Late Paleozoic Gastropoda from Northern Alaska

By ELLIS L. YOCHELSON and J. THOMAS DUTRO, JR.

SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

GEOLOGICAL SURVEY PROFESSIONAL PAPER 334-D

Descriptions and illustrations of 34. species and I new genus, with brief discussion of their strati- graphic significance

UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1960 UNITED STATES DEPARTMENT OF THE INTERIOR FRED A. SEATON, Secretary

GEOLOGICAL SURVEY Thomas B. Nolan, Director

For sale by the Superintendent of Documents, U.S. Government Printing Office Washington 25, D.C. - Price 50 cents (paper cover) CONTENTS

Page Page Abstract-._ _-______---_-_-______-___-___ 111 Systematic paleontology------131 Introduction-_------_-______.___.__ Ill Superfamily Bellerophontacea______13] Stratigraphic distribution of the gastropods.______113 Superfamily Euomphalacea______133 Superf amily Pleurotomariacea______135 Rock units-______-______-_ 113 Superfamily Platyceratacea______140 Faunal zones_------_---_--___-______- 115 Superfamily Microdomatacea_____---__----_-_--__ 141 Stratigraphic distribution___-__-______-___._____ 115 Superfamily Anomphalacea.______142 Lower Mississippian undifferentiated. 115 Superfamily Neritacea-_____-_------__--_- 142 Upper Mississippian.______118 Superfamily Murchisoniacea______144 Permian,______118 Superfamily Loxonematacea._____--_------144 Ecological and paleogeographical data______119 Superfamily Subulitacea.______144 General considerations.______121 Class Scaphopoda______144 References cited____-______-__-_____-_-----____ 145 Register of localities-______122 Index-______147

ILLUSTRATIONS

[Plates follow p. 148] PLATES 12, 13, and 14. Late Paleozoic Gastropoda. pa&e FIGURE 23. Index map of northern Alaska._____-______--_____--__-_-_------_-_-__ 112 24. Mississippian Stratigraphic nomenclature and faunal zones.______--_--_----__------_--_ 114 25. Ranges of gastropod species.______120 26. Schematic representation of terms for direction of growth lines______121 27. Fossil-collecting localities in parts of the Misheguk Mountain quadrangle (^4), the Noatak quadrangle (B), the Point Hope quadrangle (C), and the Howard Pass and Misheguk Mountain quadrangles (D), Alaska______123 28. Fossil-collecting localities in parts of the Killik River and Chandler Lake quadrangles (A), and the Chandler Lake and Philip Smith Mountains quadrangles (B), Alaska.______124 29. Fossil-collecting localities in parts of the Demarcation Point and Table Mountain quadrangles, Alaska and adja­ cent parts of Canada (A), and the Sagavanirktok and Mount Michelson quadrangles, Alaska (B)______125

TABLE

TABLE 1. Distribution and number of Late Paleozoic gastropods in northern Alaska______---_- 116

SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

LATE PALEOZOIC GASTROPODA FROM NORTHERN ALASKA

by ELLIS L. YOCHELSON and J. THOMAS DUTRO, Jr.

ABSTRACT Late Paleozoic gastropods from northern Alaska occur in describing a poorly preserved Permian gastropod rocks of both Mississippian and Permian age; most of the fauna from Mexico, remarked: "* * * a collection of fossils studied came from the Mississippian. Although the gastropods are of use for dating the rocks only in the broadest fossils from beds in a region previously unstudied may terms, locally they are useful in establishing informal faunal tell us much, even though the specimens themselves zonation. On the basis of predominant occurrence of certain are too poorly preserved to warrant detailed descrip­ gastropods, it is possible to distinguish rocks of Early Mis­ tions or naming of species/' Most of the fossil gas­ sissippian, Late Mississippian, and Permian age. Two divi­ tropods from northern Alaska are poorly preserved; sions, based on the distribution of gastropods, are distinguished in the Upper Mississippian. One collection, consisting entirely nevertheless, their study contributes to our under­ of specimens of Glabrocingidum and Trepospira, may indicate standing of the classification and geographic distri­ the presence of rocks of Pennsylvanian age. Occurrence and bution of Paleozoic gastropods. In addition, it pre­ distribution data are summarized in tabular form. sents detailed information useful in regional strati- The gastropod faunule is composed primarily of euomphala- graphic studies. ceans, platycerataceans, pleurotomariaceans, neritaceans, and bellerophontaceans, in that order of abimdance. There is no Mississippian gastropods were first collected from indication that a distinct boreal fauna is represented. Many the Brooks Range by Philip S. Smith in 1911 (Smith, of the specimens are poorly preserved, though some well-pre­ 1913). George H. Girty listed gastropods from north­ served shells occur, particularly among the pleurotomariaceans. ern Alaska in several U.S. Geological Survey Bulle­ Thirty-four species are recognized in the systematic treat­ tins, but did not describe any of the species. Most ment ; nine of these are formally named as new species and one is referred to a previously described species. One new of his identifications are summarized in a single chart pleurotoniariacean genus, Nodospira, is described. At least (Smith and Mertie, 1930, facing p. 182). Specimens two other new genera may occur in the faunule but specimens identified by Girty were reexamined during the pres­ are too incomplete for adequate taxonomic description. The ent investigation. A few dozen specimens were col­ occurrence of two scaphopod specimens is reported. lected by A. G. Maddren, J. M. Jessup, and G. L. Most of the fossils were collected from the Brooks Range during field work in connection with geologic investigations of Harrington during the geologic reconnaissance of the Naval Petroleum Reserve No. 4 and adjacent areas. Some Alaska-Canada boundary (Maddren, 1912, p. 297- earlier collections from northern Alaska were restudied. 314). Finally, several gastropods were obtained by E. de K. Leffingwell (1919) from the Canning Fiver INTRODUCTION district. This study deals primarily with specimens collected The paleontologic literature of Alaska is well in­ from 1944 to 1953 during the geologic exploration of dexed. Dutro (1956) compiled an annotated bibliog­ Naval Petroleum Reserve No. 4. This is one of a raphy of Alaskan Paleozoic paleontology; in addition, Alaska is included in the excellent "Arctic Bibliog­ series of papers by members of the U.S. Geological raphy11 (U.S. Department of Defense, 1953-57). Survey planned to describe the various groups of Pale­ Neither of these sources records late Paleozoic gastro­ ozoic fossils collected in northern Alaska. Mackenzie pods from Alaska. About half a dozen papers illus­ Gordon, Jr. (1957) has completed a study of the Mis­ trate a few specimens from other parts of the Arctic, sissippian cephalopods. Work on certain other fos­ but all figures examined are small-size reproductions sil groups is in progress. of poorly preserved specimens. These few specimens The philosophy that has guided this work was ex­ are either unnamed or are compared with species de­ pressed by J. Brookes Knight (1953, p. 84) who, in scribed from western Europe. Ill to

140°

O

168 164 160° 156 152° 148° 144°

Outcrop of Mississippian rocks Approximate limit of outcrop of Siksikpuk formation

Approximate limit of outcrop of Approximate limit of outcrop of unnamed Permian formation Sadlerochit formation

FIGURE 23. Index map of northern Alaska showing quadrangles referred to In text, locations of figures 27, 28, and 29, generalized outcrop belt of Misslssippian rocks, and approximate distribution of Permian rn<>k units. LATE PALEOZOIC GASTROPODA FROM NORTHERN ALASKA 113 C. C. Branson's bibliographic index of Permian fos­ STRATIGRAPHIC DISTRIBUTION OF THE GASTROPODS sils described through 194:1 (Branson, 194:8) aids a The assemblage of gastropod genera dates the rocks search of the literature for previously named species. as late Paleozoic, but the gastropods themselves are Mississippian fossils, on the other hand, have not been of little value in correlating individual stratigraphic systematically indexed for many years. To the best units with rock sequences in regions outside Alaska. of the writers' knowledge, the last major papers deal­ With the exception of PortlocMetta sp., Rkineo- ing with gastropods of Mississippian age or early derma'l sp., and Twho-nellinal lata, n. sp., no g?,nera Carboniferous, are those of Koninck (1881, 1883). or species thought to be limited to rocks of Mississip­ Literature describing American Mississippian gastro­ pian age are known. No species or genera diagnostic pods is scant. of Permian age were identified. The Brooks Eange physiographic province includes On the other hand, fieldwork has demonstrated that several distinct groups of mountains extending from some of the gastropods are useful, locally, in provid­ near the 165th meridian eastward to the Canadian ing supplementary evidence that helps determine the boundary. For most of its length the range lies es­ position of certain rock units. Units currently rec­ sentially along the 68th parallel, forming the back­ ognized in northern Alaska are discussed below on bone of Alaska and constituting the divide for drain­ the basis of distribution of the gastropods. age to the Pacific and Arctic Oceans. Eastward from the 150th meridian the range makes a crescentic bend ROCK UNITS northeastward until the mountain front is only about Rocks of late Paleozoic age in northern Alaska can 25 miles south of the Arctic coast. The regional set­ be assigned to at least six formations. The Missis­ ting and topography were described in detail by sippian system, represented largely by a complex ar­ Smith and Mertie (1930) and summarized by Payne ray of carbonate facies, is divided into two major and others (1951). The index map (fig. 23) shows parts. The nomenclature of Mississippian rock units the quadrangles from which gastropod specimens were in the central Brooks Range (fig. 24:) has been re­ collected. vised by Bowsher and Dutro (1957, p. 3-7). The The topography of the Brooks Range has been ex­ lower part, essentially a black shale with a sandstone member at the base and argillaceous limestone beds tensively modified by glacial action. Glaciers are not near the top, is designated as the Kayak shale. The now common, but the climate remains severe. The upper part, the Lisburne group, consists of the Wachs- isolated position of the region has complicated and muth limestone below and the Alapah limestone above. handicapped fossil collecting. Many collections were Elsewhere in northern Alaska, the Lisburne group has backpacked by geologists from the collecting locali­ been subdivided into several formations, not as yet ties and cached in places accessible by airplane. This formally published. The approximate limits of the necessarily limited the number and size of the fossil Mississippian outcrop belt are shown in figure 23. collections. A few of the localities were visited more No rocks of undoubted Pennsylvania!! age are known than once; most have been only casually sampled. from northern Alaska. A carbonate rock sequence in More than customary acknowledgment is due the the eastern Brooks Range, lying above the Alapah fieldmeii because fielclwork in northern Alaska is rig­ limestone, may represent some part of the Pennsyl­ orous and requires physical effort not normally asso­ vania!! system. Fossils are rare in these rocks and no ciated with fossil collecting. Members, or former gastropods have been collected from them. members, of the U.S. Geological Survey who collected The Permian is represented by three quite different fossil material on which this paper is based are: A. L. formations, each of which represents a predominantly clastic facies. The approximate limits of outcrop of Bowsher, W. P. Brosge, R. M. Chapman, R. L. Det- these units are shown in figure 23. The Sadlerochit terman, J. T. Dutro, Jr., Alien Feeler, W. A. Fischer, formation of Permian and Early Triassic age in the George Gryc, C. J. Gudim, A. S. Keller, B. H. Kent, eastern Brooks Range was first defined as the Sad­ C. E. Kirschner, A. H. Lachenbruch, M. D. Mangus, lerochit sandstone by Leffingwell (1919, p. 103). Its R. H. Morris, W. W. Patton, Jr., H. N. Reiser, E. G. fauna was studied by Girty and, although the fc^ma- Sable, I. L. Tailleur, and R. F. Thurrell, Jr. tion was originally called Pennsylvania!!, it was Girty Dr. J. Brookes Knight, Smithsonian Institution, re­ who recognized affinities with faunas now considered tired, examined some of the specimens and made per­ to be of Permian age (Smith, 1939, p. 32). The Sik- tinent taxonomic suggestions. Photographs were sikpuk formation of Permian(?) age in the central taken by Nelson W. Shupe, U.S. Geological Survey. Brooks Range was described recently by W. W. Pat- 114 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

FORMATION FAUNAL ZONE

Upper limestone

Gigantoproductus striato-sutmtus (Schwetzoff) Fine-grained limestone

Light-gray limestone Lithostmtiontlla* sp. Chert-shale Cmiatitft crtnistna Philhl

Sciophyltum lambarti Marker and MacLaren Alapah limestone

Platy limeston Eunietria ivstata (Hall)

Dark limestone Lithostrotwn aff. L. asiatieum (Yabe and Hayasaka)*

Shaly limestone tf tNaheopstsl suturimmpta Yochelson and Dutro*

Banded chert-limeston Bmrhythyris suborheu/aris (Hall)*

Spirifer tenuteostatus (Hall) Wachsmuth limestone

Crinoidal limestone "Zaphrentis" komntki s. 1. Milne Edwards and Haime*

CryptMastus aff C. pis«n Red limestone (Meek and Worthen) Upper black shale

Leptatna analiign (Phillips)

* Gastropod bearing. FIGURE 24. Mississippian stratigraphic nomenclature and faunal zones in the Shainin Lake area, central Brooks Range (modified from Bowsher and Dutro, 1957). LATE PALEOZOIC GASTROPODA FROM NORTHERN ALASKA 115 ton, Jr. (1957, p. 41-43). It is essentially a fine­ Several informal faunal zones have been distinguished grained clastic facies of the Sadlerochit formation. in Dutro's research on the younger Permian, par^icu- In some areas a minor amount of silicification is re­ larly in the unnamed rocks of the western Brooks corded. The third formation of Permian age, as yet Range. The only zone pertinent to this gastropod unnamed, is a thick sequence of sandstone, quartzose study is one characterized by Licharewia, a spiriferoid limestone, shale, chert, and conglomerate that crops brachiopod that is of widespread occurrence in the out extensively in the western part of the Brooks upper Permian of Russia and parts of Europe and Range. This unit has produced the greatest variety Asia. The gastropod Mo-urlmiml reloba, n. sp. oc­ of Permian fossils in northern Alaska and is correla­ curs in this zone in northern Alaska. tive, in part, with the Sadlerochit and Siksikpuk Stratigraphic position was assigned to the individ­ formations. ual collections either by the collector or by D itro. FAUNAL ZONES Dutro based certain of the assignments on observa­ tions made during fieldwork, knowledge of the lithol- Mississippian collections yielding gastropods are ogy and regional stratigraphy, study of the general listed in table 1 according to the faunal zones from aspect of the fauna, and position of the collection which they were collected. These faunal zones were within measured sections. These assignments are used established by Bowsher and Dutro (1957, p. 5 and 6). in placing collections in the faunal or rock units listed Gastropods were collected from zones characterized in table 1. Within each unit, collections are listed in by Scalaritu'ba sp., Leptaena analoga (Phillips), numerical order. "Za-phrentis"1 konincki Milne Edwards and Haime Principal causes of uncertainty as to stratigraphic (sensu lato), Brachythyris sul>orl>icularis (Hall), N. placement of collections are increasing stratigraphic (Nnticopsis} suhmcompta Yochelson and Dutro, refinement as the fieldwork progressed, incomplete Lithostrotion cf. L. axiaticum (Yabe and Hayasaka), stratigraphic sequences, and poor preservation of fos­ and Go-niatites crenistria Phillips (fig. 24 and table 1). sils. Collections from measured type sections, or from Gastropods were the basis for the erection of one of closely associated sections on which considerable reli­ the faunal zones of Bowsher and Dutro. The fauna ance as to correct stratigraphic assignment can be of the iVaticopsts houn Dawson zone (Bowsher and placed, are indicated by reference to footnote 1 pre­ Dutro, 1957, p. 6) is essentially limited to gastropods. ceding the locality number. The species referred to as N. howi by Bowsher and Dutro is described in this paper as Naticopsis (Nati- STRATIGBAPHIC DISTBIBUTION copsis] suturicompta, n. sp., and the name of the zone- is changed accordingly. LOWER MISSISSIPPIAN TTNDIFFEKENTIATED By an analysis of the cephalopoda of the Gomatites The Lower Mississippian rocks of northern Alaska crenistria zone, these beds have been correlated with include the Kayak shale and the Wachsmuth limestone, the latest Middle Visean and early Upper Visean by each of which contains three faunal zones (fig. 24). Gordon (1957, p. 15 and table 2). Regarding the The few snails collected from these zones provide, in cephalopod faunule, Gordon states (1957, p. 15) : themselves, 110 basis for distinguishing any one zone from another. Accordingly, most collections fron lo­ In the British section, forms identical with and closely re­ lated to the Alaskan species of the black chert and shale mem­ calities other than type sections are treated as Lower ber are distributed through stratigraphic thicknesses of 150 Mississippian imdifferentiated. to nearly 400 feet. In the northern Alaska section, the fossils The most important difference between the Lower are limited to the lower 60 feet of the black chert and shale and Upper Mississippian gastropod faunules is the member. Goniatites suggesting three different subzones (B2, apparent abundance of platycerataceans in the earlier Pla and Pic) have been found at roughly the same strati- graphic level but each in a different river valley. Whether beds compared with a virtual absence in the later this means that the ranges of certain goniatite genera are beds. This may be simply a matter of facies, Platy- somewhat telescoped in the Alaskan section, or whether the ceras apparently being able to live only on pelmato- black chert and shale member transgresses the section rather zoan echinoderms (Bowsher, 1955). Suitable habi­ irregularly, is not determinable on the basis of present evi­ tats for crinoids apparently were few in Late Mis­ dence. sissippian seas of northern Alaska. Most platycera- No faunal zones have been set up, as yet, for the tid specimens occur in dark bioclastic limestone con­ Permian system in Alaska. The gastropod Straparol- taining much crinoidal debris. Platyceratids do cccur his (Euomphalus} alaxkensis, n. sp. is commonly found in Permian rocks and, rarely, in the Upper Mississip­ in the lower part of the Siksikpuk formation, but has pian of this region. Their presence is not, in itself, also been found in the other two Permian formations. an index of an Early Mississippian age. 116 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

CD CD Naticopsis Lithostro-or WOI ; rt N tionzone Z66 £ ! *66 ~ rt 00 -t rt 9Z6 i ^ 8 Alapahlimestone 90* rt \ rt i 80m IN ] P» i eeeei ^ CO "* Naticopsiszone i Z8IS ~ £ N i IZIS * rt lOZIE « N i WE rt rt o- i880£ o S i BZSOE rH rt Z60H N N Z6m "< eem - rt fsesi * - « zfesi rt IWSl rt IN (N rt 00 OfrEEI ^ zseei IN « 9EEET - CO C-, S£SEl rt CN - rt - ir CO ~ ^ c- - undiflerentiatedLowerMississippian, reest 00 ZESEI

