i.——....—.....——...... ——- 118 guttata—— ——...—.— ...... ———————————————— 124 Scapharca (Scapharca)———————:——...———.——————————-—— 25 sayana-.. ______. ______. __ ...... ____ . __ .„ 10,12 Siliquaria————...... ———————————...————— 107,108 (Agriopoma) castoriana_____ T— —— ______- ____ 15, 126, pi. 19 Tagelus gibbus——.————————————————— 16,107,'lOS, pi. 22 chioneformis—— _ . _ . __ . _ . ___ ... . _____ ... 15, 126-127, pi. 19 Venus.__——_———————...... ————————————— 132 sayana ______124-126, pi. 19 fMereenaria) campechiensis———.—.——.—————————— 15,132,pL20 caloosaensis, Diplodonta..-. — ____ .. —— _ ... ————— ..---.-. —— . 80,pl.l4 carpenteri, Cooperella————...__————„———...... —— 15,119-120,pi. 14 calpix, Sportella— . __ ... ______. 15, 84, pi. 14 Caryatis plionema..._..————..——.— —.....—————,————*~'~ 124 Tellina(Moerella?)— H— — — — — -— — — .———..—— 16, 98, pi. 17 Caryocorbula______...... __...... —_... ——— ————————— 139 INDEX Page Page eastoriana, Oallocardia (Agriopoma)______..______15,126, pi. 19 confraga, Spisula.----.—.———.———————————————————————— 6 centenaria, Area (Barbatia)______:___ 6 congesta, Hemimactra———————————————————.—————————— 113 Area (Striarca)—-_...--___.._—.._____——..._———— 9,10 Mactra ——_....——_—.———_—.—.——1————————-„— 113 Asaphis______119 Mulinia————..__.____—~——.__- 8,9,10,11,12,16,113-114, pi. 23 Petrieola——————————:——_——————————————_ 118,119 Standella..———.—.————.———————————————.——-. 113 Pleiorytis————————————————— ————————— 7,10,119,pi. 15 congregata, Chama__——_—.——~—-—.—————————————— 9,11 Cerastoderma______'_ 89 conradi, Astarte (Ashtarotha) concentrica______._._„___ 14,60, pi. 12 acutilaqueatum______90-91, pi. 16 Corbula (Caryocorbula)—'...... '.. 16,139-140, pi. 23 laqueatum______.______90, pi. 16 Isorardia——....—.—.—————.———.—.—.———————,—„ 67 virginianum...—.—...... _.___.____.______91, pi. 16 Macoma__..._—...... ————————————------———.———.— 99 Chama—.——...—..______88 virginiana-——————————————.-——.——————— 16,99-100, pi. 17 angostior.————————.———...______._ 107 Thraeia—-_-__—______———.———...-———. 14,43, pi. 10 congregata———————————————————————....______9,11 conradinus, Mytilus..———————————————————————— -———— 11 cor.__.___„______67 constricta, Amphidesma—————————————.———————,——...... 83 eorticosa- Fabella——————————————————————.—.,— 83 cristella... Lepton,(Fabella)——'—...__—._.—____—._.—————„ 83 dosta-—...—...——————————————.______...... ___...... 120 Sportella——————————————.———————— 15, 83-84, pi. 14 lazarus______88 Syndosmya.._..:———————————'...... • 83 striata—...... ———....—.—...... __...... 15,88, pi. 13 contractus, Phaeoides (Lucinoma)______-.._.— 7,10,11 trapezia.______.______..______69 Conusadversarins.-—--_———.——_————.—„————————----- 8 Chamelea.______129-130 diluvianus___—_____——....—_-_._—.._—..——.„ 6,13 Chione___.______127-130 marylandicus-_-_^______....__..-—..—..—.... 7,9,10,13 athleta_____.______.______.____ 6 convexa, Callista...—--——„———————...„..————————————— 124 cortinaria—...————...._•——...... _.__.....______9,15,127 Cytherea.------___ ...... ^...... 124 cribraria.______._._ 128 eookei, Macoma._—_____.._.-.-.___---_------16, 100, pi. 17 dallL——...... ————...... _...... _...... 129 Cooperella——————————————————-—--——— 119-120 parva___.______128 carpenterL————.——-.———..——————.— —— - 15, 119-120, pi. 14 (Chamelea) dalli...-—————————...... 7,13,15,129-130,pi. 19 scintilloeformis-.______119 (Chione) cortinaria—-.——.———————————————___ 127-128,pi. 19 cor, Chama__.'__„—„•——.——————————————————————— 67 cribrariai______„______128 Coralliophaga.______.____.'.—___..___._.———....—— 66 grus-.—...... ————...—...... 128-120, pi. 19 coralliophaga-..—————.————————————————————————— 66 (Timoclea) gras.....—————...._.____....——...... —.... 16,128 microreticulata___...... ——— — ..„.._———. — ..— 14,66-67, pi. 9 chioneformis, Calloeardia (Agriopoma)______15,126-127, pi. 19 Corbicula..—------_..——.„._-----_.__-.-.___.— 64-65 Ohlamys..______31-32 densata..------——-———-—.—-—-——-———--——-_-— 15,65, pi. 15 decemnaria______,______31-32, pi. 5 Corbula-.-.—————————.-——.——————————— 139-141 (Aequipecten) comparilis______37, pi. 7 alabamiensis______._____.__._—.——:——... 139 eborea..—.—.....————————.———————____.... 36-37, pi. 7 guineensis——————————————————————————————————— 139 (Chlamys) decemnaria______31 idonea.______———.——„—.————————————————— 6 (Lyropecten) ernestsmithi______.. 34-35,pi. 6 raaequalis.__.___...... —.—...... —„.„——————— 7,9,12 jeffersonia..———.——.._...... _.__...... _____ 32-34,pi. 4 sulcata-----.-.——-——-——-———————————— 139 jeffersonia edgecombensis-_____<______:_____ 33 sp____-----_———————————————————————————————— 6 jeffersonia septenaria______33,34, pi. 4 (Caryocorbula) conradL.___——————————.. 16,139-140, pi. 23 madisonia______. ____ 32, pis. 4,9 conradi retusa.___._____...... _._„....—-... 16,140, pi. 23 • peedeensis——————...—...... _._.______36, pi. 6 scutata————____—-__.______.__— 16,140-141, pi. 23 planicosta————.——————————.—...... __,_____.. 34, pi. 9 corbnloidea, Thraeia__._-_,_—....—.„..————————————— 42 (Placopecten) clintonia...——.—.„__.______37-38, pi. 6 corbuloides, Bornia_____..—.'.———-—————.. ——————————— - 82 (Placopecten) marylandica...______38, pis. 5,6 coronatum, Busycon__._—__ -—————-———.—————"————— 13 virginiana...... ————.—.——.————.———...... 38-39,pi. 4 corpulenta, Mya______-___—__———-—-——————— 138 (Plagioctenium) comparilis.————.—...__T______37 eorticosa, Chama-——.———————————————————————————— 89 eboreus eboreus_—_._.______36 Fseudocbama.___-...„..——————.——————-—— 15, 89, pi. 13 Choptank formation, description of______5-6, fig. 1 cortinaria, Chione__^_. _____-_-_———————————— 9,15,127 fossils in______5-6 Chione (Chione)-———.——— — -—— ————,——— 127-128,pi. 19 Shattuck's zones in.______..__...______5, fig. 1 Dione (Chamelea)------—------—————-A————————— 127 chowanensis, Aligena..______15,87, pi. 14 Venus______.___.___.-.—....—-_—————.——————— 127 Verticordia (Trigonulina)______14,51, pi. 10 Costacallista.———————————————————————- 123-124 TJzita—...... __...... _____._...__._....___ 12 costata, Crepidulaaculeata.-.--—-———————————————————•— 8,10,11 chuckatuckensis, Donax______16,106, pi. 23 Pholas—...... _——————————_____—...... 141 clathrodon, Bahgia. ______10 costatum, Cardium__..—————.—————————————————————— 89 clavata, Pholas..—.—.—.———...... ______:___ 142 costatus, Pholas- __————————.————.— ——.———,—-— 141 Cleidlopbora crassa...______._ 47 crassa, Cleidiophora—-—....———————1——————————————— 4fr Clidfophora- ——__._____.______.__._...... _.... 46-50 Crassatella.------__———————-——————————————-——— 61 clintonia, Chlamys (Placopecten)-..„______37-38,pi. 6 clintonios, Pecten.___.______37 CrassatelliteB. ——————————————————————— 61-62 Pecten (Chlamys)_.-—————....—..„.—______.___.__ 37 marylandicus_.———————————->——————————————————— 5-6 (Placopecten).-...--——.—....—...... _...... _...... 6,7,9,11,14,37 meridionalis surryensis_ _———————————————————————— 6,7 CocbJodesma.__-______42 sinuatus______._._—.——.—————————————— 61 antiquatum___—.„...._..__.....______42 turgidulus...__—————-———————————————————————— 5 Codakia cribraria______T______j... 78 uodulatus--—-—————————————————— 7,9,10,11,12 coheni, Astarte..————.—.———.———.—.._.______9,53, pi. 12 cyclopterus____.______———.—-———————————— 6,9 colomba, Hemicardium___...... _...... ______93 urbannagnsis__...... ——————————————————————— 6 columbiana, Carditamera..______69, pj. 15 (Crassinella) dupliniana___....—.————————'—————————— 64 Carditamera arata --______15 comparilis, Chlamys (Aequipeeten)______37, pi. 7 lunulatus______-_——^. ————————————— ——— - 62 Chlamys (Plagioctenium)-.—.-..__...... ______37 crassidens, Mactra—.—-————~T————————————————————— 113 Pecten_———„——___._„______37 Mulinia.. ——————————————————————————— 113 (Chlamys)—.-______37 Pandora._____.——..._.————-——-———————-——-———. 46 eboreus_.....___.______37 (Clidiophora).———...... ————...... 46-47, pi. 10 compressa, Petricola___——————4——.—___._____.___ 85, pi. 14 Crassinella-....--———————————————————————— 62-«4 Sportella.————______._____-...-_____ 15,85, pi. 14 dupliniana-_———______16,64, pi. 13 compsonema, Astarte-..______61 galvestonensis——___-_——————————————————— 9,10,16,64 concentrica, Artemis__..„.—..._———...... _._____._____ 122 lunulata------..--_-_-__-_____-______J- 14,62-68, pi. 19 Astarte——...... —.——...... ————...... _...__... 59,61 harrisi---_....._...... ______————————————. 14,63, pi. 14 (Ashtarotha)_...______.__...... _... 10,12,14,5S-60, pi. 12 nansemondensis___—.