aneariee enessietocsoraree etary thy Rnb rey TEN eG ree Owe Grane tshnamonteerteae aes SoH ae ge VPN SITIES ey rinhe ge eG eEees cf i\g tive ee =) ' HARVARD UNIVERSITY Mele OD LIBRARY OF THE Museum of Comparative Zoology : — aS. ee a ate ~ 4a oa “ Re tee ~. é« a — ‘in 4 Pa ea Lilies yas 4 j i Pydn iy Bh Api We Ab i u vey MAA) Aa i the MUS. COMP, ZOOL on ign pe 2/1 VS By he acpi y OF AMERICAN PALEONTOLOGY VORMXIAY NUMBER 204 LATE CENOZOIC PELECYPODS FROM NORTHERN VENEZUELA BY NORMAN E. WEISBORD 1964 PALEONTOLOGICAL RESEARCH INSTITUTION ITHACA, NEW YORK aS. A. PALEONTOLOGICAL RESEARCH INSTITUTION 1963-1964 ARIE SID EIN Ui ees sees ae ic rs Be ee ee ete oak, A sas teseensecsadel AXEL A. OLSSON RANGE = REGU RIN tiene cnt eee nace ae 2 a 8 ae ee DoNALD W. FISHER RCM ROAR =i ROA GITRIR Rito (eee a Rin aera fo sees St cusacvondetemee sctenade REBECCA S. HARRIS PUTER ISTOR( tn tenet heck stan tcl es eet) eee a ree KATHERINE V. W. PALMER COUN RO FRE PSS cree Sas ao Se8. Poke eS, A ee Oi ee ee: ee ARMAND L, ADAMS REPRESENTATIVE AAAS COUNCIL ..............--.0---- soe eee Se KENNETH E, CASTER Trustees KENNETH E, CASTER (1960-1966) KATHERINE V. W. PALMER (Life) DoNnALpD W. FISHER (1961-1967) WILLIAM B. HeEroy (1963-1968) Resecca S. Harris (Life) AXEL A. Otsson (Life) SoLoMON C. HOLLIsTER (1959-1965) HANs G. KUGLER (1963-1969) Joun W. WELLS (1958-64) BULLETINS OF AMERICAN PALEONTOLOGY and PALAEONTOGRAPHICA AMERICANA KATHERINE V. W. PALMER, Editor Mrs. FAy Bricos, Secretary Advisory Board KENNETH E, CASTER HANS KUGLER A. Myra KEEN JAy GLENN MARKS Complete titles and price list of separate available numbers may be had on application. All volumes will be available except vol. I of Palaeontographica Americana. For reprint, Vols. 1-6, 8-16, Bulletins of American Paleontology see Kraus Reprint Corp., 16 East 46th St., New York 17, N.Y., U.S.A. Subscription may be entered at any time by volume or year, with average price of $16.00 per volume for Bulletins. Numbers of Palaeontographica Amer- icana invoiced per issue. Purchases in U.S.A. for professional purposes are deductible from income tax. For sale by Paleontological Research Institution 109 Dearborn Place Ithaca, New York U.S.A, BULLETINS OF AMERICAN PALEONTOLOGY (Founded 1895) Vol. 45 No. 204 LATE CENOZOIC PELECYPODS FROM NORTHERN VENEZUELA By Norman E. WEIsBorpD Department of Geology The Florida State University February 18, 1964 Paleontological Research Institution Ithaca, New York, U.S.A. Library of Congress Catalog Number: GS63-300 MUS. COMP. ZOOL LIBRARY MAR 16 1964 HARVARD UNIVERSITY. fa CSS Oe F urdh hola Printed in the United States of America CONTENTS Page 1.5) SE) NG pe Re es wir ene DSN UWS unr nary PP eM eyo ee or 5 SCE YATE RRO Tel ene PED A Lin iano sed bie 5 Acknowlearinentswr..2e See, tues ae Peon Aoi al ly erie ole tes, Seok ot 6 LEGS goat A ht ih tal Din a ler, one kPa Oa e P beae ata 7 Belecypods frompnortherm, Venezuela: ecco ocean ssh cs cscs ca ccc evscectenesaeeed 9 Recent pelecypods from Playa Grande and Higuerote ....0..2.........c-:-scesecc-ceeseoees 15 ipelecypods trom, La, Salind, de Guai gua Za an. aioossccscsenncesctes-socesnceasnsenscesseoressacernecs 16 EbhemCabopblancomProupe cena te eel eels Res. cee eat 18 SEGALL 2 LAD Wie wroceses rece acresrcvseer eee rancans tacts sites roctccterteeereet ree tests seen iol eterna 18 elecypods,of the, Abisinia , form ation? jaisss sacs coos sass eceactra Seventeen 19 pelecypods) ot them Mare SOrmatiOn .) ek -f iene Senet =e ecalh ot ES mee $96 O0@ 9p 006m 14 PES G88 B46 e se PR ee ik ole ee ee ee Cee bd re 14 * a ee ol ee ol anpitaarial iP p = _— F 4 a ih Tat illest sehen teens GE Kaeets ey LATE CENOZOIC PELECYPODS FROM NORTHERN VENEZUELA Norman E. WEIsBorpD Department of Geology The Florida State University ABSTRACT . One hundred and seventy-two species of pelecypods are described, com- pared, and illustrated. Of this total, 29 forms are Recent, 22 are Recent and fossil, and 121 are fossil. One of the Recent shells—Donax higuerotensis Weis- bord—and 63 of the 121 fossil shells are believed to be new. The Recent pelecy- pods were collected on the beach at Playa Grande in the Distrito Federal, and at Higuerote, in the State of Miranda. The fossils were collected from the Guaiguaza clay at La Salina de Guaiguaza in the State of Carabobo, and from the Cabo Blanco group, in the Distrito Federal. The fossiliferous units of the Cabo Blanco group are, from younger to older, the Abisinia formation, the Mare formation, and the Playa Grande formation. Combining the pelecy- pods with the gastropods described in a previous work (Weisbord, 1962), and utilizing the Lyellian principle of chronological classification together with stratigraphic control (Weisbord, 1957), the Abisinia formation is assigned a Pleistocene age, the Guaiguaza clay a late Pliocene age, and the Mare and Playa Grande formations an early Pliocene age. The observation is made that although the pelecypod species are less numerous than the gastropod species, a significantly greater percentage of the pelecypods have survived to Recent time. Concerning the problem of correlation, it is postulated that the Playa Grande and Mare formations of the Cabo Blanco group are directly contem- poraneous with the Cumana beds of eastern Venezuela and roughly equivalent to the Caloosahatchee deposits of Florida; that the Playa Grande formation may be the time counterpart of the Punta Gavilan formation in the State of Falcon, Venezuela; and that the Guaiguaza clay was laid down at some time during the interval of deposition of the Matura formation of Trinidad and the Moin formation of Costa Rica. INTRODUCTION This is the second of a series of monographs dealing with late Cenozoic and Recent invertebrates collected by the writer between 1955 and 1957 in northern Venezuela. The first monograph (Weis- bord, 1962) was concerned with the Gastropoda; the present one deals with the Pelecypoda;! and a third, now in progress will be devoted to the Scaphopoda. The material described in these works was obtained from three locations in Venezuela: La Salina de Guai- guaza, approximately 6 kilometers west of Puerto Cabello, in the State of Carabobo; the Cabo Blanco area, about 17 kilometers northwest of Caracas, in the Distrito Federal; and Higuerote, some 88 kilometers east of Caracas, in the State of Miranda. The fossil shells were collected from La Salina de Guaiguaza and from the Cabo Blanco area, the Recent ones from the Cabo Blanco area 1The support given for this work by the National Science Foundation through its Research Grant NSF-8699, awarded 15 November 1959, is gratefully acknowledged. 6 BuLLeTIN 204 (on the beach at the Playa Grande Yachting Club), and at Higue- rote. In the 1962 paper, 288 species of gastropods were described, compared, and illustrated, and in the present one 172 species of pelecypods, both fossil and Recent, from one or the other of the localities mentioned above, are so treated. Most of the fossil pele- cypods were obtained in the Cabo Blanco area, and each species from that area is given its stratigraphic position as determined from field observations by the writer and presented in his paper (Weisbord, 1957) titled “Notes on the Geology of the Cabo Blanco Area, Venezuela.” The systematic study of the pelecypods was started in July of 1960, and the manuscript submitted to the Paleontological Re- search Institution in May of 1962. The format of the present work is patterned after the gastropod paper, and again, as in that, the references to a species under synonymy rests on the authority of the one who has identified the species. For comparative studies of the Pelecypoda, the writer spent a total of ten weeks examining collections and consulting literature in the U. S. National Museum, Washington, D. C., the Academy of Natural Sciences of Philadelphia, the Museum of Comparative Zoology of Harvard College, and the Paleontological Research Institution in Ithaca, New York. Many of the references under the heading of Bibliography were consulted in the libraries of the above-mentioned museums. The bibliography in the present monograph contains a number of references given in my gastropod monograph, but most of the items are additional ones. For all of the titles listed thus far, the Bibliography of both mono- graphs should be consulted. The pelecypods described in this work are deposited with the Paleontological Research Institution, Ithaca, New York, United States. ACKNOWLEDGMENTS I wish to express again to my colleagues? in the Department of Geology at Florida State University my appreciation for their con- stant encouragement and support of my research efforts. I thank Katherine V. W. Palmer, editor of the Bulletins of American Pa- leontology, for coping with the problems involved in bringing this *B. Frank Buie, chairman, George W. DeVore, H. Grant Goodell, Donn S. Gorsline, John Kenneth Osmond, William F. Tanner, Lyman D. Toulmin, and Stephen S. Winters. VENEZUELAN CENOZOIC PELECYPODS: WEISBORD 7 monograph to publication, and for her help and advice during its preparation. For allowing me untrammeled access to the expertly curated collections and to the literature contained in the museums with which they are affiliated, and for their unstinted co-operation, I am indebted to William J. Clench of the Museum of Comparative Zoology; to G. Arthur Cooper, Harald A. Rehder, and Wendell P. Woodring of the U.S. National Museum; to R. Tucker Abbott and Horace G. Richards of the Academy of Natural Sciences of Phila- delphia; and to Katherine V. W. Palmer, director of the Palaeonto- logical Research Institution. I was fortunate in being able to ex- amine the fine collection of Florida fossils in the Florida Geological Survey through the courtesy of its director, Robert O. Vernon. It is a pleasure to acknowledge the assistance given me by the staff of the Robert Manning Strozier Library at Florida State University in arranging for the acquisition or loan of certain rare publications essential to the pursuit of my studies. I thank J. Wyatt Durham of the University of California for lending me the types of Pecten (Euvola) ziczac caboblancoensis described in a thesis written under his direction by Daniel Druckerman. Frances de Rivero, professor of Paleontology at the Universidad Central de Venezuela, was good enough to discuss with me, prior to publication in the Léxico Estratigrafico de Venezuela, the nomenclature of the formations comprising the Cabo Blanco group. I am grateful to the late Prof. Royo y Gémez, also on the faculty of the Universidad Central de Venezuela, for the opportunity I had to accompany him on a field trip to the Cabo Blanco area on 19 February 1955. Many of the fossils described in this work were subsequently collected from localities pointed out by him on that occasion. The photographs of the pelecypods were taken and processed by Hal F. Riehle and Werner Vagt of Florida State University, and the drawings were made by Andrew R. Janson of the Florida Geological Survey and by Phyllis Garman of Florida State University. LOCALITIES The localities from which the pelecypods were obtained, and the formations in which they occur are listed below. The letter preceding the locality description is the same as that prefixing the BuLLETIN 204 number given to each species in the explanation of plates. All of the localities, except La Salina de Guaiguaza in the State of Cara- bobo, are shown on the geologic map accompanying the writer’s paper (Weisbord, 1957) on the geology of the Cabo Blanco area. On the 1957 map field stations are marked by the letter “W”, and some of the localities listed below refer to these stations. A. B. C. L. Beach, at Playa Grande Yachting Club, Distrito Federal. Recent. Beach, southeast of Higuerote, State of Miranda. Recent. Near south shore of La Salina de Guaiguaza, 5.6 kilometers west of Puerto Cabello, State of Carabobo. The fossils were collected from a drainage ditch about one meter in depth. . Eastern edge of Playa Grande village at W-30. Abisinia for- mation. . Approximately 115 meters south-southwest of the crossing of Quebrada Mare Abajo and coast road, and 90 meters southwest of W-12. Upper Mare formation. . Hillside above west bank of Quebrada Mare Abajo at W-14. Upper Mare formation. . Hillside above west bank of Quebrada Mare Abajo near W-14. Mare formation. . 15 meters south of axis of Punta Gorda anticline at W-25. Mare formation. Hillside above west bank of Quebrada Mare Abajo at W-13. Lower Mare formation. Small stream 100 meters west of Quebrada Mare Abajo and 125 meters west-southwest of the intersection of Quebrada Mare Abajo and the coast road. Lower Mare formation. . Bluff 125 meters west of the intersection of the Playa Grande Yachting Club road and coast road, and about 95 meters due south of the shoreline. Playa Grande formation (Catia member). South side of Playa Grande road about 200 meters west of W-15. Playa Grande formation (Catia member). M. South side of Playa Grande road 40 meters southwest of its intersection with the Playa Grande Yachting Club road. Playa Grande formation (Catia member). VENEZUELAN CENOzoIC PELECYPoDS: WEISBORD 9 N. Near W-21 and to the south of that station in stream flow- ing along the strike of the north flank of the Litoral anti- cline. Playa Grande formation (Catia member). O. Dip slope 100 meters west of Costa fault and 130 meters south of shoreline at W-22. Playa Grande formation (Catia member). P. North bank of Quebrada Las Pailas 35 meters south of Mare Abajo fault and 150 meters southwest of the intersection of the Mare Abajo fault and Maiquetia anticline. Playa Grande formation (Maiquetia member). Q. Quebrada Las Pailas at, and in the vicinity of W-4. Playa Grande formation (Maiquetia member). R. Quebrada Las Bruscas at W-26 approximately 125 meters upstream from junction with Quebrada Las Pailas. Playa Grande formation (Maiquetia member). S. Near Lithothamnium reef at W-23, north flank of Punta Gorda anticline. Playa Grande formation (Maiquetia mem- ber). T. Stream 250 meters south-southwest of the mouth of Que- brada Las Pailas and 255 meters east-northeast of wireless station. Upper Mare formation. U. South side of coast road at east end of the village of Catia La Mar. Playa Grande formation (Catia member). V. Scarp at W-18 about 200 meters south of the intersection of the Costa fault with the shoreline. Playa Grande formation (Catia member). X. In Quebrada Las Pailas at W-3, south side of Mare Abajo fault near its intersection with the Bruscas fault. Playa Grande formation (Maiquetia member). PELECYPODS FROM NORTHERN VENEZUELA Following is a list of the pelecypods from northern Venezuela collected by the writer. Under the heading of “Formation” the ab- breviations used are these: Re=Recent Sal=La Salina de Guaiguaza Ab=Abisinia formation 10 BuL_eTIN 204 Ma=Mare formation PGm=Playa Grande formation (Maiquetia member) PGc=Playa Grande formation (Catia member) Species Nucula (Nucula) venezuelana Weisbord, n. sp. Nucula (Ennucula) mareana Weisbord, n. sp. Nuculana (Saccella) karlmartini Weisbord, n. sp. Nuculana (Saccella) axelolssoni Weisbord, n. sp. Nuculana (Saccella) marella Weisbord, n. sp. Nuculana (Saccella) species Nuculana (Jupiteria ?) species Adrana cf. tellinoides (Sowerby) Arca (Arca) zebra Swainson Arca (Arca) zebra abisiniana Weisbord, n. subsp. Arca (Arca) imbricata Bruguiére Barbatia (Barbatia) candida (Helbling) Barbatia (Acar) domingensis (Lamarck) Barbatia (Fuglgria) tenera (C. B. Adams) Arcopsis adamsi “Shuttleworth” (E. A. Smith) Anadara (Larkinia) notabilis (Réding) Anadara (Larkinia) species Anadara (Lunarca) ovalis (Bruguiére) Anadara (Lunarca ?) caboblan- quensis Weisbord, n. sp. Anadara (Lunarca ?) mareana Weisbord, n. sp. Anadara (Cunearca) brasiliana (Lamarck) Anadara (Cunearca) chemnitzi (Philippi) Anadara (Cunearca) cumanensis (Dall) Anadara (Cunearca) species indeterminate Glycymeris (Glycymeris) undata (Linnaeus) Glycymeris (Tucetona) pectinata (Gmelin) Glycymeris (Glycymerella) decussata (Linnaeus) Formation PGm; Ma Ab Re; Ab; Sal Re; Ab Re; Ab Re Re; Sal Re; PGm PGc Re; Ma PGm; Ma Geologic range of known species Recent Middle Miocene—Recent Lower Miocene—Recent Lower Miocene—Recent Lower Miocene—Recent Recent Lower Miocene—Recent Middle Miocene—Recent Upper ? Miocene—Recent Upper Miocene—Recent Pleistocene—Recent Mid. ? Miocene—Pliocene Middle Miocene, Pliocene Miocene—Recent Middle Miocene—Recent Re; Ma; PGm Middle Miocene—Recent VENEZUELAN CENOZOIC PELECYPODS: WEISBORD 11 Brachidontes (Ischadium) recurvus (Rafinesque) Modiolus americanus Leach Musculus lateralis (Say) Crenella divaricata (d’Orbigny) Lioberus ? marensis Weisbord, n. sp. Isognomon alatus (Gmelin) Pinna aff. carnea Gmelin Atrina (Servatrina) seminuda (Lamarck) Atrina (Servatrina ?) aff. seminuda (Lamarck) Atrina (Servatrina) serrata ? (Sowerby) Plicatula gibbosa Lamarck Plicatula venezuelana Weisbord, n D. sp. Pecten( Pecten) caribeus Weisbord, n. sp. Pecten (Pecten) maiquetiensis Weisbord, n. sp. Pecten (Pecten) species Pecten (Pecten ?) remulus Weisbord, n. sp. Pecten (Euvola) ziczac caboblan- coensis Druckerman Pecten (Amusium) papyraceus (Gabb) Pecten (Amusium) marensis Weisbord, n. sp. Chlamys (Chlamys) ornata (Lamarck) Chlamys (Chlamys) benedicti Verrill and Bush Aequipecten muscosus (Wood) Chlamys (Leptopecten) desultoria Weisbord, n. sp. Chlamys (Argopecten) gibbus antecessor Weisbord, n. subsp. Chlamys (Argopecten) imitata Weisbord, n. sp. Lyropecten (Nodipecten) nodosus ? (Linnaeus) Lyropecten (Nodipecten) arnoldi Aguerrevere Lyropecten (Nodipecten) species Lyropecten (Nodipecten) species “b” Spondylus americanus Hermann Lima (Limaria) pellucida C. B. Adams Anomia mareana Weisbord, n. sp. Anomia catiana Weisbord, n. sp. . Sp. Plicatula caribbeana Weisbord, n. sp. Pecten (Pecten) catianus Weisbord, 6,9) Re Upper Miocene—Recent Re Recent Ma Pliocene—Recent PGm; Ma Upper Miocene—Recent Re Pleistocene—Recent Ma; Ab Pliocene ?—Recent Re Miocene ?, Recent PGc Miocene ?, Recent PGc Lower Pliocene—Recent PGm; Ma Pliocene—Recent PGm Ma PGc Ma Ma PGc PGm PGc; PGm; MaPliocene PGc Oligocene ?—Recent Ma Re Pleistocene—Recent PGc Recent PGc Pliocene—Recent Ma PGc; PGm; Ma PGc PGc Lower Miocene ?—Recent PGc Pliocene Ma PGce PGc; PGm Pliocene—Recent Re Recent Ma PGe 12 BuL.etTin 204 Pododesmus rudis (Broderip) Ostrea (Ostrea) libella Weisbord, n. sp. Ostrea (Ostrea) pannucea Weisbord, n. sp. Ostrea (Ostrea) lixula Weisbord, n. sp. Ostrea (Ostrea) caraboboensis Weisbord, n. sp. Ostrea (Crassostrea) virginica Gmelin Ostrea (Crassostrea) species Ostrea (Crassostrea) rhizophorae Guilding Ostrea (Alectryonia) vespertina venezuelana Weisbord, n. subsp. Ostrea (Alectryonia ?) caboblan- quensis Weisbord, n. sp. Ostrea (Agerostrea ?) antecursor Weisbord, n. sp. Eucrassatella (Hybolophus) antillarum (Reeve) Crassinella aduncata Weisbord, n. sp. Crassinella triquetra Weisbord, n. sp. Cardita (Carditamera) gracilis Shuttleworth Venericardia (Glyptoactis) wendell- woodringi Weisbord, n. sp. Mytilopsis leucophaeatus ? Conrad Diplodonta (Diplodonta) mareana Weisbord, n. sp. Diplodonta (Diplodonta) semiaspera Philippi Lucina (Cavilinga) trisulcata blanda (Dall and Simpson) Lucina (Callucina ?) species Lucina (Bellucina) katherinepalmerae Weisbord, n. sp. Lucina (Parvilucina) ephraimi Weisbord, n. sp. Lucina (Parvilucina) multilineata Tuomey and Holmes Lucina (Lucinisca) muricata (Spengler) Codakia (Lentillaria) orbicularis (Linnaeus) Codakia (Jagonia) orbiculata (Montagu) Codakia (Jagonia) pectinata (C. B. Adams) Codakia (Jagonia) umbonicostata Weisbord, n. sp. Divaricella ? species Bornia tacaguana Weisbord, n. sp. Chama congregata Conrad Ma Pliocene—Recent Re Oligocene—Recent Re Pleistocene—Recent PGc; PGm; Ma PGc; PGm; Ma PGm Ma Pliocene—Recent Ma Ma Re; Ab; Ma_ Recent Re Pleistocene—Recent Re Pliocene—Recent Ma Recent PGm; Ma PGm Upper Miocene—Recent Sal Ab; PGm Middle Miocene—Recent Re Pliocene ?