(Euompkalus)StraparoUussp_ indet.euomphalacean_____ Trepospira(Trepospira)sp... Bembezia?invmbilicata,n.sp._ Indet.pleurotomariacean..... Indet.murchisoniacean..._ (Retispiraf)Knightitessp..... (Euomphalus)Straparollus Amphiscapha(Cylicioscapha) TurbonelUnaflata,n.sp..-_-_ Trepospira(Angyomphalus!) Mourloniaminiita,n.sp_---_- Mourlonialreloba,n.sp...... Olabrocingulum(Olabrocingu- Platyceras(Platyceras)sp..-.. Anematinarockymontanum Naticopsis(Naticopsis)sutu- Indet.Ioxonematacean...._ Totalnumberofspecimens. bellerophontacean--.-.Indet. Nodospiraornata,n.sp.._-.. MurchisoniaAf.cf.sp______Genusindet-__.__.... .% , 5 a £ f. ty f)rfhnnii?hia}(sn o a 'c ^ ,C hrnnlfxfnxixnsn Phinfndfrma.1sn Knirnxrnlnnf«sn ,£ < PC S? 05 c fr- *- Tnnthinonxixfsn V fr- ricomnta.nsn 1 ,= TZiinhrmitr.*sn Pleurotomariacea: IN Cf Microdomatacea: EH hontelleropBacea: c "1 s Lnrnnfmn.sn Euomphalacea: 1 '°$ ^ (Shimpri « Murchisoniacea: Plnfiiztina.sn & | Platyceratacea: Anomphalacea: 1 Loxonematacea: 1 I I ai c Scaphopoda: S . S t Cb Subulitacea: 5 C Neritacea: +. t .S S 1 a J T i 1 (£ 1 1 ^ 2 t LATE PALEOZOIC GASTROPODA FROM NORTHERN ALASKA 117 suaniioads jo jaqninjvj JE}O j, S ^686 III! ! rt I i I I 1 II 1 I | | 1 I II ^ 3 ^ S Z86 III! ; l ; i 1 ; I 1* II i | II II a 286 I'll * ! ; ; | I 1 1 ! rt 1 ! i ! II 1 I CN 6Z6 1 I I 1 1 | I | 1 I 1 II II I i II II 1 "* 096 1 I I 1 I | I | 1 1 1 1 I 1 I ; ; I I I I -H 380f 1 I 1"1 1 i ; ] | [ ] II II i ; II I I 1"1 rt 3 i 69IH I I I I I ; i | ; j II II I I I I 1 I Tf i 9T2££ I I 1 I ! I ; l rt II ! | II II 'H i 9IS£I I 1 I I !"* ; ; ] N i ii i i II 1 I CO £S8TT 1 1 !*" CO i ; ; j [ ! rt 1 I ; ; II 1 1 CO i 6S89t III! "" ! ; ] ; ; ; ; II II ^ ; ; ; : '-' i 9289T 1 1 I I ! i 1 ; l rt ! i I 1 1 ii ii 1-1 i -.1891 1 1 1 1 i ; ! i j j i rt i i ; | II II llo -^ ^ t- 03 £1891 1 1 1 I "" I | ! | ; ; ii ii ; ; II II I 1 ,' '"' * r qgTIZ ! ; ! ; ; ; ICO ii 1 | I ! I ! ICO * OTOT I 1 1 I I ! ; ; !"* I 1 i l II 1 I 6001 1 1 I I 1 ; | | ; ; ! rt I 1 1 ; 1 I 1 I CO 8001 III! I ; ; ; ! rt II II I ] II I I ^ i £9Wt III! J I i ; ; « 1 1 I"1 I 1 I l II 1 I CO f-ZIH 1 1 I I | i ! rt j j N II 11 I ; II II CO i Win III! ° i i ! ; ] | 1 I II ; | II II 05 I i i i ^ * i 660H i | ; ; 1 I II I | II 1 1 1 II t 9T8TI i i i i t* I I ! | JT 1 1 1 I II | | II II oo 1 t 9T8TI III! i(N I | ] i II II | | II I ! N N 1 i H8TI I 1 1 I £ | 1 I ; ] ] II II ! | 1 1 II O 1 1 CO i 98-.II III! S ! i i ; II II I ; II 1 I 1 1 CO Cb i S92.ll I 1 I I f£ ; ; ] | II II I | ! I I 1 I ICO ii CO imi i i i i ! i I i i j j | i i 1 a ^ a CO mm i 1 i I I 1 i i i i i i i i i r ~ i i 1 ^ O £86H III! ; ; J I i i i I I ! I "~ 1 ! II 1 1 O 10 9£OH 1 I ! I I ! 1 1 i i i II I"5 | ! ! I II Mississippian, undifferentiated ITf 1 1 !"* «* oo Upper 66ZTT i i i i i II II | | 1 1 I ! i2TenSve/(ienlredtYP6SeCtldSely1nassoclatedsectionwhichconsiderable°nrreliancebeplacedontocorrectstratigraphicassignments.canas tifiration OZ80T 1 I r-° ! 1 1 i i i i 1 1 II | ; I I 1 CO ^ 966 I 1 ^ ; ; ; ; i i i II II ; | I I 1 i73 92.6 i i 00 1 | 1 | i i i 11 II 1 I I I 1 I s Z2.6 ^ S 1 1 ! 1 i i ] I ; | ! rt I 1 ; ; 1 I II 12.6 1 I I I ! rt i i 1 1 1 II ! I ] l 1 I II rt 8f£SI I I I I ! | ! ] O i i II 11 ! ; 1 ! II o Probable Goniatites '"'III 1 1"* N zone znzi ! ; ; ] ; ; | ; ; ! ! 1 II Cl i i 1 1 I 1 i 1 ; C-< l l 1 1 1 ! ! 1 I II o onzi 8 998TT 1 1 1 I i 1 1 ^ 1 1 1 II II ; ; I 1 I t- me 1 1 I 1 | | ; 111 O 1 I II I 1 « 1 I II S IN 1 "* c rcm 1 ,' : ~ ; ; ,' l"" ! 1 ! ; ; ! 1 ,' ! I I I I I ! ; ; CO 1 1 1 1 1 I I II II jo Goniatites 1 09m zone i 62.2.ZI I 1 I I ; ; 1 | i iCO 1 I ! ! | I I I CO mzi 05 1 1 1 1 I ! l 1 I 1 ! N 1 1 ! I 1 ! II s i i CO i CO i 8S8IT 1 1 I I 1 1 ] ] 1 1 I 1 I I I 1 ! 111 uo AlapahlimestoneContinued i 8980T I 1 I I I I I | ill C- II 1 I 1 I 1 I II N 1 I 05 N i S980T I I 1 I ! | 1 ; II II ; ; 1 I II 88S£I III! 1 I 1 l I 1 1 1 I I I "" I | II II ^ i88T£ I I I I N I I I 1 I II II i i II II N Lithostrotion ^ zone i 98T£ III ^ I 1 1 1 1 I 1 I 1 I 1 1 I ^ i Z2.1S *" 1 1 I I ! | 1 1 1 1 I 1 1 | ! I I I i69l£ 1 1 1 1 ! rt 1 ! 1 I 1 1 I II 1 | I ! I ! ^ i _,9I£ I 1 I I ITH -H 1 I III ^ i uo ii ! rt ! rt 1 1 N i i i i IN N i -,80£ | | i I 1 ! 1 1 I II I i I I I I I""1 1-1 99*91 I 1 I I I I I 1 1 1 I 1 ! 1 ; I I 1 I OSF91 ! ! ! I IN ! ,' ! ,' f ,' ; ,' ,' ^ ; ; ! 1 1 CO 1 I"1 ^ Naticopsisor Lithostrotion Continuedzone S66H i 1 1 1 1 1 ! ! l I I I I 2.8ZSI I"1 1 I i I | 1 I I 1 I 1 ! | ! ^ N CO w -.816 I | I I I 1 1 1 I II I I I | Z2.ZS 1 1 ,' ,' ,' ,' 1 1 i I I 'H ! ! N i CO 1^ rt 9TOT 1 1 1 I i 1 1 1 1 II 11 ; | II II HOI 1 1 1 ! | I 1 1 I 1"* II i i II II 1 N

Trepospira(Trepospira)sp.... (Angyomphalus'!)Trepospira § KniuhtitesRetispirat)(sp-._... Straparollus(Euomphalus) tstraparollus(Euomphalus)sp. Amphiscapha(Cylicioscapha) Anematinarockymontanum si>...... Mourloniaminuta,n.sp___._ Mourlonia'!reloba,n.sp____ Bemberiu'!inumbilicata,n.sp__ inaurocinguium(Uiauroangu- liim)sp..-. Platyceras(Platyceras)sp___._ Naticopsis(Naticopsis)sutii- MurchlsoniaM.cf.sp.-._ __ a bellerophontacean.....Indet. brooksensis,n.sp....__ Newgenus?A... (Naticopsis)sp...... alaskensis,n.sp--__ Indet.euomphalaeean... Nodospiraornafa,n.sp- Phymatopleurasp-____-__ Indetpieurotomariacean.. Indet.loxonematacean_ _. a Tiirbonellina'!lata,n.sp (Orthonychia)sp.... (Shimer)-....____ Indet.neritacean.. Indet.inurchisoniacean Euphemitessp.,-... Spiroscalacf.S.sp-__ O Yunnajtiasp.... gX grada,n.sp.--_ Ffhineoderma"!sp. '* W ricompta,n.sp lanthinopsis"!sp.. 03 Bellero[ihoiisp.. Portlockiella'!sp- Newgenus?B. Pleurotomariacea: f'n»vtltltmn'>or. Microdomatacea: Bellerophontacea: Neilsoilia'!sp Cj f^, Murchisoniacea: Loionemasp a Euomphahicea: Platyceratacea: Platyzonasp Loxonematacea: Genusindet ^"S, Scaphopoda: "3 JNeritacea: Subulitacea: "o 118 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

Turbonellina'l lata n. sp. is found only in rocks of 11799 and 13287. On much less certain grounds, col­ Early Mississippiaii age. Several other species are lections from USGS localities 976 and 5430 may also known from single specimens and little reliance can represent the Naticopsis zone. Other collections can­ be placed on them for stratigraphic determinations. not be assigned to either zone with any degree of Ammatina rocky montanum (Shinier) is more com­ confidence. mon in the Lower Mississippiaii than in the Upper Goniatites zone and probable Goniatites zone. This Mississippiaii. Euomphalaceans, mostly indeterminate assemblage, dominated by the large pleurotomaria- as to genus and species, are more common in the Lower ceans Benibexial inunibilicata^ 11. sp. and Nodospira Mississippiaii; bellerophontaceans, also mostly inde­ ornata^ 11. gen., n. sp., is the most distinctive of the terminate as to species, are less abundant. Pleuro- gastropod faimules studied. With the exception of tomareans are less common and individual specimens Euphemites and Loxonema, of which one and two are smaller in the Lower Mississippiaii than in the specimens, respectively, occur in the Lower Mississip­ Upper Mississippian. Finally, iieritaceans are much pian, all specifically identifiable gastropods from rocks rarer in the Lower Mississippiaii than in later beds. assigned to this zone are limited to it. Within this zone, cephalopods and gastropods occur together at UPPEK MISSISSIPPIAN USGS localities 11828, 11865, and 1208-t. Naticopsis and Lithostrotion zones. Collections These gastropod studies suggest strongly that the from the Naticopsis zone of the Upper Mississippian collections listed as "probable Goniatites zone" in table Alapah limestone, constitute a gastropod faunule 1 should be referred to that zone without question. composed primarily of large neritaceans and large Nettsonial sp. and Euphemites sp. occur in both sets bellerophontaceans. Most specimens are steinkerns in of collections, along with Nodospira orrmta, n. sp. and a blocky black limestone matrix. One specimen of Bembexial iniimbilicata, 11. sp. In addition, Mour- Anenmtina and an indeterminate euomphalacean were lonia mimita, n. sp. is present in collections question­ also collected from rocks of this zone. ably referred to the Goniatites zone and may be rep­ The Lithostrotion- zone yields a more diversified resented by a steinkern in a collection definitely from gastropod faunule. Nearly half the specimens are the Goniatites zone. euomphalaceans, a considerable number of which can­ Upper Mississippian, undi-fferentiated. All speci­ not be assigned to genus with any degree of confi­ mens referred to this listing are exceedingly poorly dence. Several specimens are identified as Straparol- preserved. No significant stratigraphic statement can lus (Euomphalus} brooksenxis, n. sp. Other gastro­ be made on the basis of the available material. pods from this zone are single specimens of Porflock- ?WZa? sp., Rhineoderm-a-1. sp., AnomphaJus sp., an in­ PERMIAN determinate niiirchisoniaceaii, and an indeterminate Euomphalaceans constitute nearly two-thirds of the neritaceaii. Two specimens each of Anematina and Permian gastropod assemblage. Pleurotomariaceans, an indeterminate species of pleurotomariacean com­ most of which are indeterminate as to genus and spe­ plete the faunule. cies, comprise much of the remainder but they are Neither zone can be distinguished solely on the widely distributed and occur in nearly as many col­ basis of gastropod species present, although collec- lections as the euomphalaceans. Several indetermi­ lections from the Lithostrotion zone show more taxo- nate bellerophontaceans and Platyceras complete the nomic variety than those from the Naticopsis zone. assemblage. The presence of Platyceris in beds of In addition, many of the species and genera found in Permian age indicates that, in Alaska, the genus can­ these two zones also occur in rocks of Early Missis­ not be used as a guide to the Mississippian. sippiaii age. Among these are Betterophon sp., Ane- The euomphalacean species appear tc be relatively matina rockymontanum- (Shimer), fttraparottus (Eu- reliable guide fossils to the Permian rocks. Two of omphahts} brooksensis, 11. sp., and, tentatively, these species, StraparoUus (Euomphah'-s) alaskensis, Naticopsis (Naticopsis} sutiiricompta, n. sp. Never­ 11. sp. and Am.phiscapha (Cylicioscapha) grada, n. sp. theless, fieldwork has demonstrated that the dark are described. Among the pleurotomariaceans, Mour- matrix and large size of the specimens from the lonial reloba, 11. sp. is the most common species. Naticopsis zone are distinctive. Many kinds of pleurotoniariaceans seem to be repre­ Certain collections from among those listed in table sented in the poorly preserved material from the Per­ 1 as '''Naticopsis or Lithostrotion- zones'1 seem more mian of northern Alaska. likely to represent the Naticopsis zone. In this cate­ The gastropods suggest faunal relationships among gory are USGS (U.S. Geological Survey) localities the Siksikpuk, Sadlerochit, and unnamed Permian LATE PALEOZOIC GASTROPODA FROM NORTHERN ALASKA 119 formations. StraparoUus (EuompJialus} alaskensis, await the publication of research by other specialists. n. sp. occurs in all three formations, and Amphiscapha 1. Platyceras commonly occurs here in crinoidal lime­ (C ylicioscapha] grada, n. sp. is present in the latter stone. This partially supports the hypothesis con­ two. Finally, Mourfonia'l reloba, n. sp. occurs in the cerning life relationships of platyceratids on pelma- unnamed formation, is tentatively identified in collec­ tozoan calyxes (Bowsher, 1955). tions from the Siksikpuk formation, and may be pres­ 2. In the Lower Mississippian where Platycerc# is ent in the Sadierochit formation. common, the associated gastropods show less ^ari- USGS locality 14174, assigned to the Siksikpuk ety than in the Upper Mississippian. This sug­ formation on the basis of rock type, is atypical. The gests that areas of limestone deposition favorable collection consists of two specimens of Glabrocingulum for crinoids were unfavorable for most benthonic (Glabrocingulum) sp. and one specimen of Trepospira gastropods. (Trepospira) sp. Except for one questionable occur­ 3. StraparoUus occurs in limestone, sandstone, silt- rence, Trepospira is unknown in Permian faunas else­ stone, and shale. This suggests that species of this where in the world. Furthermore, the specimens of genus had considerable ecologic tolerance. Glabrocijiguhim differ from Permian species known 4. Although large gastropods (an inch or mor?, in from the southwestern United States and other well- height) are not confined to the coarse clastic facies, known areas of Permian exposures. It may be that they are the only snails that have been collected this collection is actually of Pennsylvaniaii age. More from rocks of this facies. These large gastropods fieldwork in northern Alaska and additional collec­ apparently lived in a zone of heavy surf, the prob­ tions are needed to confirm the presence of Pennsyl- able sedimentary depositional environment of the vanian rocks. coarse clastic material. Some of the large shells Known ranges of the more significant species are occur in a siliceous conglomeratic matrix contain­ shown in figure 25. ing pebbles half an inch in diameter. 5. Cephalopods are rarely associated with the gastro­ ECOLOGICAL AND PALEOGEOGRAPHICAL DATA pods; the 2 groups occur together at only 6 lo~ali- Representatives of five superfamilies euomphala- ties. Corals and gastropods also appear to be nearly ceaiis, platycerataceans, pleurotomariaceans, nerita- mutually exclusive, although details of coral distri­ ceans, and bellerophontaceans, in that order of abun­ bution have not been published as yet. On the dance comprise virtually all the gastropods studied. other hand, except in the Naticopsis sutnricampta The groups are represented by nearly equal numbers zone, gastropods are commonly associated with nu­ of specimens, with the euomphalaceans being perhaps merous taxonomically diversified brachiopods. Ap­ half again as abundant as the bellerophontaceans. parently environments favorable for diversified Although many of the pleurotomariaceans are poorly brachiopod faunas afforded optimum conditions for preserved, this group has considerably more generic abundant gastropods. Conversely, it seems that only diversity than the others. certain kinds of gastropods were able to live in en­ Individual collections show little taxonomic variety. vironments well suited for corals and cephalop ods. Less than 10 percent of the collections contain more 6. In the Naticopsis suturicompta zone, except for one than three taxa. This lack of diversification may re­ collection, fossil assemblages consist entirely of gas­ flect the small amount of collecting or it may, in part, tropods. There is no obvious explanation for this reflect a time of unfavorable or relatively uniform en­ apparent exclusion of other fossil invertebrates', vironment. For example, fossils of Lower Mississip­ Mississippian collections include genera known to pian strata of the western United States have been be common in the lower Carboniferous elsewhere in collected for nearly 100 years, but relatively few gas­ the world. Heretofore they have not been reported tropods are known. It could be more than coincidence from the American Arctic, and knowledge of their that both regions were the sites of predominantly clas­ stratigraphic occurrence and geographic distribution tic limestone deposition during the late Paleozoic. fills an important gap in our information on paleogeo­ Ecologic and paleogeographic inferences drawn graphic distribution. There is no evidence at the from this study are listed below. Further work is family level, and most probably none at the gereric needed before the generalizations can be applied to level, that any of the groups is conspicuously present upper Paleozoic gastropods from other regions. These or absent because of cold-water conditions. So far as inferences involve examination of other fossil groups can be interpreted from this study, a boreal marine in the late Paleozoic faunas of the region. Docu­ invertebrate fauna did not exist in Mississippian time. mentation of some of the statements must necessarily The snail faunule is not particularly different, in gen-

507218 to o

"~~~~~- - ^____SiYSTEM CARBONIFEROUS PERMIAN MISSISSIPPIAN PENNSYLVANIA!!!?* Lisburne group TAXON~~~~^--^^__^^ Kayak shale Lower Upper Wachsmuth limestone Alapah limestone

Belleroptwn sp. 1 1 H 1

Straparollus (Euompkalus) brooksensis 1 Yochelson and Dutro, n. sp. M

Straparollus (Euomphalns) alaskensis H 1 Yochelson and Dutro, n. sp. 7 T Amphiscapka (Cylicwscapka) grada j i_? Yochelson and Dutro, n. sp.

Trepospira (Trepospira) sp. ? 1 ?

7 Mourlonia minuta 7 j ? Yochelson and Dutro, n. sp.

T Mourtonia1! reloba | i td Yochelson and Dutro, n. sp. d iH i Nodospira ornata O 1 ? * Yochelson and Dutro, n. sp. 00

Bembexial inumbilicata 1 H Yochelson and Dutro, n. sp.

Glabrocingulum (Glabrocingulum) sp. ? 1 ?

Neilsonial sp 1 ? ? Platyceras (Platyceras) sp. ? Platyceras (Orthonychia) sp. ?-H | | 1 i

Anematina rockymantanum 1 1 1 1 -H « (Shimer)

Naticopsis (Natieopsis) suturicompta 1 -HI 1 Yochelson and Dutro, n. sp.