——————————————————————— 16,64, pi. 13 Venus..__...... __...___._____.....___.__... 120»122 cravenensis, Gemma______._—,—.——————————.— 187-138, pi. Jt 172 INDEX Page Page Grenella— —————— ——-_—_—————— , ——-——--— — ..—— — ——- — — _ — 30 Diplodonta—Continued. precursor...... -.-. — ._ — ...... — ------__ .... 14, 30, pi. 3 subvexa____-___...__——_—..—-———————————- 5 Phaooides (Parvllucina) _ ..-. _ ------_ _.—.—————————__ 78 yorkensis______-__-...—.———.—... 119 crenulatus, Phacoides ______.-. ___ ...... 5,9,11 (Phlyetiderma) soror...—.——.——.....—..-...—..—.—.... 15,81,pi. 14 Orepidulaaculeatacostata..--.. ______. ______. ___ 8,10,11 dislocatus, Pecten-.______._____—..———.—.—————— 31 fornicata— ...... _ .-._- _ _ ___ ...... _ -.. _ _ --.--... _ .,.. 10 Pecten irradians______31 cymbaeformis---- ___ . _ ..-- ___ _ .... _ ------_ .... 8,12 dispalatus, Pecten...____...___._.._—..—————.————;— 31 plana— . ____ ... ______--- ______- ____ - 10 djsparilis, Ostrea--———————————————————.—— 6,7,9,10,11 cribraria, Chione.— _ . _____ - ______. _ . _ . __ ...... — 128 Divarieella quadrisuleata__..____——_.——.————————————, 7 Ghione (Chione)------_ ——..——.——_————_ — _ — 128 donacia, Mactra__-...-.-._..-.-—--—_— — ——— ——— ..«. —— 115 Codakla ______. ______.... ____ .... 78 donacina, Tellina___------_.___:..._------——------—— M Dione (Chamelea).. . ______. ______- _ - _ -.--.... 128 Donax______.______.____._..__„_————.——„———— 105 Lucina— --—- ————-——-_ — ———-— — ——_ ——- — -- — -_——--——...-_ 78 aequilibrata______.__.__..:.., 106, pi. 17 (Lucinisca)-----. ------_ —————— — — ——— — 78 ehuckatuckensis—--——-—__._..___.....__-_—..—.. 16,108, pi. 23 Venus...- _ - _ . ____ . ______—— ... ___ ... 128 emmonsi______...—..——,,.—_—- I05,pl.23 cribrarius, Phacoides (Lucinisca) ______- __ - __ . 7, 15, 77-78, pi. 13 preaequilibrata------__——,_".——„—— —__..... 16,105-106, pi. 23 crispatus, Pholas-- __ - ___ ... ____ . _ - ____ ...... ____ .. 142 fossor—...... - — - — —— ——————,—-—...... 16,106-107, PL 23 cristella, Chama-. __ -- __ _ .. __ _ ------_ .-- _ _ .... 89 protracta____..__.______..__.__.--.————————— 106 Oroatan sand, exposure of ______... ____ .-. __ .. 13 rugosa....__-----_-..-____.._—..——-———————— — -—— ,105 Crucibulum grande ____ ... ______.. ___ . ___ 9 variabilis.-- —-.—-- — -—.- — - — ————-———- ———.-. 106 ---— ———————— - — — -———-——— — -—— 74-76 dosin, Chama..______.....—_..._——— 120 microimbricata.. _ . ___ ------______.... ______. _ 15, 75-76, pi. 13 Dosinia—...... _...... _._...... _....._------120 speciosa---. _ . __ - ______- ____ . ___ .. _ . ______... 15t 75,pl. 13 acetabulum-______,-..--„. —.———— 120 Cultelluscariboeus..- _ .... _ . __ . _ .. ______..... ____ _._-__ 107,108 africana__.___..______._.._...... — 120 Cumingia medialis ______..-..._ ___ _ ------_ ... _ .._-.... 12 ...... ^ 122 Cunearca.-- ______. ___ . ______- _ -....__... 26 obovata....—....—.—.——.—.—.—.————.—..—-...=——-,. 120 cuneiformis, Martesia—. _ - ______- ______... _ .. 16, 143, pi. 23 sp.-——-————.--—--.---.---.-.------—----—.....—.—-— 6 Pholas— - — — -—-——- ——— ——-'—— —— ——— — — ——— — 143 (Dosinidia)acetabulum_. —„ — -——-—-..———— 7,10,15,120rl22,pl.ll cyclopterus, Crassatellites undulatus. ______...... 6,9 elegans-...... _.....____._...._—.—....„ 15,122, pi. 11 cymbaeformis, Crepidula fornicata __ __ _ ._ _ ...- ______..._..... _ 8, 12 Dosinidia-—- — —————.—._—.....__------_------120 Oypricardia arata.-— ... _ — .... ___ .. _ -... ______... _ ... __ . 68 "Drillia" myrmecoon-______.___.- » 8^ Cyprina tridacnoides _ . ______- _ - ______._-._— — 132 lunata.-..------___...._...... _—..———. ...:... 7,10 Cyrena densata _ ------_____ . __ . _ --.__-. _ ...... _ __ ...... 65 pyrenoides____.-..___-______-._-_.. 10 Cytherca sayana. — __ . __ . _ ...- —— _ .. __ . ______124 dubia, Psammotea______—__.-_——. 83 Cytherea convexa ______. 124 ducatellii, Modiolus..————————..—.—.—- ————-•—-— 12 obovata— — —— — — — — ——— ———————————— ——— 120 duplicatus, Polynices_.____.__...'.—_____...——.——.———— a 9 pandata.. _____ . __ . __ . __ . ______123 dupliniana, Crassatellites (Crassinella). ______.__-_——. 64 reposta.. ______123 Crassinella----.--.-.-__-_..._- —— ———....__...... 15,64, pi. 13 sayana— ------__ - _ .. __ . _ ~ _ — ______... ______124 TeTlina (Angulus)-—_.—_———_——.—-———————————— 96 texasiana -.--.- _ . — ... __ -..-- — ...... _ _ .-----.-.-.. __ — — 124 (Moerella)——————————————————.-- ——.— 96-97 duplinensis, Glycymeris______..____...—..——. 14,27,pis.2,5 Spisula (Hemimactra).______.______. 112 dalU,Chione--. — ———.....„...... —...... 129 ' (Mactromeris)—.———,————————————— - 112-113,pL22 Chione (Chamelea)—...... ————.——. 7,13,15,129-130, pi. 19 Duplinmarl_...______-_------13 Pandora (Kennerjia)....—..--..-....—....—-....-...... -... 14, 45-46, pi. 10 dysera, Venus.-__,.______...__------127 DaUocardia——-----—--—--—-.—---——————-.—.———— 92 decemcostata, Qlans (Pleuromeris) tridentata__..__..__.. _ 70, 71, pi. 13 E Pleuromeris. — ____-__.___...__.______....____._ 70,71 eborea, Chlamys (Aequipeeten)______...—__. 90-37,pi. 7 tridentata------______...-_-__-_-______15 eboreus, Chlamys (Plagioctenium)_____.__..-.—...-———.,——-— 36 Venericardia (Pleuromeris) tridentata-.---.-_...._.___._.___ 71 Oliva——— — — .——..___--.-___-.____.-____---.-_.-- 13 decemnaria, Chlamys.___._..__.._.-... — -___..____... 31-32, pi. 5 Pecten.,-..- —— ...... ___...———.———— 8,9-11,12.36 decemnarius, Chlamys (Chlamys)-_.....___.___...... __-_.... 31 (Chlamys).. —————————..—————,——--—— — - 36 Pecten—_____-_-______._-_..__-____-__...__ 31 (Plagiwtenium)...—_—_,—--—---——--—. ———- — — -— 14,36 (Chlamys).-—...-.--..-- — ---.-.--- — --..-----..—„....--.... 9,10,31 eburnifemm, Cardium______._-„.——.- — —.. 91 decipiens, Pododesmus.______.___...._.___..._._.. 40 Ecphora tricostata___.______.__ ../...... 5 dech'vis, Tellina..------_-_— - —— - — ——— ——— _ — - — — _ 12,94,95 edgecombensis, Cblamys (Lyropecten) jeffevsonia—....._-.....--.... —— _. 33 Tellina (Angulus)-_——— — ————- ———————— ——_ ————_ 95 Pecten jeffersonius——______.__------——.————— 8,9,10,12 (Moerella)———————-'-—————————.-—.- 94-95 edule, Cardium.----.--______---._-_-...—------— -- — ....— 89 Thracia——....-—. — .— — . — ..— — -..—.—.. ——...... , 43 edulis, Ostrea______..______._ — _...„.——— 41 decussatus, Mytilus.---:______... — .______...______. 30 egena, Tellina-..————— ———————————————— 16, 98, pi. 17 deformis, Venus..-___.....____.--.-----..---..---....___.. 132 Tellina (Peronidia).—...... '.————.——————————,- 68 deltoidea, Abra aequalis.————————————— — ——— 16,104-105, pi. 17 egmontianum, Cardium______..._..._ — ——————————— -— 91 Astarte (Ashtarotha) undulata. ——...-.-....-.-...... 6, 7, 9,11, 14, 59, pi. 12 ele?ans, Artemis..------_-..-——.—— —. — - ———_— ———— — — - 122 dehimbis, Spisula___...._____------_...... ___...__. 8,12 Dosinia...—————_.—___.....—.——. — —— -.—....•.„ 122 densata, Corbicula...____..._-______...______15,65, pi. 15 Dosfnia (Dosinidia)-———————— ———————-—- 15, 122, pi. 11 Cyrena-______.__.__.____.___...__ 65 elongata, Erycina carolinensis——__————— —— ------——— — 15, 82, pi.'14 Dentalium attenuatum.. —-__..._..___-__._.______.. 7,11 emmonsi, Donax.__.....—A——.——————————————————- — 105, pi. 23 carolinense...__..______1___- —...__._.... — -.___. 13 Macrocallista (CostacalUsta) —————— —— ———— 15,123-124, pi. 19 diaphana, Nucula__-______-_._-----__•__.. 20-21, pi. 1 emmonsii, Cardium (Trachyeardium).-__-_.——- —— -———————>.- 92 diffonnis, Venus...--.....-...----..... ——--...... -....;—...... 132 Trachycardium__.____------—— ——— — — ———— 92 Diluvarca.—_—- — — ——_—- — -——-—————.—— ———. 23 Verticordia—— __.—__—.——----- — — ———————————————— 50 diluvianus, Conus-_.______..___-„.._-___-----_..._ 6,13 (Trigonulina) ——...... ———. ———————— 14, 50-51, pi. 10 Dione obovata_...-__.--_-_ ....^...... __------120 eoleana, Diplodonta leana_.___.... ——.. — -————————-——— 80, pi. 14 reposta------.------.-.------__---,_--- 123 Eontiacarolinensis------— — —— — — ——— - — — — — - ——— --- 12 , sayana___-__.-__------__------__.__ — 124 trigintinaria.-_ —._—. ——————— ————————— - —— -———— 9 (Chamelea) cortinaria- —_-.._------__------_-_ 127 Eriphylagalvestonensis—----————————————————————,~———— 64 cribraria-..____..__.____.._-___.__„_____ 128 ernestsmithi, Chlamys (Lyropecten)———————————————-——\34~S5, pi. 6 Dtplodonta—. —— -..-- — -..-..-.--. — .—-..---.-----.-.--- — .-„. 79-81 Peeten—------—...... —.....——.—-———————— 34 caloosaensis_._...__.