—Recent Re Recent PGm Middle Miocene—Recent VENEZUELAN CENOozoic PELECYPODS: WEISBORD 13 Chama macerophylla Gmelin Chama florida Lamarck Chama sinuosa bermudensis Heilprin Pseudochama radians (Lamarck) Pseudochama ? species Echinochama species “a” Echinochama species “b” Trachycardium (Dallocardia) muricatum (Linnaeus) Trachycardium (Trachycardium) cf. isocardia (Linnaeus) Trigoniocardia (Trigoniocardia) caboblanquensis Weisbord, n. sp. Trigoniocardia (Americardia) media (Linnaeus) Laevicardium ? species Papyridea aff. soleniformis (Bruguiére) Dosinia (Dosinidia) concentrica prosapia Weisbord, n. subsp. Anomalocardia brasiliana (Gmelin) Anomalocardia venezuelana Weisbord, n. sp. Tivela (Tivela) mactroides (Born) Tivela (Planitivela) venezuelana Weisbord, n. sp. Gouldia venezuelana Weisbord, n. sp. Gouldia ? diffidentia Weisbord, Nn. sp. Transennella caboblanquensis Weisbord, n. sp. Transennella venezuelana Weisbord, n. sp. Macrocallista maculata (Linnaeus) Pitar (Pitar) albida (Gmelin) Pitar (Pitar) maiquetiensis Weisbord, n. sp. Pitar (Pitar ?) antillensis Weisbord, n. sp. Pitar (Nanopitar ?) marensis Weisbord, n. sp. Pitar (Pitarella ?) scutellaris Weisbord, n. sp. Pitar (Hysteroconcha) dione (Linnaeus) Periglypta aff. listeri (Gray) Antigona (Ventricolaria) aff. rigida Dillwyn Antigona (Ventricolaria) rugatina (Heilprin) Chione (Chione) cancellata (Linnaeus) Chione (Chione) pailasana Weisbord, n. sp. Re; Ab; PGm Middle Miocene—Recent Re Pleistocene—Recent Sal; Ab Recent Re; Ab Recent Ab Ma Ma Re; Sal; Ma; PGm Pliocene—Recent PGm; Ma Pliocene—Recent PGm; Ma Re; PGm Middle Miocene—Recent Ma Ma Pliocene—Recent Ma; PGm; PGc Sal Upper Miocene—Recent Sal ; Re; Ab Pleistocene—Recent Ma PGm; Ma Ma PGm; Ma PGm Sal; Ma; PGm PGc Lower Miocene—Recent Sal Pliocene—Recent Ma Ma Ma Ma Re; Ab; Ma _ Pliocene—Recent Ma Pleistocene—Recent PGm Pliocene—Recent Pliocene—Recent PGm Miocene—Recent 14 BuLuLeTin 204 Chione (Chione ?) mamoensis Weisbord, n. sp. Chione (Chione ?) laciniosa Weisbord, n. sp. Chione (Timoclea) tacaguana Weisbord, n. sp. Chione (Chionopsis) subrostrata (Lamarck) Chione (Lirophora) riomaturensis Maury Chione (Lirophora) cultellata Weisbord, n. sp. Petricola (Naranio) lapicida (Gmelin) Petricola (Rupellaria) typica (Jonas) Pleiorytis venezuelensis Weisbord, n. sp. Tellina (Tellina ?) sp. indet. Tellina (Eurytellina) punicea Born Tellina (Eurytellina) nitens C. B. Adams Tellina (Eurytellina) alternata ? Say Tellina (Merisca) cristallina Spengler Strigilla pisiformis (Linnaeus) Strigilla carnaria (Linnaeus) Macoma (Psammacoma) hybrida Weisbord, n. sp. Semele purpurascens (Gmelin) Semele proficua (Pulteney) Semelina nuculoides (Conrad) Donax denticulatus Linnaeus Donax striatus Linnaeus Donax higuerotensis Weisbord, n. sp. Donax vagus Weisbord, n. sp. Donax marensis Weisbord, n. sp. Sanguinolaria (Psammotella) operculata (Gmelin) Tagelus plebeius (Solander) Solen (Solena) obliquus Spengler Solen species Solecurtus cumingianus (Dunker) Mactra (Mactrellona ?) iheringi (Dall) Mulinia cleryana (d’Orbigny) Labiosa (Raeta) aff. plicatella (Lamarck) Ervilia nitens venezuelana Weisbord, n. subsp. Ervilia antilleana Weisbord, n. sp. Ervilia caribbeana Weisbord, n. sp. Ervilia mareana Weisbord, n. sp. Corbula (Juliacorbula) aequivalvis Philippi Ma Re; Ab Re; Ab; PGm Recent Pliocene Pliocene—Recent Pliocene—Recent Pliocene ?, Recent Recent Upper Miocene—Recent Mid. Miocene ?—Recent Lower Miocene—Recent Pleistocene—Recent Upper Miocene—Recent Pliocene—Recent Upper Miocene—Recent Pleistocene—Recent Pliocene—Recent Recent Recent Upper Miocene—Recent Miocene—Recent Pliocene—Recent Recent Recent Upper Miocene—Recent Pliocene—Recent VENEZUELAN CENOzoIC PELECYPoDS: WEISBORD 15 Corbula (Caryocorbula) cf. lavalleana d’Orbigny Sal; Ma Pliocene—Recent Corbula (Notocorbula) bruscasensis Weisbord, n. sp. PGm Corbula (Notocorbula) punta- gordensis Weisbord, n. sp. Ma Martesia striata (Linnaeus) Re Pliocene—Recent Periploma margaritacea (Lamarck) Re; Ma Recent Cyathodonta cf. tristani Olsson PGm; PGc Middle—upper Miocene Pholadomya cf. candida Sowerby PGc Pleistocene—Recent RECENT PELECYPODS FROM PLAYA GRANDE AND HIGUEROTE Dead shells of Recent bivalves were collected on the beach west of the breakwater at Playa Grande in the Distrito Federal (Fig. 2), and on the beach southeast of the town of Higuerote in the State of Miranda. The air-line distance between the beaches is 102 kilometers. At neither locality are the shells especially abundant. The beach southeast of Higuerote is sandy, and shelves gently sea- ward, whereas much of the shore at Playa Grande is floored with Quaternary beachrock. The beachrock extends seaward as well as landward, and the littoral marine mollusks are mostly gastropods. Conversely, the sandy bottom at Higuerote is more favorable for pelecypods and these outnumber the species of gastropods. At both localities the intertidal zone is narrow, and the difference in tide level is small. The surface salinity of the seawater is of the order of 36.5 parts per thousand during July-September, and the average monthly air temperature, as recorded by the U.S. Weather Bureau from shipboard observations, varies from 87.5°F. in February to 82.8°F. in September. According to Donn S. Gorsline® of the Oceano- graphic Institute at Florida State University, the air temperature compares closely with the surface temperature of the ocean in this general area. At a depth of 200 meters the temperature is about 59°F., and this is fairly constant. The main thermal variation in seawater is confined to the uppermost 50 to 60 meters. Below is a list of the pelecypods collected at Playa Grande and Higuerote. Species Playa Grande Higuerote Arca (Arca) zebra Swainson x Arca (Arca) imbricata Bruguiére x 8’Written communication dated 9 May 1958. 16 BuLueTin 204 Barbatia (Barbatia) candida (Helbling) Barbatia (Acar) domingensis (Lamarck) Barbatia (Fugleria) tenera (C. B. Adams) Arcopsis adamsi “Shuttleworth” (E. A. Smith) Anadara (Larkinia) notabilis (Roding) Anadara (Lunarca) ovalis (Bruguiére) Anadara (Cunearca) brasiliana (Lamarck) Anadara (Cunearca) chemnitzi (Philippi) Glycymeris (Glycymerella) decussata (Linnaeus) Brachidontes (Ischadium) recurvus (Rafinesque) Modiolus americanus Leach Isognomom alatus (Gmelin) Atrina (Servatrina) seminuda (Lamarck) Chlamys (Chlamys) ornata (Lamarck) Lima (Limaria) pellucida C. B. Adams Ostrea (Crassostrea) virginica Gmelin Ostrea (Crassostrea) species Ostrea (Crassostrea) rhizophorae Guilding Cardita (Carditamera) gracilis Shuttleworth Mytilopsis leucophaeatus ? Conrad Diplodonta (Diplodonta) semiaspera Philippi Codakia (Jagonia) orbiculata (Montagu) Codakia (Jagonia) pectinata (C. B. Adams) Chama congregata Conrad Chama macerophylla Gmelin Chama florida Lamarck Pseudochama radians (Lamarck) Trachycardium (Dallocardia) muricatum (Linnaeus) Trigoniocardia (Americardia) media (Linnaeus) Tivela (Tivela) mactroides (Born) Pitar (Hysteroconcha) dione (Linnaeus) Antigona (Ventricolaria) rugatina (Heilprin) Chione (Chione) cancellata (Linnaeus) Chione (Chionopsis) subrostrata (Lamarck) Petricola (Rupellaria) typica (Jonas) Strigilla pisiformis (Linnaeus) Strigilla carnaria (Linnaeus) Semele purpurascens (Gmelin) Semele proficua (Pulteney) Donax denticulatus Linnaeus Donax striatus Linnaeus Donax higuerotensis Weisbord, n. sp. Sanguinolaria (Psammotella) operculata (Gmelin) Tagelus plebeius (Solander) Solen (Solena) obliquus Spengler Mactra (Mactrellona ?) iheringi (Dall) Mulinia cleryana (d’Orbigny) Martesia striata (Linnaeus) Periploma margaritacea (Lamarck) xX PA PS PA PA PS Pd PS Bd Bd DX BA PS i lala PA 4 PA PS PSPS PS PS PSS m4 MMrM MM al at a ao a PA Pd PA PS PS PM Pd Bd PELECYPODS FROM LA SALINA DE GUAIGUAZA For the little geologic information available on the area around the salt pond known as La Salina de Guaiguaza the reader is referred VENEZUELAN CENOozoIcC PELECYPoDS: WEISBORD 17 to my 1962 paper. All of the fossils at La Salina were collected from gray and brown clays at a depth of about one meter below the surface, in a drainage ditch near the south end of the pond. The pelecypods obtained there are the following: Geologic range Geologic range of Species or known species nearest related species Arca (Arca) imbricata Bruguiére Low. Miocene—Recent Arcopsis adamsi “Shuttle- worth” (E. A. Smith) Low. Miocene—Recent Ostrea (Ostrea) libella Weisbord, n. sp. Pleistocene—Recent Ostrea (Ostrea) caraboboen- sis Weisbord, n. sp. Lower Miocene Lucina (Lucinisca) muricata (Spengler) Pliocene—Recent Chama sinuosa bermudensis Heilprin Recent Trachycardium (Dallocar- dia) muricatum (Linnaeus) Pliocene—Recent Anomalocardia brasiliana (Gmelin) Up. Miocene—Recent Anomalocardia venezuelana Weisbord, n. sp. Up. Miocene—Recent Macrocallista maculata (Linnaeus) Low. Miocene—Recent Pitar (Pitar) albida (Gmelin) Pliocene—Recent Chione (Chione) cancellata (Linnaeus) Miocene—Recent Corbula (Juliacorbula) quivalvis Philippi Mid-Miocene-Recent Corbula (Caryocorbula) cf. lavalleana d’Orbigny Pliocene—Recent Fourteen species of pelecypods were collected, and 11 of them, or 78 per cent are living today. Of the gastropods obtained from the same clays (Weisbord, 1962), 9, or 36 per cent are living to-day, and it is anticipated that some of the new species of gastropods will eventually be found in the Recent fauna. Combining the gastropods and pelecypods, 51 per cent of the 39 species collected at La Salina are known to be still extant. Applying Lyell’s principle for the sub- division of the Cenozoic era into epochs, but without putting too fine a point on it, the percentage of mollusks in the La Salina fauna which have survived to the present, suggests that the Guaiguaza clays are Pliocene—probably late Pliocene—in age. 18 BuLueTin 204 THE CABO BLANCO GROUP STRATIGRAPHY The Cabo blanco group is a sedimentary complex forming the terrain between the Venezuelan Coast Range and the Caribbean Sea, and occupying a narrow east-west belt between La Guaira and Catia La Mar in the Distrito Federal. The stratigraphy of the Cabo Blanco group is summarized in the following table. Thickness Formation (meters) Description Sub-Recent and Bench- forming _ beachrock Quaternary a and reefs, and reworked clays, sands, and gravels. Abisinia formation 13 (max.) Clays, silts, sands, and grav- els. Locally with fossils. Disconformity Mare formation 19 (max.) Friable grits at base, soft siltstones above. Highly fos- siliferous. Unconformity Maiquetia member + 34 Shales, siltstones, calcareous sandstones, and conglomer- ates. Bioherms of coralline algae. Other fossils moder- Playa ately abundant. Grande Catia member 156-233 Calcareous ssiltstones and formation sandstones, conglomerates, some shales and limestones, and occasional coquinas. Fos- sils, often as molds and casts. Unconformity Las Pailas formation 375 + Non-fossiliferous mudstones, siltstones, sandstones, and conglomerates (Fig. 1). Noteworthy features of the section at Cabo Blanco are 1) the beds of subrecent to Recent beachrock, and 2) the fossil bioherms and biostromes of calcareous algae. The beachrock (Fig. 2) occurs along the shore and is especially well displayed from the mouth of Quebrada Las Pailas westward to the Playa Grande Yachting Club. The beachrock is essentially a beach conglomerate composed of such beach debris as rocks, shells, and reef-dwelling remains which VENEZUELAN CENOZzOIC PELECYPoDS: WEISBORD 19 have been cemented by calcium carbonate. Inland from the shore- line, the Cabo Blanco beachrock forms the floor of some of the small streams near their debouchment, and seaward from the shore- line the beachrock may extend some scores of meters to form the sea bottom. The planed surface of the beachrock indicates marine abrasion, and the dip of the beachrock is at a low angle toward the sea. If memory serves me correctly, I recall having seen a bottle- cap or some man-made contrivance cemented by calcareous car- bonate into the beachrock, and this would mean that the processes of calcium carbonate precipitation and cementation are going on to-day. The problem of beachrock formation has aroused consider- able interest in recent years, and a study of the occurrences along the shore at Cabo Blanco may prove to be informative. Bioherms and biostromes of calcareous algae are present in some abundance in the Playa Grande formation, especially in the Maiquetia member. The largest bioherm, observed in this member occurs at W-23 on the north flank of the Punta Gorda anticline (see geologic map in Weisbord, 1957) where it is 150 meters long and about 2 meters thick. The bioherm here (Figs. 6, 7) is composed of cemented spherular masses of an undetermined species of orange- colored alga which seems to belong to the family Corallinaceae and which I have referred to under the catch-all generic name of Litho- thamnium. Some 400 meters southwest of the orange bioherm is a northeasterly striking ridge of a white algal limestone 90 meters or so in length, and there are several similar thin, southdipping algal limestones outropping in the upper course of Quebrada Las Pailas. A small exposure of algal limestone was observed east of the Playa Grande Yachting Club in the Catia member of the Playa Grande formation, and individual spherules of calcareous algae have been collected at several places in the Mare formation. PELECYPODS OF THE ABISINIA FORMATION The youngest formation of the Cabo Blanco group proper is the Abisinia. The following species of pelecypods were found in it @Fies'3): 20 BuL_eTin 204 Geologic range Geologic range of Species of known species nearest related species Arca (Arca) zebra abisini- ana Weisbord, n. subsp. Mid. Miocene—Recent Arca (Arca) imbricata Bruguiére Low. Miocene—Recent Barbatia (Barbatia) candida Helbling Low. Miocene—Recent Barbatia (Acar) domingen- sis (Lamarck) Low. Miocene—Recent Pinna aff. carnea Gmelin Pliocene ?—Recent Cardita (Carditamera) gracilis Shuttleworth Recent Codakia (Lentillaria) orbic- ularis (Linnaeus) Mid. Miocene—Recent Chama congregata Conrad Mid. Miocene—Recent Chama macerophylla Gmelin Mid. Miocene—Recent Chama sinuosa bermudensis , Heilprin Recent Pseudochama radians (Lamarck) Recent Pseudochama ? species Recent Tivela (Tivela) mactroides (Born) Pleistocene—Recent Pitar (Hysteroconcha) dione (Linnaeus) Pliocene—Recent Chione (Chione ?) mamoen- sis Weisbord, n. sp. Recent Petricola (Rupellaria) typica (Jonas) Pliocene—Recent Strigilla pisiformis (Linnaeus) Low. Miocene—Recent Strigilla carnaria (Linnaeus) Pleistocene—Recent Of the 18 species recorded, 15, or 83 per cent are living to-day. At least one of the remaining three species of pelecypods may even- tually prove to be the same as a living form, and that would raise the number to 16, or 90 percent which have survived to Recent time. Taking the gastropods into account, 27, or 7/7 per cent of the 35 species collected from the Abisinia formation have survived to Recent time, and this figure might be as high as 88 per cent. Combining the totals, 79 to 89 percent of the 53 species thus far identified have continued their existence to the present, and these percentages indicate that the Abisinia formation is Pleistocene— possibly early Pleistocene—in age. PELECYPODS OF THE MARE FORMATION The Mare formation disconformably underlies the Abisinia for- VENEZUELAN CENOZOIC PELECYPODS: WEISBORD 21 mation. The species of pelecypods collected from the Mare formation are listed below. Geologic range Geologic range of Species of known species nearest related species Nucula (Nucula) vene- ‘ : zuelana Weisbord, n. sp. Mid. Miocene Nucula (Ennucula) mareana : Weisbord, n. sp. Miocene ?, Recent Nuculana (Saccella) karl- ‘ martini Weisbord, n. sp. Miocene—Recent Nuculana (Saccella) axelols- : . soni Weisbord, n. sp. Mid. Miocene, Recent Nuculana (Saccella) marella \ ¢ Weisbord, n. sp. Mid. Miocene, Recent Adrana cf. tellinoides (Sowerby) Recent Anadara (Lunarca) ovalis : (Bruguiére) Up. ? Miocene—Recent Anadara (Lunarca ?) cabo- blanquensis Weisbord, n. : ap. Up. Miocene—Recent Anadara (Lunarca ?) ‘ mareana Weisbord, n. sp. Up. Miocene—Recent negara sf Cuncarca) Mid. ? Miocene—Pliocene Glycymeris (Glycymeris) . undata (uinnzecs) Miocene—Recent Glycymeris (Tucetona - 4 eae (Gmelin) ) Mid. Miocene—Recent Glycymeris (Glycymerella) decussata (Linnaeus) Mid. Miocene—Recent Musculus lateralis (Say) Pliocene—Recent Crenella divaricata A (d’Orbigay) Up. Miocene—Recent Lioberus ? marensis Weisbord, n. sp. Recent Pliocene ?—Recent Pinna aff. carnea Gmelin Zs Pliocene—Recent Plicatula gibbosa Lamarck Plicatula caribbeana Weisbord, n. sp. Miocene—Recent Pecten (Pecten) caribeus Weisbord, n. sp. Oligocene—Pliocene Pecten (Pecten) maiquetien- sis Weisbord, n. sp. Mid. Miocene, Recent Pecten (Euvola) ziczac caboblancoensis Drucker- : man Pliocene Pecten (Amusium) marensis Weisbord, n. sp. Oligocene ?—Recent Chlamys (Leptopecten) de- sultoria Weisbord, n. sp. Up. Miocene—Pliocene 22 Chlamys (Argopecten) gib- bus antecessor Weisbord, n. subsp. Lyropecten (Nodipecten) species “a” Anomia mareana Weisbord, D. sp. Pododesmus rudis (Broderip) Ostrea (Ostrea) lixula Weisbord, n. sp. Ostrea (Alectryonia) ves- pertina venezuelana Weisbord, n. subsp. Ostrea (Alectryonia ?) caboblanquensis Weisbord, n. sp. Eucrassatella (Hybolophus) antillarum Reeve Crassinella aduncata Weisbord, n. sp. Crassinella triquetra Weisbord, n. sp. Cardita (Carditamera) gracilis Shuttleworth Venericardia (Glyptoactis) wendellwoodringi Weisbord, n. sp. Diplodonta (Diplodonta) mareana Weisbord, n. sp. Lucina (Cavilinga) trisul- cata blanda (Dall and Simpson) Lucina (Bellucina) kather- inepalmerae Weisbord, n. sp Lucina (Parvilucina) eph- raimi Weisbord, n. sp. Codakia (Jagonia) umboni- costata Weisbord, n. sp. Bornia tacaguana Weisbord, n. sp. Chama congregata Conrad Echinochama species “a” Echinochama species “b” Trachycardium (Dallo- cardia) muricatum (Linnaeus) Trachycardium (Trachy- cardium) cf. isocardia (Linnaeus) Trigoniocardia (Trigonio- cardia) caboblanquensis Weisbord, n. sp. Laevicardium ? species BuLieTin 204 Miocene—Recent ? Mid. Miocene—Recent Pliocene—Recent ’ é Low. Miocene, Mid. Pliocene Pliocene Miocene—Recent Pliocene—Recent Up. Miocene Up. Miocene Recent Miocene, Recent Pliocene ?—Recent Recent Pleistocene—Recent Mid. Miocene—Recent Mid. Miocene Recent Mid. Miocene—Recent Pliocene—Pleistocene Miocene—Recent Pliocene—Recent Pliocene—Recent Low.-mid. Miocene, Pliocene, Pleistocene Pliocene—Recent VENEZUELAN CENozoIc PELECYPODS: WEISBORD 23 Papyridea aff. soleniformis (Bruguiére) Pliocene—Recent Dosinia (Dosinidia) con- centrica prosapia Weisbord, n. subsp. Up. Miocene—Recent Tivela (Planitivela) vene- zuelana Weisbord, n. sp. Recent Gouldia venezuelana Weisbord, n. sp. Mid. Miocene Gouldia diffidentia Weisbord, n. sp. ? Transennella caboblanquen- sis Weisbord, n. sp. Recent Macrocallista maculata (Linnaeus) Low. Miocene—Recent Pitar (Pitar) maiquetiensis Weisbord, n. sp. Recent Pitar (Pitar ?) antillensis Weisbord, n. sp. Recent Pitar (Nanopitar ?) marensis Weisbord, n. sp. Recent Pitar (Pitarella ?) scutel- laris Weisbord, n. sp. Pleistocene—Recent Pitar (Hysteroconcha) dione (Linnaeus) Pliocene—Recent Periglypta aff. listeri (Gray) Pleistocene—Recent Chione (Chione) cancellata (Linnaeus) Miocene—Recent Chione (Chione ?) laciniosa Weisbord, n. sp. Mid. Miocene Chione (Lirophora) rioma- turensis Maury Pliocene Chione (Lirophora) cultel- Up. Oligocene—Low. lata Weisbord, n. sp. Miocene Pleiorytis venezuelensis Weisbord, n. sp. Mid.-up. Miocene, Recent Tellina (Eurytellina) punicea Born Pliocene ?, Recent Tellina (Eurytellina) nitens C. B. Adams Recent Tellina (Merisca) cristallina Spengler Mid. Miocene ?—Recent Macoma (Psammacoma) hybrida Weisbord, n. sp. Pliocene—Recent Semele proficua (Pulteney) Pliocene—Recent Donax vagus Weisbord, Nn. sp. Pliocene, Recent Donax marensis Weisbord, n. sp. Up. Miocene—Recent Solen species Pliocene—Recent Solecurtus cumingianus (Dunker) Pliocene—Recent Ervilia nitens venezuelana Weisbord, n. subsp. Recent 24 BuLLETIN 204 Ervilia antilleana Weisbord, n. sp. Recent Ervilia mareana Weisbord, n. sp. Corbula (Caryocorbula) cf. lavalleana d’Orbigny Pliocene—Recent Corbula (Notocorbula) puntagordensis Weisbord, Nn. sp. Pliocene—Recent Periploma margaritacea (Lamarck) Recent Pliocene—Recent The total number of pelecypods listed above is 82, and of this number 32, or 39 per cent are living to-day. Among the new species and subspecies described by this writer, at least four might be considered by some paleontologists to be identical with known Re- cent species, as in borderline cases of identity there is a judgment factor involved. If these are added to the list, the number of Recent species of pelecypods would come to 36, or 44 per cent. Adding two more species that might eventually be found as having survived to the present, the number of Recent pelecypods in the Mare formation would be 38, or 46 per cent. A comparable analysis of the 144 species of gastropods from the Mare formation (Weisbord, 1962) indicates that only 25, or 17 percent are living to-day; however 15 others are borderline and might be the same as Recent forms, and an additional 10 species may yet be found in the Recent fauna. This would bring the number of Recent gastropods in the Mare forma- tion to 50, or 34 per cent. Combining the gastropods and pelecypods (226 species) collected from the Mare formation, the minimum num- ber of species living to-day is 57, or 25 per cent, but because of the subjective bias inherent in identification, and the probability that a certain number of Mare species will be found in the Recent fauna, the number of surviving gastropods and pelecypods could be 88, or 34 per cent. Considering the geologic range of known species to which the new species are most closely related, it is seen that the overwhelming majority of the related species range from middle Miocene to Recent and that 46 per cent (105 out of 226 gastropods and pelecypods) of those are known from the Recent fauna. Based in part, then, on Lyell’s percentage principle as well as on strati- graphy, and considering the similarity of the distinct species to geologically young forms, the mollusks in the Mare formation suggest VENEZUELAN CENOozoIc PELECYPops: WEISBORD 25 that the Mare formation is Pliocene—possibly lower Pliocene—in age. PELECYPODS OF THE PLAYA GRANDE FORMATION MAIQUETIA MEMBER Unconformably below the Mare formation is the Playa Grande formation. The Playa Grande formation is made up of two members, the Maiquetia (Fig. 8) above, and the Catia (Fig. 4) below. The pelecypods from the Maiquetia member of the Playa Grande forma- tion are the following: q Geologic range of Geologic range nearest related Species of known species species Nucula (Nucula) venezuelana Weisbord, Nn. sp. Nuculana (Saccella) karlmartini Weisbord, n. sp. Miocene ?