400 400 800 1200 Feet I_ I

FIGURE 25. Known ranges of the more significant late Paleozoic gastropod spectes in northern Alaska. Thickness of Mississippian rocks plotted to scale of type sections; Pennsyl­ vania^?) and Permian thicknesses diagrammatic. Known occurrences indicated by vertical lines; question marks indicate doubt as to precise position with respect to type sections. Stratigraphic range, controlled by two or more occurrences, shown by horizontal bar; dashed bar indicates questionable range. LATE PALEOZOIC GASTROPODA FROM NORTHERN ALASKA 121 eral aspect, from faunules found in Mississippian agrammatically in figure 26. Linear measurements in limestones of the western United States. millimeters are given for the types of new species. The abundance of many kinds of rugose corals, in­ Angular measurements were made with the axis of cluding both solitary and colonial forms, is contribut­ coiling vertical. They represent approximate rather ing evidence to the consideration of the Mississippian than precise slope angles. Most ornament can be in northern Alaska as a time of relatively warm shal­ classed as either "colabraV parallel to the outer lip low seas. and growth lines, or "spiral,11 revolving around the Permian collections are, unfortunately, too small whorls and parallel to the suture. and too scattered geographically to give any indica­ Because most of the collections contain few indi­ tion about climatic zonation. Stehli (1957) suggests viduals, it is difficult to determine the variation within that tropical and temperate zones occupied wider belts what might be considered a single population. More of latitude in Permian time than at the present. than one-third of the collections include only 011°, gas­ tropod specimen, and about three-fourths of th°. col­ GENERAL CONSIDERATIONS lections have less than five gastropod specimens. The A new classification of Paleozoic gastropods was number of specimens identified in each taxon is listed completed recently by Knight, Batten, and Yochel- on table 1. son (in press). That classification is employed The collection from USNM (U.S. National Mu­ in this paper, except that Amphiscapha Knight is seum) locality 3089 differs from the others in that it treated as a distinct genus rather than as a subgenus consists of silicified shells recovered by dissolving of Straparollus Montfort. Systematic descriptions are limestone blocks in hydrochloric acid. Commonly, arranged in biologic order rather than in stratigraphic more and better preserved specimens can be obtained order. by this method than can be collected by mechanical Morphologic terminology employed is that of preparation from limestone. Further collecting in the Knight (1941, p. 23-28) *and Cox (1955). Three region should be directed particularly toward a search terms not in common usage, referring to the course for silicified fossils. of growth lines over the shell, are "opisthocline," a Most of the specimens are not well preserved; the course forward and downward; "orthocline," essen­ illustrated specimens constitute a significant percent­ tially straight downward; and "prosocline," backward age of the better specimens. Taxonomic and strati- and downward with reference to the aperture of the graphic conclusions based on poorly preserved mate­ shell and the axis of coiling. These are shown di- rial are necessarily less satisfactory than those based on better material. Preservation seems to be related directly tc two factors. First, most of the collections are from rela­ tively compact limestone. Because of the structure of the molluscan shell, exfoliated specimens are com­ monly produced when material is broken from a dense carbonate matrix. By way of contrast, identifiable brachiopods, and other types of fossils, commonly may be broken from a limestone matrix. Second, the se­ vere climate of the high latitudes apparently permits little chemical weathering of shales and shaly lime­ stones. In addition, an insignificant amount of dis­ integration appears related to frost action. In other regions, limy shales often produce the most abun­ dant and best preserved molluscan shells. The small amount of weathering also seems to limit the actual number of specimens available at any one outcrop. Because few specimens are available for study, an open system of nomenclature has been adopted, and formal names have been applied only to well-preserved material. Specific names are applied to 10 of tH 34 FICURE 26. Schematic representation of terms for direction of growth lines. forms recognized. In addition, because this is the 122 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY first study of gastropods from northern Alaska, the cance based on studies of other elements of the total authors have proposed new names in every case but fauna, may eventually lead to the solution of some of one, rather than use the terms "cf." or "aft1." to com­ the local stratigraphic problems. All specimens briefly pare these specimens with species described from clis- mentioned are listed as indeterminate on table 1. stant localities. Future studies based on new collec­ tions may place some of these names in synonymy REGISTER OF LOCALITIES with species described from regions far removed from Locality Nos. 3087 through 3279 refer to collections northern Alaska. As a general principle, however, it in the possession of the U.S. National Museum. Fol­ seems wiser to erect new species. Indiscriminate iden­ lowing them, localities of the U.S. Geological Survey tification of material with previously named species are listed. Except for types and figured specimens can imply unwarranted correlations. transferred to the National Museum, tlnse collections This study suggests that several new generic cate­ are in the possession of the Geological Survey. Lo­ gories are needed for Mississippian gastropods. With cality 7118b is a "green1" number in an old general one exception the number of specimens available is too register of Paleozoic localities. All ether numbers small or the specimens themselves are too poorly pre­ refer to the "blue" register of localities currently be­ served to serve as a suitable basis for establishing new ing maintained by the Upper Paleozoic Unit, Paleon­ genera. Revision of the Mississippian gastropods, tology and Stratigraphy Branch. Collections 406 particularly the pleurotomariaceans, is needed to make through 1015 were made by members of earlier sur­ them more useful for stratigraphic and biologic veys. Collections from localities 9184 through 15829 studies. were made by members of the Navy Oil Unit, Alas- One unorthodox treatment is incorporated in this kan Geology Branch. taxonomic study. Following each superfamily a brief Latitude and longitude given for the localities are section is devoted to material which would normally based on the best data available to the collectors at be considered as indeterminate. The possible syste­ the time this register was compiled (January 1957). matic placement of some of the specimens is discussed Many geographic positions were plotted on the briefly. It is recognized that these suggested identi­ 1:250,000-scale quadrangle map series published by the Geological Survey. Other positions were taken fications are not well founded, and, accordingly, they from the 1:48,000-scale preliminary mr p series com­ are clearly separated from the rest of the systematic piled for the Geological Survey program of geologic study. These should be considered only as first ap­ mapping in Navy Petroleum Reserve No. 4 and adja­ proximations. Because of the considerable effort and cent areas. relatively great expense involved in collecting the ma­ Index maps (figs. 27, 28, and 29) showing the ap­ terial from nothern Alaska, we feel that this attempt proximate positions of the localities are based on the to obtain the maximum amount of stratigraphic in­ World Aeronautical Chart series (maps 62-64, and formation is justified. These scraps of additional in­ 76) published by the U.S. Coast and Geodetic Survey, formation, together with suggestions of age signifi­ (scale 1:1,000,000). LATE PALEOZOIC GASTROPODA FROM NORTHERN ALASKA 123

161' 160° 162°30'

11865 X (H861 U1867 11890 68° 30' -

B

166 C

68°45'-

159" 158' 157 C *

68*30'

D

FIGDRE 27. Fossil-collecting localities in parts of the Misheguk Mountain quadrangle (A), the Noatak quadrangle (B), the Point Hope quadrangle (C), and the Howard Pass and Misheguk Mountain quadrangles (D), Alaska. 124 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

154 C 153' 152'

68° 30

151" 150° 149° 148°

68°30' A? Nanushuk , Lake ^3107 Itkillik 3087 Laker, X^3172 3087a 3089X 3173 3091 /x 13170 X 13272 3113 3088 3100 3115 3167 3186 3182 3188 14954

CHANDLER LAKE PHILIP SMITH MOUNTAINS

FIGURE 28. Fossil-collecting localities in parts of the Killik River and Chandler Lake quadrangles (A) and the Chandler Lake and Philip Smith Mountains quadrangles (B), Alaska. LATE PALEOZOIC GASTROPODA FROM NORTHERN ALASKA 125

142° 141°

147° 146° 145°

69° 30' -~

FIGURE 29. Fossil-collecting localities in parts of the Demarcation Point and Table Mountain quad­ rangles, Alaska, and adjacent parts of Canada (A) and the Sagavanirktok and Monnt Michelson quadrangles, Alaska (B). 126 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY Register of localities

Locality No. Field No. Collector, year of collection, and description of locality Stratigraphic posi'fon and age

USNM 3087 F 7 of 11 June. Bowsher, A. L., Dutro, J. T., Jr., Gudim, C. J.; 1949; Dark limestone member, Alapah F 1 of 13 June Chandler Lake quadrangle; Shainin Lake area, limestone Lithostrotion aff. L. F 3 of 16 June southwest corner of ridge, top of Sugarloaf Hill; lat asiaticum zone; Upper Missis- 68°19'20" N., long 150°55'30" W.; measured sec­ sippian. tion J, 84.5-93.3 ft above base of Alapha limestone. 3087a F 1 of 16 June. Bowsher, A. L., Dutro, J. T., Jr., Gudim, C. J.; 1949; Shaly limestone member, Ala­ same locality as 3087; 49 ft above base of Alapah pah limestone; Naticopsis sut- limestone. uricompta zone; Upper Missis- sissippian. 3088 F 5 of 24 July. Bowsher, A. L., Dutro, J. T., Jr., Gudim, C. J.; 1949; Shaly limestone member, Alapah Chandler Lake quadrangle; Nanushuk Lake area, limestone; Naticopsis suturi- along west side of main ridge southeast of lake; lat cornpta zone; Upper Mississip- 68°22'20" N., long 150°29'34" W., 80 ft above base pian. of Alapah limestone. 3089 F 2 of 27 August.___ Bowsher, A. L., Dutro, J. T., Jr.; 1949; Philip Smith Crinoidal limestone member, Mountains quadrangle; Itkillik Lake area, north Wachsmuth limestone; " Za- slope of hill about 11,100 ft S. 85° E. of Itkillik Lake phrentis" konincH zone; Lower camp; lat 68°24'15" N., long 149°43'20" W.; 139- Mississippian. 145 ft above base of Wachsmuth limestone. 3091 F 1 of 3 June. Bowsher, A. L., Dutro, J. T., Jr.; 1949; Chandler Lake Crinoidal limestone member, quadrangle; Shainin Lake area, top of lower massive Wachsmuth limestone; "Za- cliff, southwest slope of Mount Wachsmuth; lat phrentis" konind'i zone; Lower 68° 18'50" N., long 150°55'25" W.; measured section Mississippian. I, 141.6-148 ft above base of Wachsmuth limestone. 3095 F 3 of 22 June. Bowsher, A. L., Dutro, J. T.. Jr.; 1949; Chandler Lake Argillaceous limestone member, quadrangle; Shainin Lake area, head of small creek Kayak shale; Leptaena analoga about 14,700 ft. S. 8° E. of Shainin Lake camp; lat zone; Lower Mississippian. 68°16'25" N. long 150°57'25"W.; 720-777 ft above base of Kayak shale. 3098 F 1 of 22 June. Bowsher, A. L., Dutro, J. T., Jr., Gudim, C. J., Feder, Crinoidal limestone member, A.; 1949; Chandler Lake quadrangle; Shainin Lake Wachsmuth limestone; " Za- area, north side of first valley south of Pinnacles; lat phrentis" konind'i zone; Lower 68° 17' N., long 150°55'15" W., 187-198 ft above Mississippian. base of Wachsmuth limestone. 3100 F 2 of 20 August..-- Bowsher, A. L., Dutro, J. T. Jr.; 1949; Philip Smith Crinoidal limestone member, Mountains quadrangle; Itkillik Lake area, 8,500 ft Wachsmuth limestone "Za- S. 40° E. of Itkillik Lake camp; lat 68°23'15" N., phrentis" konincH zone; Lower long 149°45'50" W.; 73-75 ft above base of Wachs­ Mississippian. muth limestone. 3107 F 2 of 21 July_-.___ Bowsher, A. L., Dutro, J. T., Jr., Gudim, C. J.; 1949; Crinoidal limestone member, Chandler Lake quadrangle; Nanushuk Lake area, Wachsmuth limestone; " Za- south side of ridge, 10,000 ft N. 12° W. of Nanushuk phrentis" konincH zone; Lower Lake camp; lat 68°25'10" N., long 150°30'15" W. Mississippian. 3110 F 6 of 23 July ____ Bowsher, A. L., Dutro, J. T., Jr., Gudim, C. J.; 1949; Crinoidal limestone member, Chandler Lake quadrangle; Nanushuk Lake area, Wachsmuth limestone; "Zaph- 6,800 ft east of Nanushuk Lake camp; lat 68°23'30" rentis" konincki zone; Lower N., long 150°26'20" W. Mississippian. 3113 F 3 of 3 August.---- Bowsher, A. L., Dutro, J. T., Jr.; 1949; Chandler Lake Banded limestone n ember, Wach­ quadrangle; Shainin Lake area, south face of Sugarloaf smuth limestone; Brachythyris Hill; lat 68°18'50" N., long 150°55'35" W.; 957 ft suborbicularis zone; Lower Mis­ above base of Wachsmuth limestone. sissippian. 3115 F 1 of 12 July Bowsher, A. L., Dutro, J. T., Jr.; 1949; same locality as Banded limestone member, Wach­ 3113; 845-849 ft above base of Wachsmuth limestone. smuth limestone; Brachythyris suborbicularis zone; Lower Mis­ sissippian. 3164 F 2 of 24 July ____ Bowsher, A. L., Dutro, J. T., Jr., Gudim, C. J.; 1949; Shaly limestone member, Alapah Chandler Lake quadrangle; Nanushuk Lake area, limestone; Naticopsis suturi- about 1,800 ft S. 34°E. of Nanushuk Lake camp; lat compta zone; Upper Missis­ 68°23'10" N., long 150°28'45" W.; lower 30 ft of sippian. Alapah limestone. 3167 F 6 of 24 July. Bowsher, A. L., Dutro, J. T., Jr., Gudim, C. J.; 1949; Dark limestone member, Alapah Chandler Lake quadrangle; Nanushuk Lake area, limestone; Litho->trotion aff. L. about 6,900 ft S. 6° W. of Nanushuk Lake camp; lat asiaticum zone; Upper Mis­ 68°22'15" N., long 150°29'35" W.; 97-113 ft above sissippian. base of Alapah limestone. 3169 F 1 of 28 August..__ Bowsher, A. L., Dutro, J. T., Jr., Gudim, C. J.; 1949; Dark limestone member, Alapah Philip Smith Mountains quadrangle; Itkillik Lake limestone; Lithostrotion aff. L. area, about 13,900 ft N.60° E. of Itkillik Lake camp; asiaticum zone; Upper Mis­ lat 68°25'25" N., long 149°43'40" W.; 86.3 ft above sissippian. base of Alapah limestone. 3170 F 1 of 23 Julv. Bowsher, A. L., Dutro, J. T., Jr., Gudim, C. J.; 1949; Shaly limestone member, Alapah Chandler Lake quadrangle; Nanushuk Lake area, limestone; Naticopsis suturi- about 2,500 ft N. 65° E. of Nanushuk Lake camp; lat compta zone; Upper Missis­ 68°23'40" N., long 150°28' W.; about 60 ft above sippian. base of Alapah limestone. LATE PALEOZOIC GASTROPODA FROM NORTHERN ALASKA 127 Register of localities Continued

Locality No. Field No. Collector, year of collection, and description of locality Stratigraphic position and a^e

USNM 3171 F 4 of 11 August____ Bowsher, A. L., Dutro, J. T., Jr.; 1949; Philip Smith Shaly limestone member, Alapah Mountains quadrangle; Itkillik Lake area, about limestone; Naticopsis suturi- 13,600 ft N. 60° E. of Itkillik Lake camp; lat 68°20'25' compta zone; Upper Missis- N., long 149° 43'05" W.; 63 ft above base of Alapah sippian. limestone. 3172 F 3 of 23 August..__ Bowsher, A. L., Dutro, J. T., Jr., Gudim, C. J.; 1949; Dark limestone member, Alapah same locality as 3171; about 140 ft above base of limestone; Lithostrotion aff. L. Alapah limestone. asiaticum zone; Upper Mis- sissippian. 3173 F 2 of 25 August.... Bowsher, A. L., Dutro, J. T., Jr., Gudim, C. J.; 1949; Crinoidal limestone member, Philip Smith Mountains quadrangle; Itkillik Lake Wachsniuth limestone; "Zaph- area, about 12,200 ft N. 65° E. of Itkillik Lake rentis" konincki zone; Lower camp; lat 68°25'12" N., long 149°43'10" W.; float at Mississippian. b&SG of SGction 3182 F 1 of 26 July. Bowsher, A. L., Dutro, J. T., Jr.; 1949; Chandler Lake Shaly limestone member, Alapah quadrangle; Nanushuk Lake area, about, 6,900 ft S. limestone; Naticopsis suturi- 6° W. of Nanushuk Lake camp; lat. 68°22'25" N., compta zone; Upper Mississip­ long 149°43'40" W.; 80 ft above base of Alapah lime­ pian. stone. 3186 F 4 of 7 August. Bowsher, A. L., Gryc, G., Fischer, W.; 1949; Chandler Dark limestone member, Alapah Lake quadrangle; Shainin Lake area, near south end limestone; Lithostrotion aff. L. of Sugarloaf Hill; lat 68°19'25" N., long 150°55'30" asiaticum zone; Upper Missis­ W.; 172 ft above base of Alapah limestone. sippian. 3188 F 5 of 7 August. Bowsher, A. L., Gryc, G., Fischer, W.; 1949; same Dark limestone member, Alapah locality as 3186; 0.3 ft above locality 3186. limestone; Lithostrotion aff. L. asiaticum zone; Upper Missis­ sippian. 3247 F 6 of 6 July _. Bowsher, A. L., Dutro, J. T., Jr.; 1949; Chandler Lake Argillaceous limestone member quadrangle; Shainin Lake area, about 8,000 ft S. 32° Kayak shale; Leptaena analoga W. of Shainin Lake camp; lat 68°17'45" N., long zone; Lower Mississippian. 150°56'30" W.; 795.3-798 ft above base of Kayak shale. 3272 F 3 of 24 August-... Bowsher, A. L., Dutro, J. T., Jr.; 1949; Philip Smith Dark limestone member, Alapah Mountains quadrangle; Itkillik Lake area; lat limestone; Lithostrotion aff. L, 68°25'30" N., long 149°42'40" W.; 91 ft above base asiaticum zone; Upper Missip- of Alapah limestone. pian. 3279 F 1 of 20 June. Bowsher, A. L.; 1950; Chandler Lake quadrangle; upper Shaly limestone member (?), Alapah Creek, about 600 ft S. 80° E. of Alapah Wachsniuth limestone; "Zap- Creek camp; lat 68°10'18" N., long 150°46'20" W.; hrentis" konincki zone; Lower lower 44 ft of Wachsniuth limestone.- Mississippian. USGS 7118b 19 D-__-_- Leffingwell, E. de K.; 1908; Mount Michelson quad­ Sadlerochit formation; Permian. (Green) rangle, Ikiakpaurak vallev; approximate lat 69°28' N., long 145°50' W. USGS 406 11 Md 26._ Maddren, A. G.; 1911; International Boundary Survey; Alapah limestone (?), Lisburne about 4 mi south of east camp on Joe Creek of Firth group; Upper Mississippian(?). River; lat 68°53'40" N., long 140°57'30" W. 408a 11 Md 28a. Maddren, A. G.; 1911; International Boundary Survey; Permian (?). about 2 mi west of west camp on Joe Creek; lat 68°57' N., long 141°22'30" W. 960 12 Md31._ Jessup, J. M.; 1912: International Boundary Survey; Permian (?). west side of You Creek, north end of ridge; lat 68°44' N., long 141°04'25" W. 971 12 Md 40.. Jessup, J. M.; 1912; International Boundary Survey; Lisburne group; Upper Mississip­ northeast slope of main fork of Incog Creek; lat pian. 68°46'30" N., long 140°56" W. 972 12 Md 41__ Jessup, J. M.; 1912; International Boundary Survey; Alapah limestone, Lisburne northeast slope of main fork of Incog Creek, near group; Upper Mississippian. head of creek; lat 68°47'10" N., long 140°57'55" W. 975 12 Md 44_. Jessup, J. M.; 1912; International Boundarv Survey; Alapah limestone, Lisburne southwest slope of Turner Mountain; lat 68°48'50" group; Upper Mississippian. N., long 140°56'W. 976 12 Md 46__ Maddren, A. G.; 1912; International Boundary Survey; Alapah limestone, Lisburne west end of Turner Mountain, on east slope of upper group; Upper Mississippian. Boulevard Creek; lat 68°49'50" N., long 140°58'35" W. 979 12 Md 49. Harrington, G. L.; 1912; International Boundary Sur­ Permian (?). vey; mountain spur 2}£ mi southeast of Joe Creek camp; lat 68°53'40" N., long 140°56' W. 982 12 Md 53- Jessup, J. M.; 1912; International Boundary Survey; "Pennsylvanian shales" (of Mad­ 1 mi south of Joe Creek and % mi east of 141st dren)"; Permian (?). meridian; lat 68°54'30" N., long 140°59'30" W. 987 12 Md 59- Maddren, A. G.; 1912; International Boundary "Pennsylvanian shales" (of Mad­ Survey; I}i0 mi west of 141st meridian, south of Joe dren); Permian (?). Creek*; lat 68°55' N., long 141°03' W. 989a 12 Md 61- Maddren, A. G.; 1912; International Boundary "Pennsylvanian shales" (of Mad­ Survey; north bank of Joe Creek, % mi west of 141st dren); Permian (?) meridian; lat 68°55'30" N., long 141°02' W. 128 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY Register of localities Continued

Locality No. Field No. Collector, year of collection, and description of locality Stratigraphic position and age