__....._._._____.__-___.. 80, pi. 14 (Chlamys)-.——-—————————————————— — 34 leana..--.------_---..----_.-.---.—-..-..„...-.--..--..-.-.... 15,80 (Nodipecten).-—-----__...... -..—.—————— — .—— 14 eoleana..--_-_------__.___.__ — — _..._-__ 80, pi. 14 Ervilia.------_...—__...... —------——._.——.. 116 semiaspora_.___.....___.._.___....______- 81 lata——— — ————————————————— W, 115-11*, tf. 2* sorer—_-_..--.------_____-....-„-..... — ___--.-_-.----__- 81 radiata——-—————-———————.—.———- 16, lie, pi: 23 INDEX 173 Page Page Erycina.----—".______81 Granoarea—__.-.-.______f...... 22 earolinensis______^______15,81-82, pi. 14 granulata, Veneribardia— ...... ^...... 6,7,9,10,11,12 elongata.—...-.———————————————___. 15, 82, pi. 14 griftonensis, Astarte (Ashtarotha)______14,57, pi. 12 pellueida-.____..______81 grinnelli, Petricola (Claudiconcha).______--...-..____ 117 erycina, Venus...._.-.-._.______.....__.._....._._.._ 123 Petricola (Rupellaria)______....___,______-__ 15,117,pi. 15 Erycinella...... 73-74 grus, Chione (Chione)..————— ———————————— — 128-129,pi. 19 ovalis...... 15, 73-74, pi. 14 Chione (Timoefea) — .„.. — ...... i.-...... 15,128 estrellanus, Lyropecten.______32 Tapes. ...„..-.-__-...... -..-..---._.-..—..—..--..._...... 128 Euloxa..__.______.__ .-'...... 65 guineensis, Corbula—„_.___.__.—__-__..__——-.-...___ 139 latisulcata..--.---.--...... 6, 65-66, pi. 15 Solen...... —— ...—..... ——...... 107 europaeum, Cardium______.__ 93 guttata, Callocardia.... —--————-———.——.—_——..——.—..—— 124 Euvola...___...... __...... _...... _...... 30 exaltata^Astarte...... —..-.....--....--....--.--...... 6, 7, 9, 14, 52, pi. 12 exilis, Fusinus—,—__.___..._.___..______10 hamatus, Brachydontes______29 Mytilus__.__.....__...... _..___._...... ___ 29 Mytilus (Hormomya).-..__...... „•.....—...... _...... 29 Fabella constricta...______._ 83 harrisi, Crassinella lunulata____.__....._:______'..... 14,63,pi. 14 Fasciolaria rhomboidea.___...______.______... 8 harrisii, Petricola (Rupellaria).______.______119 fllosum, Busyeon maximum______.13 Hemicardium columba__..__..__.___..__.___._.._____ 93 Fissuridea_-.„______...______9,11 Hemimactra______-______-______110 nearnassula..__.______..______.______7 congesta-..—".——-...——.—.. —. — - — ...-—...-...—...... 113 redimicula._.______.______7,9,10,11 heros, Polynices....___._.-.---.----.--._._...-_ ..*...... 10 fistula, Teredo...... __———————.——.———————..———.. 143 hertfordensis, Astarte...__.....___.__.______.__ 11,14,53-54, pi. 12 floridana, Pandora (Clidiophora)....—___.__.______49 hians, Area.___——.______._____.___.____ 22 floridanum, Cardium...___.______.______92 holbrookii, Pecten....___..._..__._..._____....___ 36 fluminalis, Tellina______64 Horsehead Cliffs, Va., section at______.______'...... 5 fornicata, Crepidula...——...... ——_.—.„..___.______10 humanum, Cardium-______.______..______67 Petricola____.__.—__...______117 humile, Calliostoma.-----.-_--—--_-_---.-_------______13 fossor, Donax?______.. _____ 16,106-107, pi. 23 hyperborea, Yoldia.._.______.__-___-__ —.__._.______21 fragilis, Mactra....---..-.---.---...-.-----.-.----.-.--..._...... 109 Mactra (Mactrotoma).______.______109, pi. 18 fraterna, Bucardia————.. —.—.———.—_„___—______.._. 67 idonea, Area———-- —————. ————————..-- ———————————— - — -. 6,7,13 Isocardia—-——-—-——.—————————————— 5, 7,15, 67, pi. 11 Corbula..._.___.--_____.____--______..______6 Fulgur eanalieulatum canaliferum______. ______8 Hyanassa schizopyga.—._____..._..___-___-.__.___.___ 8 Fusinus exilis_——————————.——————_.___.___—__._ 10 granifera.— ____..---__----...—._------.----.-.-__—__ 8 parilis_._-.—..__--—...... --__...___...___...._...... 13 sexdentata...... —__—__—...-.-- —————.-—__..___ 12 propeparilis.——————————————————- — --..--.._ —— _-... 7,9,13 improcera, Area..______.____--.______._ 8,12 inaequalis, Corbula.______.____-__.______7,9,12 Q inaequivalvis, Periploma....___...._...... —_——.__. — ___._ 42 gallina, Venus,______.-..__.______———.__..______129 Tellina.....----...... ----__------_.....--_.-_-.-„.._..... 44 galvestonensis, Crassatellites (Crassinella)...____._-....____.. 63 incile, Area (NoStia)—...... _—„...—-....- — -————.„_.. 9,10,13 Crassinella^.-—~~~-~~~~~~~--~~—------9,10,15,64 incongrua, Area.._—.....---...——.———.... ———— --...————__ 26 Eriphyla—.————-—-—-_.-...... -.-.-.---...... -.__...... 64 inflata, Venus plena"....____.- — _ — — _.--..--..-. — — ..-.-.„-.._. 134 Gemma...____._____--__._._____.._.______135-138 Venus (Mercenaria) plena..____._...... __...__.. 15,134, pi. 21 eravenensisl——— ——— ———---—.—.—--..-„.„...... 137-138, pi. 19 ingens, Cardium_....--- —..... —....---.-..—.———.. ——— ———... 90 magna._——._—— ——————————_—— —— —...—— 9,135-136 insulcata, Gemma magna..—__—.... —...———————.——...- 15,137,pi. 19 tosulcata.--—.—- — ———————— ————— 15, 137, pi. 19 Introduction_..__-_-——.-,——..—.--..——------— ------_- 1 majorlna———— ——————————————— 15, 136-137, pi. 19 Ischadium_.. —— ———————————— —— —————.... —— _. ——. —— —._ 29 virginiana.__....——._._-—..————_...._.. 16,136, pi. 19 Isocardia--.——...... —.——.——————.——————'_. —————— 11,67 verdevma———————————————————————— 138, pi. 19 Cardium.--...-.——.————....—————..-—-——————- 91 gemma, Venus_——————————————————— — ————————..—. 135 (Trachycardium)...-----„---—„.—.-.—...... 15,91 Geologic ranges of certain species—.—.—.———.....—.—..„ 13,14-16 (table 2) Carolina__.._. —.. —. ——— — ————- — --—-. —— —..——— 67 gibba, Ostrea__-———.——————————.:———————————.._ 31 conradi..——...——. ———— ———.--... —— —.-. —. ——— . ——— 67 gibberosa, Sportella.._-...-...--....-.._.—...—...... _. 15, 84-85, pi. 14 gibbus, Pecten (Chlamys)..———....--.....--...-.....—...... 31 fraterna—— — ,————————- — — —————— 5,7,15, 67, pi. 11 Peeten (Plagioctenium).————.-..„————.———.——_„_ 14, 31, pi. 5 Carolina. — .——————— — ——-————— 9,11,15,67-68, pis. 11, & Solecurtus (Tagelus).-.....—„ — — ...„.„...... —...... 107 glenni...-..... — — ..————————————— — — — 15,68, pi. 16 Solen———...... ——..————.————.———..— 107 rustica.———...——.——————————————————————————— 67 Tagelus—————..—————————...... 16,107-108, pi. 22 isocardia, Trachycardium...———————.——————————————— 91-92.pl. 15 gigantea, Mactra.___——...—————————...... ———————...... 110 Venus______.___.....______122 Qlans..——————...—.———————.—...... —...... ——.. — .. 69-73 jeffersonia, Chlamys (Lyropecten),___..__._...—_———.—. 32-34, pl.4 (Pleuromeris) tridentata_——..—.————...--.___„__.__._ 70-71 jeffersonius, Pecten-.———...——.———.—————...... —— 6,7,9,11,12,32 tridentata decemcostata._.___..______.___.... 70,71, pi. 13 Pecten jeffersonius...——-. ———— —— ———— —————— --————.—— 8 (Pteromeris) perplana.______...______72, pi. 13 (Lyropecten)---——————————————————————————————— 33 perplana abbreviata______—______72-73, pi. 13 johnsoni, Nassa___—-- ———.-- —— —— ------—— ————— - — —.—— 8 glenni, Isocardia fraterna______:.. 15, 68, pi. 16 Glossus rusticus..___.___—__———...__..___...__._____ 67 K Glycymeris.-.----.------.--..------...------.------.-...—...... 26-28 Kellia triangula. .——————————————————————————— 82 americana...—.—... —— .-..—...---.-..--...--—_ r——.. 10,13, 27-28, pi. 1 Kennerlia------.————— ———————— — — —— — ——— —————— 45 Area______-______-_.-____-_-___-___-_ 26 kiawahensis, Lucina_.-. ————————————— ———— -- ———— —— ———— 81 duplinensis______14, 27, pis. 2,5 Kuphus..———.....——...... —.....——————————...—.— 143-144 laevis——————————————————————. 14, 26-27, pi. 1 calamus—————'j—————__....„.————— 6,9,10,16,143-144, pi. 23 orbicularis_.___—___.._——_——„.—.—.——_—__-... 26 subovata______.______6,7,10,12 plagia...... __..__—————————————--.-———.—_— 7,9 Laevicardium.-.______.___-__—————————————.————— 93-94 tuomeyi______—__—__——_____.__-___... 9,11 sublineatum.—.———.—————...... ——....————————— 94, pi. 15 tumulus-.....--....-.-.———————————.—————— 6,13,14,27, pi. 1 laevis, Glycymeris.....—————— L...... 14, 26-27, pi. 1 goldfussli, Panope___———.———————.——..——.-——————..—— 12 Nucula.-____-_——__—.----.—————..——.-.-—-————— 21 gouldiana, Pandora______...__.______._____ 49 Pectunculus.-_...__——...—..-. ————————— ——————— ——— 26 grande, Crueibulum______9 Yoldia...——————————————————— — -—- 10,14,21, pi. 1 jgranifera, Hyanassa______.___—__—__—__——_—__—— 8 lapicida, Venus __———————.————————————————————————— 116 graniferum, Cardium-._.--...-.--.-_--..--..----__...___._ 93 laqueata, Ptychosalpinx..————————————————————————,-,—-. JO 401033—43———15 174 INDEX Page Pag* laqueatum, Cardium...———————————————————————————,— 90 majorina, Gemma magna—-_——————--—.