NOTES ON THE FAUNA OF THE CHIPOLA FORMATION- XX A SECOND SPECIES OF PETRICOLA (PETRICOXENICA) (MOLLUSCA: BIVALVIA) HAROLD E. VOKES TULANE UNIVERSITY

While the writer's recent (Vokes, 197 6) The present species suggests that the description of the new petricolid subgenus heavily pustulate ornamentation is a signifi­ Petricola (Pe tricoxenica) and its Pliocene cant subgeneric character but that the nodes, type species, P. (P.) concoralla, was in press, which appear subsequent to the develop­ a collecting trip was made to the type area ment of the pustules, are probably of lesser of the Chipola Formation in Calhoun importance than was originally believed. In County, Florida. At that time a large head of the Chipola specimens nodes appear to be a poritid coral was secured that contained present only in the latest (gerontic ?) stages numerous b oring and nestling bivalve of growth. . species, one of which proved to be a second It is also to be noted that P. concoralla species of Petricoxenica. This find prompted attains a size considerably larger than that of a careful examination of the extensive the holotype specimen. One pair of valves Tulane Chipola collections and four more from TU 1177 has a length of 52.3 mm, v alves were found, representing three height 32.4 mm, an~ a diameter of 23.0 mm, additional localities. This new species, from being 60% greater in length and 77% greater strata of late lower Miocene (Burdigalian) in height. In this specimen, as well as in the age, is here described. On the basis of the four known left valves of the Chipola evidence that it affords, together with addi­ species, the median left cardinal tooth, tional information obtained from specimens which is bifid in the smaller holotype speci­ of the subgenotype species found at a men, is entire through broadened and with a second locality (TU 1177) approximately six median groove on its dorsal surface. miles west of the original site, opportunity is taken to modify somewhat the original sub­ PETRICOLA (PETRICOXENICA) generic diagnosis. Mr. and Mrs. Hoerle, West HOERLEAE H. E. Vokes, n. sp. Palm Beach, Florida, collected several pairs Text figures 1-3 of P. (P.) concoralla from crevices in a porous coralline lime-rock, thus confirming Diag11osis: Shell elongate-ovate, mode ra tc ly the nestling habit of that species. inflated; umbones low, not prominent, situated at the anterior fourth of the length of the valve; anterior margin rounded, ventral margin broadly Family PETRICOLIDAE Deshayes, 1839 and regularly arched and rounding sharply, a!most Genus PETRICOLA Lamarck, 1801 subangulately, to the gently convex posterior end: Type sp ecies, by subsequent designation (Schmidt, dorsal margin straight, slightly ascending. A low, 1818): Petricola costata Lamarck = Venus relatively inconspicuous groove extending from the lapicida Gmelin. Pliocene to Recent, .south posterior side of the umbo!'e to the middle of thL Carolina to Texas, the Antilles and Canbbean posterior end of the valve. Surface orname.nted by regions. well-developed pL stulation over the cntu·e area except the immediate umboral region, which is smooth, although ont. 1'11mature example <>~ggests Subgenus PETRICOXENICA H. E. Vokes that area was originally abo pustulose With the Pe tricoxenica VOKES, Tulane Stud. Geol. Pale­ pustules being lost as a result of subsequent Jb"a ant., vol. 12, no. 1, p. 47. sion. At ab0ut mid-growth the valves are nurked 1 Type species: Petricola (Pe tricoxenica) concoralla by strong concentnc growth lamellatw·~s, which n H. E. Vokes, * Pliocene, Caloosahatchee Forma­ the later stages toward the vdlve m.ngm:; tt'nd to tion(?), Florida. develop an irregularly nodose outer .su,.t'ac.e: i'l ~he para type right v .tlvC' these pus .. ula t10'lS bet o~·ng elongated tow~rd t~e po:tt'ro-v~ntr~l ~dge 1'1 J manner suggestiVe 0f 1rregu ar vad1al nbbmg. *The formal designation of the type species of the Hinge and interior typical ot t~t subgenus. subgenus as Petricolaria [sic] (Petricoxenica) Holotype: USNM 647713; !ength 41.0 :nm, concoralla was an obvious and regrettable lapsus height 24.2 mm, diameter (left valve 1 7. 9 mm. on th e part of the writer. Locality: TU 548. 163 164 Tulane Studies in Geology and Paleontology Vol. 12

Paratype A: USNM 647714; length 36.0 mm, was collected from a coral-rich faunal associ­ height 20.5 mm, diameter (right valve) 7.0 mm. ation in a spoil bank pile dredged from a Locality: TU 459. drainage canal. The type lot was not found Paratype B: USNM 647715; length 31.3 mm, height 15.5 mm, diameter (paired valves) 15.6 mm. in an association such as to demonstrate Locality: TU 1196. beyond doubt that it was a nestling species, Remarks: Petricola (Petricoxenica) as are so many of the forms assigned to the hoerleae, n. sp., differs most noticeably from genus Petricola. However, as noted above, P. (P.) concoralla Vokes, type of the sub­ subsequent specimens have confirmed that it genus, in the absence of the strongly nodose was a nestler. The small, rather worn, paired ornament that marks almost the entire valves of Paratype 647715 were found in surface of the valves in that species; other place in a bored hole in a coral head, thus characters are essentially identical. establishing beyond question the nestling The specific epithet for the Pliocene habit for both presently known species of species, concoralla, was applied because it Pe tricoxenica.