USGS 994 12 Md 66. Harrington, G. L.; 1912; International Boundary Alapah limestone, Lisburne group; Survey; ridge north of Joe Creek, from bed above Upper Mississippian. reddish-weathering slaty limestone; lat 68°56'10" N., long 140°57'15" W. 996 12 Md 68- Jessup, J. M.; 1912; International Boundary Survey; Alapah limestone, Lisburne group; east slope of gulch north of Joe Creek, about % mi Upper Mississippian. east of 141st meridian; lat 68°56'10" N., long 140°58' W. 997 12 Md 69- Jessup, J. M.; 1912; same locality as 996; about 250 ft Alapah limestone, Lisburne group; north of 996, along strike. Upper Mississippian. 1004 12 Md 76- Maddren, A. G.; 1912; International Boundary Alapah limestone, Lisburne group ; Survey; northwest corner of limestone outcrop west Upper Mississippian. of Tub Mountain; lat 68°58'50" N., long 141°06'35" W. 1008 12 Md 79-. Harrington, G. L.; 1912; International Boundary "Artinskian limestone" (of Mad­ Survev; south side Joe Creek, about 6^2 nil west of dren) ; Permian. 141st'meridian; lat 69°56'30" N., long 141°18' W. 1009 12 Md 80__ Harrington, G. L.; 1912; same locality as 1008; about "Artinskian limestone" (of Mad­ Ko mi west. dren) ; Permian. 1010 12 Md 81_. Jessup, J. M.; 1912; International Boundary Survey; "Artinskian limestone" (of Mad­ north side Joe Creek valley about 1M mi west of dren) , Permian. 141st meridian; lat 68°56' N., long 141°21' W. 1014 12 Md 85- Jessup, J. M.; 1912; Internitional Boundary Survey; Alapah limestone(?), Lisburne north slope of gulch on vrest side Clarence River, group; Upper Mississippian. about 1% mi west of 141so meridian; lat 69°25' N., long 141 °04' W. 1015 12 Md 85a_ Harrington, G. L.; 1912; same locality as 1014, from Alapah limestone. (?), Lisburne talus below outcrop. group; Upper Mississippian. 9184 45 AKr 58- Kirschner, C. E.; 1945; Killik River quadrangle; east Alapah limestone, Lisburne group; bank of Okpikruak River, 16% mi S. 4° W. from Upper Mississipnian. forks of Killik River; lat 68°34'30" N., long. 153°31' W. 9186 45 AGr !___ Gryc, G.; 1945; Chandler Lake quadrangle; bluffs Lisburne group; Lower Missis­ west of northernmost tip of Chandler Lake; lat sippian (?). 68°17'30" N., long 152°36' W. 9187 45 AGr 2__. Gryc, G.; 1945; Chandler Lake quadrangle; bluffs Alapah limestone (?), Lisburne west of northernmost tip of Chandler Lake; lat group; Upper Mississippian. 68° 17' N., long 152°36' W. 10862 49 APa 384. Patton, W. W., Jr.; 1949; Chandler Lake quadrangle; Alapah limestone; Goniatites cren- cutbank on north side of Monotls Creek; lat 68°22'- istria zone; Upper Mississip­ 35" N., long 152°54' W.; from limestone bed over­ pian. lying chert-shale member of Alapah limestone. 10868 49 ATr 399- Tailleur, I. L.; 1949; Killik River quadrangle; cutbank Alapah limestone Goniatites cren- on east side of Middle Fork of Okpikruak River; lat istria zone; Upper Mississip­ 68°33' N., long 153°31' W.; near top of Alapah lime­ pian. stone. 10870 48 ASa 47 _- Sable, E. G., Lachenbruch, A. H.; 1948; Mount Michel- Lisburne group; Upper Mississip­ son quadrangle; north slope of Kikittut Mountain pian. about 1 mi west of Hulahula River; lat 69°28' N., long 144°25' W. 11785 50 ABe 201. Brosge, W. P.; 1950; Philip Smith Mountains quadran­ Siksikpuk formation; Permian(?). gle; Galbraith Lake area; approximate lat 68°29' N., long 149°13' W.; about 560 ft above base of Siksikpuk formation. 11786 50 ABe 200. Brosge', W. P.; 1950; same locality and level as 11785__ Siksikpuk formation; Permian(?). 11799 50 ARr 49_. Reiser, H. N.; 1950; Chandler Lake quadrangle; Sik­ Alapah limestone (middle part); sikpuk River area; approximate lat 68°20' N., long Upper Mississipiian. 151°50' W.; about 800 ft above base of Alapah lime­ stone. 11807 50 ABe 115_ Reiser, H. N.; 1950; Chandler Lake quadrangle; Chan­ Wachsmuth limestone; Lower dler Lake area, about 10,000 ft S. 85° E. of astronom­ Mississippian. ical point on Little Chandler Lake; lat 68° 16'40" N., long 152°36'50" W.; 280 ft above base of Wachsinuth limestone. 11808 50 ABe 44_- Brosge, W. P.; 1950; same locality as 15408; 575 ft Wachsmuth limestone; Lower above base of Wachsmuth limestone. Mississippian. 11814 50 AKe 238- Keller, A. S.; 1950; Chandler Lake quadrangle; cutbank Siksikpuk formation; Permian(?). on east side of Skimo Creek, a tributary of Tiglukpuk Creek; lat 68°17' N., long 151°53' W.; basal 60 ft of Siksikpuk formation. 11815 50 AKe 240- Keller, A. S.; 1950; same locality as 11814; possibly Siksikpuk formation; Permian (?). slightly different Stratigraphic level. 11816 50 AKe 242_ Keller, A. S.; 1950; same locality as 11814; possibly Siksikpuk formation; Permian (?). slightly different Stratigraphic level. 11823 50 AKt 329_ Kent, B. H.; 1950; Howard Pass quadrangle; station K Unnamed Permiar formation (?); 280; lat 68°36' N., long. 158°22' W.; in structurally Permian (?). complex area, Stratigraphic position unknown. LATE PALEOZOIC GASTROPODA FROM NORTHERN ALASKA 129 Register of localities Continued

Locality No. Field No. Collector, year of collection, and description of locality Stratigraphic position and age

USGS 11828 50 ATr 45- Tailleur, I. L.; 1950; Howard Pass quadrangle; Etivluk Lisburne group; Goniatites cren­ River valley; lat 68°35' N., long 156°38' W. istria zone; Upper Mississip- pian. 11843 50 ATr 189_ Tailleur, I. L.; 1950; Howard Pass quadrangle; Ipnavik Lisburne group(?); Lower Mis- River valley; lat 68°35' N., long 157°29' W. sissippian. 11858 50 ASa 227 _ Sable, E. G.; 1950; Misheguk Mountain quadrangle; Lisburne group (lower forma­ station Sa 350, Utukok River valley; 2 mi north of tion) ; Lower Mississippfan. west fork of Utukok River; lat 68°34'40" N., long 161°10'30" W. 11861 50 ASa 235. Sable, E. G.; 1950; Misheguk Mountain quadrangle; Lisburne group (lower forma­ 2,800 ft southeast of locality 11858; lat 68°34'20" N., tion) ; Lower Mississippian. long 161°10' W. 11865 50 ASa 150. Sable, E. G.; 1950; Misheguk Mountain quadrangle; Lisburne group (upper forma­ station Sa 249, head of west fork of Utukok River; tion); Upper Mississippian. lat 68°34'40" N., long 161°16'50" W. 11867 50 ASa 236 _ Sable, E. G.; 1950; Misheguk Mountain quadrangle; Lisburne group (lower forma­ station Sa 350(15), north side of Kogruk Mountain, tion; Lower Mississippian. Utukok River valley; about 400 ft south of locality 11861; lat 68°34'20" N., long 161° 10' W. 11890 50 AMg 149__ Mangus, M. D.; 1950; Misheguk Mountain quadrangle; Lisburne group (lower forma­ divide between Iligluruk Creek and Kugururok tion) ; Lower Mississippian. River; lat 68°34' N., long 161°20'30" W. 12084 F3 of 12 June. Bowsher, A. L., Gryc, G.; 1950; Chandler Lake quad­ Chert-shale member, Alapah lime­ rangle; Anaktuvuk River valley; 1,500 ft east of stone; Goniatites crenistria Kanakutk Lake; lat 68°18' N., long 151°21' W. zone Upper Mississippian. 12340 50 ACh 41___. Chapman, R.; 1950; Killik River quadrangle; Colam- Alapah limestone (?); Upper Mis­ nagavik River valley; lat 68°35' N., long 154°32' W. sissippian (?). 12342 50 AKe 226_ _. Keller, A. S.; 1950; Chandler Lake quadrangle; 100 ft Alapah limestone; Upper Mis­ south of locality 11814; lat 68°17' N., long 151°53' sissippian. W.; upper 75 ft of Alapah limestone. 12348 46 ATh 8... Thurrell, R.; 1946; Killik River quadrangle; upper Alapah limestone (?); Upper Mis­ Oolamnagavik River valley; lat 68°35' N., long sissippian (?). 154°32' W. 12355 50 ABe 112. Gudim, C. J; 1950; Philip Smith Mountains quadrangle; Shaly limestone member, Alapah Galbraith Lake area; approximate lat 68°28'30" N., limestone; Naticopsis suturi- long 149°21' W.; about 60 ft above base of Alapah compta zone; Upper Missis­ limestone. sippian. 12700 11 AS 46__. Smith, P. S.; 1911; Misheguk Mountain quadrangle; Lisburne group (lower forma­ central Noatak River vallev; cutbank on south side tion?); Lower Mississipnian. of river; approximate lat 68°01' N., long 159°02' W. 12701 11 AS 51-_- Smith, P. S.; 1911; Misheguk Mountain quadrangle; Lisburne group; Lower Missis­ central Noatak River valley, cutbank on north side sippian. of river; approximate lat 68°07'48" N., long 159°53' W. 12709 50 ADu 16_ Dutro, J. T., Jr.; 1950; Misheguk Mountain quad­ Lisburne group (lower forma­ rangle; Nimiuktuk River valley; lat 68°22'18" N., tion); Lower Mississippfan. long 159°53'45" W. 12773 51 ATr 14_. Tailleur, I. L.; 1951; Howard Pass quadrangle; Ipnavik Lisburne group; Lower Missis­ River valley; approximate lat 68°22' N.. long sippian. 157°28' W. * 12779 51 ABe 5-_. Brosge, W. P.; 1951; Chandler Lake quadrangle; Chert-shale member, Alapah lime­ Monotis Creek section; lat 68°20' N., long 152°50'15" stone; Goniatites crenistria W. upper 100 ft of Alapah limestone. zone; Upper Mississipp; an. 12785 11 AS77__. Smith, P. S.; 1911; Noatak quadrangle; lower Noatak Lisburne group; Lower Missis­ River valley; approximate lat 67°14'30" N., long 162°30' W." sippian. 12788 50 ADu 77 _ Dutro, J. T., Jr.; 1950; Misheguk Mountain quad­ Lisburne group; Lower Missis­ rangle; Nimiuktuk River valley; lat 68° 16'23" N., sippian. long 159°57'36" W. 12798 50 ADu 44. Dutro, J. T., Jr.; 1950; Misheguk Mountain quad­ Lisburne group; Lower Missis­ rangle; Nimiuktuk River valley; lat 68°24' N., long sippian. 159°53' W. 13215 51 ARr 100- Reiser, H. N.; 1951; Howard Pass quadrangle; station Unnamed. Permian formation; 79d, Kiligwa River valley; lat 68°39' N., long Permian. 158°38' W. 13216 51 ARr 101- Reiser, H. N.; 1951; same locality as 13215; station Unnamed. Permian formation; 79e. Permian. 13219 51 ARr 84- Reiser, H. N.; 1951; Howard Pass quadrangle, Kiligwa Kayak shale(?); Leptaena analoga River valley; lat 68°35' N., long 158°20' W. zone(?); Lower Mississiopian. 13222 51 ARr 107- Reiser, H. N.; 1951; Howard Pass quadrangle; same Kayak shale(?); Scalarituba locality as 13219. zone(?); Lower Mississippian. 13225 51 ATr 1__- Tailleur, I. L.; 1951; Howard Pass quadrangle; Ipnavik Lisburne group; Lower Missis­ River valley, lat 68°21' N., long 157°18' W. sippian. 13228 51 ATr 10-- Tailleur, I. L.; 1951; Howard Pass quadrangle; Ipnavik Lisburne group; Lower Missis­ River valley; lat 68°22'30" N., long 157°15' W. sippian. 13231 51 ATr 346- Tailleur, I. L.; 1951; Howard Pass quadrangle; Kuna Kayak shale; Leptaena analoga River valley; lat. 68°22' N., long 157°42' W. zone; Lower Mississippfan. 130 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY Register of localities Continued

Locality No. Field No. Collector, year of collection, and description of locality Stratigraphic posit'on and age

USGS 13232 51 ATr 347_ Tailleur, I. L.; 1951; same locality as 13231. Lisburne group; Lower Missis- sippian. 13234 51 ATr 350_ Tailleur, I. L.; 1951; same locality as 13231... Lisburne group; Lower Missis- sippian. 13235 51 ATr 351_ Tailleur, I. L.; 1951; same locality as 13231... Lisburne group; Lower Missis- sippian. 13236 51 ATr 352_ Tailleur, I. L.; 1951; same locality as 13231.. Lisburne group; Lower Missis- sippian. 13237 51 ATr 353- Tailleur, I. L.; 1951; same locality as 13231. Lisburne group; Lower Missis- sippian. 13238 51 ATr 354- Tailleur, I. L.; 1951; same locality as 13231... Kayak shale(?); Leptaena analoga zone; Lower Miesissippian. 13240 51 ATr 392_ Tailleur, I. L.; 1951; Howard Pass quadrangle; Kiligwa Lisburne group; Lower Missis- River valley; lat 68°32' N., long 158°51' W. sippian. 13241 51 ATr 393_ Tailleur, I. L.; 1951; same locality as 13240___-.-.-- Lisburne group; Lower Missis- sippian. 13242 51 ATr 394- Tailleur, I. L.; 1951; same locality as 13240 Lisburne group; Lower Missis- sippian. 13245 51 ATr 406. Tailleur, I. L.; 1951; Howard Pass quadrangle; Kiligwa Kayak shale(?); Scalarituba River valley; lat 68°33' N., long 158°53' W. zone(?); Lower Mississippian. 13246 51 ATr 412. Tailleur, I. L.; 1951; Howard Pass quadrangle; Kiligwa Lisburne group; Upper Missis­ River valley; lat 68°30'30" N., long 158°48' W. sippian (?). 13247 51 ATr 162- Reiser, H. N.; 1951; Howard Pass quadrangle; Kiligwa Kayak shale(?); Leptaena ana­ River valley; lat 68°33' N., long 158°54' W. loga zone; Lower Mississippian. 13252 51 ATr 323- Tailleur, I. L.; 1951; Howard Pass quadrangle; station Kayak shale (?); Leptaena ana­ T-91, Kiligwa River valley; lat 68°25' N., long loga zone(?); Lower Missis­ 158°26' W. sippian. 13254 51 ATr 328- Tailleur, I. L.; 1951; Howard Pass quadrangle; station Lisburne group; Lower Missis­ T-92, Kiligwa River valley; lat. 68°25' N., long sippian. 158C 27' W. 13255 51 ATr 329 _ Tailleur, I. L.; 1951; same locality as 13254__-._.-.. Lisburne group; Lower Missis­ sippian. 13258 51 AKi 124. Kent, B. H.; 1951; Howard Pass quadrangle; Kuna Kayak shale; Leptaena analoga River valley; lat 68°22' N., long 157°42' W. zone(?); Lower Mississippian. 13278 50 ABe 31.- Brosge., W. P.; 1950; Chandler Lake quadrangle; Wachsmuth limestone; Brachy- Chandler Lake area; lat 68°18'30" N., long thyris sub orbicular is zone; 152°40'30" W.; section B-20, 40 ft above base of Lower Mississipnian. Wachsmuth limestone. 13286 50 ABe 43. Brosge, W. P.; 1950; Chandler Lake quadrangle; Wachsmuth limestone; Brachy- 11,000 ft N. 86° E. of astronomical point on Little thyris suborbicvlaris zone(?); Chandler Lake; lat 68° 17' N., long 152°36'30" W.; Lower Mississipnian. about 500-550 ft above base of Wachsmuth lime­ stone. 13287 50 ABe 45__ Brosg4, W. P.; 1950; same locality as 13286; from float Alapah limestone (?); Naticopsis about 800 ft above base of Lisburne group (may be suturicompta zone or Lithostro- basal Alapah limestone). tion zone; Upper Mississippian. 13288 50 ABe 46_ _ Brosge, W. P.; 1950; same locality as 13286; from Alapah limestone; Lithostrotion about 200 ft above base of Alapah limestone. aff. L. asiaticum zone; Upper Mississippian. 13292 50 ABe 117_ Gudim, C. J., Reiser, H. N.; 1950; Chandler Lake Wachsmuth limestone; Lower quadrangle; 5 mi west of Little Chandler Lake, from Mississippian. southern Lisburne klippe; lat 68° 18' N., long 152°45' W.; about 250 ft above base of Wachsmuth lime­ stone. 14035 50 ARr 18-- Reiser, H. N.; 1950; Philip Smith Mountains quad­ Alapah limestone (upper part?); rangle; Galbraith Lake area; lat 68°29' N., long Upper Mississippian. 149°13' W., possibly from upper part of formation. 14074 49 AMg91_ Mangus, M. D.; 1949; Howard Pass quadrangle; Wachsmuth limestone; "Zaph- about 5 mi east of Howard Pass Lake; lat 68° 12' N., rentis" konincki zone(?); Lower long 156°38' W. Mississippian. 14097 49 ALa 5__- Lachenbruch, A. H.; 1949; Howard Pass quadrangle; Wachsmuth limestone; Lower Etivluk River valley, cutbank in Fay Creek, 5 mi Mississippian. west of Etivluk River; lat 68°20' N., long 156°53' W. 14099 50 ARr 23_ _ Reiser, H. N.; 1950; Philip Smith Mountains quad­ Siksikpuk formation (basal part) ; rangle; Galbraith Lake area; lat 68°29' N., long Permian (?). 149° 13' W.; basal bed of Siksikpuk formation. 14150 53 APa 105- Patton, W. W., Jr., Bowsher, A. L., 1953; Chandler Chert-shale member(?); Alapah Lake quadrangle; cutbank near head of Kiruktagiak limestone; Goniatites crenistria River; lat 68°20'30" N., long 152°54' W.; top of zone; Upper Mi«sissippian. Alapah limestone. 14151 53 ABo. Patton, W. W., Jr., Bowsher, A. L.; 1953; same locality Chert-shale (?) member; Alapah as 14150. limestone; Goniatites crenistria zone; Upper Mississippian. 14152 53 APa 122_ Patton, W. W., Jr., 1953; same locality as 11814..._.. Siksikpuk formation (basal part); Permian(?). 14169 53 ASa 43-- Sable, E. G.; 1953; Misheguk Mountain quadrangle; Unnamed Permian formation; Nuka River valley; lat 68°39'30" N., long 159° 16' W. Permian. LATE PALEOZOIC GASTROPODA FROM NORTHERN ALASKA 131 Register of localities Continued

Locality No. Field No. Collector, year of collection, and description of locality Stratigraphic position and age

USGS 14174 49 ATr 449A. Tailleur, I. L.; 1949; Chandler Lake quadrangle; rubble Siksikpuk(?) formation; Per- west of Kiruktagiak River; lat 68°23' N., long mian(?). 152°54' W. 14947 53 ATr 79__- Tailleur, I. L.; 1951; Misheguk Mountain quadrangle, Lisburne group; Upper Missis­ Nuka River valley; lat 68°36' N., long 159° 18' W. sippian (?). 14954 F4 of 2 June. Bowsher, A. L.; 1950; Chandler Lake quadrangle; Banded limestone member, Shainin Lake area; lat 68°19'21" N., long 150°55' W. Wachsmuth limestone; Brachy- thyris suborbicularis zone; Lower Mississippian. 14965 F3 of 10 June. Bowsher, A. L.; 1950; Chandler Lake quadrangle; Crinoidal limestone member, Shainin Lake area; lat 68°19'20" N., long 150°53'30" Wachsmuth limestone; "Za- W. phrentis" konincki zone; Lower Mississippian. 14984 50 ABe 22. Brosge', W. P.; 1950; Philip Smith Mountain quad­ Alapah limestone (lower part) rangle; Galbraith Lake area; lat 68°26' N., long Upper Mississippian. 149°22' W. 14992 50 ABe 3_- Brosge, W. P.; 1950; Chandler Lake quadrangle; Anak- Alapah limestone (lower part); tuvuk River valley; lat 68°16'30" N., long 151°34' W. Upper Mississippian. 15408 50 ABe 33. Brosge', W. P.; 1950; Chandler Lake quadrangle; Alapah limestone; Naticopsis su- Chandler Lake area; lat 68° 17' N., long 152°36'30" turicompta zone; Uppe"1 Missis­ W.; from section B-17. sippian. 15430 47 AGr 182. Gryc, G.; 1947; Mt. Michelson quadrangle; Canning Alapah limestone; Upper Missis­ River area; lat 69° 17' N., long 145°59' W. sippian. 15453 53 ASa 247_ Sable, E. G.; 1953; Point Hope quadrangle; Cape Siksikpuk formation; Permian(?). Lisburne area, north side of Lisburne Hills; lat 68°49' N., long 165°58' W. 53 ABo 18__ Bowsher, A. L.; 1953; Point Hope quadrangle; Cape Lisburne group; Upper Missis­ Lisburne area; approximate lat 68°52' N., long sippian. 166°08' W. 51 ADt 147. Detterman, R. L.; 1951; Philip Smith Mountains Sadlerochit formation (basal quadrangle; Lupine River; lat 68°49' N., long part); Permian. 148°22'30" W. 51 AKe 162. Keller, A. S.; 1951; Philip Smith Mountains quad­ Sadlerochit formation; Permian. rangle; Ribdon River, about 3 mi southwest of Elusive Lake; lat 68°40'10" N., long 148°27'45" W.; 100 ft above base of Sadlerochit formation. 15826 52 AMo 5_- Morris, R. H.; 1952; Sagavanirktok quadrangle; Sadlerochit formation; Permian. Kemik Creek; lat 69°20'30" N., long 147°02' W.; 10 ft above base of Sadlerochit formation. 15829 52 AMo 37 _ Morris, R. H.; 1952; Mt. Michelson quadrangle; Cache Sadlerochit formation (basal Creek, Canning River; lat 69°28' N., long 145°49' W. part); Permian.