——...... —— 15,136-137, pi. 1* Cardium (Cerastoderma).._——————.———.————....—_._. 90 Myaalto-..—-.———.—-.—— ———.———..—. 16, 86-87, pi. 14 Cerastoderma—————————————————....———.— 90, pi. 16 Pandbift(Clidiophora) crassidens...-.----..---.--..-.—...... 47-48, pi. 10 lata, Eryilia——.—.——...... -....—.———...... 16,116-116, pi. 23 Mangilia ak. magnoliana.----...------.-—...... ---.-.-.------.-.——.... 12 Semele--.___.._——_ ——...——.—————.—.._...__._ 102 marginata^Plicatula.—„...... —...... —.4—.. 9,10,14, 40, pi. 11 lateralis, Mactra.-————————————————————————————...—— 113 MarginenlTbella—————.————-————-—-—————_ 8,12 (Mulinia)------————...... —...... —...... :...... 113 limatuia.———..———————--—-———-———-—- 8,12 latisulcata, Euloxa.— .___..__—__—————___.____ 6,65-66, pi. 15 Martesia--.——— —————.—————————————————.—— 142-143 Venus...-.—— —————.——————. ————————.————-----— 65 cuneiformis. ——————————————-—-——— 16,143, pi. 23 lazurus, Chama.—-.-_-----_——-.-——..-——-----—___.____ 88 Maryland, Miocene stratigraphy of, summary of.——.————— -————— 1-2, 18 leana, Anatina_------—— ------_-.-__-- 42 marylandjca, Chlamys (Placopecten)__——..—.—————————— 38, pis. 5, 6 Diplodonta...____._____-______._____ 15,80 Septastrea._„.._.————————————————-——————-—— 9 entiformis, Pectunculus..-—_——-..——--———__—'.______27 marylandieus, Conus____.__—..—. ——————————.————— 7,9,10,13 Lepton (Fabella) constricta-..___-.__.-..___-______83 Crassatellites- —..-——————.—————.—————.-. 5-6 lienosa, Anadara-....__——__——-_.—------—._____ 23-24,pi. 2 , Pecten-,-...—-——.—-———————————————- 38 Area-..-._——-———--. ——.-———-——-----——___.____ 24 (Chlamys).--....-.--.—-—————————------—————... 38 (Anadara)-- 23 (Placopecten?)...... ——...————.. 8,14,38 (Scapharca).. 14 maxillatum, Pedalion..,-——_———.————————————————_—— 8,6,7,13 Scapharca.. -.— 23 maxima, Ostrea_...... —.. ———.. —— -- ——— ———— ————————— 30 limatula, Marginella. 8,12 media, Trfeoniocardia (Americardia)...—.—_—————....————.—— 93 Nucula...... 21 medialis, Cumingia.-_—.—————————————————————————— 12 "limatula," Yoldia.. 21 medium, Cardium..___.._—.....———————————————————— 93 lineata, Astrangia.... 9 Cardium (Fragum)..—.....———..—.-.------.-----_—....——.— 93 lineolata, Astarte__ 61 meherrinensis, Astarte hertfordensis—.——.—————————————— 14,54, pi. 12 Xiirosoma sulcosa.... 10,11 Mercenaria.— ———————— ———--..-— ——.—....—...... 130-135 lithophaga, Venus... 116 carolinensis_..__..-_————————————————————————— 132 Lucina cribraria— — 78 notata—.. ——— ...... —.————...—...... I——... 130 kiawahensis__- 81 percrassa..._...... ——..————————————————:———————— 132 multilineata..... 78 tridacnoides-______—_———————————————————— 132 soror.. --..--.----._..._-..-_--.._— ——— — —_...._.._. 81 mercenaria, Mya..._._-_------——— -- —— ——— —— — ——— —— 138 tenuisculpta__-.-_._--.-.-_-.-.._-____-.__._..__._. 78 Meretrix sayana_____~__———————————————-———————— 124 (Lucinisca) cribraria______....I______. 78 Mesodesma..___.._----_... —— — ——— ——— ————————— — 115 Lucinisca_____.______.______._____.______. 77-78 spatha______--.______16,115, pi. 18 lucinoides, Psammocola.. —— — — --—_------.--...-.-----.__.... 80 mieroimbricata, Ctena.------.------.—------15, 76-76, pi. 13 lunata, "Drillia".---.-..____-...___._.___-...._....__. 7,10 microreticulata, Coralliophaga?.------14, 66-67, pi. 9 lunulata, Astarte_.____.._--....„.-...... „._._.______. 62 middlesexensis, Pectensantamaria—.--.-.--..--- — ------—. ——.-..—— 6,7 lunulatus, Crassatellites (Crassinella).._...... ____...______. 62 mUleri, Anachis...... ——————————————————— 12 lunulata, Crassinella_.____.----...... „....._..._.....__ 14,62-63, pi. 19 mitchelli, Calliostoma... — ...—...... ——...——.—.. — ..——.——... 9 lupina, Venus..__.._.__....__...... _..... — ...______. 79 Mitramorpha, mltrodita...... —————— —.. —.— —————— --.—— 8 lusoria, Tellina.._.....__...... __.....___...... 98 mitrodita, Mitramorpha_--._.-—.„.... — .——...—————————.——— 8 (Peronaederma).._...... _..._..___.___.______. 99 modicella, Spisula (Hemimactra)-———... — —— .'...—- — ..—.- 16, 111,pi.23 Lyropecten.._.___...... _...... 32-34 Modiola carolinensis.__.....—-———. —. ————. ————————— — 29 estrellanus_.__.__._...... _....___...._..__._____. 32 sulcata--———————.—————————————————————————— 29 Modiolus ducatellii—...... ————..—...———.,——— — . 12 M pulchellus.------— — — -.- —————— -- ———— ---- ——— -- 9 macilenta, Tellina (Angulus).__---..__.--.__.______...... __. 97 Moerella——————.————————————————-——— 94-98 Tellina (Moerella)------.---..--..-.--..----..---.---.--...... 97, pi. 17 Monia..—______—. ————————— -——————————————— 41 Macoma._—------___...._...... _.-...____------.____.__ 98-100 mortoni, Amusium_____.._——... —————————————— _————— 39, pi. 8 carolinensis.----.-----...-._--..----.--..-...... __-_...... _... 100 Pecten—------——------39 conradi.------_...... ______99 (Amusium)....-.————— ——— ———————————————. 14,39 cookei..--.-.—...... - — .....-—...... 16,100, pi. 17 Mulinia— — — ——— —————————————— ———————— 113-115 tenera...---..--..-.------..------...----...... -...... 98 .—————— —— —————————. 8,9,10,11,12,16,113-114, pi. 23 virginiana...—-—— — __-_- — ___--_._-_.___._._.-______16,98-99, pi. 17 ma,gnoliana__.----._ — -•.....-- — — — -___ —— ------——. 114-115 conradi....-.—...... —...... 16,99-100, pi. 17 crassidens-_—„ ——._-_ —... —. — - ————————— -———————— 113 Macrocallista.—__-.____.__._...__.....______._.___ 122-124 triquetra--__.__—_ ———————.———————————————— 113 reposta...... ——_ — -—___ — _—_ — ___—_ — _____._——_ 15,123, pi. 19 multilineata, Lucina.._____...... ————————J——————————.— 78 (Costacallista) emmonsi...... ___..._._.. 15,123-124, pi. 19 Parviludna—————. — — — .— ————— ——————————-- 79 Mactra...-__.._.....__...--._._.....__._.__.____... 109 multilineatus, Phacoides (Parvuucina)..——————————— 15,78-79,pi. 13 congesta._...... _._....___ 113 multistria|M8, Phacoides—.—-————-———————————— 12 crassidens.--__.__...-._...... ____.._.....______,___ 113 Phacoides (Cardiolucina) trisulcatus.___.-.._———.———— 76-77.pl. 13 donacia..__...... __.___._._...... _..__..._...___ 115 (Cavilucina) trisulcatus-_———————————————————————— 9,15 fragDis.__'.„...... ___...___._..__.._...... ______109 murfreesborognsis, Phacoides eontractus—. ——— —.——————————— 11 gigantea...... 110 muricatum, Cardium__------———— — — ———— ——— — — — ———— 92 lateralis...... ____-.-__.._-.._____------_----...... __... 113 Cardium (Traehycardium)-. ——— ————————— ——————- 92 similis-...... _ i...... __-______.__.______.... Ill Trachycardium.——————————————— ———————— 92-93, pi. 15 solida...._--.--__-.-_.....---...... --.-._...... _...... __. 110 mutabilis, Seaphella (Aurinia)..— —— ———— ————————.——.——— 9,12 solidissima.---.-..---.-.--..--.----..-...--...... _.. 110 stultorum.-_._....___...... _____.__.____.____._ 109 mutica, Olivella———————————————————————-————————— W tenuis..__.____...._.__..______.______103 Mya————————————————————————————— 138-139 triquetra..___.__.._.___...... _____._.._...... ___. 113 acuta.------—... ————— - — ——— - — — ———-——— — ——— -- 138 (Mactrotoma) fragilis____..___....._...... ______'109, pi. 18 arenaria... — ——————————————————————— 138-139, pi. 22 fragilis precursor...... ___...___-„...... _ 16,109-110, pi. 18 corpulenta._—....—. —. ————... ————— - — —— -——————— 138 (Mulinia) lateralis...______...... _..---.--.-...... _. 113 mercenaria-----_._ —... -,-————————— -———- — —————— 138 Mactromeris._.-.-_.__._____._-.-.....--...... _.._...... _... 112 truncata...--.... — „ — —— — —.... — — — ———..-..-.- ————.. 138 Mactrotoma...... ______.__..,.-..__.....__.___._.__...... 109 myrmecoon, Drillia". —— ---———— — -——— —— -—-- ————— 8 maddelysensis, Thracia.-.-..__.._.__...... _...... _____ 14, 44, pi. 10 Mysella..--. ——————————— ————————————————— 85-87 madisonia, Chlamys (Lyropecten)______..._...... _ 32, pis. 4, 9 anomala..------————————————————--———————— 86 madisonins, Pecten_...... _....__-.-..----j-...... __.... 32 bladenensis—_...——————__———__...... —————. 15,86, pi. 14 Pecten (Chlamys)....__.____.______...... ______32 majorina—————— — —————————————— 15,86-87, pi 14 (Lyropecten)...... -...... 5,14,32 stantonl.———————————————————————— 86, pi. 14 magellanicus, Pecten._._____.______...______37 v61aini—------_-_...———.——————__ — ....———.— 16,86, pi. 14 magna, Gemma.-______._..______9,135-136 Mytilus conradinus...—.——————————————.————————————— 11 magnoliana, Anadara...____.._..__--..-______25, pi. 3 deeussatus-——————————.