—Recent Nuculana (Saccella) axelolssoni Weisbord, Middle Miocene n. sp. Middle Miocene—Recent Anadara (Larkinia) notabilis (Réding) Middle Miocene—Recent Anadara (Lunarca ?) caboblanquensis Weisbord, n. sp. Upper Miocene—Recent Anadara (Cunearca) cumanensis (Dall) M. Miocene ?—Pliocene Glycymeris (Glycymeris) undata (Linnaeus) Miocene—Recent Glycymeris (Glycymerella) decussata (Linnaeus) Middle Miocene—Recent Crenella divaricata (d’Orbigny) Upper Miocene—Recent Plicatula gibbosa Lamarck Pliocene—Recent Plicatula venezuelana Weisbord, n. sp. Recent Pecten (Pecten ?) remulus Weisbord, n. sp. Upper Miocene—Pliocene Pecten (Euvola) ziczac caboblancoensis Druckerman Pliocene Chlamys (Argopecten) gibbus antecessor Weisbord, n. subsp. Miocene—Recent Spondylus americanus Hermann Pliocene—Recent 26 BuLueTin 204 Ostrea (Ostrea) pannucea Weisbord, n. sp. Pleistocene—Recent Ostrea (Alectryonia) vespertina venezuel- ana Weisbord, n. subsp. Pliocene Ostrea (Alectryonia ?) caboblanquensis Weisbord, n. sp. Miocene—Recent Ostrea (Agerostrea ?) antecursor Weisbord, n. Sp. Middle Miocene—Recent Venericardia (Glyptoactis) wendellwoodringi Weisbord, n. sp. Miocene—Recent Lucina (Callucina ?) species Recent Lucina (Parvilucina) ephraimi Weisbord, n. sp. Middle Miocene—Recent Lucina (Parvilucina) multilineata Tuomey and Holmes Upper Miocene—Recent Codakia (Lentillaria) orbicularis (Linnaeus) Middle Miocene—Recent Chama congregata Conrad Middle Miocene—Recent Chama macerophylla Gmelin Middle Miocene—Recent Trachycardium (Dallo- cardia) muricatum (Linnaeus) Pliocene—Recent Tracycardium (Trachy- cardium) cf. isocardia (Linnaeus) Pliocene—Recent Trigoniocardia (Trigonio- cardia) caboblanquensis Lower—middle Miocene, Weisbord, n. sp. Pliocene, Pleistocene Trigoniocardia (Ameri- cardia) media (Linnaeus) Middle Miocene—Recent Dosinia (Dosinidia) concentrica prosapia Weisbord, n. subsp. Upper Miocene—Recent Gouldia venezuelana Weisbord, n. sp. Middle Miocene Transennella cabo- blanquensis Weisbord, n. sp. Recent Transennella venezuelana Weisbord, n. sp. Upper Miocene—Pliocene Macrocallista maculata (Linnaeus) Lower Miocene—Recent Antigona (Ventricolaria) aff. rigida Dillwyn Pliocene—Recent Chione (Chione) cancellata (Linnaeus) Miocene—Recent VENEZUELAN CENOzoIC PELECYPODS: WEISBORD aT Chione (Chione) pailasana Weisbord, n. sp. Middle Miocene Chione (Chione ?) mamoensis Weisbord, n. sp. Recent Chione (Timoclea) tacaguana Weisbord, n. sp. Miocene—Recent Petricola (Naranio) lapicida (Gmelin) Pliocene—Recent Tellina (Tellina ?) sp. indet. Recent Tellina (Eurytellina) nitens C. B. Adams Recent Tellina (Eurytellina) alternata ? Say Upper Miocene—Recent Strigilla carnaria (Linnaeus) Pleistocene—Recent Semelina nuculoides (Conrad) Upper Miocene—Recent Solecurtus cumingianus (Dunker) Pliocene—Recent Labiosa (Raeta) aff. plicatella (Lamarck) Upper Miocene—Recent Ervilia nitens venezuelana Weisbord, n. subsp. Recent Ervilia antilleana Weisbord, n. sp. Recent Ervilia caribbeana Weisbord, n. sp. Middle Miocene, Recent Corbula (Notocorbula) bruscasensis Weisbord, Upper Oligocene—lower n. sp. Miocene Cyathodonta cf. tristani Olsson Middle—upper Miocene Of the 53 species of pelecypods from the Maiquetia member listed above, 23, or 43 per cent are living to-day. Another six forms are separated from known Recent species by such slight differences that some paleontologists might consider them the same and there- by increase the ratio to 55 per cent. Speculating further, it may not be unreasonable to assume that two of the remaining species will be found eventually in the Recent fauna, and this would bring the total number of Recent pelecypods in the Maiquetia member to 31, or 58 per cent. A similar analysis of the 82 species of gastropods col- lected from the Maiquetia member indicates that 10 to 28 per cent of those mollusks occur in the Recent faunal assemblage. Combining the data to include both gastropods and pelecypods, the number of species livng to-day is 31, or 24 per cent, but could be as high as 54, 28 BuL.eTiIn 204 or 40 per cent. The great majority of analogous but distinct species of gastropods and pelecypods of the Maiquetia member range from Miocene to Recent, and of these analogues 66 per cent occur in the Recent. Equating the percentage bracket with geologic time, and taking into consideration its stratigraphic position, the Maiquetia member of the Playa Grande formation is believed to be Pliocene— probably lower Pliocene—in age. The unconformity between the Maiquetia member and the overlying Mare formation suggests a longer time interval than is actually evidenced by the faunal assem- blages in each, and it must be concluded that the time span between the erosion of the Maiquetia member and the initial deposition of the Mare formation was geologically short. CATIA MEMBER Because of faults and Quaternary cover, the stratigraphic re- lationship of the Catia and Maiquetia members is not clearly estab- lished. Indirect evidence, however, suggests that the Catia member makes up the lower and preponderant part of the Playa Grande formation, the Maiquetia member the upper. The fossils collected from the Catia member are the following: Geologic range of Geologic range of nearest related Species known species Species Nuculana (Saccella) species ry Nuculana (Jupiteria ?) species Middle Miocene Anadara (Larkinia) species Miocene—Recent Atrina (Servatrina ?) aff. seminuda (Lamarck) Miocene ?, Recent Atrina (Servatrina) serrata ? (Sowerby) Lower Pliocene—Recent Pecten (Pecten) catianus Oligocene—middle Weisbord, n. sp. Miocene Pecten (Pecten) species Oligocene—Pliocene, Recent Pecten (Euvola) ziczac caboblancoensis Druckerman Pliocene Pecten (Amusium) papyraceus (Gabb) Oligocene ?—Recent Chlamys (Chlamys) benedicti Verrill and Bush Recent VENEZUELAN CENOZOIC PELECYPODS: WEISBORD Aequipecten muscosus (Wood) Chlamys (Argopecten) gibbus antecessor Weisbord, n. sp. Chlamys (Argopecten) imitata Weisbord n. sp. Lyropecten (Nodipecten) nodosus ? (Linnaeus) Lyropecten (Nodipecten) arnoldi Aguerrevere Lyropecten (Nodipecten) species “b” Spondylus americanus Hermann Anomia catiana Weisbord, Nn. sp. Ostrea (Ostrea) lixula Weisbord, n. sp. Ostrea (Alectryonia) vespertina venezuelana Weisbord, n. subsp. Ostrea (Alectryonia ?) caboblanquensis Weisbord, n. sp. Divaricella ? species Dosinia (Dosinidia) concentrica prosapia Weisbord, n. subsp. Macrocallista maculata (Linnaeus) Cyathodonta cf. tristani Olsson Pholadomya cf. candida Sowerby 29 Pliocene—Recent Miocene—Recent Middle Miocene—Recent Low. Miocene ?—Recent Pliocene Miocene—Pliocene Pliocene—Recent Middle Eocene, Miocene —Recent Miocene, Pliocene Lower middle Pliocene Miocene—Recent Miocene—Recent Upper Miocene—Recent Lower Miocene—Recent Middle—upper Miocene Pleistocene—Recent Of the 26 species of pelecypods from the Catia member, 8, or 31 per cent are also Recent. Two other species are so close to living forms that they might be considered the same by some paleontolo- gists, and that would bring the total of Catia species surviving to the present to 10, or 40 per cent. Of the six gastropod species de- scribed from the Catia member, none was identified by the writer to occur in the Recent although two, or 33 per cent are in the border- line category. If the gastropods and pelecypods are considered joint- ly, the species in the Catia member that are living to-day range, depending on the judgment factor, from 25 to 37 per cent. In my work on the gastropods (Weisbord, 1962) I stated that the gastro- pods from the Catia member were too few in number to arrive at an age determination, though on the basis of relationship and strati- 30 BuLLETIN 204 graphic position they might be indicative of the later Miocene. Now, however, with the data of both the gastropods and pelecypods at hand, I am inclined to consider the Catia member of the Playa Grande formation as lower Pliocene in age. GEOLOGIC AGE OF FORMATIONS The succession of formations as determined in the field by the writer is given below. The geologic age assigned to these formations is based on the fossils thus far determined and on stratigraphy. In the chronological analysis of known species, the Lyellian percentage method of subdividing the Cenozoic era into epochs has been ap- plied; in the analysis of new species, considerable weight has been given to the geologic range of the nearest analogues. Percentage of La Salina de surviving Presumed Guaiguaza Cabo Blanco Group species geologic age Coastal beachrock Not determined Subrecent-Recent Disconformity ? Abisinia formation 79-89 Pleistocene Disconformity Guaiguaza Clay ea 8e Se eo eer ene 2 50+ Upper Pliocene Mare formation 25-34 Lower Pliocene Unconformity Playa Grande Maiqueti member 24-40 Lower Pliocene formation (Catia member 25-37 Lower Pliocene Unconformity Las Pailas formation Unfossiliferous Middle Tertiary Probable unconformity In the table, the percentages of the species still living apply only to the combined totals of the gastropods and pelecypods described thus far by the writer. The Abisinia formation is assigned a Pleisto- cene age by virtue of the high percentage of living forms as well as by its superior stratigraphic position. Stratigraphic control of the Guaiguaza clay is wanting, but with at least 50 per cent of the mollusks having survived to Recent time, a late Pliocene age is indi- cated. In the analysis of the pre-Pleistocene formations of the Cabo Blanco group, it is seen that the percentages of species which have survived to Recent time is roughly the same for both the Mare and Playa Grande formations even though the Mare formation lies VENEZUELAN CENOzoIC PELECYPODS: WEISBORD 31 above, and is separated from the Playa Grande formation by an angular unconformity. Relating these percentages to Lyell’s original division of the Tertiary, the age of these formations is postulated as lower Pliocene. As the age determinations in this work have been based in good part on the Lyellian concept of Cenozoic classification, it might not be amiss to re-state, in Lyell’s own words, the philosophic principle* behind his Tertiary timetable. Sir Charles Lyell was not only a per- ceptive observer of the geolgic scene but a logician as well. His per- sonal charm enabled him to enlist the ideas of others, and, investing these ideas with his own leaven, he could present them in lucidly written prose that is a pleasure to read. From his own observations in Italy, France, and England, and with the contributions of such colleagues as Signor O. G. Costa, Prof. Viviani, Dr. Sasso, M. Des- noyers, and particularly the then dean of paleontology M. Deshayes, Lyell, in his preface to the “Principles” (p. xiii), succinctly intro- duced his concept of geochronology in the following sentence: On my return to Paris, in February, 1829, I communicated to M. Deshayes some of the new views to which my examination of Sicily had led me, and my intention to attempt a classification of the different Tertiary formations in chronological order, by reference to the comparative proportion of living species of shells found fossil in each. | ; “eb ; : After developing and discussing the implications of his thesis, Lyell (p. 59) summarized his now well-known concept as follows: In reference to the organic remains of the different groups which we have named, we may say that about a thirtieth part [3.3 per cent] of the Eocene shells are of recent species, about one-fifth [20 per cent] of the Miocene, more than a third [33 per cent], and often more than half [50 per cent], of the older Pliocene, and nine-tenths [90 per cent] of the newer Pliocene [Pleisto- cene]. In 1855, Beyrich® proposed the term Oligocene for deposits con- taining 10 to 15 per cent of Recent species of Mollusca. No one, I think, knew better than Lyell that his classification was limned in broad strokes, but if anything, not only are Lyell’s general conclusions standing the test of time, but even his specific ranges in certain provinces are proving surprisingly close to the 4Charles Lyell, Principles of Geology, volume 3. London, John Murray, xxxi + 398 pp., + Appendix I, pp. 1-52; Appendix II, pp. 53-83; Index, pp. 85-109 +93 figs. 4 pls., 1 geol. map, 1833. 5Stellung der hessischen Tertidrbildungen. Berl. Akad. Wissensch., Monatsber. for 1854, p. 664. 32 BuLteTin 204 mark. Limitations of the Lyellian method have been discussed by Vaughan® among others, but such limitations, it seems to me, may lie in interpretation rather than in the principle itself. For example, the percentage of surviving species of Mollusca in the Mare and Playa Grande formations (lower Pliocene) is much the same as it is (32.5 per cent) for the roughly equivalent Caloosahatchee shell de- posit at North St. Petersburg, Florida, whereas, according to Dur- ham,’ the gastropods and pelecypods in the lower Pliocene San Carlos formation of Baja California which have survived to the Recent is 46 per cent based on 37 species examined. As their stand- ard, Lyell and Deshayes compared the fossils of the Italian Pliocene with the Recent mollusks of the Mediterranean; the Caloosahatchee Pliocene deposits of Florida have been compared with the Recent Western Atlantic mollusks by Heilprin, Dall, Olsson and Harbison, and others; the Cabo Blanco Pliocene fossils have been compared in my studies with the living mollusks in Western Atlantic, Caribbean, and Eastern Pacific waters; the Pliocene fossils of Baja California have been compared by Durham and predecessors with living ones in the Eastern Pacific; and the Pliocene of New Zealand has been established in part by the ratio of fossil species to the living species now inhabiting the surrounding sea. Because of such factors as geography, climate, ecology, the rate of organic change of species, the depositional and structural history, the abundance of species for statistical control, and the taxonomic discernment of the paleontolo- gist, each geologic epoch within the Cenozoic era, and each biologic province within each epoch will have its own percentage standard. Nevertheless, Lyell’s calendar is an important tool—perhaps the single most important tool—in dating the Cenozoic, and in this work I have been strongly influenced by it. NOTES ON CORRELATION At least 60 per cent (and probably a much larger proportion) of the mollusks collected from the Playa Grande and Mare forma- 6Criteria and status of correlation and classification of Tertiary deposits. Geol. Soc. Amer., Bull., vol. 35, pp. 677-742, 1924. TE. W. Scripps cruise to the Gulf of California. Pt. 2. Megascopic paleontology and marine stratigraphy. Geol. Soc. Amer., Mem. 43, p. 6, 1950. BULL. AMER. PALEONT., VOL. 45 FIGURES 1, 2 ms - oz es we 5) Fig.1. Looking west to Cabo Blanco from Punta Gorda. The gray sediments dipping to the south are in the Las Pailas formation, and are unfossiliferous. The Cabo Blanco lighthouse is on the highest hill in the background. 2 os ¥ 7 fas be! .. . Y eee, eRe oer ~ Ey ot ate ats , A. Se ON La - Fig. 2. Looking west from Cabo Blanco lighthouse. The Recent shells were collected just beyond the breakwater, upper right. The village of Playa Grande is situated on the terrace (Abisina formation) to the left of the breakwater. Subrecent to Recent beachrock is exposed here and there along the shore. BULL. AMER. PALEONT., VOL. 45 FIGURES 8, 4 Fig. 3. Fossiliferous gravels in the Abisinia formation (Pleistocene) at east- ern edge of Playa Grande village. The gravels here are overlain by red sand and are underlain by sandy limestone of the Catia member of the Playa Grande formation, forming the floor of the bulldozed area in the foreground. Fig. 4. Ae and bedded sandy iintetonie of the ‘Gate aeepee of the Playa Grande formation at west plunge of Litoral anticline, Playa Grande village. BULL. AMER. PALEONT., VOL. 45 FIGURES 5, 6 a Gd fi at 4 Fig.5. Wedge of highly fossiliferous Mare sandstone at W-25, south flank of Punta Gorda anticline. The wedge is seen at left center just above talus slope, and is overlain by non-fossiliferous cobble to boulder gravels of the Abisinia formation. oo a Per SO a es een a gence) em as “ . tee ve Fig. 6. “Lithothamnium” bioherm at W-25, north flank of Punta Gorda anti- cline, immediately overlain by poorly sorted conglomerates, both within the Maiquetia member of the Playa Grande formation. BULL. AMER. PALEONT., VOL. 45 FIGURES 7, 8 Fig. 7. Close-up of “Lithothamnium” bioherm shown in fig. 6. The mollusks collected in the immediate area were found on and near the bioherm. the Maiquetia member of the Playa Grande formation, on which are draped cobble to boulder gravels of the Abisinia formation. VENEZUELAN CENOzOIC PELECYPoDS: WEISBORD 33 tions of the Cabo Blanco group are identical with the fossils con- tained in Collection No. 18408 of the U. S. National Museum, from near Cumana, Venezuela. The Cumana fossils were collected by P. Henry and J. A. Tong in September 1931, from a point 2.5 kilo- meters N 80°E from the Cumana Castle and S 30°W from the village of Caiguire Abajo, in yellowish brown marl about 30 feet thick, dipping steeply northward. Although the Cumana locality is 310 kilometers (186 miles) east of the type locality of Playa Grande-Mare formations, there are so many of the same species in common that the deposits in question are believed to be directly contemporaneous. The strata in which the U.S. National Museum’s fossils in Collection No. 18408 occur are included in the formation known as the Cumana beds. There is an excellent discussion of this formation by Frances de Rivero in the Stratigraphical Lexicon of Venezuela (English edition), and in the Lexicon the Cumana beds is assigned an age of upper Miocene or lower Pliocene. An advocate for the Pliocene is Wendell P. Woodring,’ and his analysis is sus- tained first by the percentage of living species, secondly by the relatively large number of analogous but distinct species which have survived to Recent time, and thirdly by the relative scarcity of species that are common to the upper Miocene Springvale formation of Trinidad or to the middle Miocene of the Caribbean area. Granting the equivalence of the Playa Grande-Mare formations and Cumana beds, and their Pliocene age, there remains the question of correlating these formations with others within and around the Caribbean province. Among the more highly fossiliferous deposits that have been considered Pliocene in age are 1) the Caloosahatchee formation of Florida, 2) the Moin formation of Costa Rica, 3) the Matura formation of Trinidad, and 4) the Punta Gavilan formation of Venezuela. 1. Caloosahatchee formation. This is believed to be equivalent, at least in part, with the remarkable shell deposit at North St. Petersburg, Florida. The fossils from North St. Petersburg have been described by Olsson, Harbison, and Pilsbry® and reported by SEED ea on and sea through the ages. Geol. Soc. Amer., Bull., vol. 65, No. 8, p. 729. ®Pliocene Mollusca of southern Florida with special reference to those from North Saint Petersburg. Acad. Nat. Sci. Philadelphia, Mon. No. 8, 457 pp., 65 pls. 1953. 