SYSTEMATIC PALEONTOLOGY Steinkerns, or internal fillings of the shells, have Class GASTROPODA been referred to this species in one instance. These Superorder PROSOBRANCHIA steinkerns are of the same general size and shape and Order ARCHAEOGASTROPODA occur in the same collection as identifiable specimens Superfamily BELLEROPHONTACEA Family SINTTITIDAE of Euphemites. To check this identification, an artifi­ Subfamily EUPHEMITINAE cial steinkern was prepared by removing the shell from Genus EUPHEMITES Warthin, 1930 a specimen. This steinkern and the naturally occur­ ring ones all show slightly wider umbilici with steeper Euphemites sp. walls than do steinkerns referred to Belterophcn. Plate 12, figures 2-4 Illustrated specimens. USNM 136507a, 136507b; USGS lo­ Discussion. Several specimens retain patches of cality 12084. Occurrence and abundance. Lower Mississippian undifferen- shell showing the spiral lirae characteristic of the tiated: USGS locality 12340, two. Alapah limestone: USGS lo­ genus. One specimen has at least 18 lirae from one cality 12084, nine. umbilicus to near the selenizone; all other specimens are less complete and lirae cannot be counted. The Family BELLEROPHONTIDAE selenizone is relatively wide and slightly depressed. Subfamily BELLEROPHONTINAE Genus BELLEROPHON Montfort, 1808 At least the first third of the body whorl is sec­ ondarily smoothed by a thin inductural layer or lay­ Bellerophon sp. ers. Most specimens are of uniform size, about 12 mm Plate 12, figures 5-9 across the axis of coiling. All are regularly and Discussion. Bellerophontacean steinkerns are com­ smoothly coiled. mon; three of these retain patches of shell showing

507218 O 6C 132 SHORTER CONTRIBUTIONS TO GENERAL! GEOLOGY growth lines and a selenizone characteristic of Bel­ Illustrated specimens USNM 136508a, 1365(Fb, USNM lo­ lerophon. Other steinkerns were identified as Bel­ cality 3088; USNM 136509, USGS locality 11799; USNM 136510, USGS locality 15408. lerophon by comparison with these three specimens. Occurrence and abundance. Lower Mississippian undifferen- Most identifications of steinkerns as Bellerophon were tiated: USGS locality 11807, one; 11808, one; 13234, one; based on the character of the umbilical openings. 13235, one. Alapah limestone: USGS locality 976, eight; Among the Alaskan specimens at least, the umbilical 13287, four; 15408, two; USNM locality 3088, nine; 3172, one. openings are relatively narrower and have more arched Upper Mississippian undifferentiated: USGS locality 11799, four. walls and a slightly less abrupt juncture of side and umbilical opening than in umbilici in steinkerns re­ Subfamily KNIGHTITINAE Genus KNIGHTITES Moore, 1941 ferred to Euphemites. It is to be emphasized that Submenus RETISPIRA Knight, 1945a these are not characters of the shell; there is sug­ Knightites (Retispira?) sp. gestive evidence that the shell itself may have been anomphalous. Some of the steinkerns that exceed the Plate 12, figure 1 size of the largest known specimens of Eupheinites Discussion. Identification is based on a single in­ are called Bellerophon sp. even though the umbilical complete Mississippian specimen, showing spiral lirae characters of the steinkern are not certainly known. and a raised selenizone. Uncertainty as to identifica­ Although some specimens are well rounded along tion arises from two sources. First, the specimen is the dorsum, having only a faint ridge at the position so incomplete that apertural characters, particularly of the selenizone, others have flattened sides and a the presence or absence of a ridge on the floor of the more prominent crestlike dorsum. In several, the dor- aperture, cannot be determined. Second, there is a sum is wide and depressed in the center. It is pos­ slight chance that the specimen may be a pleuroto- sible that these belle rophontaceans with flattened mariacean, genus indeterminate, with the upper part of the shell destroyed. Orienting plate 12 with the sides represent another taxon. Until better specimens left margin, downward shows the basis for this pos­ are obtained so that this hypothesis can be tested, sible identification. all the material is assigned to one species with some A second small poorly preserved specimen, of ques­ of the specimens presumed to have been compressed tionable Permian age, is more certainly referable to during deformation of the enclosing strata. the subgenus. It cannot be determined if it is con- Several of the specimens are quite large for the specific with the other specimen, and it is too poorly genus; such an individual, measuring over 70 mm preserved to be illustrated or treated separately. across the aperture, is shown on plate 12, figure 9. The only described American late Paleozoic species Illustrated specim en. USNM 136506, USGS locality 11843. Occurrence and abundance. Lower Mississippian undifferen­ that approaches this size is the poorly known Bel­ tiated: USGS locality 11843, one. ?Permian: USGS 408a, lerophon giganteu-s Worthen. Slightly larger speci­ one. mens of Bellerophon have been illustrated by Ko- INDETERMINATE BELLEROPHONTAC! A.NS ninck (1883) from the Carboniferous of Belgium. Discussion. In addition to the material discussed In most cases steinkerns are of little use in paleon­ above, other poorly preserved and indeterminate speci­ tology and, indeed, specific identification of them can mens may represent this superfamily. For a few of often do more harm than good. It may well be that them, however, it is possible to assay a generic assign­ several biologic species are included here under Bel- ment. Collections not commented upon b?,low can be leropho>n sp. However, inasmuch as many of these determined only to the superfamily level. specimens come from a single stratigraphic unit, it Occurrence and abundance. Kayak shale: USGS locality seems reasonable to conclude that these specimens be­ 13245, may be Euphemites sp.; 13258, one, may be a Bellero­ phon, matrix differs from that yielding Bellerophon sp. Wachs- long to a single species. The occurrence of bellero- muth limestone: USNM locality 3115, one, may be a Bellero­ phontacean steinkerns of this sort has been shown to phon, matrix differs from that yielding Selleropt on sp. Lower be a good field guide to rocks of the lower part of the Mississippian undifferentiated: USGS locality 11867, not a Bellerophon, in gross form this specimen reseirbles Sinuitina Alapah limestone and its equivalents. Because of the Knight, 1945a. Alapah limestone: USGS locality 406, one; occurrence of similar steinkerns in both older and 1004, six; 14151, one; 14992, one. Upper Misstesippian undif­ younger rocks in northern Alaska, caution is urged ferentiated: USGS locality 975, eight, slight indication this in their use for age determination. At best, these may be Bellerophon sp.; 996, one, slight indication this may be Bellerophon sp.; 10870, one. Sadlerochit formation: USGS steinkerns should be used only to supplement more locality 7118b (green), one, probably a bellercphontid, form positive evidence of the age of a rock unit. approaches Bellerophon sp., but collection is krown to be of LATE PALEOZOIC GASTROPODA FROM NORTHERN ALASKA 133 Permian rather than Mississippian age. Unnamed Permian tematically restudied, no comparison between them formation: USGS locality 11823, one, similar to BeUerophon and S. (EuoEUOMPHALIDAE Measurements. Measurements of the illustrated specimens Genus STRAPAROLLTTS Montfort, 1810 (in mm) are given below: Submenus EUOMPHALTTS Sowerby, 1814 Height of Width of Specimen Height Width aperture aperture Straparollus (Euomphalus) brooksensis Yochelson and Dutro, n. sp. USNM 136513___-_--_-_ 5.4 13.0 ______136514______- » 23 41.7 14.6 ' 16 Plate 12, figures 15, 20-23 136515______10.7 21.0 __..__ ------Description. Low-spired euomphalids having a 1 Estimated. sharp upper angulation and rounded umbilical whorls; Occurrence and abundance. Wachsmuth limestone: USNM juvenile whorls well rounded and discoidal, sutures locality 3107, one; 3091, cf. one. Lower Mississippian undif- ferentiated: USGS locality 11890, one; 13235, two; 13240, cf. impressed only in this growth stage; mature shell low one. Alapah limestone: USNM locality 3087, two; 3186, one. spired with body whorl embracing penultimate whorl at periphery; upper whorl surface flattened, inclined Straparollus (Euomphalus) alaskensis Yochelson and Dut~o, n. sp. upward nearly 10° from horizontal in early growth Plate 12, figures 10-14, 16-19 stages, nearly horizontal to upper shoulder at ma­ Description. Very low spired euomphalids with turity; upper shoulder angulated in most growth nearly vertical umbilical walls; sutures distinc*, rela­ stages but not bearing a carina, the angulation be­ tively deep in early growth stages; nucleus and ju­ coming less distinct with age so that large specimens venile whorls discoidal with rounded whorls, the up­ show a differentiation of upper and outer whorl faces per angulation being poorly developed on largest but no sharp angulation; outer whorl face distinctly juvenile whorl; mature whorl produced downward arched with periphery near midwhorl, becoming slightly so that it embraces penultimate whorl above steeper and with a lower periphery in the gerontic midwhorl; upper whorl surface distinctly flattened, stage; basal whorls well rounded in all growth stages, inclined 5°-10° from horizontal to a sharp, distinct, the profile following the arc of a circle from outer noncarinate outer angulation, the inclination of the whorl face to umbilicus; umbilical sutures distinct; upper whorl face increasing with age; outer whorl growth lines gently prosocline on upper whorl sur­ face inclined outward and downward following a con­ face, gently prosocline to orthocline from upper an­ cave outward curve for the upper one-third cf face, gulation to periphery, seemingly gently prosocline be­ the lower edge of the curve being at the periphery, low on outer whorl face, on basal whorl surface and below which the outer whorl face is inclined inward up into umbilicus. 20°-30° from vertical for most of distance below the Discussion. The low spire, relatively large size, and periphery, curving more strongly near base; basal rounded umbilical whorls differentiate Straparollus whorl face distinctly flattened, set off from the um­ (Euomphalus) ~brooksensis from other Alaskan Eu- bilicus by a sharp circumbilical angulation in all ex­ omphalidae. Several specimens bridge the gap from the discoidal earliest stages to the low-spired adult. cept the late mature and gerontic stages; umbilical In view of the long stratigraphic range of this form, walls turning abruptly from circumbilical angulation it may very well be that more than one species is to nearly vertical; umbilicus wide and relatively deep included. The number of specimens is so small and for size and height of shell; growth lines gently proso­ preservation is such that attempts to differentiate cline from suture to upper angulation, on outer whorl Lower Mississippian from Upper Mississippian forms face very gently opisthocline to periphery, there turn­ have been unsuccessful. Pending study of additional ing to prosocline and continuing straight down the specimens, it is assumed that this is a single species. lower part of the face across the base and into the Several incomplete specimens have been tentatively umbilicus. referred to the species. These are indicated by the Discussion. The nearly vertical walls of the um­ reference to footnote 2 in the proper column of the bilicus readily distinguish Straparollus (Euomphalus) distribution chart (table 1). alaskengi-s from other known Permian species. The Numerous low-spired euomphalids with rounded umbilical walls are even steeper than those of IS. whorls have been named, particularly in European (Euomphalus} levicarinatus Yochelson from the mid­ literature. Until these named forms have been sys­ dle Permian of the southwestern United States (1956. 134 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY p. 217). Most cross sections do not appear to show larly in the character of the umbilicus, this species is the two shell layers characteristic of the family similar to Straparollus (Euomphalus) crateriformis (Knight, 1934, pi. 26), but they can be observed on a (Koninck) from the Tournaisian of Belgium, but in few of the well-preserved specimens. The seeming that species the base is distinctly wider than the up­ lack of an outer shell layer, coupled with the poor per surface. A second incomplete small specimen has development of the upper angulation in the earlier been tentatively referred to this species. growth stages, suggested at first that specimens were Illustrated specimen. USNM 136516, USGS locality 14954. only subinternal molds, that is, specimens lacking the Occurrence and abundance. Wachsmuth limestone: USGS outer shell layer. Subsequent finding of large speci­ locality 14954, one. Alapah limestone: USGS locality 997, cf. mens with a reasonably well developed upper angula­ one. tion ruled out this possibility. Genus AMPHICAPHA Knight, 194fl As in the case of other species described herein, Subgenus CYLICIOSCAPHA Yoehelson, 1956 some poorly preserved specimens have been tentatively Amphiscapha (Cylicioscapha) grada Yochelson and Dutro, n. sp. referred to this species. These are distinguished by Plate 12, figures 27-29 reference to footnote 2 in the appropriate column of the distribution chart (table 1). Description. Discoidal euomphalids w; th a shelf on outer whorl face and a prominent basal angulation; Illustrated specimens. Holotype: USNM 136512, USGS locality 11823; Paratypes: USNM 13651 la, 136511b, and juvenile whorls rounded, depressed slightly below gen­ 136511c, USGS locality 11814. eral upper surface of shell; sutures impressed in all Measurements. Measurements of three of the illustrated growth stages; upper whorl surface distinctly in­ specimens (in mm) are given below: clined, following a curve gently concave upward from Height of Width of Specimen Height Width aperture aperture suture to a carmate angulation at the cuter edge of USNM 136511b_ 6. 0 14. 1 upper surface; outer whorl face inclined outward and 136511c- 6. 0 13. 9 5. 0 5. 1 strongly downward below sharp carina for about one- 136512_- 12 27. 7 9. 1 third of its total width, then bending abruptly to Occurrence and abundance. Siksikpuk formation: USGS nearly horizontal for a short distance, rext abruptly locality 11785, six; 11814, twelve; 11816, seven; 14099, four, flexed downward forming a step in the profile of the 14152, nine; 11786, cf. three; 15453, cf. four. Sadlerochit formation: USGS locality 15813, one. Unnamed Permian outer whorl face; below this step the outer whorl face formation: USGS locality 11823, one. ?Permian: USGS lo­ is gently arched outward for a short distance to the cality 982, one. periphery which is located just below iridwhorl; be­ Straparollus (Euomphalus) sp. low the periphery the face steadily curves inward to Plate 12, figures 24-26 the base, there being some evidence that in later growth stages a shallow groove and essentially vertical seg­ Discussion. A third species of Euom-phalus in the ment of the face occur just above the basal angulation; Alaskan collections differs from the other two in be­ basal angulation distinct, slightly more than 90°, non- ing discoidal, with the earliest whorls depressed rather carinate; basal whorl surface flattened, nearly hori­ than low spired. The upper whorl surface is dis­ zontal, curving gently inward as umbilicus is ap­ tinctly inclined upward to a carina on the outer proached, then bending more abruptly into nearly angulation. The outer whorl face is slightly crushed vertical-walled wide umbilicus without, however, de­ in the specimen, but it appears to be arched outward veloping a circumbilical angulation; growth lines to the periphery, located below midwhorl, and then drthocline, radial from suture across inner half of up­ less strongly curved inward to a basal angulation. per whorl face, then gently curving prorocline to an­ Below this angulation, the basal whorl surface is flat­ gulation, being nearly straight opisthocline on upper tened, except near the wide shallow umbilicus. The part of outer whorl face, but straight gently proso­ umbilical walls are steep, but no circumbilical angula­ cline below the shelf, across the base, and into the tion is present; the juncture with the basal surface is umbilicus. smoothly rounded. Growth lines are orthocline on the Discussion. The characteristic "step" on the outer upper surface, essentially radial from the suture. On whorl face readily distinguishes members of this sub- the outer whorl face they are gently opisthocline to genus from specimens of Euomphalus. In detail, the periphery, prosocline below, and finally straight, Amphiscapha (Cylicloscapha) grada is discoidal, gently prosocline on the basal surface. rather than low spired as are Straparollus (Euompha­ It does not seem appropriate to give a formal name lus) brooksensis and /S. (Eu&mphalus) alaskensi, n. sp. Occurrence and abundance. Lower Mississippian undifferen- Plate 13, figures 6-9 tiated: USGS locality 11843, one. Description. Turbiniform gastropoda with globose Family EOTOMARIIDAE whorls and a narrow, bordered selenizone at periph­ Subfamily EOTOMARIINAE ery; shell moderately high spired; whorls embracing Tribe MOURLONIDES Genus MOTTRLONIA Koninck, 1883 at upper edge of selenizone, the line of contact lower­ ing very slightly with increasing maturity; sutures Mourlonia minuta Yochelson and Dutro, n. sp. gently impressed; whorls well rounded from suture to Plate 13, figures 4, 5 peripheral selenizone, being somewhat less rounded Description. Turbiniform gastropods with colabral below; anomphalous; growth lines orthocline at su­ ornament and a wide raised selenizone on the periph­ ture but, after leaving suture, prosocline, about 30° ery; nucleus unknown; body whorl embracing penul­ from vertical along upper whorl face to near edge of timate whorl at lower edge of selenizone; upper whorl selenizone where they bend a little more strongly surface inclined outward and downward, slightly more backward, below selenizone opisthocline for a short arched near the selenizone, below which the whorl distance then turning to gently prosocline and pro­ surface curves more strongly inward than above so ceeding straight to base of columella; selenizone rela­ that the upper whorl surface is distinctly more in­ clined toward vertical than the lower; base anom- tively narrow, with closely spaced lunulae, and bor­ phalous; growth lines prosocline from suture, ap­ dered by lirae; a narrow parietal inductura present proximately 30° from the vertical, proceeding straight on upper part of columellar lip, unl*nown below; for most of the distance across the upper surface, colabral ornament of strong lirae above selenizone, curving more strongly backward near the selenizone, slightly finer below, with fine colabrr.l lirae inter­ opisthocline below the selenizone for a short distance calated near the columella, the ornairent becoming then turning to nearly orthocline; selenizone rela­ less prominent with age. tively wide, unbordered, raised slightly above the gen­ Discussion. Mmirl-onia^. reloba differs from other eral level of the whorl surface, and bearing numerous pleurotomariacean species described herein in having lunulae; narrow parietal inductura in the upper part a narrow, bordered selenizone at the periphery and a of the columellar lip; colabral ornament consisting of globose whorl profile. The strong colabral ornament low rounded lirae above selenizone, somewhat weaker is not an important taxonomic character as several below, the interspaces being twice the width of the unrelated pleurotomariacean lineages possess similar lirae. ornamentation. Specimens from localities 11816 and Discussion. The relatively wide raised selenizone 15153, are poorly preserved; these have been referred distinguishes Mourlonia minuta from other pleuroto- tentatively to the species. LATE PALEOZOIC GASTROPODA FROM NORTHERN ALASKA 137 The Mourlo-nm* rel-oba form of shell with its nar­ Nodospira ornata Yochelson and Dutro, n. sp. row selenizone and globose whorls may be a distinct Plate 13, figures 14-17 phylogenetic line. A Mississippian specimen in the Description. Conical pleurotomariaceans with U.S. National Museum collections, from near Fort strong subsutural protuberances and pronounced co­ Gibson, Okla., is remarkably similar to the specimens labral lirae; earlier whorls unknown; shell moder­ illustrated. Revision of the genus must be delayed, ately high spired with body whorl embracing penulti­ however, until more well-preserved specimens are at mate whorl at lower edge of selenizone; upper whorl hand. No previously described Permian pleuroto- surface distinctly arched from suture, turning mareans are known that are comparable to M. ? reloba. abruptly to horizontal at periphery and forming a Illustrated specimens. Holotype: USNM 136525, USGS local­ relatively wide flange marking the upper borc1<3!r of ity 14169; paratype: USNM 136524, USGS locality 14169. the selenizone; below the selenizone the whorl surface Measurements. Measurements of the illustrated specimens is well curved, the profile following a curve nearly (in mm) are given below: the arc of a circle; anomphalous; outer lip gently Height of Width of Specimen Height Width aperture aperture prosocline almost to selenizone, then sweeping strongly USNM 136524 ______! 37 29 ! 22 17 opisthocline for a short distance below selenizone and ______i 20 17.0 i 14 11. 9 then swinging to distinctly prosocline on most of i Estimated. basal surface; columellar lip reflexed with a thir\ nar­ Occurrence and abundance. Unnamed Permian formation: row inductura; selenizone concave between strong bor­ USGS locality 14169, four. Siksikpuk formation: USGS locality 11816, cf. one; 15453, cf. one. dering flanges; ornament of strong colabral lirae on upper whorl surface in all growth stages known, the NODOSPIRA Yochelson and Dutro, n. gen. lirae somewhat finer below the selenizone; strong Type species. Nodospira ortiata Yochelson and closely spaced, elongate, subsutural protuberances pe­ Dutro, n. sp. riodically interrupting the smooth profile of the upper Diagnosis. Moderately high spired ornamented whorl surface. pleurotomariaceans with a bordered peripheral seleni­ Discussion. The presence of the subsutural pro­ zone and well-rounded whorls; shell moderately high tuberances immediately distinguishes Nodospira or­ spired, the body whorl embracing the penultimate nata from other large pleurotomariaceans. In addi­ whorl at the lower edge of the selenizone; whorls tion, the selenizone is wider than in Mourlonial reloba, relatively well rounded, with periphery near mid- and is raised. Colabral lirae are thicker than on whorl; concave selenizone on periphery bordered by Benibescia'i inumbilicata, and the gross shape differs, strong flanges; distinct colabral lirae. with the body whorl of this species embracing 1 igher Discussion. The genus Mourlonm Koninck appears on the penultimate whorl. These same features, and to be much in need of revision for, as presently in­ the lack of an umbilicus, distinguish N. ornata from terpreted, it includes species from Middle Ordovician through Permian in age. Nodospira is proposed in new genus? B. an attempt to separate some species from the Mour- Illustrated specimens. Holotype: USNM 136528, USGS local­ lonia complex. The well-rounded whorls and the ity 14150; paratype: USNM 136529, USGS locality 14150. selenizone bordered by distinct strong flanges serve to Measurements. Measurements of the illustrated specimens (in mm) are given below: distinguish Nodospira from Mourlonm. The colabral Height of Width of lirate ornament of this genus is similar to that of Specimen Height Width aperture aperture Ptychomphalina Fischer, which has been placed, per­ USNM 136528__------32 27.3 18.7 15.4 136529__._____ 57 51 l 37 28 haps improperly, in the synonymy of Mourlonm. i Estimated. Nodospira differs from Ptychomphalina in having Occurrence and abundance. Alapah limestone: USGS locality the selenizone at midwhorl rather than below, and in 14150, six; 12340, twenty-two; 12348, ten. having well-rounded whorls. Genus SPIROSCALA Knight, 1945 In the literature examined, no species have been found that can be referred to this genus. Mourlonia.- cf. Spiroscala sp. like forms occur in most Mississippian faunas. That Plate 13, figure 10 no previously described species can be attributed to Discussion. Two specimens are tentatively referred this genus is a reflection of the inadequacy of pub­ to this genus. The first shows a conical, relatively lished illustrations and a lack of comparative mate­ high spired form with a peripheral flangelike eeleni- rial for study. zone. The second specimen, not illustrated, is mashed 138 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY and incomplete, but shows an eavelike overhang of the The spire of the holotype is incomplete and the selenizone and an absence of ornament near the suture. aperture is slightly crushed. No meaningful meas­ Lack of ornament distinguishes these specimens from urements of the species can be presented. a Mississippian form in the collections referred to Illustrated specimen. Holotype: USNM 13"536, USGS lo­ Ph ym ato pleura. cality 10SG2. Occurrence and abundance. Alapah limestone: USGS lo­ Dlustrated specimen. USNM 136526, USGS locality 1008. cality 10802, two; 12779, three; 14151, one; 12342, one. Occurrence and abundance. Sartlerochit formation: USGS locality 1008, one; 15826, one. Genus GLABROCINGULUM Thomas, 1940 Subgenus GLABROCINGTTLUM Thomas 1940 Tribe EOTOMARIIDES Genus BEMBEXIA Oehlert, 1888 Glabrocingulum (Glabrocingtilum) sp. Bembexia? inumbilicata Yochelson and Dutro, n. sp. Plate 13, figures 11-13 Plate 13, figures 30, 31 Discussion. This species is represented by two Description. Large conical aiiomphalous gastro­ specimens from the Siksikpuk formation. They are pods with bordered selenizone forming periphery; moderately low spired, conical, and have the seleni­ earlier whorls unknown; sutures impressed; body zone located at the periphery. The upper whorl sur­ whorl embracing penultimate whorl below periphery; face bears a row of coarse nodes at the suture and at upper whorl surface inclined outward approximately least three rows of fine nodes. The narrow seleni­ 35° from vertical and gently inflated, turning abruptly zone is concave and bordered by shan lirae. The arched basal surface bears at least seven spiral carinae, to horizontal and forming the upper bordering flange all of which are noded. The base is aiiomphalous. of the selenizone at the periphery; whorl profile below The species does not warrant specific naming in view selenizone inclined steeply downward for approxi­ of the small number of specimens available. mately one-half of its length, then curving more Illustrated specimen. USNM 136527, USGS locality 14174. strongly inward to the aiiomphalous base; concave Occurrence and abundance. Siksikpuk formation: USGS selenizone located on the periphery between strong locality 14174, two. bordering flanges, the upper flange overhanging the Subfamily NEILSONIINAE lower; lunulae faint; growth lines prosocline from Genus NEILSONTA Thomas, 194C suture, approximately 20°, bending more abruptly Neilsonia? sp. backward just above the selenizone, below the seleni­ Plate 13, figure 25 zone opisthocline for a short distance then curving to prosocline, about 20° from vertical, and continuing Discussion. Two collections from northern Alaska contain small, moderately high spired pleurotomari- straight downward; columellar lip with a narrow iii- ceans. All are poorly preserved, but enough remains ductura; ornament of impressed growth lines alone. of the shell to show the main features. The upper Discussion. Bembe.ciat imniibnieata appears to be surface is distinctly inclined, but little arched. The most similar, superficially, to Tropidostropha Long- selenizone forms the outer whorl face and is nearly staff, 1912, but lacks both an umbilicus and pitting in vertical, the lower edge being at the periphery. The the shell. It differs from Bembe.via larteti (Munier- selenizone proper is concave and distinctly bordered. Chalmas), the type species, in being higher spired and Below the selenizone the basal whorl surface is nearly in having the upper flange of the selenizone, rather straight,~ ^ inclined inward for a distance about the than the lower flange, at the periphery. Because the width of the selenizone, at which place there is a significance of these differences cannot now be evalu­ distinct though slight angulation, below which the ated, generic placement of the species is questioned. basal whorl surface curves inward and strongly In addition to gross shape, Bembex'm'l rnumbilicata downward. The base is aiiomphalous. The columel­ differs from Alaskan specimens referred to Mourlo'ii'm lar lip is slightly reflexed. The upper whorl surface in lacking strong colabral ornament. It lacks nodes appears to have strong colabral ornament. No speci­ on the upper surface as are found in Nodospira or- men is complete enough to show all the details nata. The species is most similar in shape to speci­ given above, and a formal name does not appear mens referred to as New genus? B., and at one time justified. the two forms were confused. They differ however Illustrated specimen. USNM 136533, USGS locality 9184. in the nature of the umbilicus, B. '? inum'bilic'ata being Occurrence and abundance. Alapah limestone: USGS lo­ clearly aiiomphalous. cality 9184, fifty; 10868, twenty five. LATE PALEOZOIC GASTROPODA FROM NORTHERN ALASKA 139