——-——————————————————— 30 Mangilia, aff. M_...... _...... 12 hamatus__—.———.—————————————————————————— 29 Mulinia congesta.....______...______. 114-115 (Horinomya) hamatus.....————————————————————————— 29 Spisula (Hemimactra?)...... ———.————...... 114 recurvus-.-—.———.....———.„..„,;.„,„———.—.——... 14 INDEX 175 N Page * Page nansemondensis, Crassinella____..:_...... ______15,64, pi. 13 P[anopaea] cariboeus...______«.______.___—_____ 107 Nassa cf. johnsoni. ______...______.______8 Panope jjoKlfussii______._.. 12 nassula, Flssuridea, near V,...... :______7 reflexa. —— ————————.——————.— ——————— 10 naviculoides, Pandora (Kennerlia)...______.....__._ 14,46, pi. 10 parilis, FuSinus. —— —— ——————————————————————— 13 nexilis, Semele______.______i__.._.._____ 102 parva, Cnj|>ne— .———————————_——————— —— —————— 128 nlmbosa, Venus..______.____ 122 Venus :>...... ^... 128 nitidula, Oliva—....-__..-.-.._...._...... _...... _ 12 Parvilueina...—...... -...... — ...._...... —... 78 Olivella.—.—...... —.....—...... —...... 8,12 multilineata.. —.______.______79 noae, Area,______..___.....__ 22 passus, Pectunculus.-____------__-___-.___.---_.._.. 27 Nodipecten....___.______'34 Pecten.-.————— ——.—————— —— —————————- ———— 30-31 nodosa, Ostrea.______34 clintoiuus. 37 Nomini Cliffs, Va., sections at..______5 comparilis___. 37 norvegieum, Cardium.______...______._ 93 decemnarius_ 31 North Carolina, localities in.______.___ 17,18,19 dislocatus.___. 31 notata, Mercenaria..______....______.______130 dispala,tus—__. 31 Venus.———— —— ————__._...... -.---....----...- 130 eboreus bertiensis. 12 (Mercenaria) mercenaria.—______15,130, pi. 21 coipparilis—.. 37 nucea, Venus plena....__.___.______.... 134 eb'oreus.______.______.___..___ 8,9,11, 12,36 Venus (Mercenaria) plena______.______134-135, pi. 21 urbannae"nsis- —_-....-__-...--___--._---.—...... _.... 6,7 nucleus, Area.______19 6 Nueula.__.______.______.___.._ 19-21 yorkensis-. _ ------— — . _ .... _ . _ . ______10 diaphana...---.------._-.-.-..----...... --..-.--.----..--. 20-21,pi. 1 ernests.mithi _ __ ..--.---. _ ... .. __ .. ___ ..--- ______.... 34 laevis______.______.______._____ 21 holbro$kii. --.-.-—. ——— . ___ — __ . ___ — .. — ...... — — .... 36 limatula._.______._____.______21 irradians dislocatus— —— — ______— — __ __ — — 31 obliqua__.______...______..__.. 19 jeffersanius— ... ___ . _ .. __ . ______• ___ 6,7,9,11, 12,32 proxima.-.--.--__.....-.-.-.--.....-.-....----.-.--.....-.-. 12,14,19-20, pi. 1 edgecombensis _ .-----.—._ _ _ .. __ ...-...-.- _ .. _ . _ ... 8,9, 10, 12 Nuculana acuta..______...._____.______.__ 9,12 jeflersonius------__ _ ------_ .... _ --- ______-.. _ .... 8 nuculiformLs, Abra..._..__...--.-._..______-,.-._____.__ 104 septenarius— — — — - —— — -... — — — -.— — ———————— .... —— . 34 nuculoidea, Seinele. __.______.._____.___.__ 102 32 nueuloides, Amphidesma___.__ __. ______102 mageilanicus. __ . 37 Abra...... —1....—.————..——.-—..————.—....— 102 marylandicus— — 38 Semele-..-.------.-.-----.-..---.----.-..--.----...-..-.--..-...--...-. 16,102 mortoni- — - __ .-- 39 (Semelina)--—————- — ———————— —— .—— — . 102-103, pi. 17 princepoides-— — 37 Semelina...__.____.______102 raveneli------—. 14,30 nuperum, Solarium—...._—....——..——____.__.______.. 11 santai|iaria— . —— - mjddlesexensis. 6,7 0 septenarius- — .... 34 obliqua, Nucula.______.______19 viceharius— —— _ obovata, Cytherea_.__..__—______120 virginianus- 38 Dione.______.______120 30 Dosinia.—..———.....——.—...—...—.—.—...... —...... 120 (Amusium) mortoni— 14,39 obruta, Astarte___..___._-______._ 5 (Chlamys) clintonius. 37 Astarte aft. A___.__—_...__.._____.______.. 6 cbmparilis--_f—— —:i:™ 37 Oedalia subdiaphana.——————.——._—__..__-.___.__.__... 119 deeemnarius..------______.______9, 10,31 Oliva eboreus______.___..______.______.. 13 eboreus eboreus_—— —..__....-'--..-__._____,...... , 36 nitidula.-.—--——.- ——--.-———.— —— — ——————— 12 ernestsmithi_.__..__'______T______34 sayana...—..————————————..—..—_—_..__.._— 10 gibbus,.——————————-__._-—--.—-______31 Olivellamutica.——————.—.——-———.—...————.—. 12 jefiersonius septenarius—_..______34 nitidula--.--- —— — — ———--.- — -.. — -.——— — --..——— 8,12 madisonius------.----_-_.______...__...... 32 ornata, Trigonulina...... _—...—__..____.______.._..... 50 marylandicus_ — — _____._....______.. 38 opercularis, Ostrea_—.... ——.—-.----.-.-.-.._.._.--.._.._.... 35 virginianus.———.______-_____.-...... 38 orbicularis, Qlycymeris..._ — _.__...___._____._.____..... 26 (Euv^la) raveneli...__.__._____.______30, pi. 4 Ostrea-..-----—------_...... _...... — ...... 11,41 (Lyrqpecten) jeflersonius....__._.__-___...______.. 33 disparilis-.——.—————————— — — —— -- — ——— — —— 6,7,9,10,11 jeffersonius septenarius.______.______.______.. 14 edulis...... —————.———.——— ——— .——.—— -- —— ——— 41 niadisonius———.._..._.____.______5, 14,32 gibba———— — — — — ————— — — ———..————————... 31 (Nodipecten) ernestsmithi....__._..._....__..__...__.. ._... 14 maxima___.._.---.-.----..--._ — — — —— — — — ——— — — — 30 (Pectin) raveneli.-—---.__._._.______...... 30 nodosa-_____„-..„-.__——_..__.__..._____...___ 34 (Placdpecten) clintonius.___.. ______.______.__ 6,7,9,11, 14.37 opercularis-...._____._____._..._.____.______35 marylandicus__..._-..---.__...... _..__——__. — 5, 14.38 pleuronectes—— — ------.- — — _..___------_---._.-.. — - — 39 virginianus ...———...______9,10, 14,38 sculpturata.- — _.___._____._.______.... 8,9,10,12 (Plagjoctenium) eboreus_ __.______.__.______14, ^6 waeeamawensis—.___...... __.______.____.__.. 14,41, pi. 3 gibbus-— ...... ^...-.. 14,31 pi. 5 ovalis, Abra—______.______...______.--—'....- 101 planicosta.... ————..__.____...______„_____ 14 Erycinella. —- ———— ———————— ———— — — ——- 15,73-74, pi. 14 Pectunculus albidus——______.______...... 122 ovata, Pleiorytis—————.———..—-—————- ————-- — 118 americanus.———.---.------._.______-.----....._. 27 Venus..-..-..-.-—...... ___.——.———_.... 128 laevis..———————,—_____.__.__.____.______...... ,26 ,.2727' pandata, Cytherea. ___ . ___ . _ . __ _ . ______123 pulvinatus___—.——— — _.._.__..___....._...... _...._ 27 Pandora. ______44-45 quinquerugatus.-.-— ——....______.27,28 arenosa— —— .. —— _ .. . ______— — _____ 45 sulcatus... 51 bilirata—— ————————— -————— ——— -.— . —— -.——. 45 tricenarius- carolinensis _ ___ .. ______45 tumulus—. crassidens.. . ______46 undatus... gouldiana. . ______49 triltaeata. — — -————-— ——.——-— —— — — — ——— 48,49 Pedalionmaxillatum...______'... ___ 5,6,7,13 (Clidiophora) crassidens-... —— — ...... — ...... — .——...„ 46-47, pi. 10 Pelecypoda (incertaesedis)...._.-----.---.-.....__..._.-.—----.. 74,pi. 14 crassidens majorina.. ______47-48, pi. 10 pellucida, Erycina_____._____.______-— 81 floridana.— ______. ___ .. 49 peralta, Aleetrion..—....______.___....______13 prodromus ___ .-... ______...... _ ...... 48, pi. 11 percrassa, Mercenaria____...._._...... _._.... 132 trilineata.— ... ——— ...... 48-49, pi. 11 Periploma...———————.——————————————. 42 tuomeyi. .----. ------_ —-..„...„—....—.„ __ 48-49, pis. 10. 11 antiqua.....__.__.______.__...______.___.. 42 (Kennerlia) arenosa ______14,45, pi. 10 inaequivalvis..-—- — ---._____.______.._------42 bicarinata.. ______.. __ 45 (Cochlodesma) antiqua....._._._-.--.__.______— —. 42 dalli————————— ——— — ——————————— 14, 45-46, pi. 10 perplana, Astarte___-___1______-____ 7,13 navicnloides — .. —— _ — _ .. ______14,46, pi. 10 Cardita-.——.---..-....——...... __——. ————— ——— .._... 71 176 INDEX Page Pasre perplana, Astarte—Continued. propeparilis, Fusinus...... ——.. ——— ---... ——. — —— ——————————— 7,9,13 Qlans (Pteromeris)-._____.__—— —_____.__.-..-._.. 72,pi. 13 propetene.lla, Tellina (Angulus).—. — ——.——.... —— - ——————.—.— 96 Pteromeris__------_._ T ——_-.____---.._._...... 15 protracta, Anadara.- ——... — ——— ----- — — —— — —————————— 24, pis. 2,3 Petaloconchus sculpuratus-.___.__-__...... ______._.__ 8 • Area..------— —— — — — — ————--——--—.——„.- 24 Petricola.———————.———————————— — ————— 116-118 (Anomalocardia)...... _ — —.. —— — ------—— — — ——..—— 24 centenaria.--.___.___.-.___ —._....___„__..___.. 118,119 protracta, Donax_------— ------— -_-. —. — —-. ———— — — —— -... 106 carolinensis...______...______.______..__ 118 proxiina, Nucula..—--. — — --.—-——- ——— ————— 12,14, 19-20, pi. 1 eompressa_...___------_-..._-_..___ ...... __ 85 Psammocolalucinoides—_-_--_—-- — --—— —— ——— — —— —— -.——— 80 fornicata.______..._.__.__.______.__ 117 Psammotea dubia_- ————— -. —— ------—— — —— ——— ...... —— 83 pholadiformls__.._____...._...... 