34 BuL_eTin 204 them to be Pliocene in age. Of the 512 species of marine gastropods (excluding the Pyramidellidae) and pelecypods described, 165, or 32 per cent are also Recent, and 128, or 25 per cent are new. A total of 316 species has been described from the Playa Grande- Mare formations, and of this number 208, or 66 per cent are new. The proportion of Recent species in the North St. Petersburg de- posit is about the same as that in the Playa Grande-Mare forma- tions, and there are 27 species that are common to both the Floridan and Venezuelan deposits. As the assemblages of genera in both areas are similar, and as well over half of the analogous but distinct species also occur in the Recent in their respective environments, the con- temporaneity of the two during early Pliocene time is suggested. 2. Moin formation. In 1881, William M. Gabb?® named 85 species of gastropods and 45 species of pelecypods from the then- designated Limon beds near Moin in Costa Rica. Of the total (130) in the two classes, 82, or 63 per cent were believed by Gabb to be the same as Recent species, 38 species were described as new, and 10 forms were thought to be identical with Miocene species of the Caribbean area. Some of Gabb’s identifications have been revised over the years, though most paleontologists still accept Gabb’s de- termination of the Limon beds (now known as the Moin formation) as Pliocene. Only 20, or 6 per cent of the 316 species occurring in the Playa Grande-Mare formations are common to the Moin forma- tion, whereas 10, or 27 per cent of the 28 species identified in the Salina de Guaiguaza clays of Venezuela are common to the Moin formation of Costa Rica. As the proportion of Recent species (at least 50 per cent) in the Guaiguaza clay is also more nearly like that of the Moin Formation, it is inferred that these two deposits are more or less equivalent, and that their age is upper Pliocene. 3.Matura formation. According to Kugler,!! the type locality 10Descriptions of new species of fossils from the Pliocene clay beds between Limon and Moen Costa Rica, with notes on previously known species from there and elsewhere in the Caribbean area. Acad. Nat. Sci. Philadelphia, Jour., ser. 2, vol. 8, pp. 349-380, pls. 45-47. Also see Hoffstetter, 1960, [in] Lexique Stratigraphic International, vol. 5, Amérique Latine, No. 2a, Amérique Centrale, pp. 265-266. llLexique Stratigraphique International, vol. 5, Amérique Latine, No.2, Antilles, p. 75, 1958? VENEZUELAN CENOzoIC PELECYPODS: WEISBORD 35 of the Matura formation is on the east coast of Trinidad north of the Oropuche River. Typically, the Matura formation is a dark, fine- grained, calcareous sandstone some 10 feet or so in thickness, con- taining well-preserved Mollusca. Approximately 78 species of gastro- pods and pelecypods from the Matura formation were identified by Guppy, and of this number 58, or 71 percent were determined as being identical with Recent species. A later study by Maury” of 52 species of gastropods and pelecypods revealed that only 17, or 33 per cent of the Matura mollusks were the same as Recent species. It is probable that further taxonomic studies of the Matura mol- lusks will reveal that Maury’s percentage of living species should be increased, and, indeed, a number of students do attribute a late Pliocene age to the Matura formation. This would link it chrono- logically with the Moin formation of Costa Rica and the Guaiguaza clays of Venezuela. In the Playa Grande-Mare formations of the Cabo Blanco group, the proportion of living species is in the 24 to 40 per cent bracket, and only 11 (out of 316) species are common to the Matura formation. 4, Punta Gavilan formation. The most important work dealing with the molluscan fauna of this formation is a monograph by Rutsch!® on the Gastropoda. In Rutsch’s monograph a total of 58 species of gastropods are described, and of this total 19, or 33 per cent are endemic (but related to living forms), and 10, or 17 per cent are identical with, or hardly distinguishable from Recent species. Among the remainder (see Suter!+), one or two forms are known from the Pliocene only; several definite forms occur that are not known from formations older than upper Miocene; a large number of species are found elsewhere in the lower and middle Miocene, although most of these extend to the upper Miocene; and two forms are reported from the Paleocene. 124 further contribution to the paleontology of Trinidad. Bull. Amer. Paleont., vol. 25, No. 42, 250 pp., 43 pls., 1925. 13Die Gastropoden aus dem Neogen der Punta Gavilan in Nord Venezuela. Schweiz. Palaeont. Gesell., Abhandl., vols. 54-55, 169 pp., 9 pls., 1934. 14Geologic notes on the “Punta Gavilan” formation and on the eastern part of the State of Falcon. Bol. Geol. y Min., vol. 1, Nos. 2-4 (English edition), pp. 269-279, 1937 [1938]. 36 BuLueTIN 204 The type section of the Punta Gavilan formation is exposed in a bluff along the coast at Punta Gavilan, State of Falcon, Venezuela. Here, the lower two meters consist of knobby limestone with limo- nitic concretions and aggregations of well-preserved echinoids (de- scribed by Jeannet’® in 1928), and an overlying three meters of yellowish sandy limestone containing an abundant molluscan fauna, the gastropods of which were described by Rutsch. The Punta Gav- ilan formation is bounded above by Quaternary and below by the middle Miocene, and, according to Renz!® and others, its age is bracketed in the interval between late Miocene and early Pliocene time. Lithologically the Punta Gavilan beds at the type locality are similar to certain beds in the Playa Grande formation at Cabo Blanco, and a number of species of gastropods are common to both formations. For reasons mentioned earlier in the present report, this writer believes that the Playa Grande formation is lower Plio- cene in age, though initial deposition may have started toward the end of the Miocene. The proportion (17 per cent) of Recent gastro- pods in the Punta Gavilan formation is in itself too low to be indi- cative of Pliocene, but if there is a parallelism between the Punta Gavilan and Cabo Blanco areas, as I venture to presume, the per- centage of Recent mollusks in the Punta Gavilan formation will be increased by the pelecypods when they are determined. In the Playa Grande formation of the Cabo Blanco group the number of pelecy- pod species is less than the gastropods, but percentage-wise many more of the pelecypods have survived to Recent time than have the gastropods. SYSTEMATIC DESCRIPTIONS PELECY PODA NUCULIDAE Nucula (Nucula) venezuelana, new species Pl. 1, figs. 2-5 Shell minute, thin, moderately plump, obliquely subhexagonal, inequilateral. Beaks low, bluntly pointed, situated posterior to 15Contribution a étude des Echinides tertiaires de la Trinité et du Vénézuéla. Soc. Paléont. Suisse, Mém., vol. 48, pp. 1-48, 6 pls. 12 text figs. 16Punta Gavilan formation. [In] Stratigraphical Lexicon of Venezuela. Bol. Geol., Special Publ. No. 1, pp. 466-467, 1955. VENEZUELAN CENOZOIC PELECYPODS: WEISBORD 67 / center. Umbos large, somewhat inflated, the prodissoconch white and smooth. Posterior end subtruncate, ventral margin rounded (the curvature a little more pronounced near the middle), anterodorsal margin slightly convex, anterior end sharply rounded where it joins the ventral margin. There is neither a true lunule nor escutcheon, but the lunular area is large, more or less elliptical, a little de- pressed, and sculptured by raised wavy crenulate cords running at a right angle with the anterior margin of the disk. The area of the escutcheon is vaguely cordate and fairly smooth. Chondrophore small and rather shallow, its base relatively wide and gently rounded. Hinge continuous over the chondrophore, the posterior teeth num- bering 4 to 5, the anterior 9 to 13, the average 4 and 10, respectively. The anterior teeth directly above the chondrophore are the smallest, the ones on either side of the beak becoming progressively larger and longer distally up to, but not including the farthest, the teeth wedge-shaped and sharp at the tip. Interior normally with a veneer of smooth nacre, but this film is often worn off revealing the numer- ous fine radial striae of the inner layer of shell through which the concentric ribs of the exterior may sometimes be seen. Ventral margin finely and evenly denticulate, the denticles numbering 52 on the holotype. The exterior of the valve is sculptured by low regular concentric ribs which are rendered crenulate by numerous fine equal radiating threads. The concentric ribs are smaller and closer on the umbos than from the middle down; anteriorly they extend to the lunular area which they cross as somewhat irregular cords; poster- iorly they extend to the margin of the escutcheonal area but are obsolescent on the area itself. On specimens with a length of 2 mm. there are about 20-22 ribs from the base of the prodissoconch to the ventral margin. Dimensions —Holotype (G479a), left valve, length 2.7 mm.; height 2.1 mm.; thickness 0.75 mm. Paratype (G479b), left valve, length 2.1 mm.; height 2 mm.; thickness 0.6 mm. Paratype (G479c), right valve, length 1.8 mm.; height 1.6 mm., thickness 0.6 mm. Type locality—Mare formation near W-14, on hillside above west bank of Quebrada Mare Abajo. Nine specimens including six left valves and three right valves. 38 BuLueTIn 204 Other localities—Lower Mare formation at W-13, on hillside above west bank of Quebrada Mare Abajo. One right valve. Upper Mare formation, in stream 250 meters south-southwest of the mouth of Quebrada Las Pailas. One right valve. Playa Grande formation (Maiquetia member) at W-23, north flank of Punta Gorda anticline. ~ Three specimens including two right valves and one left valve. Playa Grande formation (Maiquetia member) near W-4, Quebrada Las Pailas. One right ? valve, broken. Comparisons—The distinguishing character of Nucula vene- zeulana, n. sp. is its large white prodissoconch, and this serves to differentiate the Venezuelan fossil from the following related species: N. crenulata A. Adams (1856, Zool. Soc. London, Proc., p. 52). Recent, Cape Hatteras to Barbados, 30-640 fathoms. This is also smaller and less tumid than NV. venezuelana, n. sp. N. culebrensis Smith (1885, Voyage H.M.S. Challenger, Zoology, vol. 13, p. 228, pl. 18, figs. 11, lla). Recent, off Culebra Island, West Indies in 390 fathoms. The posterior end is rounded rather than subtruncate as on JN. venezuelana, n. sp. N. dechivis Hinds (see Hertlein and Strong, 1940, Zoologica, vol. 25, pt. 4, No. 25, p. 380, pl. 1, figs. 1-3, 6-7). Recent, Mexico to Panama (Eastern Pacific), 4-30 fathoms. Subtrigonal in outline, and with less regular concentric ribs than NV. venexuelana. N. exigua Sowerby (see Hertlein and Strong, 1940, Zoologica, vol. 25, pt. 4, No. 25, p. 381, pl. 1, figs. 4-5). Recent, Baja California to Ecuador, 6-110 fathoms. Smoother than NV. venezuelana, and the posterior truncation of NV. exigua longer. N. suprastriata (Arnold, 1903, p. 96, pl. 18, fig. 6). Pleistocene, California. Similar to N. exiguwa Sowerby, but the radial striae are not so prominent. N. vieta Guppy (see Guppy, 1878, Sci. Assoc. Trinidad, Proc., p. 171, pl. 7, fig. 11). Pliocene at Matura, Trinidad. This is a subtrigonal shell, higher than long. N. baccata Guppy (see Maury, 1925b, pp. 172-173, pl. 12, fig. 5). Pliocene at Matura, Trinidad. The concentric ribs are finer than those of NV. venezuelana, n. sp. N. cahuitensis Olsson (1922, pp. 343-344), pl. 18, figs. 21-24). Middle Miocene of Costa Rica. N. venezuelana, n. sp. is close to VENEZUELAN CENOzOIC PELECYPOoDS: WEISBORD 39 N. cahuitensis especially in the general nature of the prodissoconch and the sculpture of the lunular area. However, the radial striae are more ubiquitous on N. venezuelana, and whereas N. venexuelana is rounded polyonal in outline N. cahwitensis is obliquely subtrigonal. Nucula (Ennucula) mareana, new species Pl. 1, figs. 7-10 Shell small, elongate oval, moderately inflated, inequilateral. Umbo large and full, the beak fairly low, the prodissoconch small, smooth, and white. Anterior and posterior ends sharply rounded, the posterior a little more acute than the anterior. Dorsal margin anterior to beak gently convex, the posterior strongly convex at the middle and slightly concave as it approaches the curve of the ventral margin. Ventral margin well rounded. There is neither a true lunule nor true escutcheon, but the valves are somewhat flat- tened in both areas. Chondrophore oblique, narrowly spoon-shaped, the basal margin rounded. Hinge of adult with 5-6 posterior teeth and 13-14 anterior teeth, the anterior ones enlarging progressively away from the chondrophore, the posterior ones about as large near the chondrophore as they are distally. On the left valve the posterior tooth adjacent to the chondrophore tends to be bifid, whereas on the single right valve contained in my collection that tooth is single but a trifle broader than the others. The anterior and posterior teeth away from the chondrophore are triangularly cuspate, the concave sides facing the ends of the valves. Interior (including the margin) smooth, subnacreous. A broad radial band of reinforcing shell material extends from the beak toward the pallial line. Pallial line and adductor scars scarcely visible. Exterior dull and smooth but with concentric bands and lineations that show no relief whatsoever. Whether these concentric markings are raised or grooved on perfect specimens is not known. Dimensions —Holotype (G478a), left valve, length 4.4 mm.,; height 3.3 mm., thickness 0.9 mm. Paratype (G478b), right valve, length 4 mm.; height 3.1 mm.; thickness 0.75 mm. Type locality—Mare formation near W-14, on hillside above west bank of Quebrada Mare Abajo. Five specimens including four left valves and one right valve. 40 BuLLeTIN 204 Remarks.—Subgenerically the new Venezuelan species falls be- tween Ennucula Iredale (1931, Australian Mus. Rec., vol. 18, no. 4, pp. 202, 231) and Nucolopsis Woodring (1925, Carnegie Inst. Wash- ington, Publ. No. 366, p. 14, pl. 1, figs. 2-3) but is closer to the for- mer. On Nucolopsis (also spelled Nuculopsis by Woodring) the pos- terior teeth are not reduced in size toward the chondrophore, and in this respect the Venezuelan shell is like the type N. (Nucolopsis) hill, Woodring from the middle Miocene of Jamaica. In all other respects it fits the subgenus Ennucula. Comparisons—Nucula mareana, n. sp. is comparable to N. tenuis (Montagu) (1808, p. 56, pl. 29, fig. 1), N. aegeénsis Jeffreys (1879, Zool. Soc. London, Proc., p. 581), N. cardara Dall (see Schenck, 1939, p. 34, pl. 5, figs. 12, 14, 18, 21), and N. uruguayensis Smith (1880c, p. 320). NV. tenuis is a circumboreal species which has been reported as far south as the Mediterranean in Europe, along the New England coast in the Western Atlantic, and to Baja California, Mexico, in the Eastern Pacific. As a fossil it has been reported by Dall from the “Miocene” of Alaska, according to Grant and Gale (1931, p. 111). N. tenuis is a variable shell but is always more gently rounded at the extremities than N. mareana and has a fairly well-defined escutcheon which is not present on the Venezue- lan form. The southern Western Atlantic analogue of N. tenwts is N. aegeénsis which has been recorded from Cuba, Puerto Rico, and Trinidad in 5 to 464 fathoms. NV. aegeénsis is differentiated from N. mareana in being much more rounded at the posterior end. N. cardara, a Recent Eastern Pacific shell ranging from Monterey, Cali- fornia, to Baja California, Mexico, in deep water (1090 fathoms, in mud, off San Diego, California), is considerably larger than WN. mareana, and the posterior teeth are slightly smaller near the chon- drophore than are those of the Venezuelan fossil. N. wruguayensis Smith, as figured in Voyage of H.M.S. Challenger, Zoology (vol. 13, p. 299, pl. 18, figs. 12-12b) is also much larger than N. mareana, and the valves instead of being smooth are somewhat deeply fur- rowed at stages of arrested growth. NV. wruguayensis Smith was ob- tained off Montevideo, Uruguay, from mud at 13 fathoms. NV. urugu- ayensis Marshall, also collected in Uruguay in the estuary of Rio de La Plata on the Costa de Maldonado, is different than the N. uruguayensis of Smith, having weak radial sculpture and a crenulate VENEZUELAN CENOzOIC PELECYPODS: WEISBORD 4] ventral margin. Marshall’s N. wruguayensis has been re-named JN. marshalli by Schenck (1939, Jour. Paleont., vol. 13, pp. 29-30). NUCULANIDAE Nuculana (Saccella) karlmartini, new species Pink fies vi-17; Pl. 2, figs. 14 1888. Leda acuta (Conrad) ?, Schepman [in] Martin, Bericht tiber eine Reise nach Nederlandisch West-Indien und darauf gegriindete Studien, Leiden: II—Geologische Studien, Appendix. Not Nuculana acuta Conrad, Amer. Marine Conchology, p. 32, pl. 6, fig. 3, 1832. Shell small, inflated, equivalve but inequilateral, a little elon- gate, the beaks slightly forward of the middle. Anterior end well rounded and a little produced, the posterior end prolonged to a moderately acute tip. Ventral margin rounded, the curvature gen- erally a little more pronounced just anterior to the middle, the mar- gin near the anterior end often forming a shallow embayment. Dorsal margin anterior to umbo evenly convex; posterior to the umbo, the margin is slightly concave to nearly straight from the chondrophore to above the farthest tooth, then concave again from there to the posterior tip. Young specimens are less elongate than adults. On the exterior there is a shallow anterior depression running from near the umbo to the base, the depression widening toward the ventral margin; posteriorly there is a narrow, moderately pro- nounced ridge diverging away from the rim of the escutcheon. Lunule long, narrow, lanceolate, defined by a slightly sunken, feebly impressed groove, the lunular edges of the valves a little raised. The concentric ribs at the summit of the valve end abruptly at the margin of the lunule, the lunule itself marked with faint longitudinal striae and short corrugations running at a right angle to the long axis of the shell. Escutcheon large, deeply sunken, elongate cordate, bordered by a keeled rim over which the concentric ribs of the valves are accented, the ribs continuing with slight obliqueness and somewhat diminished strength on the escutcheon itself. Hinge with a deep, rounded-triangular chondrophore. On specimens 10-12 mm. in length there are 17 to 22 teeth on the hinge anterior to the chon- drophore, and 14 to 19 teeth posterior to the chondrophore. The teeth are small and crowded near the chondrophore, longer and 42 BuLueTiIn 204 more widely separated away from it, the larger teeth angulately cuspate, the concave sides facing toward the extremities. Pallial line rather distant from the basal margin, the pallial sinus relatively large, subrectangular, and oblique, the apex broadly U-shaped, the connection with the pallial line acute, the re-entrant of the sinus reaching to about a line under the seventh tooth from the end. Anterior adductor scar larger and lower than the posterior. Interior not nacreous, generally smooth and porcelaneous but sometimes with the external ribs reflected through. External sculpture consisting of fairly regular concentric ribs parallel with the ventral margin, and extending to the extremities of the disk as well as on the umbo to near the tip of the beak. The ribs are close together on the umbos, farther apart and often recurved below and, on a specimen 10 mm. in length, there are 35 of them. The interspaces are generally smoothish, although on the anterior end of large specimens there may be faint microscopic radial striae locally. Dimensions —Holotype (1473a), a doublet, length 12.2 mm.; height 6.8 mm.; thickness 5 mm. Paratype (1473b), right valve, length 10.2 mm.; height 5.5 mm.; thickness 2.1 mm. Paratype (1473c), left valve, length 11.4 mm.; height 6.8 mm.; thickness 2 mm. Paratype (G473c), left valve, length 4.1 mm.; height 2.6 mm.; thickness 0.8 mm. Paratype (G473d), left valve, length 8.8 mm.; height 4.9 mm.; thickness 2.0 mm. Paratype (G473e), right valve, length 9.5 mm.; height 5.1 mm.; thickness 2.0 mm. Type locality—Lower Mare formation at W-13, on hillside above west bank of Quebrada Mare Abajo. Thirty-eight specimens including fourteen right valves, seventeen left valves, and seven doublets. Other localities —Mare formation near W-14, on hillside above west bank of Quebrada Mare Abajo. Seven specimens including three right valves, two left valves, and two doublets. Upper Mare formation, 115 meters south-southwest of the crossing of Quebrada Mare Abajo and coast road. Two specimens including one right valve and one left valve. Upper mare formation, in stream 250 meters south-southwest of the mouth of Quebrada Las Pailas. Three specimens including two left valves and one night valve. Playa Grande formation (Maiquetia member) at W-23, north flank of VENEZUELAN CENOzOIC PELECYPODS: WEISBORD 43 Punta Gorda anticline. Two specimens including one right valve and one left valve. Playa Grande formation (Maiquetia member) at W-26, in Quebrada Las Bruscas about 125 meters upstream from junction with Quebrada Las Pailas. Three specimens including one right valve, one left valve, and one doublet. Comparisons.