Family PORTLOCKIELLIDAE lirae. The body whorl, on the other hand, is smooth Genus PORTLOCKIELLA Knight, 1945 except for growth lines and a noded subsutural lira. Portlockiella ? sp. Illustrated specimen. USNM 136532, USGS locality 13234. Plate 13, figures 18, 19 Occurrence and abundance. Lower Mississippian und !fferen- tiated: USGS locality 13234, one. Discussion. A single specimen is questionably placed in this genus. It is a low-spired, relatively Family uncertain wide form. The specimen is either narrowly phaner- New genus? A omphalous or pseudoiimbilicate. Ornament consists Plate 13, figures 26-28 of five widely spaced, low, spiral carinae. A selenizone Discussion. A new genus of pleurotomariaceans probably occurs just below the last carina, below mid- may occur in the Wachsmuth limestone. It is repre­ whorl, but just above the periphery. Growth lines, sented by a single distorted specimen and, therefore, however, are not clear. On the base, below this pre­ the taxon is not formally named. The specimen does sumed selenizone, ornament consists of revolving lirae, show several interesting morphological details. the exact number not determinable. The shell is conical and moderately low spirei, and Illustrated specimen. -USNM 136530, USNM locality 3167. has a peripheral selenizone located well below mid- Occurrence and abundance. Alapah limestone: USNM lo­ cality 3167, one. whorl. Sutures are distinct and impressed. Because of distortion the shape of the upper whorl surface Family GOSSELETINIDAE cannot be determined with certainty, but it appears Subfamily GOSSELETININAE Genus GOSSELETINA Fischer, 1885 to have been essentially flattened from near the su­ ture almost to the selenizone. The selenizone is nar­ Gosseletina? sp. row, raised and rounded, strongly convex outward. Plate 13, figures 20, 21 Below the periphery, the basal surface bends sharply Discusswn. A single specimen is characterized by inward. The base is anomphalous. Ornament con­ a narrow selenizone high on the whorl, a distinctive sists of two elements, a series of short lirae Formal feature of Gosseletina. The selenizone is concave and to the suture and fine threads normal to the growth strongly bordered. Below the selenizone the whorl is lines. The intersections of these two sets form a ornamented by numerous spiral lirae. Whorls are reticulate pattern on the upper whorl surface. Growth moderately rounded and the specimen is relatively lines are prosocliiie, about 30°, curving back more high spired for a pleurotomariacean. Except in the strongly near the selenizone. Below the selenizone, position of the selenizone, none of the features de­ growth lines are orthocline, abruptly curving to pro- scribed are found on the low-spired smooth type spe­ socline on the base. In gross shape the specimen re­ cies of Gosseletina. It may be that this form repre­ sembles Phymatopleura, but the convex selenizone of this specimen is distinctive. It is possible thrt this sents a new genus but, as with many of the specimens convexity is a result of distortion; more specimens discussed, formal systematic treatment must be de­ are needed to determine this point. Phylogenetic po­ ferred until more specimens are available. sition of this form within the Pleurotomariacea is Illustrated specimen. USNM 136531, USGS locality 13236. most uncertain. Occurrence and abundance. Lower Mississippian umlifferen- tiated: USGS locality 13236, one. Illustrated specimen. USNM 136534, USGS locality T110. Occurrence and abundance. Wachsmuth limestone: USNM Family PHYMATOPLETTRIDAE locality 3110, one. Genus PHYMATOPLETTRA Girty, 1939 New genus? B Phymatopleura sp. Plate 14, figures 26, 27 Plate 13, figures 22-24 Discu-ssion. Two specimens from the unnamed Per­ mian formation, may represent another new genus. Discussion. A single well preserved specimen of One specimen is exceedingly fragmentary. Tl ^ sec­ Phymatopleura was collected from the Lower Missis­ ond, illustrated, was partially cleaned from r, very sippian. It shows the characteristic conical shape with resistant matrix. This specimen is incomplete and the a narrow, bordered, peripheral selenizone. The flat­ body whorl has been offset by a small fracture. tened base is ornamented by six revolving lirae. Or­ The specimens are quite similar to Bembexial in- nament of the upper whorl surface is unusual in umbilicata. They appear to be slightly lower spired, showing pronounced ontogenetic change. The penulti­ and have the body whorl embracing lower on the mate whorl and earlier whorls bear five sharp spiral penultimate whorl. As there are only slight differ- 140 SHORTER CONTRIBUTIONS TO GENERAD GEOLOGY ences between the two forms, incomplete specimens lerochit formation: USGS locality 7118h green, three, could be readily confused. They differ in that this possibly Mourlonial reloba,; 1009, one, pleurotomaria­ form has a depression in the base. Unfortunately, it cean; 1010, one, may be cf. Spiroscala sp.; 15817, cannot be determined if a true umbilicus is present. one, doubtfully Mourlonial reloba,. Unnamed Permian There is some similarity to the Mississippian genus formation: USGS locality 11823, one moderately high Tropidostropha Longstaff, 1912, but comparisons must spired with a concave selenizone near periphery, and be delayed until more complete specimens are avail­ spiral lirae on base, possibly a genus not otherwise able. So far as is known, this occurrence is unique recorded in the fauna; 13216, one, may t*> Mourlonial in the Permian. reloba. Permian: USGS locality 982, one, pleuroto­ Illustrated specimen. USNM 136551, USGS locality 13215. mariacean; 987, four, two genera present, one moder­ Occurrence and abundance. Unnamed Permian formation : USGS locality 13215, two. ately high spired with a vertical outer whorl face, a selenizone at the juncture of upper and outer whorl INDETERMINATE PLEUROTOMARIACEANS faces, and spiral ornament, and may be a genus not Discussion. Numerous poorly preserved specimens otherwise recorded in the fauna, the otrer, identifica­ can be referred to the Pleurotomariacea. Some few tion of pleurotomariacean uncertain. can be placed questionably in the taxa previously de­ scribed. Others appear to represent additional genera Superfamily PLATYCERATACEJ! Family HOLOPEIDAE and species too poorly preserved to discuss in detail. Genus YTTNNANIA Mansuy, 1912 Still others are so incomplete that they cannot be Yunnania sp. placed in any taxon satisfactorily. Occurrence and abundance. Kayak shale: USGS Plate 13, figure 29 locality 13222, one, identification as pleurotomariacean Discussion. One specimen is placed in this genus. uncertain. Wachsmuth limestone: USNM locality It is moderately high spired with the upper whorl 3173, three, two genera present, one with spiral orna­ surface flattened, inclined outward and d ownward; su­ ment suggestive of Rhiiwoderma.'l sp., the other mod­ tures are not impressed. The outer whorl face is erately high with a conical shape and possibly a genus nearly vertical, and the basal surface is flattened, in­ not otherwise recorded in the fauna. Lower Missis­ clined inward and more strongly downward. The sippian undetermined : USGS locality 11807, one, may specimen is anomphalous. Ornament consists of spiral be Phymatopleura sp. ; 12700, one, pleurotomariacean; lirae on all three whorl faces, there beirg at least ten 12701, three, with spiral ornament suggestive of on the body whorl. The specimen is a steinkern re­ RJi,meodenna,\ sp. ; 12785, three, moderately low spired taining only one small patch of shell which does not and ornamented by spiral lirae, possibly a genus not show growth lines. It may be that this species is otherwise recorded in the fauna; 13234, one, identifi­ actually a pleurotomariacean, but slight evidence sug­ cation as pleurotomariacean uncertain; 13235, two, two gests that the outer lip did not possess a slit. genera present, one a pleurotomariacean, the other, so Illustrated specimen. USNM 136535, USGS locality 12785. incomplete that identification as pleurotomariacean is Occurrence and abundance. Lower Mississirnian undifferen­ uncertain; 13236, one, identification as pleurotomaria­ tiated: USGS locality 12785, one. cean uncertain. Alapah limestone: USNM locality 3167, five, two genera present, similar, respectively, to Family PLATYCERATIDAE Genus PLATYCERAS Conrad, 1810 those listed for USNM locality 3173; USGS locality Submenus FLATYCERAS Conrad, 18*0 1014, one, with spiral ornament suggestive of Rhineo- derma'* sp. ; 12084, two, may be Mourlonia, minuta. Flatyceras (Flatyceras) ,sp. Upper Mississippian undifferentiated : USGS locality Plate 14, figure 28 972, one, conical with sutures little impressed and or­ Discussion. The genus Platyceras has been divided namented by spiral lirae, possibly a genus not other­ into several subgenera (Knight, Batten, and Yochel- wise recorded in the fauna. ?Upper Mississippian: son, in press), the typical subgenus being restricted to USGS locality 14947, thirteen, moderately high spired those forms which have at least the earliest whorls in with a peripherial selenizone and colabral ornament, contact. This feature can be shown with certainty only may be a genus not otherwise recorded in the fauna. for two collections of specimens, one from the Lower Siksikpuk formation : USGS locality 15453, one, pleu­ Mississippian and one from the Upper Mississippian. rotomariacean with spiral ornament on base. Sad- Except for the earlier whorls, the specimens are poorly LATE PALEOZOIC GASTROPODA FROM NORTHERN ALASKA 141 preserved and in other respects are similar to those two; USGS locality 14965, two. Lower Mississippian undif- identified as P1atycera$ (Orthonychia) sp. As used ferentiated: USGS locality 9186, one; 12773, one; 12785, two; 12798, one; 13225, one; 13228, one; 13232, two; 1323", one; here, the grouping of Platyceras (Platyceras) sp. prob­ 13237, two; 13254, four; 13292, one. Upper Mississippi un- ably has no biologic meaning. differentiated: USGS locality 14984, one. Sadlerochit forma­ Numerous species of Platyceras have been described, tion: USGS locality 1009, two. ?Permian: USGS locality particularly from rocks of Mississippian age, but no 960, one 979, one. synthesis of the family has been attempted. Individ­ Superfamily MICRODOMATACEA ual variation is great and definitive work on Platy- Family ELASMONEMATIDAE ceras should properly discuss the host echinoderms of Genus ANEMATINA Knight, 1933 the several species. Additional species names would Anematina rockymontanum (Shimer) only further complicate study of this family. Plate 14, figures 10-16 Illustrated specimen. USNM 136552, USGS locality 14035. Occurrence and abundance. Lower Mississippian undiffereii- Loxonema rockymontanum Shinier 1926, Canada Geol. Survey tiated: USGS locality 11807, three. Upper Mississippian un- Museum Bull. 42, p. 81-82, pi. 4, figs. 9a, b; 10. differentiated: USGS locality 14035, five. Description . High-spired subtrochiform gastropods Subgenus ORTHONYCHIA Hall, 1843 with a flattened outer whorl face; in early growth stages sutures distinct and impressed; outer whorl face Platyceras (Orthonychia) sp. straight, little arched in juvenile stages, with increas­ Plate 14, figures 17-19 ing age developing a low spiral ridge at suture, below Discussion. Orthonychia differs from the typical which the whorl face is slightly concave to near mid- subgenus of Platyceras in having all growth stages, whorl, becoming slightly convex to the periphery lo­ including the earliest, out of contact so that a mature cated low on the whorl, the overall face being strongly specimen does not complete as much as one whorl. inclined downward; in maturity the whorl face gently Specimens in nine of the collections preserve the ear­ but distinctly arched; below the periphery the whorl liest whorls, and in six others enough of the shell is preserved to indicate that it is unlikely that the early curving strongly and rather abruptly inward to base growth stages were coiled. Other incomplete speci­ in early growth stages, the base itself being flattened mens have been referred to this taxon as a conven­ to about 10° or 15° from horizontal, becoming slightly ience rather than having them listed separately as arched and less clearly set off from the upper whorl indeterminate platycerataceans. face with increasing maturity; base probably anom- Most of the specimens are tubelike, but a few are phalous but, doubtfully, minutely phaneromphalous; flattened, patelliform. None of the specimens is well growth lines on outer whorl face straight, pro~ocline enough preserved to warrant detailed description; al­ at about 15°, crossing periphery and forming a wide most all lack the aperture. A detailed study of the shallow sinus on the base; columellar lip rot re- shape of the apertures of some specimens might reveal flexed; ornamented by numerous spiral lirae which information about the host echinoderms (Bowsher, are finer than the fine growth lines, the lirae becom­ 1956), but poor preservation makes this extremely un­ ing more obscure with increasing size; shell thin. likely. Discussion. The flattened outer whorl face and flat­ The platyceratids show considerable individual vari­ tened base of the early growth stages, combined with ation because of their life, attachment to echinoderm the large size, mark this as a distinct species The calices. Variation results from the orientation of the type species, Anematina proutana (Hall), is charac­ gastropod on the calyx and the shape of the tegmen. terized by extremely small size and by rounded whorls Little is known of specific limits of platyceratids. The in all growth stages. Anematina, rocky?nor,tamum grouping used here probably does not reflect a bi­ (Shimer) seems to be closely related to A. laqueata ologically valid species. Orthonychia is of little value (Koniiick) from the Visean of Belgium, but differs in in dating rocks because it is known from beds of lacking a spiral ridge on the base. Devonian through Permian age. Through the kindness of Dr. Hans Frebold, Chief Illustrated specimens. USNM 136544a, 136544b, USNM lo­ of the Section of Stratigraphic Palaeontology, Geo­ cality 3089; USNM 136545, USGS locality 9186. logical Survey of Canada, we were able to examine Occurrence and abundance. Kayak shale: USNM locality H. W. Shimer's original specimens of Loxonema rovky- 3095, three; 3247, three; USGS locality 13231, six; 13238, two; 13252, two; 13258, two. Wachsmuth limestone: USNM local­ montanum (Shimer, 1926, p. 81). Geological Survey ity 3089, thirty three; 3100, one; 3113, one; 3173, two; 3279, of Canada No. 5093 is the holotype, the original of 142 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY Shimer's figures 9a and 9b. Geological Survey of Anematina? sp. Canada No. 5093a is a figured paratype, the original Discussion. Ten high-spired specimens listed below of Shimer's figure 10. The specimens were numbered are questionably placed in Anematina because of the some years after the original description was pub­ poor quality of preservation. In spite of the present lished. Four additional specimens are included in uncertainty it seems reasonable to suggest that fur­ 5093. They are poorly preserved but may belong to ther collecting will indicate that only a single species this species. Shinier also studied two specimens from of the genus is present in Mississippian rocks of lot 5095, an associated locality. These are so poorly northern Alaska. preserved that they cannot be referred even question­ Occurrence and abundance. Lower Mississippian undifferen­ ably to this species. With the exception of one natu­ tiated: USGS locality 13242, one. Alapah limestone: USNM ral cross section, all of Shimer's specimens were bro­ locality 3167, one; USGS locality 1014, one. Upper Mississip­ ken from limestone. pian undifferentiated: USGS locality 975, seven. There is no doubt that the specimens from northern Alaska are conspecific with Shimer's species. The Superfamily ANOMPHALACEA Family ANOMPHALIDAE close similarity between the types and the Brooks Genus ANOMPHALTTS Meek and Worthier. 1867 Range material is illustrated on plate 14. Unfortu­ nately, many of the Alaskan specimens have been dis­ Anomphalus sp. torted. Others are incomplete or are steinkerns. This Plate 14, figures 7-9 less well preserved material is only tentatively re­ Discussion. One small well-preservec1 rotelliform ferred to the species. gastropod is placed in this genus. The shell surface Small steinkerns of Anematina can be separated is typically polished and smooth except for two faint from those of Loxonema by two characters. First, spiral lirae near the suture. Sutures are impressed. the more angular whorl face and flattened base are Growth lines are gently opisthocline on the upper reflected in the steinkem; the profile of Loxon-ema is surface to nearly halfway between suture and periph­ relatively well rounded. Second, the Anematina shell ery, where they swing backward becoming distinctly is thinner than that of Loxonema. This feature re­ prosocline on the lower part of the outer whorl face. sults in a relatively smaller gap between whorls of the The umbilicus is relatively wide and seemingly with­ steinkem. out any sort of an inductural constriction or filling, In the holotype, the outer whorl face is flattened although preservation is such that the possibility of a and set off rather abruptly from the flattened basal pseudoumbilicate condition cannot be ruled out. whorl surface. The slightly larger paratype, on the The species lacks the short radial ornament at the other hand, has a somewhat more rounded body whorl suture which apparently characterizes Anomphalus with the outer and basal faces distinctly arched and nerviensis Koninck, from the Lower Carboniferous of not so clearly separated. Although the whorl profiles Belgium. of mature specimens of Loaconema and Anematina are Illustrated specimen. USNM 136547, USNM locality 3167. not too dissimilar, the growth lines are fundamentally Occurrence and abundance. Alapah limestone: USNM lo­ different. Poorly preserved specimens of the two cality 3167, one. genera could be confused. Superfamily NEBITACEA Family NERITOPSIDAE Illustrated specimens. Holotype: GSC 5093; paratype: GSC Subfamily NATICOPSINAE 5093a; hypotype: USNM 136542, USGS locality 13288; hypo- Genus NATICOPSIS M'Coy, 1844 type: USNM 136543, USGS locality 11808. Subgenus NATICOPSIS M'Coy, 1844 Measurements. Measurements of the illustrated specimens Naticopsis (Naticopsis) suturicompta Yochelson and Dutro, n. sp. (in mm) are given below: Plate 14, figures 20-25 Specimen Height Width GSC 5093______20.5 1 10 Description. Well-rounded neritopsic's with orna­ 5093a.______* 14 ment on a subsutural ramp developed ir intermediate USNM 136542______1 26 i 12 growth stages; sutures distinct, becoming more im­ 136543______1 14 5. 9 1 Estimated. pressed with age; shell low spired, the body whorl Occurrence and abundance. Wachsmuth limestone: USNM embracing the penultimate whorl above the periphery; locality 3098, one; 3173, cf. one; USGS locality 13278, one. Lower whorls relatively well rounded, "apple shaped," a nar­ Mississippian undifferentiated: USGS locality 11808, two; 12785, row subsutural ramp in all intermediate growth one; 12701, cf. one. Alapah limestone: USNM locality 3182, one, 3272, one; USGS locality 13288, one; 9187, cf. two. stages, followed by a smooth curve which near the LATE PALEOZOIC GASTROPODA FROM NORTHERN ALASKA 143 periphery approaches the arc of a circle, and a slight guishes them from the Upper Mississippian species. elongation of the whorl below the periphery; growth If they do represent another species, it would indicate lines straight, gently prosocline from suture to colu- that ornament alone is an unreliable criterion for iden­ mella; inductura and other apertural features un­ tification of poorly preserved or immature specimens. known; ornamented by distinct subsutural lirae which appear after the earliest growth stages, coincident ally Illustrated specimens. Holotype: USNM 136549, USGS local­ ity 9187; paratypes: USNM 136548, USNM locality, 3088; and with the development of the subsutural ramp, and USNM 136550, USNM locality 3170. disappear at maturity simultaneously with disappear­ Measurements. Measurements of the illustrated specimens ance of the ramp. (in mm) are given below: Height of Width of Discussion. The subsutural ornament' of Naticop- Specimen Height Width aperture aperture sis (Naticopsis) suturicompta is similar to that of USNM 136548------1 55 55 47 43 species referred to N. (Jedria) Yochelson, 1953. The 136549_-___._--_ 26 24 20 16 relatively high-spired, elongate shape of the latter, 136550.-._..--_- '25 26 20 18 however, is quite distinct from the well-rounded "ap­ i Estimated. ple shape'' of the typical subgenus. As closely as can Occurrence and abundance. Lower Mississippian undifferenti- ated: USGS locality 11808, cf. one; 12701, cf. one; ir240, cf. be determined, this combination of well-rounded two. Alapah limestone: USNM locality 3088, twenty; 3164, whorls and subsutural ornament is confined to this spe­ one: 3170, two; 3171, one; 3182, cf. one; USGS locality 9187, cies. Certain American and Belgian species approach three; 12355, three; 15430, one; 994, cf. one. Upper Missis­ the shape of N. (Naticojms) suturicompta, but orna­ sippian undifferentiated: USGS locality 11799, three. ment either is not present or was overlooked and not Naticopsis (Naticopsis) sp. figured by earlier workers. Plate 14, figure 5 This species characterizes the " Naticopsis howi zone""1 of Dutro and Bowsher (1957") and is the same form Discussion. A single small specimen from the Mis­ referred to by them. sissippian Lisburne group differs from juvenile speci­ Partially exfoliated specimens show the presence of mens of Naticopsis (Naticopsis) suturicompta. It is two shell layers. They also show, on the inner layer, markedly higher spired, and has an elongate, poorly growth lines parallel to those on the outer layer. rounded body whorl with the periphery well below These lines have not been observed on silicified speci­ midwhorl. No subsutural ramp is developed. The mens from the Permian of west Texas. Kather, the specimen has fainter subsutural ornament than is inner shell layer of those forms is characterized by characteristic of N. (Naticopsis) suturicompta, but structures essentially normal to the growth lines. this may be a feature of immaturity. The specimen is As with most of the gastropods from northern too poorly preserved to warrant a formal specific name. Alaska, preservation of specimens presents problems with the taxonomic treatment. The type of this spe­ Illustrated specimen. USNM 136540, USGS locality 13235. Occurrence and abundance. Lower Mississippian undifferen­ cies and a few other smaller specimens show the char­ tiated: USGS locality 13235, one. acteristic ornament. Most of the specimens do not preserve the early whorls or, if they are present, they INDETERMINATE NERITACEANS are partially exfoliated or are steinkerns. However, Discussion. As with most of the other sup°,rfam- in these specimens the shape of the mature body whorl ilies treated herein, there are some specimens referable agrees closely with the type. The alternatives of re­ to the superfamily that are quite poorly preserved. garding these less well preserved specimens as a sepa­ rate species or only tentatively comparing them to this Unlike the material from the other groups, most of species have been considered but rejected, and all Up­ these are not steinkerns, but are either distorted speci­ per Mississippian specimens of fair preservation are mens or juveniles. It seems probable that most of placed in one species. these specimens are referable to Naticopsis in the broad Several specimens from the Lower Mississippian are sense. Specific identification is not possible. tentatively referred to the species. These are all small Occurrence and abundance. Kayak shale: USGS locality nearly globular shells possessing subsutural ornament 13247, one. Wachsmuth limestone: USGS locality 132^6, one. but lacking a subsutural ramp. Some neritacean spe­ Lower Mississippian undifferentiated: USGS locality 12701, eight; 12709, one; 12785, three; 12788, one; 13234, one; 13235, cies are known to undergo considerable ontogenetic one; 13254, one; 13255, one. Alapah limestone: USGS local­ change. Further collections may show that the ma­ ity 976, one; 997, one; USNM locality 3167, one. ?Upr^r Mis­ ture stage of these Lower Mississippian forms distin­ sissippian : USGS locality 13246, one. 144 SHORTER CONTRIBUTIONS TO GENERAL- GEOLOGY