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T.ext figure 1.' USNM 647713, holotype; a) exterior left valve; b) interior left valve; c) portwn of :xte~wr ornamentation, greatly enlarged. Text figure 2, USNM 64 7714, paratype A; a) e~tenor ~1ght valve; b) interior right valve. Text figure 3, USNM 647715, paratype B; dorsal VIew, pa1red v.alves. (All specimens except 1c magnified X 1 :Y2) No.3 Fauna of the Chipola Formation -XX 165

It gives me much pleasure to dedicate the 825. Farley Creek at abandoned mill about~ mile present species to Mrs. Robert C. Hoerle of west of bridge at Florida Highway 2 7 5 ( SW ~ West Palm Beach, Florida, who sent the Sec. 21, TlN, R9W). specimens upon which the present subgenus 1196. North bank of Farley Creek about 0.8 mile is based. (map distance) east of bridge of Florida High­ way 275 (NE ~Sec. 29, TlN, R9W). 1177. Caloosahatchee Fm., Mule Pen Quarry, LOCALITY DATA north of Florida Highway 846 and 9.1 miles The following Tulane University fossillocalittes east of U.S. Highway 41 at Naples Park (SE ~ are all in the Chipola Formation, Calhoun County, Sec. 24, T48S, R26E), Collier County, Florida. Florida. 459. Steep bank on east side of Chipola River about 1500 feet above the mouth of Taylor LITERATURE CITED Lake Branch (NW ~Sec. 29, T1N, R9W). VOKES, H. E., 1976, A new subgenus and species 548. West bank of Chipola River at bend about of Petricola (Mollusca:Bivalvia) from the Plio­ 1800 feet south of mouth of Farley Creek (NW cene of southern Florida: Tulane Stud. Geol. ~Sec. 29, T1N, R9W). Paleont., vol. 12, no. 1, p. 47-48, text fig. 1.

September 15, 1976

REVIEW

THE STUDY OF TRACE FOSSILS, A logical, paleoecological and environmental Synthesis of Principles, Problems, and significance of ichnofossils, is considered. Procedures in Ichnology, edited by The chapters in Part III - Selected Robert W. Frey. Published by Springer­ Groups of Trace Fossils include, plant trace Verlag, New York, Heidelberg, and Berlin, fossils, borings as trace fossils and the proc­ 197 5, xiv + 562 pp., illus., 8 pp. errata, esses of marine bioerosion, boring micro­ $57.80 organisms and micro borings in carbonate substrates, traces of predation, vertebrate In this work, a comprehensive VIew of fossil traces and impressions. vetebrate bur­ Ichnology is presented in a well organized rows, unusually large burrows, trace fossils and coherent textbook approach to this in carbonate rocks, and trace fossils at omis­ highly significant subdiscipline of paleontol­ sion surfaces. In Part IV - Recent Aquatic ogy. Each chapter is written by one or more Lebensspuren, the recent as a potential key contributors selected for their expertise in to the past is considered, including recent the subject and has been reviewed by two or lebensspuren in nonmarine aquatic environ­ more co mpetent critics. Unlike so many ments, recent biocoenoses and ichnocoeno­ multiple author works, however, each chap­ ses in shallow-water marine environments. ter has been extensively edited by Mr. Frey and animal traces on the deep sea floor. In to establish a more-or-less uniform literary Part V Techniques in the Study of Lebens­ style throughout and to insert cross-refer­ spuren, the main emphasis is upon method ences to other portions of the text, thus ology, its experimental approaches and the rendering it much more comprehensible. techniques utilized in study of fossil and Part I - Introduction to Ichnology, in­ recent traces. cludes five chapters beginning with the This volume is very well designed and history of Invertebrate Ichnology and its handsomely illustrated. Only the rather high scope and definition. Other portions treat price of the book will prevent its being the classification and preservation of trace widely used as a supplementary text in pale­ fossils, and the last deals with false or mis­ ontology curricula. It is a highly u-;eful refer leading traces. In Part II, the Geological ence volume in a subject which is becoming Significance of Trace Fossils, including the increasingly important in paleontological paleontological, stratigraphical, sedimento- study. --H.C.S.