—Although this is probably the same species as the one identified by Schepman as Leda acuta ?, I do not think it is the Nuculana acuta of Conrad as that is a smaller shell with more numerous concentric riblets than the Cabo Blanco species. It is true that NV. acuta is as variable as it is widespread (Miocene to Recent, and from Maryland, U.S.A., to the West Indies as well as, according to Dall (1909, p. 250), from California to Chile in west America, but all of the many specimens of N. acuta I have examined at the Academy of Natural Sciences of Philadelphia are smaller and more closely ribbed than N. karlmartini, n. sp. Actually, the new species is just as close to the Pleistocene and Recent NV. elenensis (Sowerby) (see Hertlein and Strong, Zoologica, vol. 25, pt. 4, No. 25, pp. 393-394, pl. 1, figs. 12, 14-19, 22) from the west coast of the Americas, the principal difference being that equivalent- sized forms of N. elenensis have fewer teeth on the hinge than JN. karlmartim, n. sp. The middle Miocene JN. feltella (Dall) (see Woodring, 1925, p. 16, pl. 1, figs. 4-5) from Bowden, Jamaica, has a more centrally located beak than N. karlmartini and is sculptured by more numerous concentric ribs, Remarks —Nuculana (Saccella) karlmartini, n. sp. is named in honor of Prof. [Johann] Karl [Ludvig] Martin, eminent Dutch geologist, who visited Venezuela in 1885 while on a scientific mis- sion to the West Indian colonies of the Netherlands, and author of one of the early papers dealing with the geology of the Cabo Blanco area of Venezuela. Nuculana (Saccella) axelolssoni, new species Pl. 2, figs. 5-10 Shell small, a little inflated, elongate-lenticular, equivalve but inequilateral, the beaks a little forward of the middle. Anterior end well rounded and a little produced, the posterior end tapering to a slightly blunted point. Ventral margin rounded except near the 44 BuLueTiIn 204 anterior end where it may be shallowly sinuate. Dorsal margin anterior to umbo evenly convex; posterior to the umbo, the mar- gin representing the edge of the valve is somewhat raised to about a point over the farthest tooth on the hinge, and a little concave therefrom to the posterior tip. On the exterior of the valve there is a slight radial depression near the anterior end, the depression widening toward the ventral margin; posteriorly there is also a radial depression bounded by the elevated rim of the escutcheon and by a feeble ridglet extending from the beak to the basal margin. Lunule long, narrow, lanceolate, defined by a feebly impressed groove; the concentric ribs of the valve terminate in strength at the lunular groove but continue weakly on the lunule itself which is, however, marked with short corrugations running at a right angle to the long axis of the shell. Escutcheon large, depressed, elongate cordate, bordered by a keeled rim over which the con- centric ribs of the valve are accentuated, the ribs continuing with slight obliqueness and diminished strength on the escutcheon itself. Hinge with a fairly deep, small, more or less triangular chondro- phore. On 2 specimens, each about 6 mm. in length, there are, in- cluding the crowded ones near the chondrophore, 17 teeth anterior to the chondrophore and 12 teeth posterior to the chondrophore. The teeth are longer and larger toward the ends of the hinge and are angulately cuspate, the concave sides facing toward the ex- tremities. The pallial line and pallial sinus are not visible, nor are the adductor scars clear. Interior not nacreous, gently corrugated by the external ribs which are reflected through. External sculpture consisting of concentric ridges which are fine and close together on the umbos, farther apart, and subequally spaced below. The beak itself is smooth. On the disk proper the ridges tend to be recurved and rounded, but in the depressed areas fore and aft, the ridges are a little narrower and sharper. On the keel of the escutcheon there is often a short concentric riblet between the main ones, the former becoming obsolescent in the posterior radial depression. On specimens 6, 7, and 8 mm. long there are, respectively, 18, 22, and 23 concentric riblets. The interspaces are generally smoothish, al- though there may be a narrow zone adjacent to the depressions with a few very fine short radial threads. VENEZUELAN CENOZOIC PELECYPOoDS: WEISBORD 45 Dimensions.—Holotype (G474a), left valve, length 6.3 mm.; height 3.5 mm.; thickness 0.8 mm. Paratype (G474b), right valve, length 4.5 mm.; height 2.4 mm.; thickness 0.8 mm. Paratype (G474c), immature left valve, length 2.4 mm.; height 1.3 mm.; thickness 0.3 mm. Type locality—Mare formation near W-14, on hillside above west bank of Quebrada Mare Abajo. Three specimens including two left valves and one right valve. Other localities —Playa Grande formation (Maiquetia member) at W-23, north flank of Punta Gorda anticline. Eight specimens including five right valves and three left valves. Comparisons.—This species is similar to N. karlmartini, n. sp. but is not so plump and has fewer concentric ridges. The closest Recent shell is the Eastern Pacific N. tmpar (Pilsbry and Lowe) (1932, pp. 106-107, pl. 17, figs. 3-6) from Mexico to Costa Rica, but on N. wmpar the ribs become closer together from the middle of the valve to the ventral margin whereas on the Venezuelan JN. axel- olssont, n. sp. the ribs are more or less equally spaced from the middle down. The closest fossil species are N. dodona (Dall) (1898, pp. 589-590, pl. 32, fig. 6) and N. trochila (Dall) (1898, p. 590, pl. 32, figs. 4, 12), both from the middle Miocene of Florida. N. dodona is characterized by “even, high, blunt-edged, slightly recurved la- mellae, with deeply excavated, wider interspaces, which are striated by lines of growth,” but on NV. axelolssom the ribs are less numerous and less elevated, and the interspaces are not spirally striate. On N. trochilia the keel of the escutcheon is much less strongly ribbed than on the new Venezuelan species. Remarks.—The new species is named in honor of Axel A. Olsson in recognition of his contributions to American paleontology over a span of nearly half a century. Happily, his work continues with unabated vigor. Nuculana (Saccella) marella, new species Pl 2, figs. 1, 12 Shell small, thin, moderately inflated, inequilateral, the dorsal margin and forward end of the valve broken away, the posterior 46 BuLLETIN 204 end rostrate. Posterior dorsal margin convex to a little beyond the farthest tooth on the hinge, sinuate therefrom to the extremity. Ventral margin gently rounded forward from the posterior depres- sion. Posterior depression caret-shaped, forming an angle of 37 degrees, and extending from the posterior side of the umbo to the basal margin. The ridge bordering the depression is smooth, rela- tively broad and high, prolonged somewhat at the base, the ter- mination subacute. The rise of the disk at the forward side of the depression is gentle. Escutcheon narrowly cordate, relatively high and thin at the valve edge, sunken a little adjacent to the posterior ridge, defined from the ridge by a feebly impressed groove, and marked by microscopic, hardly discernible oblique striae. Hinge with about six teeth posterior to the beak, the teeth increasing in size toward the far end. Exterior of shell sculptured by low rounded prominent concentric ribs (estimated at 18 in all), the ribs smaller and closer together on the umbo than below, where, from about the middle down, they are about equal in size and spacing. The ribs are obsolescent in the posterior depression and seem absent or evan- escent on the posterior ridge bordering the escutcheon. The in- terior is thinly enameled in part, smoothly corrugated by the im- pressions of the external ribs. The pallial line and pallial sinus are not visible. Dimensions —Holotype (F475a), broken right valve, length 1.3 mm.; width 0.9 mm. Type locality —Mare formation at W-14, on hillside above west bank of Quebrada Mare Abajo. One broken right valve, the holo- type. Remarks.—The seeming prolongation of the posterior ridge may perhaps be due to breakage of the ventral margin. In other respects the shell resembles NV. axelolssoni, n. sp., and it might turn out that it is an immature specimen of that species. However, the posterior depression diverges much more than that of N. axelolssoni and the posterior ridge bordering the depression is completely smooth where- as on NV. axelolssoni, n. sp. and N. karlmartini, n. sp. the ridge is sculptured by sharp concentric ridges. Until more specimens are available of this small shell it seems best to consider it distinct. VENEZUELAN CENOZOIC PELECYPODS: WEISBORD 47 Nuculana (Saccella) species Plo 2 figes13 Illustrated is the internal filling of a left valve. The shell is small, inflated, a little inequilateral, somewhat prolonged posteriorly. There is a fairly pronounced radial depression near the posterior end and the merest suggestion of an anterior one. The beak is relatively high, and there are at least 11 anterior and at least 10 posterior teeth on the hinge. The anterior dorsal margin is slightly convex, the posterior dorsal margin slightly concave, the ventral margin of the disk gently rounded. Dimensions.—Figured specimen O476a (extremities broken away ), length 4.5 mm.; height 2.9 mm. Locahty.—Playa Grande formation (Catia member) near W-22, on dip slope 100 meters west of Costa fault. One specimen. Remarks.—The mold is not dissimilar to that of N. karlmartini, n. sp. but without more to go on the species must remain inde- terminate. Nuculana (Jupiteria ?) species PE 23, fic The internal filling is of a small plump subtriangular shell with a high umbo. The dorsal anterior margin is gently convex, the dorsal posterior margin slightly concave with a somewhat more inclined slope than the anterior. Basal margin evenly rounded. Pos- terior end of valve subtruncate. There are about 13 teeth on the hinge anterior to the beak, but the posterior ones are missing. Dimensions.—Specimen O476b, left valve, length 4.5 mm.; height 3.2 mm. Locality.—Playa Grande formation (Catia member) near W-22, on dip slope 100 meters west of Costa fault. One specimen. Remarks.—tThis internal mold suggests a similarity to NV. bow- denensis bowdenensis (Woodring) (1925, Carnegie Inst. Washing- ton, Publ. No. 366, p. 19, pl. 1, figs. 11-12) from the middle Miocene of Jamaica, but until better Venezuelan specimens are available a definitive determination cannot be made. Adrana cf. tellinoides (Sowerby) Pl. 2, figs. 14-15 1815. Nucula tellinoides Sowerby, The Genera of Recent and Fossil Shells, Nucula, vol. 1, pl. 82, fig. 2. Cumana, Venezuela. 48 BuLueTiIn 204 1828. Arca tellinoides (Sowerby), Wood, Index Testaceologicus, Supplement, p. 6, pl. 2, Arca, fig. 5b. 1866. Leda tellinoides (Sowerby), Thes. Conchyl., vol. 3, p. 108, pl. 227, fig. 36. 1939. Nuculana tellinoides (Sowerby), Rehder, Nautilus, vol. 53, No. 1, p. 17. Shell thin, translucent, compressed, long elliptical, subequilater- al, Anterior and posterior dorsal margins forming an angle of about 170 degrees, the anterior margin straight, the posterior gently con- cave. Beak small, glassy, smooth, subcentral, scarcely projecting. Escutcheon long and narrow, sunken below the bordering keel-like ridge, the valve margin a little elevated, thin, and strongly sloping. The ridge bordering the escutcheon is low, narrow, sharply rounded, marked with numerous sharp regularly disposed threads which are curved near the umbo but become more and more slanted toward the posterior; these threads are the continuations of the concentric threads on the disk but are more accentuated than they are on the valve proper; on the escutcheon itself the threads are present near the beak but become obsolescent distally. Lunule long and extremely narrow, also sunken in some measure below the anterior dorsal mar- gin of the disk. Chondrophore large but shallow, broadly triangular, bisected by a vertical resilial groove a little aft of the middle. Teeth of hinge numerous, thin, erect, sharply pointed, smaller and closer near the chondrophore, a little more widely spaced and longer toward the extremities of the hinge. The total number of teeth is not known as the ends of the single specimen are broken away, but on this right valve there remain about 30 posterior teeth and 33 anterior teeth. Interior of valve glossy, the pallial line and pallial sinus not visible. Exterior of valve sculptured by sharp fine con- centric threads extending from the umbo (the beak proper is com- pletely smooth and hyaline) about halfway down the disk, the threads crowded on the umbo but widening progressively toward the ventral margin. There are approximately 25 of these concen- tric threads, all but the bottom 3 shallowly encircling the disk from the border of the lunule to the escutcheon. The three lowest threads extend from the lunule to about the middle of the disk and there become obsolescent. On the umbo there are three or four threads which splay off the concentric ones as straight rays roughly parallel with the posterior dorsal keel but extending only a short distance VENEZUELAN CENOzOIC PELECYPODS: WEISBORD 49 across the disk. Below the bottommost concentric thread there are broad concentric bands parallel with threads, the bands probably representing former threads which have been worn down. The ventral margin of the valve is broken away as are the anterior and posterior ends. There is a barely perceptible radial furrow or de- pression diverging from the anterior side of the umbo toward the anterior ventral margin and possibly a similar posterior furrow radiating to the posterior ventral margin below the ridge bordering the escutcheon. The posterior dorsal area below the posterior ridge is smooth. Dimensions.—Figured specimen T544a, right valve, (extremi- ties and base missing), length 9.5 mm.; height 2.7 mm. Locality—Upper Mare formation, in stream 250 meters south- southwest of mouth of Quebrada Las Pailas. One incomplete right valve. Remarks.—Sowerby’s 1866 English description of A. tellinoides was as follows: Elongated, lanceolated-elliptic, slightly flexuous, bending down a little in front, and inclining upwards a little behind; thin, glossy, snow-white, com- pressed; smooth behind, elsewhere striated; striae curved and slanting in the middle, almost concentric in front. Sides very nearly equal, gradually and nearly equally tapering to either extremity; anterior end rotundately peaked; posterior end angular above, rounded below. Dorsal slopes very slight; the front one plano-convex, the hinder one barely subretuse. Ventral margin sub- arcuated throughout, with an extremely slight anterior, and no posterior re- tusion. Dorsal areas inconspicuous; the hinder one impressed, its edges crenu- lated. Teeth very numerous on both sides.—Besides the longitudinal striae, a few symmetrical lines of growth may be discerned beneath the front dorsal edge, and a few still more indistinct ones (but no striae) on the opposite side. In mature examples similar lines are likewise manifest in the middle, near the lower margin. The immature Cabo Blanco fossil is exceedingly close to the Recent A. tellinoides originally described from Cumana, Venezuela, but whether it is the same or not cannot be determined without more material. The fossil closely resembles Sowerby’s illustration, but comparison with an adult Recent specimen from Cumana in the collection at the Academy of Natural Sciences of Philadelphia (No. 43333) shows the dorsal margin of the Cumana shell to be gently convex overall whereas on the Cabo Blanco fossil the margins diverge at an angle of about 170 degrees. It is not unlikely, however, 50 BuL_etin 204 that the configuration of the dorsal margin becomes more rounded with growth. Comparisons—Among other Recent species of Adrana, the Cabo Blanco fossil is closest perhaps to A. notabilis Rehder (1939, Nautilis, vol. 53, No. 1, pp. 16-17, pl. 6, figs. 4, 12) from the Para- guana Peninsula, Venezuela, and is reminiscent of A. scaphoides Rehder (1939, Nautilus, vol. 53, No. 1, pp. 17-18, pl. 6, fig. 5) from near Cartagena, Colombia. Inasmuch as the ventral margin is broken away on A. cf, tellinoides (Sby.) a comparison by shape cannot be made but the angle of the hinge line is a little more acute on notabtlis (165 degrees compared with 170 degrees on A. cf. tellinoides). The dorsal areas of A. notabilis are smooth whereas on A. cf. tellinoides not only is the keel of the escutcheon heavily threaded but there are short strong corrugations on the escutcheon itself near the beak, the corrugations running at right angles to the keel and becoming obsolescent away from the beak. Furthermore the concentric nbbing on the umbo is sharper on A. cf. tellinoides than on A. notabilis. The sculpture of A. scaphoides Rehder consists of “fine concentric grooves which cut slightly diagonally across the growth lines,” and A. sca- phoides lacks the keel-like ridge bordering the escutcheon. Among fossil species, the Cabo Blanco shell is somewhat similar to A. mont- serratensis (Maury) (1925, pp. 176-177, pl. 12, fig. 1) from the late Miocene Springvale deposits of Trinidad, but A. montserratensis, in addition to being differently sculptured, has a virtually horizontal hinge before and after the beak. A. quitanensis Olsson (1922, p. 346, pl. 18, fig. 29) from the middle Miocene of Costa Rica may be distinguished from A. cf. tellinoides (Sby.) by the anterior location of the beaks. Nine Recent species of Adrana have been described from tropical west American waters (see Hertlein and Strong, 1940, Zoologica, vol. 25, pt. 4, No. 25, pp. 406-412), but the Venezuelan shell appears to be distinct from all of them. ARCIDAE Arca (Arca) zebra (Swainson) Pl. 2, figs. 16-17 1831. Byssoarca zebra Swainson, Zoological Illustrations, No. 26, pl. 118 (ex parte). Not Reeve 1844. 1845. Arca barbadensis d’Orbigny, [in] La Sagra, Hist. Fis. Polit. Nat. Isla de Cuba, pt. 2, vol. 5, Moluscos, p. 345. 1847. 1853. 1864. 1864. 1864. 1866. 1867. 1871. 1874. 1876. 1878. 1878. 1885. 1886. 1889. 1889. 1891. 1891. 1898. 1901. 1903. 1907. 1907. 1913. 1916. 1917. 1920. 1922. 1923. 1923. 1925. VENEZUELAN CENOzOIC PELECYPODS: WEISBORD 51 Arca occidentalis Philippi, Abbildungen und Beschreibungen Conchylien, vol. 3, p. 14, pl. 176, figs. 4a-c. Arca barbadensis d’Orbigny, [in] La Sagra, Hist. phys. polit. nat. l’Ile de Cuba, Mollusques, vol. 2, pp. 321-322. Arca noae Linnaeus, Krebs, The West Indian Marine Shells, p. 125. Not of Linnaeus. Arca occidentalis Philippi, Krebs, The West Indian Marine Shells, p. 125. Arca noae Linnaeus, Guppy, Sci. Assoc. Trindad, Trans., p. 36, Not of Linnaeus Arca noae Linnaeus, Guppy, Geol. Soc. London Quart. Jour., vol. 22, p. 293. Not of Linnaeus. Arca noae Linnaeus, Guppy, Sci. Assoc. Trinidad, Proc., p. 163. Not of Linnaeus. Arca noae Linnaeus, Coues, Acad. Nat. Sci. Philadelphia, Proc., vol. 23, p. 132. Not of Linnaeus. Arca occidentalis Philippi, Guppy, Geol. Mag., decade 2, vol. 1, p. 343. Arca occidentalis Philippi, Guppy, Geol. Soc. London Quart. Jour., vol. 32Zp. SSI: Arca zebra Swainson, Arango y Molina, Contribucién a la Fauna Mala- colégica Cubana, p. 262. Arca occidentalis Mérch, Catalogue of West-India Shells, p. 15. Arca noae Linnaeus, Smith, Voyage H. M. S. Challenger, Zoology, vol. 13, p. 258 (part). Arca noae Linnaeus, Dall, Mus. Comp. Zool., Bull., vol. 12, p. 243. Not of Linnaeus. Arca Noae Linnaeus, Dall, U. S. Nat . Mus., Proc., vol. 12, No. 773, p. 259. Not of Linnaeus. Arca Noae Linnaeus, Lorié, Samml. Geol. Reichs-Mus. Leiden, ser. 2, vol. 1, pp. 119, 141. Not of Linnaeus. Arca occidentalis Philippi, Kobelt, Syst. Conchylien-Cabinet, Arca, p. 66, pl. 19, figs. 1-4. Arca noae Linnaeus, Baker, Acad. Nat. Sci. Philadelphia, Proc., vol. 43, p. 46. Not of Linnaeus. Arca occidentalis Philippi, Dall, Wagner Free Inst. Sci., Trans., vol. 3, pt. 4, p. 620. Arca occidentalis Philippi, Dall and Simpson, U. S. Fish Com., Bull., vol. 20 for 1900, pt. 1, pp. 459-460. Arca noae Linnaeus, Dall, U. S. Nat. Mus., Bull. 37, p. 40. Not of Linnaeus. Arca zebra (Swainson), Lamy, Jour. Conchyl., vol. 55, pp. 17-19. Arca noae Linnaeus, Verrill, Connecticut Acad. Arts and Sci., Trans., vol. 12, p. 186, pl. 35b, figs. 6, 6a. Not of Linnaeus. Arca occidentalis Brown and Pilsbry, Acad. Nat. Sci. Philadelphia, Proc., vol. 65, p. 496. Arca occidentalis Philippi, Sheldon, Palaeontographica Americana, vol. 1, No. 1, p. 8, pl. 1, figs. 8-11. Arca occidentalis Philippi, Maury, Bull. Amer. Paleont., vol. 5, No. 29, D327.) pl.429,, tigies. Arca occidentalis Philippi, Maury, Bull. Amer. Paleont., vol. 8, No. 34, p. 43. Arca occidentalis Philippi, Olsson, Bull. Amer. Paleont., vol. 9, No. 39, pp. 189, 193, 199, 353-354, pl. 22, fig. 1. Arca occidentalis Philippi, Remington, Nautilus, vol. 35, No. 4, p. 121. Arca occidentalis Philippi, Clench, Nautilus, vol. 37, No. 2, p. 55. Arca (Arca) occidentalis Philippi, Woodring, Carnegie Inst. Washing- ton, Publ. No. 366, pp. 29-30, pl. 2, figs. 8, 9. 