Order MESOGASTROPODA Superfamily LOXONEMATACEA Superfamily MURCHISONIACEA Family LOXONEMA.TIDAE Family MURCHISONIIDAE Genus LOXONEMA Phillips, 1841 Genus MURCHISONIA Archiac and Verneuil, 1841 Loxonema sp. cf. Murchisonia sp. Plate 14, figure 6 Plate 14, figure 1 Discussion. Specimens referred to this species are Discussion. A single specimen is tentatively re­ typical of the genus. They are exceedingly high ferred to this genus, as used in the broadest sense. spired, have deep sutures and well-rounded whorls. The specimen is high spired, has impressed sutures Growth lines are arcuate, forming a wide, quite shal­ and apparently well-rounded whorls. There is a spiral low sinus, the most posterior portion of which is near lira below the periphery forming what appears to be midwhorl. This sinus distinguishes the specimens the lower border of a gently concave selenizone. The from those called cf. Murchisonia sp. All the speci­ specimen is exceedingly poorly preserved, but it is mens are small and it is assumed that they are im­ unique in the fauna and has been figured. mature. A second, even more poorly preserved specimen is Illustrated specimens USNM 136541, USGS locality 11828. Occurrence and abundance. Alapah limestone: USGS lo­ questionably placed in this taxon. cality 11828, three. Illustrated specimen. USNM 136537, USGS locality 13240. Occurrence and abundance. Lower Mississippian undiffereii- INDETERMINATE LOXONEMATACHANS tiated: USGS locality 13240, one. Alapah limestone: USGS Discussion. Specimens placed here are poorly pre­ locality 9184, cf. one. served steinkerns. It should be pointed out that ref­ erence to cf. MurcMsonm sp. would be nearly as fea­ Family PLETHOSPIRIDAE Subfamily PITHODEINAE sible, because either of these fundamentally different Genus PLATYZONA Knight, 1945 shells, when exfoliated, produce almost identical stein- Platyzona sp. kerns. Plate 14, figure 2 Occurrence and abundance. Lower Mississippian undifferen- tiated: USGS locality 9186; two, possibly Loxonema,; 13235, Discu-ssion. This species, identified from a single five, four to five times size of specimens of Loyonema sp.; specimen, is not named. The specimen is fairly well Alapah limestone: USGS locality 976, seven, doubtfully Loxo­ preserved, but is incomplete. The shell is moderately nema. high spired. Sutures are impressed and whorls are Order NEOGASTROPODA Superfamily STTBULITACEA relatively broad and well rounded, being flattened near Family SUBUIITIDAE the suture. A broad concave selenizone is located on Subfamily SOLENISCINAE the periphery. Growth lines on the upper whorl sur­ Genus IANTHINOPSIS Meek and Wortlen, 1866 face are prosocline, sweeping backward from the su­ lanthinopsis? sp. ture to the selenizone. Below the selenizone they are Plate 14, figure 3 gently opsithocline for about the upper third of the Discussion. Two specimens from the Lower Mis­ lower whorl surface. Details of the aperture and base sissippian show the low-spired subglobular shape char­ are unknown. acteristic of some of the soleniscinids. They are ques­ Illustrated specimen. USNM 136538, USGS locality 13246. tionably placed in lanthinopsis, this being the most Occurrence and abundance. ?Upper Mississippian: USGS common upper Paleozoic genus. Keith?r shows fea­ locality 13246, one. tures of the columellar lip, critical fc1** more exact INDETERMINATE MURCHISONIACEANS placement. The specimens are in part exfoliated; the rest of the shell has been recrystallized. Discussion. Four specimens are placed in this Illustrated specimen. USNM 136539, USGS locality 12785. grouping. The first is a steinkern retaining patches Occurrence and abundance. Lower Mississipnian undifferen- of shell. The other three are incompletely silicified tiated: USGS locality 11867, one; 12785, one. shells. Glass SCAPHOPODA Occurrence and abundance. Lower Mississippian undifferen- Genus indeterminate tiated: USGS locality 13240, one, whorls ornamented by sev­ Plate 14, figure 4 eral spiral lirae; more angular than cf. Murcliisonia sp. Ala- pah limestone: USNM locality 3167, one, may show evidence Discussion. A single, incomplete scaphopod is pres­ of a selenizone; 3272, two, may show evidence of a selenizone. ent in the collection from USGS locality 13246. Faint LATE PALEOZOIC GASTROPODA PROM NORTHERN ALASKA 145 traces of annular growth lines can be seen, but if other ___ 1941, Paleozoic gastropod genotypes: Geol. Soc. ornament was originally present, it is not preserved. America Spec. Paper 32. ___ 1942, Four new genera of Paleozoic Gastropoda: The specimen does not warrant description and is in­ Jour. Paleontology, v. 16, no. 4, p. 487-488. cluded here only because Mississippian scaphopods are ___ 1945a, Some new genera of the Bellerophontacea: relatively rare and occurrences should be recorded. A Jour. Paleontology, v. 19, no. 4, p. 333-340, pi. 49. ___ 1945b, Some new genera of Paleozoic Gastropoda: second specimen from TJSGS locality 13240 seems to Jour. Paleontology, v. 19, no. 6, p. 573-587, pis. 79, 80. lack transverse ornament, and in that respect is simi­ ___ 1953, Gastropoda, in Cooper, G. A. and others, Per­ lar to PT.agioglypta Pilsbry and Sharp (1897). mian fauna at El Antimonio, western Sonora, Mexico: Smithsonian Misc. Colln., v. 119, no. 2, p. 83-90, plf, 24, 25. Illustrated specimen. USNM 136546, USGS locality 13246. Knight, J. B., Batten, R. L., and Yochelson, E. L., 1960, Paleo­ Occurrence and abundance. Lower Mississippian undifferen- zoic Gastropoda, in Treatise on invertebrate paleontology; tiated: USGS locality 13240, one. ?Upper Mississippian: pt. I. Gastropoda : Geol. Soc, America. (In presf) USGS locality 13246, one. Koninck, L. G. de, 1881, Faune tlu calcaire carbonifere de la Belgique, 3e partie, Gasteropodes: Mus. royal d'Histoire REFERENCES CITED nat. Belgique Annales, Ser. Paleont., t. 6. Archiac, E. J. A. cT, and Verneuil, E. P., 1S41, Note stir le genre _____ 1883, Faune du calcaire carbonifere de la Pelgique, MurcJiisonia,: Soc. geol. France Bull., 1st ser., v. 12, p. 4e partie, Gasteropodes (suite et fin.) : Mus. roy^l d'His­ 154-160. toire nat. Belgique Annales, Ser. Paleont., t. 8. Bowsher, A. L., 1955, Origin and adaptation of platyceratid Leffingwell, E. de K., 1919, The Canning River regior. north­ gastropods: Kansas Univ. Paleont. Gontr. Mollusca, Art. ern Alaska: U. S. Geol. Survey Prof. Paper 109. 5. p. 1-11, pis. 1, 2. Longstaff, J. D., 1912, Some new Lower Carboniferous Gas­ _____ 1956, The effect of the crinoid host on the variability teropoda : Geol. Soc. London Quart. Jour., v. 68, p. 295- of Permian platyceratids, in Yoehelson, E. L., Permian 309, pis. 27-30. Gastropoda of the southwestern United States; [pt. 1.]: M'Coy, Fi'eclerick, 1844, A synopsis of the characters of the Am. Mils. Nat. History Bull., v. 110, art. 3, p. 261-263. Carboniferous limestone fossils of Ireland: Dublin, Mc- Bowsher, A. L.. and Dutro, J. T., Jr., 1957, The Paleozoic section Glashon and Gill. in the Shainin Lake area, central Brooks Range, Alaska: Maddren, A. G., 1912, Geologic investigations along the Canada- U. S. Geol. Survey Prof. Paper 303-A. Alaska boundary: U. S. Geol. Survey Bull. 520-K. Branson, C. C., 1948, Bibliographic index of Permian inverte­ Mansuy, Henri, 1912, Etude geologique du Yun-nan oriental, brates: Geol. Soc. America Mem. 26. 2e partie, Paleontologie: Indochine Service g£ol. Mem., v. Conrad, T. A., 1840, Third annual report on the palaeontologi- 1, 1, fasc. 2. cal department of the Survey: New York Geol. Survey Meek, F. B., and Worthen, A. H., 1866, Descriptions of inverte­ Ann. Rept. 4, p. 199-207. brates from the Carboniferous system, in Illinois Geol. Cossmann, Maurice, 1915, Essais de paleoconchologie comparee: Survey v. 2, Paleontology, p. 143-410, pis. 14-32. _____ 1867, Contributions to the paleontology of Illinois Paris, v. 10, [1916]. and other western states: Acad. Nat. Sci. of Philadelphia Cox, L. R., 1955, Observations on gastropod descriptive termi­ Proc. for 1866, p. 251-275. nology: Malacological Soc. London Proc., v. 31, pts. 5 and Montfort, Pierre Denys de, 1808, Conchyliologie systeniatique, 6. p. 190-202. et classification methodique des coquilles; offrant leurs Dutro, J. T., Jr., 1956, Annotated bibliography of Alaskan figures, leur arrangement generique, leurs description ca- Paleozoic paleontology: U. S. Geol. Survey Bull. 1021-H, racteristiques, leurs noms; ainsi que leur synonymic en p. 253-287. plusieurs langues; tome 1. Coquilles univalves, cloisonnees: Fischer, Paul, 1885, Manuel de conchyliologie et de paleon- Paris, F. Schoell. tologie conchyliologique, ou histoire naturelle des niollus- _____ 1810, Conchyliologie systematique, et classification ques vivants et fossiiles, fasc. IX: Paris, p. 785-896. methodique des coquilles; offrant leurs figures, leur ar­ Girty, G. H., 1939, Certain pleurotomariid gastropods from rangement generique, leurs descriptions caracteristiques, the Carboniferous of New Mexico and Texas: Washing­ leurs noms; ainsi que leur synonymie en plusieurs langues; ton Acad. Sci. Jour., v. 24, no. 1, p. 21-36. tome 2. Coquilles univalves, non cloisonnees: Paris, F. Gordon, Mackenzie, Jr., 1957, Mississippian Cephalopoda from Schoell. northern and eastern Alaska: U. S. Geol. Survey Prof. Moore, R. C., 1941, Upper Pennsylvanian gastropods from Kan­ Paper 283. sas : Kansas Geol. Survey Bull. 38, pt. 4, p. 121-163, pis. Hall, J. W., 1843, Geology of New York, pt. 4, comprising the 1-3. survey of the fourth geological district: Albany, Charles Oehlert, D. P., 1888, Descriptions de quelques epeces clevo- Van Benthuyson and Sons. niennes du department de la Mayenne: Soc. d'Etrdes Sci- Knight, J. B., 1933, The gastropods of the St. Louis, Missouri, entifiques d'Angers Bull. 1887, p. 65-120, pis. 6-10. Pennsylvanian outlier; V. The Trocho-Turbinidae: Jour. Patton, W. W., Jr., 1957, A new upper Paleozoic formation, Paleontology, v. 7, no. 1, p. 30-58, pis. 8-12. central Brooks Range, Alaska: U. S. Geol. Survey Prof. _____ 1934, The gastropods of the St. Louis, Missouri, Paper 303-B. Pennsylvanian outlier; VII. The Euomphalidae and Platy- Payne, T. G., and others, 1952, Geology of the Arctic slope of ceratidae: Jour. Paleontology, v. 8, no. 2, p. 139-166, pis. Alaska: U. S. Geol. Survey Oil and Gas Inv. Map, OM- 20-26. 126, 3 sheets. 146 SHORTER CONTRIBUTIONS TO GENERALi GEOLOGY