117 Pseudochama—__-—.__- — — _-— — — — - —— — — ------—— —— —,- ——.. 89 (Claudiconcha) grinnelli-.._____._...... __------_ 117 corticosa__.______—._____-______—__———— 15, 89, pi. 13 (Petricolaria) carolinensis_...... _....._-.__...... __-___. 118 Pteromeris----. ——_- — ------— - — _... ——— --- —— ———. ——.... 71-73 pholadiformis__------...... 117-118 perplana—--_-.--.--..------.„.- ———— —— ————— - —— ——— --.... 15 (Rupellaria) grinnelli...... -. ——.-...... -... 15,117,pi. 15 abbreviata_-.....-.--.-.------„------.----. — ——— ——..—— 15 harrisii...... _____.______-_.__._ 119 Ptyehosalpinx altilis——.... —— _————————-—————-—————————— 10 Petricolaria_.————- — .—_-_-_._-_._----_-_——— — _ — — . 117 laqueata.------—— ——.... ——— ------—— - —— — — ——— —— — — — 10 Phacoides—. — ——— — ———————— ———— — —— — ———— 76-79 pulchellus, Modiolus--—.-—------—.... —..-.---.. —— —. — — —— -. 9 anodonta.__.______.___.___.___..___. 9 pulvinatus, Pectunculus-—....—— ——————————————— -——————— 27 crenulatus—— —__._------_._...__._--._.._.....__ 5,9,11 pygmaea, Venus.------—— ------———— -. ——— —— — — ———— -— 128 multistriatus. __ —_....._-_.__...... _.____...... 12 pyrenoides, "Drillia"-—_.- — —— ——— - — ——— ————— ——— -——— 10 (Cardiolucina) postalveatus_____.______._____ 15,77, pi. 13 trisulcatus multistriatus—------__-_———___.--.-.... 76-77, pi. 13 Q Phacoides (Cavilucina) trisulcatus....__.__._.__.__...______15 quadrans, Cardium.————.———————————————————————————— 91 trisulcatus multistriatus-______...... •_.._.___...... _.... 9,15 quadrata, Bulliopsis.-——... — ——- ———————— — ——— - —- — -————— 6 (Lueinisca) cribrarius—.. „..__—— —— .„——————_____ 7,15,77-78, pi. 13 'quadrigenerium, Cardium-- ——.. —— - — —— —— ------—— — — ——— ——— 92 Phacoides (Lucinoma) contractus__....._...______.._._ 7,10,11 quadrisulcata, Divaricella_...._..—.. ——— ------————— 7 contractus murfreesborognsis_----.------.-----.------.----.. 11 quinquerugatus, Pectunculus------——... ————-- — ------—————.. 27,28 (Parvilucina) crenella__...... -...... _-...__..-_...-...... --.. 78' multilineatus—___.___...._.______.__ 15,78-79, pi. 13 R (Pseudomiltha) anodonta-_____-__-______.______... 6 radiata, Ervilialata...—...—.—.—————.—————— 16,116,'pl. 23 philanthropum, Calliostoma._.______.._____-___._.__... 9,10 Tellina.--————————--——————— —— — - ————- 94 philippi, Pododesmus (Monia?).___....______...______.... 14,41,pi. 3 Rangia clathrodon__------—— —— - — ————— - —.. —— ————— -——— 10 Phlyctlderaia---———— — —————— ———— ——————— ——— 81 rappahannockensis, Astarte (Ashtarotha). ——. —— - ——— —— _. 14, 66-57, pi. 12 pholadiformis, Petricola...... _...._....____------_--...... -... 117 Spisula (Hemimactra)----.------16, 110-111, pi. 18 Petrieola (Petricolaria)----_...... __..._._...... _._ 117-118 raveneli, Pecten___ — — — ———. — —— — ————— — ------—— - ——— — 14,30 Pholas acuminata _____.______-______...__..-_____._.. 141 Pecten (Euvola). —..-.— — -——...... — -..„.——.....—. 30, pi. 4 arcuata——____------___.._-----_------__...... 141 (Pecten)..—- — - — - ——-————————-——- — --— 30 candidus______------__ .... _..._-..-...._.._...... _.. 141 recurvus, Brachidontes (Ischadium).——-..—-.....--—————-.—— 29-30, pi. 1 clavata.______.______.______.____ 142 Mytilus (Hormomya).- —. ——— -. ——— — —————— ——— ————— —— 14 costatus..______.______..______-_.. 141 redimicula, Fissuridea,...——— ————— ——— ——— ————————— -. 7,9, 10,11 crispatus___..___..______.._.._._...... __ 142 reflexa, Panope. ———— ——— ——————————— — —— ——————— ———— 10 cuneiformis___...______.______143 rcposta, Cytherea__—————— ————— —— — ———————————————— 123 rhomboidea__...__--__------___..__....._....____ 1"42 Oallista(Callista)..--———-..—-.————.——.—————— 123 striatus—— „.————————_.———... —... — ———— — _ 142 Dione..-—————————-—-———————————- 123 piesa, Tellina (Moerella),_.__....______.______,_ 96 Macrocallista—--——..__————.—....—------——.... 15, 123, pi. 19 pilsbryi, Turritella.....______..___...______.. 9,13 reticulata, Tellina..———————— —————————————— 100 Turritella variabilis—————— ———— _—_-—— — _-— — - 6,7 retusa, Corbula (Caryocorbula) conradi———————————————— 16, 140, pi. 23 Pitaria (Pitaria) sayana.'--______....______.____._.. 124 rhomboidea, Aligena._...—._———————————————————— 15, 87-88, pi. 14 Placopecten.-—. —____-._____.______...._____.... 37-39 Fasciolaria___—-... ———— — ——— - ———— —— — — -- ———— -—— 8 plagia, Qlycymeris subovata.____------_------_------7,9 Pholas--.- — --—————-— — — —————-—-——-—- — -— 142 plana, Crepidula- —.. —...... -.-...... 10 Zirfaea——————— — ———————————————————— 142 planicosta, Chlamys (Lyropecten)___.______._..._...... 34,pi. 9 rileyi. Venus.... ———— — —————————— ——— ———€-—— 6,10,130 Pecten (Plagioctenium).______.____-___....__-__...__ 14 Venus (Mercenaria) campechiensis__——.——————-———————— 130-132 plebeia, Turritella__.______.._.____------____.__ 6,13 roanokensis, Astarte.... ——— - —— —— -- ——— —— —— — — ————— 14,53, pi, 12 Pleiorytis———...——. — —...... - — ..-..-...-..-...-.—...... 118-119 Rochefortia—__ ————————————————— -————————————————— 86 centenaria.___...______._____...__...___ 7,10,119, pi. 15 australis—..- —— — — —. —.———-- —. —— — — -.-..- —— —— ———— 85 ovata______-______-.___._--.______.___ 118 stantoni.--.-- —.-. —— ------—. ——.. ——. ———— - ——— — —— ——— 86 plena, Venus (Mercenaria)------_------___...... 5,10 rogersi, Verticordia (Trigonulina)———-———.———————————— 14, 50, pi. 10 Pleuromeris.—______....___.__-_.....___._.... 70 rudis, Pododesmus-----——-———————————————————————————— 40 decemeostata.______._-_____.__.._....._..... 70,71 rugosa, Donax..--- — ----- —... —— -.... — — — — — - —... —— —...—— 105 tridentata...__-..__...-__------_...... _..__...... 15 rugosum, Busycon corona turn.-.-- — -. — —— — —— - —— - — —— —————.. 13 decemcostata.--.____-_------_——„_ — — _ — — _ — 15 Rupellaria——————————— ——— —— ——— —————— — — — 116-117 pleuronectes, Ostrea-— — _ —— ------_...... 39 rtistiea, Isocardia.. ——— — — —— —— - ——— —— — ——— —— — — —.—— 67 Plicatula.-. — — ..- — .—- —.....'...... i.. 39-40 rustious. Glossus..------——— — —— ——— — - — ------— - —— ...... 67 marginata..—...... 9,10,14,40,1-1. 11 plicatus, Spondylus._.______-_-----_------______.... 39 pliouema, Caryatis.--.-__..—._.—._...._._...... ___.... 124 Pododesmus—-___-...--__-__,..._------_...... 40-41 St. Marys formation, description of.———————————————————————— 6-7 decipiens...-._...._._-.------.-..--.------.-.---._____---.. 40 fossils in______————————————————————————— 6-7 rudis.------40 Shattuck's zones in_ ——. — — ———— ——— ——— -- —.- —————— ——. 5,6 (Monia?) philippi———— — .„ — -.---..----...- — ..-.-.----... 14,41,pi. 3 stratum A in...... ———————————————————————————————— 6 polita, Angulus.______.______..______96 zone 1 in_—_—._____—. — ____—--———-_-.. — -.—-— ———--———-——- 6,7 Tellina----.--—...... —...... — ...... —...... 95 zone 2 in ....______.._—__———————-——————————— 6,7 (Angulus)______.___-_.-___._..--_.--__---..___. 96 santamaiia, Pecten- —_ — - — - — — — — — — --_- — ------——. —— - — — — 6 Polynices duplicates___.______------_-----_-__.. 9 sayana, Calloeardia—— — - — ------—— — —— ——... — — —— _„. — _— 10,12 heros-_____.______.___..______.__-___ 10 Callocardia (Agriopoma) ———— — —<-————————— 124-126, pi. 19 polythalamia, Serpula._..----....----....-.----....----....-._--.....---... 143 Cytherea—— — - ——— —— — —— --- — — -—————————— 121 postalveatus, Phacoides (Cardiolucina)-__-__...--.-...... _... 15,77,pi. 13 Cytherea. — ——— — - —— — —— —— --——————-——------124 preaequilibrata, Donax emmonsL---.--__.___._------16,105-106, pi. 23 Dione.-- ——— —— — —— —— — ——————————————— 124 precursor, Crenella._._...... ______._____..____ 14,30,pi. 3 Meretrix...————— —— — ————— ————————-1——- 124 Mactra (Mactrotoma) fragilis.------16,109-110,pi. 18 Oliva.__-____,______10 princepoides, Pecten_.—.- —— ------—.--. —— ------— ———.... 37 Pitaria (Pitaria)- — — — — ——— — —— —— —————— — - 124 prodromus, Pandora (Clidiophora)___..__—____.______-_ 48,pi. 11 Venus————— — ————— — ————————————————— 124 proflcua, Tellina------..------100 sayi, Tellina.___-----——————————————————————————————— 96 propatula, Area _------_ ------—.__-----____---._ 22 Tellina (Angulus).——— ———— ———--————————---— 96 Barbatia (Granoarca)------...... „---...-.—.-.-..-..-....- 22-23, pi. 2 (Moere.Ha)————————————————————————— 16, 96-96, pi. 17 INDEX! 177 Page Pajte scalaris, Anadara (Cunearca)—————— —————...__.....