52 1925. 1926. 1926. 1927. 1929. 1932. 1936. 1936. 1936. 1937. 1938. 1939. 1939. 1940. 1940. 1942. 1943. 1943. 1944. 1945. 1946. 1949. 1951. 1952. 1953. 1954. 1955. 1958. 1958. 1958. 1959. Bu.wetin 204 Arca occidentalis Philippi, Maury, Bull. Amer. Paleont., vol. 25, No. 42, pp. 186-187, pl. 1, figs. 1, 2. ee eee Philippi, Gardner, U. S. Geol. Sur., Prof. Paper 142-A, pp. 23-24. Arca occidentalis Philippi, Weisbord, Nautilus, vol. 39, No. 3, p. 82. Arca (Arca) occidentalis Philippi, F. Hodson, H. K. Hodson, and Harris, Bull. Amer. Paleont., vol. 13, No. 49, p. 2. Arca (Arca) occidentalis Philippi, Anderson, California Acad. Sci., Proc., ser. 4, vol. 18, No. 4, pp. 147-148. Arca (Arca) occidentalis Philippi, Mansfield, Florida State Geol. Sur., BullSNors50p. 1441.5 pl. 2; 1152: Arca (Navicula) occidentalis Philippi, McLean, Soc. Cubana Hist. Nat. “Felipe Poey”’, Mem., vol. 10, No. 1, p. 39. Arca (Navicula) occidentalis Philippi, Clench and McLean, Soc. Cubana Hist. Nat. “Felipe Poey”’, Mem., vol. 10, No. 4, p. 160. Arca occidentalis Philippi, Richards, Nautilus, vol. 49, No. 4, p. 133. ae occidentalis Philippi, Smith, East Coast Marine Shells, p. 27, pl. 3. hig 7. Arca occidentalis Philippi, Richards, Geol. Soc. Amer. Bull., vol. 49, pt. 2, p. 1290. Arca occidentalis Philippi, McLean, Nautilus, Vol. 49, No. 4, p. 116. Navicula zebra (Swainson), Bartsch and Rehder, Smithsonian Miscel. Collections, vol. 98, No. 10, p. 18. Arca occidentalis Philippi, Smith, World-wide Sea Shells, p. 90, fig. 1249. Arca occidentalis Philippi, Stenzel, Nautilus, vol. 54, No. 1, p. 21. Arca occidentalis Philippi, Jaume and Pérez Farfante, Soc. Cubana Hist. Nat. “Felipe Poey’, Mem., vol. 16, No. 1, p. 38. Arca (Arca) zebra (Swainson), Reinhart, Geol. Soc. Amer., Spec. Papers No. 47, p. 6. Arca (Arca) occidentalis Philippi, Hertlein and Strong, Zoologica, vol. 43, pt. 3, No. 19, p. 155. Arca occidentalis Philippi, Hackney, Nautilus, vol. 58, No. 2, p. 56. Arca occidentalis Philippi, van Bentham Jutting, Geolog.-Mijnbouwk. Genootschap Nederland en Kolonien, Geol. Ser., vol. 14, p. 77. Arca (Navicula) occidentalis Philippi, Jaume, Soc. Malac. “Carlos de La Torre” Rev., vol. 4, No. 3, p. 98. Arca (Navicula) occidentalis Philippi, Lange de Morretes, Mus. Para- naense, Arq., vol. 7, art. 1, p. 8. ft Arca occidentalis Philippi, McLean, New York Acad. Sci. Scientific Survey of Porto Rico and the Virgin Islands, vol. 17, pt. 1, p. 13, pl. 1, fig. 7. yes occidentalis Philippi, Pulley, Texas Jour. Sci., vol. 4, No. 2, p. 180. Arca occidentalis Philippi, Olsson and Harbison, Acad. Nat. Sci. Phila- delphia, Mon. No. 8, p. 32. Arca zebra (Swainson), Abbott, American Seashells, p. 342, pl. 27n. Arca zebra (Swainson), Perry and Schwengel, Marine Shells of the Western Coast of Florida, 34, pl. 2, figs. 9a, b. Arca (Arca) occidentalis Philippi, Keen, Sea Shells of Tropical West America, p. 26. Arca zebra (Swainson), Olsson and McGinty, Bull. Amer. Paleont., vol. 39, No. 177, p. 19. Arca zebra (Swainson), Abbott, Acad. Nat. Sci. Philadelphia, Mon. No. Te ipsLo9, Arca occidentalis Philippi, Rodriguez, Bull. Marine Sci. Gulf and Carib- bean, vol. 9, No. 3, p. 277. VENEZUELAN CENOzoIC PELECYPoDS: WEISBORD 53 1959. Arca zebra (Swainson), Nowell-Usticke, A Check List of the Marine Shells of St. Croix, p. 1. 1961. Arca zebra (Swainson), van Regteren Altena, Koninkl. Nederl. Akad. Wetensch.-Amsterdam, Proc., ser. B, vol. 64, No. 2, p. 298. 1961. Arca zebra (Swainson), Warmke and Abbott, Caribbean Seashells, p. 157, pl. 30L. The Recent Venezuelan shell is inequilateral, subrectangular, and somewhat eccentric. The anterior end is subtruncate, slightly to markedly narrower than the posterior, the posterior end angu- lately rounded at the curve with the ventral margin, the upper part of the posterior margin moderately concave and a little alate. The byssal gape is asymmetric, subcentral, shallowly to strongly embayed. Posterior rostration moderately broad, shallowly depressed. Cardinal area flat, moderately wide, marked with widely separated converging ligamental grooves of which the innermost pair or two may meet under the beak to form a somewhat inequilateral caret. Hinge straight, with numerous even teeth. Muscle scars high, the posterior large, broadly oval, and oriented parallel with the long axis of the valve, the anterior one smaller and subtriangular with a rounded basal margin. Ventral margin feebly crenulate. Exteriorly there is a radially depressed area diverging obliquely from the umbo and widening to the basal margin, the depression slight to pro- nounced. Within, the depression is reflected by a convexity of the interior. Sculpture consisting of radial riblets and interstitial threads, these often rendered crenulate by fine concentric growth grooves. The external ground color is straw with broad, zigzag, zebralike stripes of dark brown. The interior is mahogany, mottled with dull cream. The periostracum is a dull brown to straw-colored fibrous mat, the fibers distinctly radial. Dimensions. —Figured specimen A369aa, right valve, length 50 mm.; height from umbo to ventral margin 20.3 mm.; thickness 12.2 mm. Locahty.—Recent, on beach of Playa Grande Yachting Club, Distrito Federal. Four specimens including three right valves and one large fragment. Remarks—The Mediterranean analogue is A. noae Linnaeus (Syst. Nat., ed. 12, p. 1140). That species is more evenly rectangular, exhibits less of a torque effect, and the basal margin is more strongly 54 BuLLETIN 204 crenulate than that of A. zebra. The west American and Eastern Pacific analogue is the Pliocene to Recent A. pactfica (Sowerby) (see Reinhart, 1943, pp. 26-27, pl. 14, figs. 3, 4), but that is more expanded posteriorly than the east American and Western Atlantic A. zebra. Range and distribution—Arca zebra is a common Recent spe- cies which attaches itself to rocks with its byssus. It has been found from Cape Hatteras, North Carolina, to Brazil, at depths to 32 fathoms. In the Pleistocene it has been reported from Florida, the Yucatan Peninsula of Mexico, Cuba, the Panama Canal Zone, St. Eustatius, Curacao, Blanquilla, and Aruba. Pliocene representatives are recorded from the Caloosahatchee marl of Florida and from Matura, Trinidad. In the upper Miocene it is found in Trinidad, and in the middle Miocene it occurs in Venezuela, Colombia, Jamaica, the Dominican Republic, Costa Rica, and Florida. Arca (Arca) zebra abisiniana, new subspecies Pl. 2, figs. 18-19 This form is much the same as A. zebra zebra Swainson except that it is wanting in the broad radial depression extending from the umbo to the base. The exterior of the valve, instead of being de- pressed a little anterior to the middle as on the typical A. zebra, is evenly and rather highly inflated throughout, and the slight byssal gape is situated far forward rather than submedially. In all other respects the present shell seems the same as A. zebra zebra, and al- though it may turn out that the shell in question is merely an indi- vidual variant, it seems best to give it a subspecific designation until more specimens become available. Dimensions —Holotype (D368a), right valve broken away pos- teriorly, length 61 mm., height 34 mm.; thickness 20.5 mm. Type locality—Abisinia formation at W-30, eastern edge of Playa Grande village. One right valve, the holotype. Arca (Arca) imbricata Bruguiére Pl. 3, figs. 1-8 1792. Arca imbricata Bruguiére, Encycl., Méth., vol. 1, p. 98, No. 3. Refers to Lister, pl. 367, fig. 207 from Jamaica. 1819. Arca umbonata Lamarck, An. sans Vert., vol. 6, p. 37. Refers to Lister, pl. 367, fig. 207 from Jamaica. 1835. Arca umbonata Lamarck, An. sans Vert., ed. 2, vol. 6, p. 432. 1842. 1844. 1847. 1864. 1870. 1873. 1878. 1879. 1881. 1885. 1886. 1887. 1889. 1890. 1891. 1891. 1895. 1895. 1898. 1900. 1901. 1907. 1913. 1913. 1915. 1915. 1916. 1917. 1919. 1920. 1920. 1921. VENEZUELAN CENOZOIC PELECYPODS: WEISBORD 55 Arca americana d’Orbigny, [in] La Sagra, Hist. phys. polit. nat. l’Ile de Cuba, vol. 2, Mollusques, pp. 317-318, pl. 27, figs. 1-2. Not of Gray. Arca imbricata Bruguiére, Reeve, Conch. Icon., vol. 2, pl. 11, fig. 73. Arca umbonata Lamarck, Philippi, Abbildungen und Bescreibungen Con- chylien, vol. 3, p. 13, pl. 17b, figs. 3a-c. Arca umbonata Lamarck, Krebs, The West Indian Marine Shells, p. 126. Arca umbonata Lamarck, Dunker, Novitates Conchologicae, p. 131, pl. 44, figs. 5-7. Arca imbricata Bruguiére, Gabb, Amer. Philos. Soc., Trans., vol. 15, p. 254 (part). Arca umbonata Lamarck, Morch, Catalogue of West-India Shells, p. 15. Arca umbonata Lamarck, Arango y Molina, Contribucién a la Fauna Malacologica Cubana, p. 261. Arca imbricata Bruguiére, Gabb, Acad. Nat. Sci. Philadelphia, Jour., ser. 2, vol. 8, p. 378. Arca imbricata Bruguiére, Smith, Voyage H.M.S. Challenger, Zoology, vol. 13, p. 259. Arca umbonata Lamarck, Dall, Mus. Comp. Zool., Bull., vol. 12, No. 6, p. 243. Arca imbricata Bruguiére, Heilprin, Wagner Free Inst. Sci., Trans., vol. 1, p. 118. Arca imbricata Bruguiére, Dall, U. S. Nat. Mus., Bull. 37, p. 40. Arca imbricata Bruguiére, Smith, Linnaean Soc. London, Jour., Zoology, vol. 20, p. 499. Arca umbonata Lamarck, Kobelt, Syst. Conchylien-Cabinet, Arca, p. 63, pl. 18, figs. 3-6. Arca imbricata Bruguiére, Baker, Acad. Nat. Sci. Philadelphia, Proc., vol. 43, p. 46. Arca imbricata Bruguiére, Gregory, Geol. Soc. London, Quart. Jour., vol. 515 p: 291° Arca imbricata Bruguiére, von Ihering, Jour. Conchyl., vol. 43, p. 212. Arca umbonata Lamarck, Dall, Wagner Free Inst. Sci., Trans., vol. 3, pt. 4, pp. 620, 659. Arca umbonata Lamarck, Dall, Wagner Free Inst. Sci., Trans., vol. 3, pt. 5, pl. 38, figs. 4, 4a. Arca umbonata Lamarck, Dall and Simpson, U. S. Fish Com., Bull., vol. 20 for 1900, pt. 1, p. 460. Arca imbricata Bruguiére, Lamy, Jour. Conchyl., vol. 55, pp. 26-27. Arca umbonata Lamarck, Brown and Pilsbry, Acad. Nat. Sci. Philadel- phia, Proc., vol. 65, p. 496. Arca imbricata Bruguiére, Brown and Pilsbry, Acad. Nat. Sci. Philadel- phia, Proc., vol. 65, p. 496. Arca umbonata Lamarck, Dall, U. S. Nat. Mus., Bull. 90, p. 118, pl. 17, figs. 6, 8. Meck imbricata Bruguiére, Bartsch, U. S. Nat. Mus., Bull. 91, p. 230. Arca umbonata Lamarck, Sheldon, Palaeontographica Americana, vol. 1, No. 1, pp. 8-9, figs. 12-17. Arca umbonata Lamarck, Maury, Bull. Amer. Paleont., vol. 5, No. 29, pp. 327-328, pl. 30, fig. 11. Arca umbonata Lamarck, Vaughan, U. S. Nat. Mus., Bull. 103, p. 564. Arca umbonata Lamarck, Maury, Bull. Amer. Paleont., vol. 8, No. 34, pp. 43-44. Arca umbonata Lamarck, Maury, New York Acad. Sci. Scientific Survey of Porto Rico and the Virgin Islands, vol. 3, pt. 1, p. 6. Arca umbonata Lamarck, Pilsbry, Acad. Nat. Sci. Philadelphia, Proc., vol. 73, No. 2, p. 403. 56 1922. 1924. 1925. 1926. 1926. 19385 1935. 1936. 1936. 1936. 1937. 1938. 1939. 1940. 1942. 1944. 1945. 1946. 1949. 1951. 1952. 1953. 1953. 1954. 1955: 1958. 1958. 1958. 1958. 1959. 1961. 1961. Bu.uetTin 204 Arca umbonata Lamarck, Olsson, Bull. Amer. Paleont., vol. 9, No. 39, p. 354, pl. 22, fig. 2. Arca umbonata Lamarck, Emery, Nautilus, vol. 38, No. 2, p. 60. Arca umbonata Lamarck, Maury, Bull. Amer. Paleont., vol. 10, No. 42, p. 1S 75 uDlaSeetien Oly pla 8, tie 4s Arca umbonata Lamarck, Gardner, U. S. Geol. Sur., Prof. Paper 142-A, pp. 24-25. Arca umbonata Lamarck, Weisbord, Nautilus, vol. 39, No. 3, p. 82. Arca imbricata Bruguiére, Trechmam, Geol. Mag., vol. 70, No. 823, p. 34. Arca umbonata Lamarck, Richards, Jour. Paleont., vol. 9, No. 3, p. 256. Arca (Navicula) umbonata Lamarck, McLean, Soc. Cubana Hist. Nat. “Felipe Poey”, Mem., vol. 10, No. 1, p. 39. Arca (Navicula) umbonata Lamarck, Clench and McLean, Soc. Cubana Hist. Nat. “Felipe Poey”’, Mem., vol. 10, No. 4, p. 160. Arca umbonata Lamarck, McLean, Nautilus, vol. 49, No. 4, p. 116. Arca (Navicula) umbonata Lamarck, Smith, East Coast Marine Shells, pp. 27-28, pl. 3, fig. 1. Arca umbonata Lamarck, Richards, Geol. Soc. Amer., Bull., vol. 49, pt. 2, p. 1290. Navicula umbonata (Lamarck), Bartsch and Rehder, Smithsonian Miscel. Collections, vol. 98, No. 10, p. 18. Arca umbonata Lamarck, Stenzel, Nautilus, vol. 54, No. 1, p. 21. Arca umbonata Lamarck, Jaume and Pérez Farfante, Soc. Cubana Hist. Nat. “Felipe Poey” Mem., vol. 16, No. 1, p. 38. Arca umbonata Lamarck, Hackney, Nautilus, vol. 58, No. 2, p. 56. Arca umbonata Lamarck, van Bentham Jutting, Geolog.-Mijnbouwk. Genootschap Nederland en Kolonien, Geol. ser., vol. 14, p. 277. Arca umbonata Lamarck, Jaume, Soc. Malac. “Carlos de La Torre”, Rev., vol. 4, No. 3, p. 98. Arca umbonata Lamarck, Lange de Morretes, Mus. Paranaense, Arq., VOled sant plESs Arca umbonata Lamarck, McLean, New York Acad. Sci. Scientific Survey of Porto Rico and the Virgin Islands, vol. 17, pt. 1, p. 14, pl. 2, figs oll, Arca umbonata Lamarck, Pulley, Texas Jour. Sci., vol. 4, No. 2, p. 180, pl. 6, figs.13-14. Arca (Navicula) imbricata umbonata Lamarck, Haas, Fieldiana - Zoology, vol. 34, No. 20, p. 203. Arca (Arca) umbonata Lamarck, Olsson and Harbison, Acad. Nat. Sci. Philadelphia, Mon. No. 8, p. 32. Arca umbonata Lamarck, Abbott, American Seashells, p. 342, pl. 27}. Arca umbonata Lamarck, Perry and Schwengel, Marine Shells of the Western Coast of Florida, p. 35, pl. 2, fig. 10. Arca umbonata Lamarck, Olsson and McGinty, Bull. Amer. Paleont., vol. 39, No. 177, p. 19. Arca umbonata Lamarck, Moore, Nautilus, vol. 71, No. 4, pp. 126, 128. Arca imbricata Bruguiére, Abbott, Acad. Nat. Sci. Philadelphia, Mon. No. 11, p. 109. Arca umbonata Lamarck, Moore, Inst. Marine Sci., vol. 5, p. 154. Arca umbonata Lamarck, Nowell-Usticke, A Check List of the Marine Shells of St. Croix, p. 1. Arca imbricata Bruguiére, van Regteren Altena, Koninkl. Nederl. Akad. Wetensch.-Amsterdam, Proc., ser. 8, vol. 64, No. 2, p. 298. Arca imbricata Bruguiére, Warmke and Abbott, Caribbean Seashells, p. 158, pl. 30e. VENEZUELAN CENOZOIC PELECYPODS: WEISBORD 57 Shell somewhat distorted, narrowly to broadly rhomboidal, in- flated, with a high sharp posterior ridge. Anterior end hardly rounded to subtruncate, the posterior angulately concave in greater or lesser degree. Byssal gape in front of middle, asymmetric, generally strongly embayed. Cardinal area broad, flattish, engraved with one or two sets of converging ligamental grooves below the beak, the grooves generally, but not always absent on the rest of the area. If there are two sets of grooves, the outer converges to a caret under the beak proper, whereas on the inner set the posterior groove is shorter and does not join the anterior one; if there is one set of grooves the posterior is invariably somewhat shorter than the anterior and does not join the anterior to form an apex to the caret. Beaks high, ob- lique, appressed on top, situated well forward. Hinge straight and narrow, widening slightly and gradually toward the extremities, the teeth numerous, equally spaced, and small. Exterior with a broad radial depression extending from the umbo to the byssal gape of the ventral margin. Surface closely sculptured by radial riblets which are crossed by concentric sublamellate ridges producing a reticulate pattern and rendering the riblets beadlike. On the posterior wing there are five or six widely separated low broad ribs which are made crenulate, nodulous, or scabrous by concentric growth jaminae or striae. Posterior muscle scar large, broadly oval, and oriented in the long direction of the shell, the anterior scar a little smaller and roundly subtrigonal in outline. The Recent shells are purplish brown and cream-colored without, light purple within. The periostracum is shaggy, fibrous, and thick, standing out in long, radially striate tufts along the posterior ridge. Dimensions—Specimen A369a, right valve, length 50 mm.; height from umbo to ventral margin 24.5 mm.; thickness 16 mm. Specimen A369b, young left valve, length 26.7 mm.; height from umbo to ventral margin 16 mm.; thickness 9.9 mm. Specimen C369a, right valve, length 66.6 mm.; height from umbo to ventral margin 33.6 mm.; thickness 18 mm, Specimen A371a, left valve, length 37.8 mm.; height from umbo to ventral margin 32.3 mm.; thickness 19.8 mm. Specimen D371a, left valve, length 40 mm.; height from umbo to ventral margin 29 mm.; thickness 15.8 mm. Localities—Recent, on beach of Playa Grande Yachting Club, 58 BuLueTIn 204 Distrito Federal. Forty specimens including twenty-two left valves, seventeen right valves, and one doublet. Abisinia formation at W-30, eastern edge of Playa Grande village. Two specimens including one left valve and one right. La Salina, west of Puerto Cabello, State of Carabobo. Five specimens including three left valves and two right valves. Range and distribution.—The living A. imbricata Bruguiére is a common species in the Western Atlantic, ranging from Cape Hat- teras, North Carolina, to Brazil, in less than 50 fathoms. The species has also been recorded from Senegal, Malaya, and near Cape York, North Australia, in 25 fathoms. Of the last-named occurrence, Edgar A. Smith (1885) had this to say in his Challenger report: “There should be, one would think, and perhaps in reality there is, a dif- ference between the West Indian and Australian shells which appear to belong to this species, but at present I am unable to discover it.” In 1890, Smith reiterated this opinion, stating that “This species was also obtained by the ‘Challenger’ Expedition at Fernando Nor- onha; and other examples were dredged near Cape York, N. Aus- tralia. This seems a remarkable distribution; still, as far as I can discover, there appears to be no difference in the shells.” Bartsch (1915, p. 230) listed A. imbricata-as having been obtained by Col. Turton at Port Alfred, South Africa. Present-day authorities consider the Indo-Pacific form to be A. ventricosa Lamarck (1819, An. sans Vert., vol. 6, p. 38). As a fossil A. imbricata has been reported from the following areas: Pleistocene—Florida, Cuba, St. Kitts, St. Eustatius, Panama Canal Zone, Barbados, Venezuela; Pliocene—Florida, Trinidad, Costa Rica; middle Miocene—Florida, Dominican Republic, Costa Rica; lower Miocene—Florida, Puerto Rico. Barbatia (Barbatia) candida (Helbling) Pl. 3, figs. 9-14; 15, 16 1779. Arca candida Helbling, Abh. Privatgesell. Bohm, vol. 4, p. 129, pl. 4, figs. 39, 40. 1791. Arca candida Gmelin, Syst. Nat., ed. 13, p. 3311. Refers to Syst. Conchylien-Cabinet, vol. 7, p. 195, pl. 55, fig. 542. 1791. Arca jamaicensis Gmelin, Syst. Nat., vol. 6, p. 3312. 1797. Arca Helblingii Bruguiére, Encycl. Méth., p. 195. 1845. Arca candida Chemnitz, d’Orbigny, [in] La Sagra, Hist. Fis., Polit. y Nat. Isla de Cuba, pt. 2, vol. 5, Moluscos, p. 344. 1864. 1873. 1878. 1878. 1889. 1895. 1898. 1901. 1907. 1916. 1920. 1921. 1921. 1925. 1925. 1936. 1936. 1937. 1938. 1942. 1945. 1946. 1949. 1951. 1953. 1954. 1958. 1958. 1958. 1958. 