Phillips, John, 1841, Figures and descriptions of the Paleozoic Stehli, F. G., 1957, Possible Permian climatic zonation and its fossils of Cornwall, Devon, and West Somerset; observed implications: Am. Jour. Sci., v. 255, p. 607-618. in the course of the Ordinance Geological Survey of that Thomas, E. G., 1940, Revision of the Scottish Carboniferous district: London, Longman, Brown, Green and Longmans. Pleurotomariidae: Geol. Soc. Glasgow, v. 20 pt. 1, p. 30- Pilsbry, H. A., and Sharp, B., 1897, Scaphopoda (part), in 72. Tryon, G. W., Manual of conchology: Acad. of Nat. Sci. Ulrich, E. O., and Scofield, W. H., 1897, The Lower Silurian of Philadelphia, Conchological Section, ser. 1, v. 17, pt. 65, Gastropoda of Minnesota, in Geology of Minnesota: Minn. p. 1-80. Geol. and Nat. Hist. Survey, final rept. 3, pt. 2, p. 813- Shinier, H. W., 1926, Upper Paleozoic faunas of the Lake Min- newanka section, near Banff, Alberta: Canada Dept. of 1081, pis. 61-82. Mines, Geol. Survey Mus. Bull. No. 42, p. 1-84, pis. 1-8. U. S. Department of Defense, 1953-1957, Arctic bibliography: Smith, P. S., 1913, The Noatak-Kobuk region, Alaska: U. S. v. 1-7. Geol. Survey Bull. 536, p. 75-78. Warthin, A. S., Jr., 1930, Micropaleontology of the Wetumka, _____ 1939, Areal geology of Alaska: U. S. Geol. Survey Wewoka, and Holdenville formations: Oklahoma Geol. Prof. Paper 192. Survey Bull. 53. Smith, P. S., and Mertie, J. B., Jr., 1930, Geology and mineral Yochelson, E. L., 1953, Jedria a new subgenus of Naticopsis: resources of northwestern Alaska : U. S. Geol. Survey Bull. Washington Acad. Sci. Jour., v. 43, p. 65. 815. _____ 1956, Permian Gastropoda of the southwestern United Sowerby, James, 1814, Mineral conchology of Great Britain, States: [pt.] 1. Euomphalacea, Trochoneinrtacea, Pseudo- nos. IX and X, or colored figures and descriptions of those remains of testaceous animals or shells, which have been phoracea, Anomphalacea, Craspedastomatacea, and Platy- preserved at various times and depths in the earth: Lon­ ceratacea: Am. Mus. Nat. History Bull., v. 119, p. 173- don, v. 1. 276, pis. 9-24. INDEX [Italic numbers indicate descriptions]

Page Pags Page Acknowledgment _ ------...-... 113 Holopeidae...------.. 140 Pelmatozoan calyxes-...... 119 Alapah limestone...------113,116,117,118 howi, Naticopsis------.---...... --.------.-. 115 echinoderms_-.....-...... -...... 115 alaskensis, Straparollus (Euomphalus) ___ . 115, Naticopsis zone...... 115,117,118,143 Phymatopleurasp.----.-- 116,117,138,139,140, pl. 13 116,117,118,119, 133, 134, pi. 12 Phymatopleuridae ___- ._._...____.. 139 Amphiscapha.------121 lanthinopsissp...... 116,117,144, pl. 14 Pithodeinae--_....__...... _.___ 144 (Cylicioscapha) grada--.- 116,117,118,119, 134, pl.12 inumbilkata, Bembexia_-__ __--__ _ 116,117, Pfapio^ypte-,------145 analoga, Leptaena...... ------.__ 115 118,137, 138, 139, pl. 13 Platyceras- --. _- .-- 115,116,117,118,119,140 Anematina lagueata.....-..-.-.-...... --...... 141 (Orthonychia) sp_._...... 116,117,141, pl. 14 proutana... -_-_- _---._ - - _- 141 (Jedria), Naticopsis...... -_-_. 143 (Platyceras) sp...... 115,116,117,118, 140, pl. 14 rockymontanurn...... -_.-_ 116,117,118, 141, pl. 14 (Platyceras), Platyceras---- 115,116,117,118, /40,pl. 14 sp_.------116,117,118,140 Kayak shale- ----.------.---__--._-_- 113,115,116 Platycerataceans-----... __--...... _.-----.. 115,119 (Angyomphalus), Trepospira. -__. 116,117,136,pi. 12 Knight, J. Brookes, ()uoted.-.___...... Ill Platyceratidae__ - _-- _ - -. 140 Anomphalidae ------_ 142 Knightites (Retispira) sp...... 116,117, ISt, pl. 12 Platyzona sp--...... 116,117,144, pl. 14 Anomphalus nerviensis..-.. ------142 Knightitinae.._---.-.__._____ . 132 Plethospiridae --.-----,------144 sp ------116,117,118,142, Pi. 14 konincki, 7.aphrenth __..,-.------115 Pleurotomariaceans ..--____ 116,117,118,119,122 asiaticum, Lithostrotion..... ------115 Portlockiellasp ...... 113,116,117,118,139, pl. 13 laqueata, Anematina------141 Portlockiellidae ------139 Bellerophon giganteus--.------132 larteti, Bembexia------...... 138 Prosocline defined - _- . - 121 proutana, Anematina.- _------_ - 141 sp...... ------116,117,118, 131, pi. 12 lata, 1 urbonellina ...... 113,116,117,118, 135, pl. 12 Bellerophontaceans -.--.-_---.__ 116,117,118,119 lepida, 1urbonellina...... _-._.___...... 135 Ptychomphalina.-... ------...... 137 Bellerophontidae. _-__-_------.--.--.-_------131 Leptaena analoga--...... 115 Raphistomatidae...... _------_--.... 135 Bellerophontinae_ __---_-..___.-._--__ 131 zone...... __------__-_-__...... 115,116 reloba, Mourlonia.------... - _ 115, Bembexia inumbilkata.. 116,117,118,137, 138, 139, pi. 13 levicarinatus, Straparollus (Euomphalus)------133 116,117,118,119, 136, 137,140, pl. 13 larteti. . - - - 138 Licharewia ...... --...... -....-- .... 115 (Retispira), Knightites.-...... 116,117,132, pl. 12 Brachythyris suborbicularis.-...... 115 Liospirinae.-. _ .- _ - ______- 135 Rhineodermasp------113,116,117,118,135,140, pl. 12 zone_____---.__-____--_--.__ 115,116 Lisburne group-_-...-.---.-...-.-.-.-.-...--- 113 rockymontanum, Anematina---- 116,117,118,141, pl. 14 Brooks Range._--__-_.__------111,113,115 Lithostrotion asiaticum------115 Loxonema-...... 141 brooksensis, Straparollus (Euomphalus)..... _-_-_ 116, zone-...... ---..-...---.-.-.--- 115,116,117,118 Rugose corals_. - -- _. - Ill 117,118,133,134, pi. 12 Loxonema rockymontanum.------141 Sadlerochit formation...... 113,115,117,118,119 sp------116,117,118,142, 144, pi. 14 Scalarituba sp.._------115 Canning River district.-- ______...._ 111 Loxonemataceans__...... 116,117 Zone--.------...-.--.------.---.---.- 115,116 crateriformis, Straparollus (Euomphalus)------134 L ox otiemat idae -.-..----.-.---.-.---.-.-.. -- 144 Scaphopod, genus indet------116,117,144,pl. 14 crenistria, Goniatites..... ------115 Siksikpuk formation...------113,115,117,118,119 (Cylicioscapha) grada, Amphiscapha...... 116, minuta, Mourlonia--...... 116,117,118, 136, 140, pl. 13 Sinuitidae. . __..__-_ -.-____ 131 117,118,119, 134, Pl. 12 Mourlonia_____._ _ _-. __-- 137,138 Sinuopeidae.. ------_- 135 minuta...... 116,117,118, 136, 140, pl. 13 Soleniscinae. __...__..-.. _...... 144 Elasmonematidae------__-_ __ _ 141-142 reloba - 115,116,117,118,119, 136,137, 140, pl. 13 Spiroscalasp...... 116,117,137,140, pl. 13 Eotomariidae.- __ ._____...... 136 Murchisonia sp__-_-__-__-._-__-_. 116,117, 144, pl. 14 Stelnkerns...... ---...--. -..-.-.-..-... 118 Eotomariinae...------___------_-_ ----- 136 Murchisoniaceans _- -__ ...... 116,117,118 Straparollus---...... __.....__..... 119,121 Euomphalaceans-.______.__... 116,117,118,119 Murchisoniidae __ .... -.---.....-.-.-.------..- 144 (Euomphalus) alaskensis ------115, Euomphalidae---- _------_------___-_- 133 116,117,118,119,133,134, pl. 12 Euomphalus ------_ -_ - _ -- 134 Naticopsinae--. .------. 142 brooksensis--..-.... 116,117,118,133,134, pl. 12 (Euomphalus), Straparollus.-_..... 116,117, 1S4, pl. 12 Naticopsis howi..-...-.-.-...-...... -----.. 115 crateriformis----- ... ------134 alaskensis, Straparollus ...___-_------__-.. 115,116, (Jedria) ___ ..__ __._._._ 143 levicarinatus--..------.------133 117,118,119, 1SS, 134, pl. 12 (Naticopsis) suturicompta-..-- 115,116,117,118, 14S sp...... 116,117,134, pl. 12 brooksensis, StraparoHus_...... 116,117, sp . __ -- 116,117, 143, pl. 14 suborbicularis, Brachythyris...... 115 118, 133, 134, pl. 12 suturicompta...... 119 Subulitldae...... --....-...... ---.---...- 144 crateriformis, Straparollus.------...... _... 134 zone-..------.------. 115,116,117,118,119,143 suturicompta, Naticopsis-...... 119 leeicarinatus, Straparollus.------133 (Naticopsis), Naticopsis-.------116,117, 143, pl. 14 Naticopsis (Naticopsis) .-..- 115,116,117,118,145 Euphemites sp...... 116,117,118, 131, 132, pl. 12 suturicompta, Naticopsis...... 115,116,117,118,142 Euphemitinae_--- __.__------131 Naval Petroleum Reserve No. 4_...... -..-. . Ill Trepospira (Angyomphalus) sp.__ 116,117,136, pl. 12 Neilsonia sp...... 116,117,118,138, pl. 13 (Trepospira) sp...... 116,117,119,135, pl. 13 giganteus, Bellerophon..... -___ _ . 132 Neilsoniinae....------...... 138 (Trepospira), Trepospira------116,117,119,135, pl. 13 Glabrocingulum (Glabrocingulum) sp_-....-.. 116,117, Neritaceans------_-.------.-._.- 116,117,118,119 Tropidostropha...... _ ._ - - 140 119, 138, pl. 13 Neritopsidae--__------____._____-.. 142 Turbonellina lata.------113,116,117,118, 135, pl. 12 (Glabrocingulum), Glabrocingulum.... ------116,117, nerviensis, Anomphalus-- --.-.----.- --.-..-. 142 lepida...... 135 119,138, pl. 13 New genus A ------116,117, 139, pl. 13 Turbonellininae._ _ -- ____-_----- 135 Goniatites crenistria. ----_- _- __ 115 B-_ _-__...-....-_---- 116,117,139, pl. 14 zone.. - ---__------__-_----_--. 115,117,118 Nodospira---.- --.------.------. 137 Visean formation.--...... 115 Gordon, Jr., Mackenzie, quoted..-_------115 ornate...... 116,117,118, 137, 138, pl. 13 Wachsmuth limestone --- _ -- 11?, 115,116 Gosseletinasp-..... -___...__.. 116,117, 139, pl. 13 Qosseletinidae-...------...-__-_- .._-. 139 Opisthocline, defined- . -___ - 121 Yunnaniasp --...... 116,117,140. pl. 13 Gosseletininae__.____..-.-.____...... _ 139 ornate, Nodospira...... 116,117,118, 137, 138, pl. 13 grada, Amphiscapha (Cylicioscapha)--...... - 116,117, Orthocline, defined...... 121 Zaphrentis konincki..------115 118,119,134, pl. 12 (Orthonychia), Platyceras...... 116,117, 141, pl. 14 zone...... 115,116 147

PLATES 12-14 PLATE 12 FIGURE 1. Knightites (Retispiral) sp. (p. 132) Oblique top view, X 2; USNM 136506, from USGS loc. 11843, Lower Mississippian. 2-4. Euphemites sp. (p. 131) 2. Oblique front view, X 2; USNM 136507a, from USGS loc. 12084, Goniatites zone, Alapah limestone. Oblique top view and side view, respectively, X 2; USNM 136507b, from USGS loc. 12084, Goniatites zone, Alapah limestone. 5-9. Bellerophon sp. (p. 131) 5. Side view of small steinkern, X 2; USNM 136508a, from USNM loc. 3088, Naticopsis zone, Alapah limestone. 6. Front view showing selenizone, X 2; USNM 136509, from USGS loc. 11799, Naticopsis zone, Alapah limestone. 7. 8. Side and top views, respectively, of a steinkern, X 1; USNM 136508b, from USNM loc. 3088, Naticopsis zone, Alapah limestone. 9. Top view of a large steinkern, X 1; USNM 136510, from USGS loc. 15408, Naticopsis zone, Alapah limestone. 10-14. StraparoUus (Euomphalus) alaskensis Yochelson and Dutro, n. sp. (p. 133) 16-19. 10. Section showing two shell layers, < 2; paratype, USNM 136511a, from USGS loc. 11814, Siksikpnk formation. 11. Slightly oblique side view, X 2; paratype, USNM 136511b, from USGS loc. 11814, Siksikpuk formation. StraparoUus (Euomphalus) alaskensis Yochelson and Dutro, n. sp. (p. 133) 12-14. Side, top, and basal views, respectively, X 2; paratype, USNM 136511c, from USGS loc. 11814, Siksikpuk formation. 16-19. Side, apertural, basal, and top views, respectively, X 1; holotype, USNM 136512, from USGS loc. 11823, unnamed Permian formation(?). 15, 20-23. StraparoUus (Euomphalus) brooksensis Yochelson and Dutro, n. sp. (p. 133) 15, 20. Basal and top views, respectively, of small specimen, X 2; paratype, USNM 136513, from USGS loc. 13235, Lower Mississippian. 21. Apertural view, X 1; paratype, USNM 136514, from USGS loc. 11890, Lower Mississippian. 22,23. Side and top views, respectively, X 2; holotype, USNM 136515, from USNM loc. 3186, L>'thostrotior> zone, Alapah limestone. 24-26. Straparollus (Euomphalus) sp. (p. 134) Top, basal, and apertural views, respectively, X 2; USNM 136516, from USGS loc. 14954, Brachythyris zone, Wachsmuth limestone. 27-29. Amphiscapha (Cylicioscapha^i grada Yochelson and Dutro, n. sp. (p. 134) Side, top, and basal views, respectively, X 2; holotype, USNM 136517, from USGS loc. 11823, urnamed Permian formation(?). 30-33. Turbonellinat lata Yochelson and Dutro, n. sp. (p. 135) 30-32. Side, basal, and oblique top views, respectively, X 2; holotype, USNM 136518, from USGS loc. 13235, Lower Mississippian. 33. Basal view, X 4; paratype, USNM 136519, from USGS loc. 13234, Lower Mississippian. 34. Rhineodermal sp. (p. 135) Top view, X 2; USNM 136520, from USNM loc. 3167, Lithostrotion zone, Alapah limestone. 35-36. Trepospira (Angyomphalus?) sp. (p. 136) Top and basal views, respectively, X 4; USNM 136521, from USGS loc. 11843, Lower Mississippian. GEOLOGICAL SURVEY PROFESSIONAL PAPER 884 PLATE 12

30 32 33 34 35 36 LATE PALEOZOIC GASTROPODA PLATE 13

FIGURES 1-3. Trepospira (Trepospira} sp. (p. 135) Basal, top, and side views, respectively, X 1; USNM 136522, from loc. USGS 14174, Siksikpuk(?) formation. 4-5. Mourlonia minuta Yochelson and Dutro, n. sp. (p. 136) Side, and top views, respectively, X 2; holotype USNM 136523, from USGS loc. 11865, Lisburne group (upper formation). 6-9. Mourlonia? reloba Yochelson and Dutro, n. sp. (p. 136) 6, 7. Side and basal views, respectively, X 1; paratype, USNM 136524, from USGS loc. 14169, unnamed Permian formation. 8, 9. Top and adapertural views, respectively, X 2; holotype, USNM 136525, from USGS loc. 14169, unnamed Permian formation. 10. cf. Spiroscala sp. (p. 137) Side view, X 2; USNM 136526, from USGS loc. 1008, Sadlerochit(?) formation. 11-13. Glabrocingulum (Glabrocingulum) sp. (p. 138) Top, adapertural, and basal views, respectively, X 2; USNM 136527, from USGS loc. 14174, Siksikpuk formation. 14-17. Nodospira ornata Yochelson and Dutro, n. sp. (p. 137) 14-16. Top, apertural, and basal views, respectively, X 1; holotype, USNM 136528, from USGS loc. 14150, Goniatites zone, Alapah limestone. 17. Apertural view, X 1; paratype, USNM 136529, from USGS loc. 14150, Goniatites zone, Alapah limestone. 18, 19. Portlockiella? sp. (p. 139) Adapertural and top views, respectively, X 3; USNM 136536, from USNM loc. 3167, Lithostrotion zone, Alapah limestone. 20, 21. Gosseletina? sp. (p. 139) Basal and side views, respectively, X 2; USNM 136531, from USGS loc. 13236, Lower Mississippian. 22-24. Phymatopleura sp. (p. 139) Adapertural, top, and basal views, respectively, X 3; USNM 136532, from USGS loc. 13234, Lower Mississippian. 25. Neilsoniat sp. (p. 138) Side view, X 4; USNM 136533, from USGS loc. 9184, Alapah limestone. 26-28. New genus? A (p. 139) Adapertural, basal and top views, respectively, X 4; USNM 136534, from USNM loc. 3110, "Zaphrentis" zone Wachsmuth limestone. 29. Yunnama sp. (p. 140) Adapertural view of steinkern, X 6; USNM 136535, from USGS loc. 12785, Lower Mississippian. 30-31. Bembexiat inumbilicata Yochelson and Dutro, n. sp. (p. 138) Apertural and side views, respectively, X 1; Holotype: USNM 136536, from USGS loc. 10862, Goniatites zone, Alapah limestone. GEOLOGICAL SURVEY PROFESSIONAL PAPER 334 PLATE 13

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LATE PALEOZOIC GASTROPODA PLATE 14

FIGURE 1. cf. Murchisonia sp. (p. 144) Side view, X 4; USNM 136537, from USGS loc. 13240, Lower Mississippian. 2. Platyzona sp. (p. 144) Side view, X 2; USNM 13658, from USGS loc. 13246, probably Upper Mississippian. 3. lanthinopsis? sp. (p. 144) Side view, X 2; USNM 13659, from USGS loc. 12785, Lower Mississippian. 4. Scaphopod, genus indeterminate (p. 144) Side view, X 2; USNM 136546 from USGS loc. 13246, probably Upper Mississippian. 5. Naticopsis (Naticopsis) sp. (p. 143) Side view, X 2; USNM 136540 from USGS loc. 13235, Lower Mississippian. 6. Loxonema sp. (p. 144) Side view, showing growth lines, X 4; USNM 136541, from USGS loc. 11828, Goniatites zone, Lisburne group. 7-9. Anomphalus sp. (p. 142) Adapertural, top, and basal views, respectively, X 3; USNM 136547, from USNM loc. 3167, Lithrostrotion zone, Alapah limestone. 10-16. Anematina rockymontanum (Shimer) (p. 141) 10. 12, 13. Two side and basal views, respectively, X 2; holotype, GSC 5093, from Lower Mississippian of Lake Min- newanka Alberta. 11. Side view, X 2; paratype, GSC 5093a, from Lower Mississippian at Lake Minnewanka, Alberta. 14. Adapertural view, X 2; USNM 136542, from USGS loc. 11808, Lower Mississippian. 15. 16. Adapertural and apertural views, respectively, X 2; USNM 136543, from USGS loc. 13288, Lithostrotion zone, Alapah limestone. 17-19. Platyceras (Orthonychia) sp. (p. 141) 17. Side view, X 1; USNM 136544a, from USNM loc. 3089, "Zaphrentis" zone, Wachsmuth limestone. 18. Side view, X 1; USNM 136545, from USGS loc. 9186, Lower Mississippian. 19. Side view, X 1; USNM 136544b, from loc. 3089, "Zaphrentis" zone, Wachsmuth limestone. 20-25. Naticopsis (Naticopsis) suturicompta Yochelson and Dutro, n. sp. (p. 142) 20. 21. Enlargement showing shell layers, and adapertural view, respectively, X 4 and X 1; paratype: USNM 136548, from USNM loc. 3088, Naticopsis zone, Alapah limestone. 22-24. Side, apertural, and top views, respectively X 1; holotype, USNM 136549, from USGS loc. 9187, Alapah limestone (?). 25. Adapertural view, X 1; paratype, USNM 136550 from USNM loc. 3170, Naticopsis zone, Alapah limestone. 26, 27. New genus? B (p. 139) Basal and side views, respectively, X 1; USNM 136551, from USGS loc. 13215, unnamed Permian formation. 28. Platyceras (Platyceras) sp. (p. 140) Top view showing early whorls, X 4; USNM 136552, from USGS loc. 14035, Upper Mississippian.

U. S. GOVERNMENT PRINTING OFFICE : I960 O -507Z18 GEOLOGICAL SURVEY PROFESSIONAL PAPER 334 PLATE 14

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