—__ 26, pi. 2 stephensoni, Astarte..__———__————..————..—————— 14,54-55, pi. 12 Area-...—...... __._...... _...... __...... »__....__.__ 26 stevensoni, Caecum...... ———_—————.————————————————— 10 (Cunearca)______.______26 Stratford Cljffs, Va., sections at___—____..._.__————————— 5 (Scapharca)..______.______.______14 striata, Aligena..———. ———————————.——————————————————— 87 Seapharca..—______.___.;______26 Chama..——————————————————————————— 18,88, pi. 13 Scalaspira strumqsa_.._____.______10 striatus, Pholas______——.._———..—————.—————————— 142 Scapharca lienosa______._____.______23 strumosa, Scalaspira.. ——————.—————————————————————.. 10 scalaris.______...__.....______26 stultorum, Mactra___...____———__——.....——————————— 109 (Scapharca) callicestosa___.______24 subdiaphana, Oedalia..__—...—..————.—————————————————— 119 carolinensis______.....___._..______25 sublineatum, Cardium...... ———.——————————————————— ———.. 94 Scaphella (Aurinia) mutabilis.______...... __.______9,12 Cardium (Laevicardium)___—...... ————..—————————— 15,94 schizopyga, Ilyanassa.. ______._.._...... _...... ___ 8 sublineatum, Laevicardium.....——————————————————————— 94,pi. 15 scintUloeformis, Cooperella.-...______--.-..._.--...._..___ 119 subobliqua, Syndosmya...—————,—————————— ——————————— -- 101 Scobinopholas__.______.______.__._.___ 141-142 subovata, Amphidesma.....——...... —————.————————————————— 100 scotica, Venus_._...____..___....____...... __.... 51 Abra (Amphidesma).....______._____——...-.———— 101 sculpturata, Ostrea.______.__...... __.__ 8,9,10,12 aiycymeris-...__.._-----__——..__...... ——.—— 6,7,10,12 sculpuratus, Petaloconchus...... _._..___.__...... __.... 8 Semele...... —...... „..„.—...... „.—.. 9,10,100-101 seutata, Corbula (Caryocorbula?)...... ------...__..-....--.-. 16, 140-141. pi. 23 subreflexa, Abra—————__———:.______.__._ 16,103-104,pi. 17 Seila adamsi.______._.______.__ 8,12 Amphidesma______——___———————————————.'-. 103 Somele—-„.—„—————————————————__.__—______.__.._ 100-103 subvexa, Diplodonta__..————..—————————————————————:. 5 bella—.----.----.----..----...... -...... ,...... _...... 101 sulcata, Corbula______———.-_——— 139 beDastriata—— ...—... —...... 16,102, pi. 17 Modiola—-——————————————.....———————— 29 cancellata._____.______,______102 sulcatus, Pectunculus__—— ——————————————— ————————— 51 lata...... ^-...... 102 sulcosa, Lirosoma____...____——___————.—————————— 10,11 nexilis...... __..______...... _...... _____.... 102 surryensis, Crassatellites meridionalis______————..——————————— 6,7 nuculoidea.______._____ 102 symmetrica, Astarte.-__——...__—...... _-.—————... 10,13,14,51-52,pi. 12 nuculoides-______....______.__ 16,102 Syndosmya constricta.....— ——...——..———————————————————— 83 subovata.-.—----.-—-._...... 9,10,100-101 subobliqua...^_——.———————————————————————————— 101 subovata alta.__.______.______16,101, pi. 17 (Semelina) nuculoides______. ______. __ 102-103, pi. 17 T Semolina...__._-..._...... _-...... _._...__....__ 102 taeniopleura, Cardium. ..——..———————————————— 13 nuculoides.-.______...... ___.______...... 102 Tagelus—-——————...... ——....——.——————. 107 semiaspera, Diplodonta__..._.._...... _--.-..___._....__. 81 gibbus..——————————————————————. 16,107-108, pi. 22 Septastrea marylandiea_...--._-_.----_._____...... _...._...... 9 carolinensis.-._———___._____——„__—.—. 16,107,108, pi. 22 septenaria, Chlamys (Lyropecten) jeftersonia.____...... 33,34, pi. 4 Tapes grus.._————...—————.——————————————————————— 128 septenarius, Pecten_...__...... __...... _._..___...... 34 Tellina....——.—————.———————————.——..——..———— 94-98 jeffersonius. —...___...... __...... _...... __ 34 calcarea._—....._———.——————————.———————————— 98 (Chlamys) jeffersonius____...... _...__._..______34 dcclivis...... ————————————.—————————— 12,94,95 (Lyropecten) jeffersonius.______....______14 donacina...----.__..————————.——.———————————————,- 94 Serpula polythalamia..______. ______143 egena..——————————————————————— 16,98, pi. 17 sexdentata, Ilyanassa granifera____._...__..____._____ 12 fluminalis_.____——.——————...——————————————— 64 Siliquaria——..'——._...._._...... _ 107 inaequivalvis—.___——...... ————...—————————————— 44 earolinensis..——___.______..______107,108 lusoria_...——————————————————————.————————-—— 98 eariboea__.______107 polita.—————————————————————...... ————— 95 similis, Mactra..______.______111 proflcua. —————...... ——.————————.—————— 100 Spisnla (Hemimactra)..__...... — ...... 16,111-112, pi. 22 radiata..—————..———————————————————— 94 simplex, Terebra.______.____..______6,13 retieulata———————...... '———.—————.—.- 100 sinuatus, Crassatellites...______.______61 sayi---———--———————————————————————— 96 Solarium nuperum._...______._____.______.__ 11 (Angulus) declivis.__————.—————————————————————— 95 Solecurtus cariboeus______.__...... ______.____ 107 dupliniana_____.____———__———————————————— 96 (Tagelus) gibbus______.______.___....___ 107 macilenta______.___————————— 97 Solen.. ———————— —— ————— ——— ——— ——— ———————— 108 polita—.--.———.——.. ————.——————.————————- 96 cariboeus._.*.'___..______.______107 propetenella..-._————. ———————————— >. ——————— 96 gibbus______.______._____.__...______107 sayi-- — .——————————————————————————— 96 guineensis.-.-___-..--.__.-.--...... _____.___..._ 107 (Moerella) ealpix...... ————...... ——————...... 16,98, pi. 17 viridis...__.—..-...... —.-.....-.-...... 16,108-109, pi. 23 declivis..——.—.———— ——————————————————'94-95 solida, Maetra______.______...._.______110 dupliniana______96-97 solidissima, Mactra____--.-._..._...... ___...._____.__.... 110 macilentai-___...... ___.—...... ———..———————— 97, pi. 17 soror, Diplodonta-__..__-______-----______.__„. 81 piesa.-..----..__————.————— —————————————— —— 96 Diplodonta (Phlyctidenna).. ______15,81, pi. 14 verdevUla..._....._...„._.._....._..__..„.__.. 97-98,pi. 17 Lucina...._r_...._.__...... _-..._....._-...___.... 81 sayi...————————————————————...... 16,9fr-96.pl. 17 spatha, Mesodesma...______.______.____.__._ 16,115,pi. 18 (Peronaedermjf) lusoria______—~___—————————————t--- 99 speciosa, Ctena_____..._-____._____....______15,75,pi. 13 (Peronidia?) egena.— —-——_-_—————————————————————— 98 spinosa, Bamea___...... __._...... _....._...__..._ 141 tenera, Macoma. „""-"——__——————————————————————————— 98 Spisula...—.—.———————————————— —————— 13,110-113 tenuis, Mactra-...'-______——___——————————————— 103 confraga._..______.._.______.______._ 6 tenuisculpta, Lucina.______._____..—__—————————— 78 delumbis_.______....______..______....___.___ 8,12 Terebra.——————————...... ———.——...——.———.—————- 8 (Hemimactra) duplinensis...______.___.__..______112 simplex______...____————.—————————— 6,13 magnoltana.______.______114 Teredo calamus______—--___——————————————— 143 modieella———------— - — — --—-.- — --._- — — --.-_ 16, lll.pl. 23 fistula.--....----.__...__...... __———_____-----__-___ 143 modicellaalta——-. — --...„--.-.-..-...-.-.-.... — ...... 16, 111, pi. 23 terstriata, Turritella————_____-----___——___——-————---- 13 rappahannockensis..._____.______... 16,110-111, pi. 18 texasiana, Cytherea____———__——.——.———————————— —— - 124 similis.-.------.------.-.----__—————._.————— 16,111-112,pi 22 thallus, Cadulus,—..——.————————————————————_—————— 9 (Mactromeris) bowlerensis..______...1__....___.. 16,112, pi. 18 Thraeia—————...—.....——... .„.....——...——.....—————— 42-44 duplinensis...... __ 112-113, pi. 22 conradi——...... ———.„————...——...————..... 14,43, pi. 10 Spondylus plicatus,------____..____....._._____._____ 39 corbuloidea______————.——————————————— 42 Sportella...... 83-85 declivis—--——————.:.-——_____._____.—————- 43 calpix..————— — -.. — _—————_—————._——————_ 15, 84. pi. 14 maddelysensis.___-...___....———————————.———— 14,44, pi. 10 compressa.-_-.---..--____....._..._..._..__..___ 15, 85, pi. 14 transversa___——.—.——————.__.__—————-———— 14,43-44, pi. 10 constricta___——___——___.______15, 83-84, pi. 14 sp—————...——————....———————————.—————— 6 gibberosa...... __.—...... _.... 15,84-85, pi. 14 Timoclea...... ————————————————————————— 128 waccamawensi?.--—-_-.---..______...... ___..... 15,85, pi. 14 Trachycardium______...____—...___.....—.—....————.— 91-93 staminea, Area...____..,.__..__..______..______5 emmonsii______————————— 92 Standella congesta...._____------_ ,. r ...... ____....______. 113 isocardia.______—-___ 91-92, pi. 15 stantoni, Mysella______.. 86, pi. 14 muricatum__...... __....————_——.....————-— 92-93, pi. 15 Roehefortia...-__..___ ._____.____...... _._..__ 86 transversa, Thraeia———————————...