1959. VENEZUELAN CENOzOoIC PELECYPODS: WEISBORD 59 Arca candida Helbling, Krebs, The West Indian Marine Shells, p. 124. Barbatia Bonaczyi Gabb, Amer. Philos. Soc., Trans., vol. 15, pp. 254- 255. Arca candida Chemnitz, Arango y Molina, Contribucién ‘al la Fauna Malacolégica Cubana, p. 263. Arca candida Helbling, Mérch, Catalogue of West-India Shells, p. 15. Arca candida Chemnitz, Dall, U. S. Nat. Mus., Bull. 37, p. 40. Barbatia candida Chemnitz, Gregory, Geol. Soc. London, Quart. Jour. vol. Silo 775i Barbatia (Calloarca) candida (Gmelin), Dall, Wagner Free Inst. Sci., Trans., vol. 3, pt. 4, p. 626. Arca (Barbatia) candida Gmelin, Dall and Simpson, U. S. Fish Com., Bull., vol. 20 for 1900, pt. 1, p. 460. Arca nivea Chemnitz, Lamy, Jour. Conchyl., vol. 55, p. 59 (part). Arca candida Gmelin, Sheldon, Palaeontographica Americana, vol. 1, No. 1, pp. 16-17. Arca (Calloarca) candida Gmelin, Maury, Bull. Amer. Paleont., vol. 8, No. 34, pp. 44-45. Arca bonaczyi Gabb, Pilsbry, Acad. Nat. Sci. Philadelphia, Proc., vol. 23, pt. 2, p. 403, pl. 39, figs. 1, 2. ? Barbatia cf. bonaczyi Gabb, Hubbard, New York Acad. Sci. Scientific Survey of Porto Rico and the Virgin Islands, vol. 3, pt. 2, pp. 106-107, pl. 14, fig. 4. Barbatia (Calloarca) candida (Gmelin), Maury, Bull. Amer. Paleont., vol. 10, No. 42, pp. 194-195, pl. 8, fig. 6. Arca candida Gmelin, Richards, Jour. Paleont., vol. 9, No. 3, p. 256. Arca (Barbatia) candida Gmelin, McLean, Soc. Cubana Hist. Nat. “Felipe Poey”’, Mem., vol. 10, No. 1, p. 40. Arca (Barbatia) candida Gmelin, Clench and McLean, Soc. Cubana Hist. Nat. “Felipe Poey”, Mem., vol. 10, pt. 3, p. 160. Arca candida Guilding, Smith, East Coast Marine Shells, p. 28, pl. 4, fig. 3. Arca candida Helbling, Schwengel and Dranga, Nautilus, vol. 52, No. 1, Da2o: Barbatia candida (Helbling), Jaume and Pérez Farfante, Soc. Cubana Hist. Nat. “Felipe Poey’, Mem., vol. 16, No. 1, p. 38. Arca candida Gmelin, van Bentham Jutting, Geolog.-Mijnbouwk. Genootschap Nederland en Kolonien, Geol. ser., vol. 14, p. 77. Arca candida Helbling, Stewart, Nautilus, vol. 60, No. 1, p. 19. Arca (Barbatia) candida Gmelin, Lange de Morretes, Mus. Paranaense, Arq. vols 7arty 15) Ds 9: Arca (Barbatia) candida Gmelin, McLean, New York Acad. Sci. Scientific Survey of Porto Rico and the Virgin Islands, vol. 17, pt. 1, pp. 14-15, pl. 2, figs. 6, 8. Arca (Cucullaearca) candida Gmelin, Haas, Fieldiana-Zoology, vol. 34, No. 20, p. 203. Barbatia (Barbatia) candida (Helbling), Abbott, American Seashells, p. 342, pl. 27r. Barbatia candida (Helbling), Moore, Nautilus, vol. 71, No. 4, pp. 126-128. Barbatia candida (Helbling), Olsson and McGinty, Bull. Amer. Paleont., vol. 39, No. 177, p. 19. Barbatia candida (Helbling), Moore, Inst. Marine Sci., vol. 5, p. 154. Barbatia (Barbatia) candida (Helbling), Abbott, Acad. Nat. Sci. Phila- delphia, Mon. No. 11, p. 110. Barbatia (Barbatia) candida (Helbling), Nowell-Usticke, A Check List of the Marine Shells of St. Croix, p. 1. 60 BuLwetin 204 1961. Arca (Barbatia) cf. candida Helbling, van Regteren Altena, Koninkl. Nederl. Akad. Wetensch.-Amsterdam, Proc., ser. B, vol. 64, No. 2, p. 298. 1961. Barbatia (Barbatia) candida (Helbling), Warmke and Abbott, Carib- bean Seashells, p. 158, pl. 30i. Venezuelan shell of medium size, thin, subrhomboidal to sub- trapezoidal, with a slight but broad subcentral radial depression on the lower fourth of the valve. Anterior end gently rounded, the pos- terior lateral margin oblique, truncate to subtruncate, a little con- cave immediately below the end of the hinge line, the curve with the ventral margin acute to subacute, the central margin gently sinuous. Byssal gape forward of the middle, hardly embayed. Beaks anterior, low, appressed. Cardinal area relatively narrow, scored with four or five irregular, obtusely angulate ligamental grooves. Posterior rostration moderately wide, a little sunken, generally well defined by the posterior rib. Hinge nearly straight, narrowest a little posterior to the beak, widening slightly and gradually toward the extremities. Inner margin fluted throughout, the flutings lying under the termini of the external ribs, larger and more widely spaced along the posterior and anterior lateral borders, smaller and more numerous on the ventral border. Surface sculptured by fairly numerous, strong, somewhat nodulous radial ribs, most of the ribs single but some of them double, those on the posterior dorsal area more widely separated than the others. Crossing the radials are growth ridges, the ridges low and obscure on the disk but much more pronounced on the anterior and posterior dorsal areas, especial- ly the latter where they form strong elevated ropy crenations on the radial ribs. Color straw without, white within. Periostracum dark brown, shaggy, longest at posterior end. Dimensions.—Specimen A338a, left valve, length 29 mm.; height 19.5 mm.; thickness 8 mm. Specimen A391al-2, paired valves, length 13.4 mm.; height 7.2 mm.; thickness of attached valves 5.6 mm. Specimen D38la, right valve, length 31 mm.; height (base broken away ) 17.9 mm.; thickness 9.6 mm. Localities —Recent, on beach of Playa Grande Yachting Club, Distrito Federal. Seven specimens including four left valves, one right valve, and two doublets. Abisinia formation at W-30, eastern edge of Playa Grande village. One poorly preserved right valve the identity of which is in doubt. VENEZUELAN CENOZOIC PELECYPODS: WEISBORD 61 Remarks.—This species is distinguished from its congeners by the strongly crenate ribs on the posterior dorsal area. Range and distribution—Lower Miocene to Recent. Living from North Carolina, U.S.A., to Brazil, in shallow water. Pleistocene of Cuba, St. Eustatius, Barbados, and Venezuela. Pliocene of Trini- dad. Middle Miocene of the Dominican Republic. Lower Miocene of Puerto Rico. Barbatia (Acar) domingensis (Lamarck) Pl. 4, figs. 1-9 1819. Arca domingensis Lamarck, An. sans Vert., vol. 7, p. 40. Refers to Lister, pl. 233, fig. 67. 1864. Arca squamosa Lamarck, Krebs, The West Indian Marine Shells, p. 126. Not of Lamarck. 1867. Arca squamosa Lamarck, Guppy, Sci. Assoc. Trinidad, Proc., pt. 3, p. 164. Not of Lamarck. 1874. Arca squamosa Lamarck, Guppy, Geol. Mag., decade 2, vol. 1, p. 443. Not of Lamarck. 1878. Arca domingensis Lamarck, Mérch, Catalogue of West-India Shells, p. 15. 1878. Arca domingensis Lamarck, Arango y Molina, Contribucion a la Fauna Malacologica Cubana, p. 263. 1885. Arca (Acar) domingensis Lamarck, Smith, Voyage H.M.S. Challenger, Zoology, vol. 13, p. 265. 1886. Arca reticulata Chemnitz, Dall, Mus. Comp. Zool., Bull., vol. 12, p. 242. Not of Gmelin. 1889. Arca reticulata Gmelin, Dall, U. S. Nat. Mus., Bull. 37, p. 42. Not of Gmelin. 1889. Arca reticulata Gmelin, Dall, U. S. Nat. Mus., Proc., vol. 12, No. 773, p. 259. Not of Gmelin. 1891. Arca gradata Broderip, Baker, Acad. Nat. Sci. Philadelphia, Proc., vol. 43, p. 47. Not of Broderip. 1895. Barbatia (Acar) domingensis (Lamarck), Gregory, Geol. Soc. London, Quart. Jour., vol. 51, p. 291. 1898. Barbatia (Acar) reticulata (Gmelin), Dall, Wagner Free Inst. Sci., Trans., vol. 3, pt. 4, p. 629. Not of Gmelin. 1901. Arca reticulata Gmelin, Dall and Simpson, U. S. Fish Com., Bull., vol. 20 for 1900, pt. 1, p. 460. Not of Gmelin. 1907. Arca plicata Chemnitz, Lamy, Jour. Conchyl., vol. 55, pp. 80 (part), 83. 1907. Arca (Barbatia) domingensis Lamarck, Verrill, Connecticut Acad. Arts and Sci., Trans., vol. 12, p. 186. 1913. Arca reticulata Gmelin, Brown and Pilsbry, Acad. Nat. Sci. Philadelphia, Proc., vol. 65, p. 496. Not of Gmelin. 1915. Barbatia (Acar) reticulata (Gmelin), Dall, U. S. Nat. Mus., Bull. 90, p. 120. Not of Gmelin. 1916. Arca (Barbatia) reticulata Gmelin, Sheldon, Palaeontographica Ameri- cana, vol. 1, No. 1, pp. 20-21, pl. 4, figs. 8-12. Not of Gmelin. 1917. Barbatia (Acar) reticulata (Gmelin), Maury, Bull. Amer. Paleont., vol. 5, No. 29, p. 330, pl. 30, fig. 16. Not of Gmelin. 1920. Barbatia (Acar) reticulata (Gmelin), Maury, New York Acad. Sci. Scientific Survey of Porto Rico and the Virgin Islands, vol. 3, pt. 1, pp. 7-8. Not of Gmelin. 62 1920. 1920 1925. 1925. 1926. 1932. 1933. 1935. 1936. 1936. 1936. 1937. 19377. 1938. 1942. 1944. 1946. 1949, 1951. 1952. 1954. 1955. 1958. 1958. 1958. 1959. 1961. BULLETIN 204 Barbatia (Acar) reticulata (Gmelin), Maury, Bull. Amer. Paleont., vol. 8, No. 34, p. 45. Not of Gmelin. Barbatia (Acar) reticulata (Gmelin), Hubbard, New York Acad. Sci. Scientific Survey of Porto Rico and the Virgin Islands, vol. 3, pt. 2, p. 106. Not of Gmelin. Barbatia (Acar) reticulata (Gmelin), Maury, Bull. Amer. Paleont., vol. 10, No. 42, pp. 195-196, pl. 8, figs. 18, 21. Not of Gmelin. Barbatia (Acar) domingensis (Lamarck), Woodring, Carnegie Inst. Washington, Publ. No. 366, pp. 37-38, pl. 3, figs. 17, 18. Barbatia (Acar) reticulata (Gmelin), Gardner, U. S. Geol. Sur., Prof. Paper 142-A, p. 27. Not of Gmelin. Barbatia (Acar) domingensis (Lamarck), Grant, Nautilus, vol. 45, No. 4, p. 128. Araca domingensis Lamarck, Trechmann, Geol. Mag., vol. 70, No. 823, p. 34. Arca reticulata Gmelin, Richards, Jour. Paleont., vol. 9, No. 3, p. 256. Not of Gmelin. Arca (Acar) reticulata Gmelin, McLean, Soc. Cubana Hist. Nat. “Felipe Poey”, Mem., vol. 10, No. 1, p. 40. Not of Gmelin. Arca (Acar) reticulata Gmelin, Clench and McLean, Soc. Cubana Hist. Nat. “Felipe Poey”’, Mem., vol. 10, No. 3, p. 160. Not of Gmelin. Arca reticulata Gmelin, McLean, Nautilus, vol. 49, No. 4, p. 116. Not of Gmelin. Arca (Acar) reticulata Gmelin, Smith, East Coast Marine Shells, p. 28, pl. 3, fig. 4. Not of Gmelin. Barbatia (Acar) domingensis (Lamarck), Mansfield, State of Florida Dept. Conserv., Geol. Bull., No. 15, p. 199, pl. 10, fig. 13. Arca reticulata Gmelin, Richards, Geol. Soc. Amer. Bull., vol. 49, pt. 2, p. 1290. Not of Gmelin. Barbatia reticulata (Gmelin), Jaume and Pérez Farfante, Soc. Cubana Hist. Nat. ’Felipe Poey’, Mem., vol. 16, No. 1, p. 38. Not of Gmelin. Arca reticulata Gmelin, Hackney, Nautilus, vol. 58, No. 2, p. 56. Not of Gmelin. Arca (Acar) reticulata Gmelin, Jaume, Soc. Malac. “Carlos de La Torre”, Rev., vol. 4, No. 3, p. 98. Not of Gmelin. Arca reticulata Gmelin, Lange de Morretes, Mus. Paranaense, Arq., vol. Agnartonley Dero Arca (Acar) reticulata Gmelin, McLean, New York Acad. Sci. Scientific Survey of Porto Rico and the Virgin Islands, vol. 17, pt. 1, p. 15, pd. 2, fig. 5. Not of Gmelin. Arca reticulata Gmelin, Pulley, Texas Jour. Sci., vol. 4, No. 2, p. 180. Not of Gmelin. Barbatia (Acar) domingensis (Lamarck), Abbott, American Seashells, p. 343, pl. 27u. Barbatia (Acar) domingensis (Lamarck), Perry and Schwengel, Marine Shells of the Western Coast of Florida, p. 37, pl. 3, fig. 11. Barbatia domingensis (Lamarck), Olsson and McGinty, Bull. Amer. Paleont., vol. 39, No. 177, p. 19. Barbatia (Acar) domingensis (Lamarck), Abbott, Acad. Nat. Sci. Phila- delphia, Mon. No. 11, p. 111. Barbatia domingensis (Lamarck), Moore, Nautilus, vol. 71, No. 4, pp. 125, 128. Barbatia domingensis (Lamarck), Nowell-Usticke, A Check List of the Marine Shells of St. Croix, p. 1. Barbatia (Acar) domingensis (Lamarck), Warmke and Abbott, Carib- bean Seashells, p. 158, pl. 30d. VENEZUELAN CENOZOIC PELECYPODS: WEISBORD 63 Shell small and solid, swollen, boxlike, subrhomboidal, more or less distorted, with a subcentral radial depression from below the umbo to the ventral margin. Byssal gape a little behind the middle, slightly to moderately embayed. Posterior ridge well defined. An- terior end subtruncate to gently rounded, the posterior end oblique and slightly rounded, the curve with the ventral margin at the termination of the posterior ridge acutely rounded. Umbos broad, situated a little forward to considerably forward of center. Cardinal area narrow, bearing several irregular ligamental grooves rudely parallel with the hinge line. Hinge very gently arcuate, narrowest a little posterior to the beaks, widening gradually toward the ends. Muscle scars pronounced. Inner margin finely denticulate, the den- ticulations extending to the ends of the hinge. Sculpture consisting of numerous elevated radial cords separated by grooves of approxi- mately the same width, crossed by larger more or less equally spaced concentric ridges, the radial cords nodulated at the intercepts. Be- tween the concentric ridges, the interradial grooves appear as deep narrow rectangular pits. Color straw on exterior, whitish or dull brown within, the muscle scars snow-white. Dimensions.—Specimen A385a, right valve, length 13.5 mm.; height 10.3 mm.; thickness 5.7 mm. Specimen A385b, left valve, length 20 mm.; height 12 mm.; thickness 5.8 mm. Specimen A385c, valves attached, length 12 mm.; height 9 mm.; thickness 7.4 mm. Specimen D 385a, right valve, length 12 mm.; height 6 mm.; thick- ness 3.4 mm. Specimen D 385b, left valve, length 12.9 mm.; height 7.5 mm.; thickness 4.1 mm. Localities—Recent, on beach of Playa Grande Yachting Club, Distrito Federal. Eighty-one specimens including thirty-three left valves, thirty-three right valves, and fifteen doublets, Abisinia for- mation at W-30, eastern edge of Playa Grande village. Thirty speci- mens including twelve left valves, eighteen right valves, and a num- ber of fragments. Remarks.—B. domingensis (Lamarck) is the West Indian shell referred to by authors as B. reticulata (Gmelin) (1791, Syst. Nat., p. 3311). B. reticulata, however, is from the Indian Ocean. Accord- ing to Woodring (1925c, p. 36), the illustration of A. reticulata by Chemnitz (1784, Syst, Conchylien-Cabinet, vol. 7, pp. 193-194, pl. 54, fig. 540) does not resemble the West Indian arcid that has been 64 BuLLeTIN 204 identified as reticulata. The nearest west American analogue of B. domingensis is B. rostae Berry (see Keen, 1958, p. 28, fig. 41) but that is not as boxlike as B. domingensis and has a much more pro- nounced radial depression. The Pleistocene to Recent west American B. gradata Broderip and Sowerby (see Keen, 1958, p. 28, fig. 40) has also been synonymyzed with D. domingensis but is much more coarsely ribbed. Range and distribution—The Recent B. domingensis (Lam- arck) ranges from North Carolina, U.S.A., to Brazil. It is usually found in shallow water under rocks but has been reported as deep as 287 fathoms by Dall (1889). In the Pleistocene, B. domingensis has been recorded from Florida, Cuba, Barbados, and the Panama Canal Zone; in the Pliocene from Florida and Trinidad; in the middle Miocene from Florida, Jamaica, and the Dominican Re- public; and in the lower Miocene from Florida and Puerto Rico. Barbatia (Fugleria) tenera (C. B. Adams) Pl. 4, figs. 10-13 1845. Arca tenera C. B. Adams, Boston Soc. Nat. Hist., Proc., vol. 2, p. 9. 1907. Arca tenera C. B. Adams, Lamy, Jour. Conchyl., vol. 55, p. 258. 1939. Arca (Barbatia) balesi Pilsbry and McLean, Notulae Naturae, No. 39, pp. 1-2, figs. 1a, b. 1950. Arca tenera C. B. Adams, Clench and Turner, Occas. Papers on Mollusks, vol. 1, No. 15, p. 348, pl. 43, figs. 1-2. 1951. Arca (Barbatia) tenera C. B. Adams, McLean, New York Acad. Sci. Scientific Survey of Porto Rico and the Virgin Islands, vol. 17, pt. 1, pals pled ties 2 1954. Barbatia (Fugleria) tenera (C. B. Adams), Abbott, American Seashells, pp. 343-344, pl. 27k. 1955. Barbatia tenera (C. B. Adams), Perry and Schwengel, Marine Shells of the Western Coast of Florida, p. 37, pl. 40, fig. 288. 1958. Barbatia tenera (C. B. Adams), Olsson and McGinty, Bull. Amer. Paleont., vol. 39, No. 177, p. 19. 1958. Barbatia (Fugleria) tenera (C. B. Adams), Abbott, Acad. Nat. Sci. Philadlephia, Mon. No. 11, pp. 110-111. 1959. Barbatia tenera (C. B. Adams), Nowell-Usticke, A Check List of the Marine Shells of St. Croix, p. 1. 1961. Barbatia (Fugleria) tenera (C. B. Adams), Warmke and Abbott, Carib- bean Seashells, p. 158, pl. 30g. Shell of medium size, thin, subtranslucent, moderately inflated, trapezoidal in outline, with a faint submedial radial depression ex- tending from below the umbo to the base. Hinge and base line subparallel, anterior end rounded, posterior end oblique, gently rounded to subtruncate, the curve with the posterior ventral margin acute, the ventral margin hardly embayed submedially. Beak an- VENEZUELAN CENOZOIC PELECYPODS: WEISBORD 65 terior, appressed on top. Cardinal area somewhat concave, narrowly sublanceolate but broader under the beaks. Hinge narrow, gently arcuate, narrowest posterior to the beak, with about 26 small teeth of which there are 16 anteriorward from the narrowest point of the hinge and 10 posterior from that point. Edge of inner margin closely but feebly fluted, the interior of the valve rayed with low fine cor- rugations reflecting the external riblets. Surface uniformly sculptured by narrow, beaded, or crenulated radial riblets generally alternating in size on the lower half of the disk, the riblets a little larger and the crenulations coarser near the well-rounded posterior ridge. The peri- ostracum is a thin fibrous mat, olive-brown in color, the fibers more closely spaced and longer on the posterior dorsal area adjacent to the posterior ridge. Shell color straw to light tan on the exterior, white within. Dimensions.—Specimen A389al-2, length 19 mm.; height 13 mm.; thickness of doublet 9.5 mm. Localty.—Recent, on beach of Playa Grande Yachting Club, Distrito Federal. Three specimens including two left valves and one doublet. Range and distribution —The living B. tenera (C. B. Adams) ranges from Florida to northern South America. I have not seen it recorded as a fossil. Arcopsis adamsi “Shuttleworth” (E. A. Smith) Pl. 4, figs. 14-17; Pl. 5, figs. 1-6 1845. Arca caelata Conrad, Fossils of the Medial Tertiary, p. 61, pl. 32, fig. 2. Not of Reeve, 1844, Conch. Icon., vol. 2, sp. 110. 1862. Barbatia (Arca) caelata (Conrad), Acad. Nat. Sci. Philadelphia, Proc., vol. 14, p. 580. Not of Reeve 1844. 1864. Arca Adamsi Shuttleworth, Krebs, The West Indian Marine Shells, p. 124. 1864. Arca solida Sowerby, Guppy, Sci. Assoc. Trinidad Proc., p. 36. Not of Sowerby, Zool. Soc. London Proc., p. 18. 1867. Arca Adamsi Shuttleworth, Guppy, Sci. Assoc. Trinidad, Proc., p. 164. 1878. Arca Adamsii Shuttleworth, Mérch, Catalogue of West-India Shells, p. 15. 1886. Arca Adamsi Shuttleworth, Dall, Mus. Comp. Zool., Bull., vol. 12, No. 6, p. 243. 1886. Arca Adamsi Shuttleworth var. Conradiana Dall, Mus. Comp. Zool., Bull., vol. 12, No. 6, p. 243. 1889. Arca Adamsi Shuttleworth, Dall, U. S. Nat. Mus., Proc., vol. 12, No. TiS; WS BSE 1889. Arca (Byssoarca) Adamsi Shuttleworth, Dall, U. S. Nat. Mus., Bull. 37, p. 42. 66 1889. 1890. 1891. 1895. 1897. 1898. 1901. 1902. 1907. 1910. 1913. 1914. 1915. 1916. 1916. 1919. 1920. 1920. 1925. 1925. 1926. 1926. 1928. 1932. 1935. 1935; 1936. 1937. 1937. BULLETIN 204 atea (Byssoarca) Adamsi var. Conradiana Dall, U. S. Nat. Mus., Bull. SD 42. Arca (Acar) Adamsii Shuttleworth MS ?, Smith, Linnean Soc. London, Jour., Zoology, vol. 20, p. 499, No. 52, pl. 30, figs. 6, 6a. Arca Adamsi Shuttleworth, Baker, Acad. Nat. Sci. Philadelphia, Proc., vol. 43, p. 47. Barbatia (Acar) Adamsii Shuttleworth, Gregory, Geol. Soc. London, Quart. Jour., vol. 51, p. 291. me (Acar) Adamsi Shuttleworth, von Ihering, Mus. Paulista, Rev., vol. 2, p. 80. Barbatia (Fossularca) Adamsi (Shuttleworth), Smith, Dall, Wagner Free Inst. Sci., Trans., vol. 3, pt. 4, pp. 629-630. Arca adamsi (Shuttleworth), Smith, Dall and Simpson, U. S. Fish Com., Bull., vol. 20 for 1900, pt. 1, p. 461. Arca (Fossularca) adamsi Smith var. conradiana Dall, U. S. Nat. Mus., Proc., vol. 24, No. 1264, p. 508, pl. 31, fig. 1. Arca Adamsi Shuttleworth, Lamy, Jour. Conchyl., vol. 55, pp. 104-105. Arca (Fossularca) Adamsi Dall, Vaughan, Carnegie Inst. Washington, Publ. No. 133, p. 171. Arca adamsi Smith, Brown and Pilsbry, Acad. Nat. Sci. Philadelphia, Proc., vol. 65, p. 496. Arca Adamsi Dall, Deussen, U. S. Geol. Sur., Water-Supply Paper 335, ps ze Barbatia (Fossularca) adamsi (E. A. Smith), Dall, U. S. Nat. Mus., Bull. 90, p. 121. Arca Adamsi var. Conradiana Dall, Sheldon, Palaeontographica Ameri- eana,-vol. 1,” No. “1; p.222, ‘pi:'"4, figs. 16-18- pl. 5, fig: 1. Arca Adamsi var. Conradiana Dall, Sheldon, Paleontographica Ameri- cana, vol. 1, No. 1, p. 22. Arca (Barbatia) adamsi Shuttleworth, Gardner and Aldrich, Acad. Nat. Sci. Philadelphia, Proc., vol. 71, p. 18. Arca (Fossularca) adamsi Shuttleworth, Maury, Bull. Amer. Paleont., vol. 8, No. 34, pp. 45-46. Arca (Fossularca) adamsi conradiana Dall, Maury, Bull. Amer. Paleont., vol. 8, No. 34, p. 46. Barbatia (Fossularca) adamsi (Shuttleworth), Smith, Maury, Bull. Amer. Paleont., vol. 10, No. 42, pp. 197-198, pl. 8, figs. 1, 8. Fossularca (Fossularca) adamsi sawkinsi Woodring, Carnegie Inst. Washington, Publ. No. 366, pp. 51-52, pl. 5, figs. 16-17. Barbatia (Fossularca) adamsi (Shuttleworth MS.), Gardner, U. S. Geol. Sur., Prof. Paper 142-A, p. 28, pl. 5, figs. 1-4. Arca (Barbatia) adamsi Shuttleworth, Weisbord, Nautilus, vol. 39, No. af5 ob Gyr Fossularca adamsi (Dall), Woodring, Carnegie Inst. Washington, Publ. No. 385, p. 18. “The subspecific name sawkinsi apparently should be sup- pressed”. See Woodring, 1925, above. Arca (Fossularca) adamsi (Shuttleworth MS.), Dall, Mansfield, Florida State Geol. Sur., Bull., No. 8, p. 45, pl. 7, figs. 1-3. Arcopsis adamsi (Smith), Reinhart, Mus. Roy. Hist. Nat. Belgique, Bull., vol. 11, No. 13, pp. 31-32. Arca adamsi Shuttleworth, Richards, Jour. Paleont., vol. 9, No. 3, p. 256. Arca (Acar) adamsi adamsi “Shuttleworth”, Smith, Clench and McLean, Soc. Cubana Hist. Nat. “Felipe Poey’, Mem., vol. 10, No. 3, p. 160. Arca (Acar) adamsi E. A. Smith, M. Smith, East Coast Marine Shells, Draoupla stig Ss Arcopsis adamsi (Dall), Mansfield, State of Florida Dept. Conserv., Geol. Bull. No. 15, pp. 16, 199-200. VENEZUELAN CENOzoIc PELECYPopDS: WEISBORD 67 1938. Arca adamsi Shuttleworth, Richards, Geol. Soc. Amer. Bull., vol. 49 pts 2pat290: 1939. Arca (Fossularca) adamsi Dall, Mansfield, State of Florida Dept. Conserv., Geol. Bull. No. 18, p. 31. 