———,——.———.... 14,43-44,pi. 10 178 INDEX Page Page transversus, Artemes.____.______..______..._.____ 122 Venus—Continued. trapezia, Chama._. ______.______. _.____ 69 lupina—.—_—..__—.———.———...————. ———.————r 79 trapezoidalis, Venus...____..._....__.._....._...... _...... 128 mercenaria notata...... — ———.. —— ———.. — — —————————— 130 trlangula, Bornia.______. ______. _____ 15,82-83, pi. 14 nimbosa______.___.___.___..__. 122 Kellia.._—————————————————————— ———_...... 82 notata..—-.—————————————_——————————„— 130 tricenarius, Pectunculus...... _..______..______27 ovata_—___..__—__——__——_————————.—..——— 128 tricostata, Ecphora______.__—.______5 parva_——_ —..__------—.—— —.... ——— ————— ———— 128 tridacnoides, Cyprina. ______132 plenainflata...——— ———————. ———————————— 134 Mercenaria______.______132 nucea______.______—_——__—— —.——_— 134 Venus—————————— ——— —— ————————————— 10,11,130,132 pygmaea..._ ———————— „ ———————— - ————————————— 128 (Mercenaria) campechiensis...______.. 15,132-133, pi. 21 rileyi.. ————.———— — —— -- — ——— — —————— 6,10,130 tridentata, Actinobolus______.______70 sayana___..__--.-._._..—.._..._------—— —— — ———_.— 124 Cardita———————— .——— —————— ————.. —...... 70,71 scotica_—————-----—-..———i—————————————————— 51 (Venericardia)_____.___.______....._..._ 70 trapezoidalis-__-__ ——__—_——.——————————————— 128 Qlans (Pleuromeris)______.______70-71 tridacnoides.. —————— — —— ————————— ——— ——— 10,11,130,132 Pleuromeris...... ___..._..._._...______.__ 15 verrucosa_._ „ —._____------____._——..———...... 130 Venericardia______70 (Mercenaria) berryi.--————— —— ——————————— 15,133-134, pi. 21 (Pleuromeris)_.______.______.__.__ __ 70,71 campechiensis carolinensis._____.__.....__——...... 15,132,pi. 20 trlgintinaria, Eontia.______.______.___.. 9 rileyi... — - ——————————— ———————. ——— —— 130-132 Trigoniocardia.._____.______._.______93 tridacnoides—.—— —— ——————————— — —— 15,132-133,pi. 21 (Americardia) media....______.______93 mercenaria notata._.__..__——_————————— 15,130, pi. 21 Trigonulina..-...—...... 50-51 plena_____.__-.___.______..______— 5,10 ornata______...______.______... 50 inflata—— ————————————————————— 15.134, pi. 21 trilineata, Pandora.______.___.______.. 48,49 nucea——— ———— — — —— —————————————. 134-135, pi. 21 Pandora (Clidiophora)....———— ———————...—...... 48-49,pi. 11 venustum, Cardium.._...... __... —...—__-..-.--——.....—__... 93 triquetra, Mactra—._. ______113 verdevilla, Cardita arata_....__——__—....——.——————————— 9 Mulinia. —...... 113 Carditamera arata______.______15, 69, pi. 15 trisulcatus, Phacoides (CavUucina)_____.______. ______15 Gemma.--—..——————————— ——— -—————..... 138, pi. 19 trossulus, Urosalpinx...__ *....___._._...____.-..------..._ 8,11 Tellina (Moerella?)——.. ———— —— ———————————— 97-98, pi, 17 truncata, Mya.______.___.__....___._..._ 138 verrucosa, Venus...... ___.__—_——————————————————... 130 tumulus, Qlycymeris...... _____...____.______.__ 6,13,14,27,pi. 1 Verticordia....————-——————— — —.——————..——— 80-51 Pectunculus.----__...______.._-,..--._.-.---..----. 27 cardiiformis__..._.—... —— ------———.————————————— 50 tuomeyi, Qlycymeris subovata..______.______....__ 9,11 emmonsii__..__...______....__—_——....——....— 80 Pandora (Clidiophora).__.— ———— ———————— ————. 48-49, pi. 10 (Tiigonulina) chowanensis______.___——..———__— 14, 51, pi. 10 turgidulus, Crassatellites...-.- ______'..._. ______5 emmonsii.______-______14, 50-51, pi. 10 Turritella-- —... ——_...... __...... _„...... _„—...——..._„„____._ 8 rogersi———.——————————————————— 14, 50, pi. 10 alticostata...... 9,10,11 vicenarius, Pecten——_——.... — ------————— ——— ———————— 36 pilsbryi...... 9,13 vicina, Astarte_———-————————————————————1———————— 52 plebeia.-.-.-....----._--.---——.-——_..——-.--———.____.— 6,13 Virginia, localities in—————— ——— —— — .————————————— 17,18 carinata. _..——————_.———_———————_.————._——— 7,13 Miocene stratigraphy of, nomenclature of..._..__——...__ 3 (table 1), 4 terstriata.______13 summary of___——__..—.———————————————————— 2,18 -variabilis______,______>.__._____ 6,12 virginiae, Area__..._——..—— — ———————————————————— 7,13 pilsbryi_____.______.______6,7 Pectunculus-.;——————————1————————————————————— 26 virginiana, Chlamys (Placopeeten) — .—————————————.—— 38-39, pi. 4 U Gemma magna______-______16, 136, pi. 19 undatus, Pectunculus..______.______28 Macoma————————...———...——...... 16,98-99, pi. 17 'undulata, Astarte__..______._.___,..._....__... 57 virginianum, Cardium._...__..... — .__.__—_——._...._ 7,9,10,91 Astarte (Ashtarotha).....—...... -—.....——... 9,14,57-58,pi. 12 Cardium (Cerastoderma)—————.———————————————————— 15,91 undulatus, Crassatellites....---.-....-----..--..-..-..------..----.--- 7,9,10,11,12 Cerastoderma______...———_—————-——————————— 91, pi. 16 urbannagnsis, Crassatellites undulatus.______,______6 virginianus, Peeten-—__——..— —...——————————————————— 38 Peeten eboreus..___.._.__..._...__--.-.__.__..... 6,7 Pecten (Chlamys),——————————————————————— 38 "Urosalpinx trossulus...... _____._..__.______....___. 8,11 (Placopeeten)—————————————————————————— 9,10,14,38 Uzita chowanensis_..__ —._...... __...... —L__...__...... 12 virginicum, Calliostoma__—__—__———————————————-—— 10 viridis, Solen..———...... ——...————...... 16,108-109, pi. 23 vaginulata, Astarte undulata..______...----..---.-.___._..__ 58 W Astarte (Ashtarotha) undulata...-..------—------6,7,9,14,58-59,pi. 12 waccamawensis, Ostrea___ ._ ..—_1—-———————————— 14, 41, pi. 3 variabilis, Donax______.______106 Sportella——————————————————————— 15, 85, pi. 14 Turritella—-_———- ———.-——.. —— —————.—— .—— ——.. 6,12 watsonensis,Pecten eboreus—————.. ————————— —————————— 6 v61aini, Mysella-.—————.————————————————— 15,86, pi. 14 wilsoni, Anadara callicestosa___...._———.————————————— 24-25, pi. 3 Venericardia granulata...... 6,7,9,10,11,12 perplana abbreviata....—...——-.... —..———_——---.-....._... 9 tridentata....- —.__——__...._——_——..———_..—__— 70 Yoldia——————...... —-....————————————....———— 21 (Pleuromeris) tridentata______.__..____ 70,71 arctica-———————————————————————————————————— 21 tridentata decemeostata.1.._..____...___--...-__..__... 71 hyperborea_.——. ————————————————————————————— 21 Venus.. ——-. — ——————————————— —— ———. —— ——.. 130-135 laevis—..-———————————————————— 10, 14,21, pi. 1 campechiensis.-—-__—___.__....__...__——__....__.. 132 "limatula".. ——————————-—-————.——...——-———— 21 campechiensis carolmensis______..___.___..___.___. 132 yorkensis, Diplddonta...———————————————————————,———— 119 cancellata....______*______127 Pecten eboreus_ ———.—————————————————————————— 10 concentrica.————————————-———•————————— 120,122 Yorktown formation, bed at Biggs farm in.——.— —————————— ——— 8-9 cortinaria.______127 description of...—._——....—————..—....—————..„.——.— 7-13 cribraria———————.—————————.———————i— 128 fossils in——————————————...... ——....—————— 7-13 deformis.------_——.———————— — — —— —————_—. 132 sections in___———————————————————————————————— 9-11 difiormis.-...—-__.....___.———.————.—— —— ————- 132 zone 1 in_____.....,.—————————————————————————— 7-8 dysera_.______---..---..-..-——...--.--_. —....——_—— 127 zone 2 in——————————————————————————————————— 8 erycina—___..___—__—.———.—————————..————— 123 gallina—————————————————————— .——————— 129 gemma..______..___..._—.... ——— —— ————————— 135 zealandica, Anomia——————————————————————————————— 41 gigantea___....__——_——.—————————————————————— 122 ziczac, Pecten..—-.:——...———...——————————.———————— 30 lapicida____.______—...————————————— 116 Zirtaea.—————————————————————————....———— 142 latisulcata__—__——.————————————————————————— 65 rhomboidea————————....-——————————— ———— 142, pi. 23 lithophaga.————————... ———————————————————— 116 Zirphaea—————————————————————————————— 142 o 03 03 o3 l~J ,r> „= isula(Mactromeris isula(Hemimactra) isula(Hemimactra) (Hemimactra)isula -^03O 5^^^'SSri_,X!X!X! S'SiiJ > (Hemimactra)isula -SrC "S O O O ft ^ II°SI|^ Mactra(Mactrotoma o353^_.»oooOooQ B 3 'CD -S 'E •- g a w 'S'^'^ ? P P S^ 2 ConradTellinfaeeena .p, .H S 03 4^ o X CD ftp 03 >> >> ^3 CD g ho bo's > OQ I-H CD oe DonaxSavfossor - S^ 0 0 03 35B 'oi SolenSavviridis /-H c3c3c3OrHo3 o a^^OOOjg o'ol :>>§•§ 15 §8 3 03 03 03 OQ X! P! -^ a CD o3 CD' ' -irS3 r^ r^ os'oQ S o3 a a a ^ ^,53 « B s*. '^ '^ 3 ^ P 0^ ^y r"! "^ ™ [Zj -_3 _O o o B T^ ** « § § fl a d g 2 *~~* OQ ^ ^ f~ FT~ F ^~ rj *H MH ft ft ft ft ft ,5^2 ^ £ O O O 03^2,^ ^^^(^5 <5 <5 GQ! GQ§ OQ!•§ < OQOQOQGQ02 g^HHOOOPQ^M PART 1. PELECZPODA 17