1939. Acar conradiana adamsi (E. A. Smith), fine and Rehder, Smith- sonian Miscel. Collections, vol. 98, No. 10, p. 18. 1942. Arcopsis adamsi (E. A. Smith), Jaume aaa Pérez Farfante, Soc. Cubana Hist. Nat. “Felipe Poey”’, Mem., vol. 16, No. 1, p. 38. 1946. Arca adamsi Smith, Stewart, Nautilus, vol. 60Nosolps 19: 1946. Arca (Acar) adamsi “Shuttleworth”, E. A. Smith, Jaume, Soc. Malac. “Carlos de La Torre”, Rev., vol. 4, No. 3, p. 98. 1947. Arca adamsi Smith, Richards, Jour. Paleont., vol. 21, No. 1, p. 26. 1949. Arca (Acar) adamsi adamsi “Shuttleworth’, E. A. Smith, Lange de Morretes, Mus. Paranaense, Arq., vol. 7, art. 1, p. 9. 1951. Arca (Acar) adamsi Smith, McLean, New York Acad. Sci. Scientific Survey of Porto Rico and the Virgin Islands, vol. 17, pt. 1, p. 16, pl. 2, fig. 4. 1953. Fossularca (Fossularca) adamsi (Dall), Olsson and Harbison, Acad. Nat. Sci. Philadelphia, Mon. No. 8, p. 36. 1954. Arcopsis adamsi (E. A. Smith), Abbott, American Seashells, p. 344, fig. 26b. 1955. Arcopsis adamsi conradiana (Dall), Perry and Schwengel, Marine Shells of the Western Coast of Florida, pp. 37-38, pl. 3, fig. 12. 1958. Arcopsis adamsi (E. A. Smith), Olsson and McGinty, Bull. Amer. Paleont., vol. 39, No. 177, p. 19. 1958. Arcopsis adamsi (E. A. Smith), Abbott, Acad. Nat. Sci. Philadelphia, Mon. No. 11, p. 111. 1958. Fossularca (Fossularca) adamsi (Dall), DuBar, Florida Geol. Sur., Geol. Bull. No. 40, p. 155. 1958. Arcopsis adamsi (E. A. Smith), Moore, Inst. Marine Sci., vol. 5, p. 154. 1959. Arcopsis adamsi (E. A. Smith), Nowell-Usticke, A Check List of the Marine Shells of St. Croix, p. 1. 1961. Arcopsis adamsi (Dall), Warmke and Abbott, Caribbean Seashells, p 159, pl. 30f. Shell small, inflated, boxlike, subrhomboidal in outline, with a slight submedial radial depression from well below the umbo to the base. Anterior end rounded, the hinge and base line parallel, the posterior end somewhat obliquely subtruncate, the ventral margin hardly embayed submedially. Posterior ridge high but rounded, the posterior dorsal area relatively broad. Beaks appressed, situated near the anterior third, the prodissoconch small and smooth. Cardinal area long and narrow, the ligamental scar a small triangular area directly below the beak. The hinge line proper is straight but the distal teeth of the hinge are arrayed in a gentle downward curve. Hinge teeth subequal, about 10 of them anterior to, and 18 posterior to the small edentulous gap underneath the ligamental caret. Muscle impressions enclosed within broad white slightly raised bands which 68 BuLLeTIN 204 converge dorsally under the umbo. The rim of the inner margin is rendered finely crenulate by the termini of the external riblets, but the border itself is smooth. Surface sculptured by numerous subequal radial riblets connected by finer concentric threads, the intercepts nodular or beaded, the pattern decussate. Toward the base, inter- stitial secondary riblets may be present. The interradial grooves of the disk are about the same width as the riblets and appear as nar- row rectangular pits, the corners made round by the nodules, the concentric threads in the interspaces separating the pits. The beads are larger and closer on the anterior than on the disk proper, and the posterior rostration is scabrous, with the ends of the nodules forming flutings or arches. The color of the Recent specimens is dull white on the surface, pale brown within except for the raised bands which are white. Dimensions —Specimen A386al-2, attached valves, length 11.6 mm.; height 7.8 mm.; thickness 6.7 mm. Specimen C386a, right valve, length 9.7 mm.; height 6.2 mm.; thickness 3 mm. Specimen C386b, left valve, length 10.1 mm.; height 6.8 mm.; thickness 3.5 mm. Specimen C396a, juvenile right valve, length 2.4 mm.; height 1.5 mm. Localities Recent, on beach of Playa Grande Yachting Club, Distrito Federal. One specimen, a doublet. La Salina de Guaiguaza, west of Puerto Cabello, State of Carabobo. Five specimens including three left valves and two right valves. Remarks.—This species is readily recognized by the small liga- mental caret on the cardinal area under beak, by the raised lateral bands converging to the umbo in the interior, and by the fluted ex- ternal ribs. The Pleistocene to Recent A. solida (Sowerby) is the west American analogue of A. adamsi, and A. afra (Gmelin) (see Hertlein and Strong, 1943, p. 158) is said to be the Eastern At- lantic congener. Typically, A. solida, which ranges from Baja Cali- fornia to Peru, is thicker and more gibbous than A. adamsi. Range and distribution—Recent, from Cape Hatteras, North Carolina to Brazil, in shallow water to 116 fathoms. Pleistocene in South Carolina, Florida, Cuba, Panama Canal Zone, and Barbados. Pliocene in North Carolina, South Carolina, Florida and Trinidad. Upper Miocene in Virginia, North Carolina, South Carolina, Georgia, VENEZUELAN CENOZOIC PELECYPODS: WEISBORD 69 Florida, and Texas (?). Middle Miocene of Jamaica and Trinidad. Lower Miocene of Florida. Anadara (Larkinia) notabilis (Réding) Pl. 5, figs. 7-10 1798. Arca notabilis Réding, Mus. Boltenianum, p. 173 (refers to Chemnitz, Syst. Conchylien-Cabinet, vol. 7, pl. 55, fig. 459). 1843. Arca Deshayesii Hanley, An Illustrative and Descriptive Catalogue of Recent Bivalve Shells, p. 157 (footnote). 1844. Arca Deshayesii Hanley, Reeve, Conch. Icon., vol. 2, Arca, pl. 7, sp. 47. 1845. Arca Deshayesii Hanley, Philippi, Abbildungen und _ Beschreibungen Conchylien, vol. 1, Arca, p. 6, pl. 2, fig. 3. 1845. ? Arca hemidermos d’Orbigny, [in] La Sagra, Hist. Fis., Polit., y Nat. Isla de Cuba, vol. 5, pt. 2, Moluscos, p. 345. 1845. ? Arca hemidermos d’Orbigny, Philippi, Abbildungen und Beschreibungen Conchylien, vol. 1, Arca, pl. 2, fig. 5. 1853. Arca notabilis Bolton, Mérch, Catalogue Conchyliorum Comes de Yoldi, vol. 2, p. 41. 1864. Arca auriculata Lamarck, A. notabilis Bolten, A. Deshayesii Hanley, Krebs, The West Indian Marine Shells, pp. 124, 125. 1878. Arca notabilis Bolten, Mérch, Catalogue of West-India Shells, p. 16. 1878. Arca auriculata Lamarck, Arango y Molina, Contribucién a la Fauna Malacolégica Cubana, p. 262. 1881. Arca Deshayesit Hanley, Gabb, Acad. Nat. Sci. Philadelphia, Jour., ser. ZeVvOle Ss Darsiios 1886. Arca auriculata Lamarck, Dall, Mus. Comp. Zool., Bull., vol. 12, No. 6, pp. 241-242. Not of Lamarck. 1889. Arca aff. Deshayesii Hanley, Lorié, Samml. Geol. Reichs-Mus. Leiden, ser. 2, vol. 1, pp. 116-118, 141, pl. 1, fig. 9. 1889. Arca (Scapharca) auriculata Lamarck, Dall, U. S. Nat. Mus., Bull. 37, p. 40. Not of Lamarck. 1891. Arca Deshayesii Hanley, Baker, Acad. Nat. Sci. Philadelphia, Proc., vol. 43, p. 47. 1896. Arca Deshayesii Hanley, Heilprin [in] Sapper, translation by Maury and Harris, Jour. Geol., vol. 4, No. 8, p. 945. 1897. Arca (Anomalocardia) auriculata Lamarck, von Ihering, Mus. Paulista, Rev., vol. 2, p. 82. 1898. Scapharca (Scapharca) auriculata (Lamarck), Dall, Wagner Free Inst. Sci., Trans., vol. 3, pt. 4, pp. 649 (part), 659. Not of Lamarck. 1898. Scapharca (Scapharca) Deshayesi (Hanley), Dall, Wagner Free Inst. Sci., Trans., vol. 3, pt. 4, p. 659. 1900. Arca Deshayesii Hanley, Dautzenberg, Soc. Zool. France, Mém., vol. Shipi236- 1901. Arca deshayesii Hanley, Dall and Simpson, U. S, Fish Com., Bull., vol. 20 for 1900, pt. 1, p. 461. 1907. Arca deshayesi Hanley, Lamy, Jour. Conchyl., vol. 55, pp. 218-221. 1913. Arca deshayesi Hanley, Brown and Pilsbry, Acad. Nat. Sci. Philadelphia, Proc., vol. 65, p. 496. 1913. Arca deshayesii Hanley, Jenkins, Amer. Philos. Soc., Proc., vol. 52, No. 211, p. 457. 1916. Arca auriculata Lamarck, Sheldon, Palaeontographica Americana, vol. 1, No. 1, p. 50, pl. 11, figs. 15-18. 1916. Arca auriculata Lamarck, Sheldon, Palaeontographica Americana, vol. 1, No. 1, p. 50, pl. 11, fig. 19. Not of Lamarck. 70 DYE 1922. 1922. 1925. 1925. 1926. 1929. 1933. 1935. 1936. 1936. 1936. 1936. 1937. 1938. 1938. 1942. 1945. 1946. 1949. 1951. 1953. 1954. 1955. 1958. 1958. 1959. 1961. BuLLeETIN 204 Scapharca auriculata (Lamarck), Maury, Bull. Amer. Paleont., vol. 5, No. 29, p. 339, pl. 28, fig. 3. Not of Lamarck. Arca deshayesii Hanley, Remington, Nautilus, vol. 35, No. 4, p. 121. Arca auriculata Lamarck, Olsson, Bull. Amer. Paleont., vol. 9, No. 39, pp. 189, 193, 362, pl. 22, fig. 3. Not of Lamarck. Arca (Scapharca) auriculata Lamarck, Maury, Bull. Amer. Paleont., vol. 10, No. 42, p. 201, pl. 4, fig. 2. Not of Lamarck. Arca (Scapharca) deshayesi Hanley, Maury, Bull. Amer. Paleont., vol. 10, No. 42, pp. 201-203, pl. 4, fig. 3. Arca (Scapharca) auriculata Lamarck, Weisbord, Nautilus, vol. 39, No. 3, p. 82. Not of Lamarck. Arca (Scapharca) auriculata Lamarck, Anderson, California Acad. Sci., Proc., ser. 4, vol. 18, No. 4, pp. 149-150. Not of Lamarck. Scapharca cf. Deshayesi Hanley var., Trechmann, Geol. Mag., vol. 70, No. 823, pp. 34-35, pl. 4, fig. 1. Arca auriculata Lamarck, Richards, Jour. Paleont., vol. 9, No. 3, p. 256. Not of Lamarck. Arca auriculata Lamarck, McLean, Soc. Cubana Hist. Nat. “Felipe Poey”, Mem., vol. 10, No. 1, p. 39. Not of Lamarck. Arca auriculata Lamarck Clench and McLean, Soc. Cubana Hist. Nat. “Felipe Poey”, Mem., vol. 10, No. 3, p. 159. Not of Lamarck. Arca auriculata Lamarck, McLean, Nautilus, vol. 49, No. 4, p. 116. Not of Lamarck. Arca auriculata Lamarck, Richards, Nautilus, vol. 49, No. 4, pp. 133-134. Not of Lamarck. Arca auriculata Lamarck, Smith, East Coast Marine Shells, p. 26, pl. 3, figs. 8a, b. Not of Lamarck. Arca auriculata Lamarck, Perry, Schwengel, and Dranga, Nautilus, vol. 52, No. 1, p. 27. Not of Lamarck. Arca auriculata Lamarck, Richards, Geol. Soc. Amer. Bull., vol. 49, pt. 2, p. 1290. Not of Lamarck. : Anadara auriculata (Lamarck), Jaume and Pérez Farfante, Soc. Cubana Hist. Nat. “Felipe Poey”, Mem., vol. 16, No. 1, p. 38. Not of Lamarck. Arca auriculata Lamarck, van Benthem Jutting, Geolog.-Mijnbouwk. Genootschap Nederland en Kolonien, Geol. ser., vol. 14, p. 77. Arca (Scapharca) auriculata Lamarck, Jaume, Soc. Malac. “Carlos de La Torre”, Rev., vol. 4, No. 3, p. 98. Not of Lamarck. Arca (Arca) auriculata Lamarck, Lange de Morretes. Mus. Paranaense, ATG: VOla/part.1. py 9. Arca (Scapharca) auriculata Lamarck, McLean, New York Acad. Sci. Scientific Survey of Porto Rico and the Virgin Islands, vol. 17, pt. 1, p. 16, pl. 2, fig. 9. Not of Lamarck. Arca (Arca) deshayesi Hanley, Haas, Fieldiana-Zoology, vol. 34, No. 20, p. 203. Anadara (Larkinia) notabilis (Réding), Abbot, American Seashells, p. 344, pl. 27p. Anadara notabilis (Réding), Perry and Schwengel, Marine Shells of the Western Coast of Florida, p. 35, pl. 1, figs. 6a, b Anadara notabilis (Réding), Olsson and McGinty, Bull. Amer. Paleont., vol. 39, No. 177, p. 19. Anadara (Larkinia) notabilis (Réding), Abbott, Acad. Nat. Sci. Phila- delphia, Mon. No. 11, pp. 111-112. Anadara notabilis (Réding), Nowell-Usticke, A Check List of the Marine Shells of St. Croix, p. 1. Arca (Anadara) notabilis Roeding, van Regteren Altena, Koninkl. Nederl. Akad. Wetensch.-Amsterdam, Proc., ser. B, vol. 64, No. 2, p. 298. VENEZUELAN CENOzoIC PELECYPODS: WEISBORD 7A 1961. Anadara (Larkinia) notabilis Roding, Warmke and Abbott, Caribbean Seashells, p. 159, pl. 30h. Shell inflated, oblong-rhomboidal, slightly tapering anteriorly, auriculate behind. Anterior end rounded, base gently curved, pos- terior margin concave above. Beaks high, well forward, separated by a moderately wide lanceolate cardinal area which is scored with several long irregular obtusely angled ligamental grooves. Hinge line fairly straight, the hinge itself bearing numerous comblike teeth of which there are 15 to 18 anterior and 35 to 39 posterior. The posterior teeth are smaller than the anterior at the point of diver- gence of the hinge and tend to over-ride the initial anterior one. The anterior teeth at the point of divergence of the hinge may be larger than the ones immediately forward but they are longest at the distal end; the posterior teeth, on the other hand, enlarge gradually and regularly toward the posterior end. The teeth do not reach the basal margin of the hinge which is thick and smooth. Inner margin broadly corrugated. Exterior sculptured by 27 or 28 straight radial ribs crossed by numerous, more or less equally spaced concentric threads which are sharp in the interspaces but form crenations on the crest of the ribs particularly on the lower half of the disk and on the ends. The interspaces on the disk are as wide as, or in places a trifle wider, than the ribs themselves. The color of the Recent shell is whitish, and such of the periostracum as remains is brown and silky. Dimensions.—Recent specimen (A382a), right valve, length 30 mm.; height 22.3 mm.; thickness 9.5 mm. Fossil specimen ($382a), left valve, length 40 mm.; height 28.2 mm.; thickness 13.5 mm. Localities —Recent, on beach of Playa Grande Yachting Club, Distrito Federal. Two right valves. Playa Grande formation (Mai- quetia member) at W-23, north flank of Punta Gorda anticline. One left valve. Remarks.—The east American A. notabilis (Roding) has often been called A. auriculata Lamarck, but as pointed out by Abbott (1954) A. auriculata is from the Red Sea. The ribs of A. notabilis are straight, those of A. auriculata slightly curved. The middle Mio- cene Jamaican form referred by Dall (1898, p. 649) to A. auriculata Lamarck is A. prephina (Woodring) (1925, pp. 44-45, pl. 4, fig. 8). 72 BuLueTIN 204 Range and distribution—The living A. notabilis (Réding) ranges from northern Florida to Brazil, and is found near shore to 40 fathoms. As a fossil it occurs in the Pleistocene of Florida, Cuba, St. Kitts, St. Eustatius, the Panama Canal Zone, Curacao, Colombia, Venezuela, Barbados and Brazil; in the Pliocene of the Yucatan Peninsula and Costa Rica; and in the middle Miocene of Costa Rica, Colombia, and the Dominican Republic. Anadara (Larkinia) species Pl. 5, figs: Tie The internal mold of fine-grained calcareous sandstone indicates that the shell is large, elongate-rhomboidal, inflated, alate behind, with the high beaks situated well forward. The anterior and ventral margins are gently rounded, the posterior end obliquely subtruncate, the posterior ridge moderately high and subrounded. Cardinal area fairly broad, lanceolate, a little concave. Hinge line straight, the hinge with 16 anterior teeth and an estimated 48 posterior ones. The distal anterior teeth are relatively long and crowded, whereas the posterior teeth increase regularly and progressively in size from the point of divergence. The inner margin is crenulate, and judging from the number of crenations it is estimated that there are 22-24 radial ribs on the exterior. Dimensions.—Specimen M367a, length of doublet 67 mm.; height 42 mm.; thickness 38 mm. Locality.—Playa Grande formation (Catia member) at W-15, south side of Playa Grande road, 40 meters southeast of its inter- section with the Playa Grande Yachting Club road. One specimen, an internal mold of the valves attached. Remarks.—It is not possible to identify this species, but it seems to be of the same general form as the Miocene to Recent A. notabilis (Roding). Anadara (Lunarca) ovalis (Bruguiére) Pl. 5, figs. 13-16; Pl. 6, figs. 1-4 1789. Arca ovalis Bruguiére, Encycl. Méth., vol. 1, pt. 1, p. 110. 1791. Arca campechiensis Gmelin, Syst. Nat., ed. 13, p. 3312. 1817. Arca campechiensis Gmelin, Dillwyn, A Descriptive Catalogue of Recent Shells, vol. 1, p. 238 (part). 1822. Arca pexata Say, Acad. Nat. Sci. Philadelphia, Jour., 1st. ser., vol. 2, p. 268. 1824. 1828. 1841. 1844. 1844. 1845. 1845. 1860. 1860. 1862. 1864. 1867. 1871. 1874. 1878. 1880. 1884. 1889. 1891. 1892. 1897. 1898. 1901. 1903. 1907. 1912. 1913. 1913. 1914. 1916. 1920. 1924. VENEZUELAN CENOZOIC PELECYPODS: WEISBORD 73 Arca pexata Say, Acad. Nat. Sci. Philadelphia, Jour., 1st ser., vol. 4, p. 78. Arca americana (Gray), Wood, Index Testaceologicus Suppl., pl. 2 Arca, fig. 1. Arca pexata Say, Gould, A Report on the Invertebrata of Massachusetts, p. 95, fig. 60. Arca americana Wood, Reeve, Conch. Icon., vol. 2, Arca, sp. 21. Arca pexata Say, Reeve, Conch., vol. 2, Arca, sp. 22. Arca pexata Say, d’Orbigny, [in] La Sagra, Hist. Fis., Polit. y Nat. Isla de Cuba, pt. 2, vol. 5, Moluscos, p. 344. Arca pexata Say, Philippi, Abbildungen und Beschreibungen Conchylien, vol. 1, p. 45, pl. 1, fig. 4. Arca americana Wood, Holmes, Post-Pleiocene Fossils of South Carolina, p. 19, pl. 4, figs. 2, 2a. Arca Holmesti Stimpson, Smithsonian Inst. Checklist, p. 2. Arca (Argina) pexata Say, Conrad, Acad. Nat. Sci. Philadelphia, Proc., vol. 14, p. 580. Arca americana Gray, Krebs, The West Indian Marine Shells, p. 124. Arca pexata Say, Guppy, Sci. Assoc. Trinidad, Proc., pt. 3, p. 164. Arca americana Gray and A. holmesii Kurtz, Coues, Acad. Nat. Sci. Philadelphia, Proc., vol. 23, p. 132. Arca americana Wood, Tryon, Amer. Marine Conch., p. 179, pl. 37, fig. 470. Arca americana Gray, Mérch, Catalogue of West-India Shells, p. 16. Arca campechiensis Gmelin, Arango y Molina, Contribucién a la Fauna Malacologica Cubana, p. 262. Arca pexata Say, Tryon, Structural and Systematic Conchology, vol. 3, p. 255, pl. 126, figs. 46-47. Arca pexata Say, A. Holmesit Kurtz, and A. Americana Gray, Dall, U. S. Nat. Mus., Bull. 37, p. 40. Arca (Argina) pexata Say, Kobelt, Syst. Conchylien-Cabinet, p. 33, pl. 11, figs. 5-6. Arca americana Gray and A. pexata Say, Singley, Geol. Survey Texas, Fourth An. Rept., p. 385. Arca indica von Ihering (mon Gmelin), Jour. Conchyl., vol. 43, p. 214. Scapharca (Argina) campechensis (Dillwyn), Dall, Wagner Free Inst. Sci., Trans., vol. 3, pt. 4, pp. 650-652, 659. Arca (Scapharca) campechensis Dall and Simpson, U. S. Fish Com., Bull., vol. 20 for 1900, pt. 1, p. 461. Arca campechiensis Gmelin, Vanatta, Acad. Nat. Sci. Philadelphia, Proc., vol. 55, p. 756. Arca (Argina) campechiensis Gmelin, Lamy, Jour. Conchyl., vol. 55, pp. 292-293. Arca (Argina) pariaensis Maury, Acad. Nat. Sci. Philadelphia, Jour., ser. 2, vol. 15, p. 47, pl. 8, figs. 7-9. Arca campeachiensis Dillwyn, Brown and Pilsbry, Acad. Nat. Sci. Phil- adelphia, Proc., vol. 65, p. 496. Arca (Scapharca) pexata var. holmesii Stimpson, Jenkins, Amer. Philos. Soc., Proc., vol. 52, No. 211, p. 457. Scapharca campechensis pexata (Say), and holmesii (Kurtz), Henderson and Bartsch, U. S. Nat. Mus., Proc., vol. 47, No. 2055, p. 412. Arca campechensis Dillwyn, Sheldon, Palaeontographica Americana, vol. 1, No. 1, pp. 61-63, pl. 15, figs. 6-13. Arca (Argina) campechensis Gmelin, Maury, Bull. Amer. Paleont., vol. 8, No. 34, pp. 51-52. Arca (Scapharca) campechiensis Gmelin, Jacot, Nautilus, vol. 38, No. 2D t9- ’ 74 1925. 1926. 1927. 1929. 1934. 1935. 1936. 1937. 1937. 1937. 1938. 1940. 1942. 1943. 1943. 1944. 1945. 1946. 1946. 1949. 1951. 1952. 19532 1954. 1961. 1961. BuLLeTIn 204 Scapharca (Argina) campechensis (Dillwyn), Maury, Bull. Amer. Pal- eont., vol. 10, No. 42, pp. 226-227, pl. 7, fig. 8. Bae (Argina) campechiensis Gmelin, Weisbord, Nautilus, vol. 39, No. ePsis2s Arca pexata Say, Wood, Nautilus, vol. 41, No. 1, p. 15. Arca (Scapharca) campechiensis Gmelin, Clench, Nautilus, vol. 43, No. pisos Arca (Argina) campechensis Gmelin, Maury, Amer. Mus. Nat. Hist., Bull., vol. 67, art. 4, pp. 160-161, pl. 18, fig. 5. Arca campechiensis Gmelin, Richards, Jour. Paleont., vol. 9, No. 3, p. 256. Arca campechiensis Gmelin, Richards, Nautilus, vol. 49, No. 4, p. 133. Arca campechiensis Gmelin, Smith, East Coast Marine Shells, p. 26, pl. 4, figs. 8a, b. Arca campechiensis pexata Say, Smith, East Coast Marine Shells, pp. 26-27, pl. 2, fig. 11. Arca campechiensis americana Wood, Smith, East Coast Marine Shells, pe 27,5 pleas tig: 13: Arca campechiensis Gmelin, Richards, Geol. Soc. Amer. Bull., vol. 49, pt. 3, p. 1290. Arca campechiensis Gmelin, Stenzel, Nautilus, vol. 54, No. 1, p. 20. Arca campechiensis Gmelin, Jaume and Pérez Farfante, Soc. Cubana Hist. Nat. “Felipe Poey”, Rev., vol. 16, No. 1, p. 38. Lunarca pexata (Gray), Reinhart, Geol. Soc. Amer., Spec. Papers No. 47, p. 75. Arca (Scapharca) campechiensis Gmelin, and A. campechiensis amert- cana Wood, Jacobson, Nautilus, vol. 56, No. 4, p. 141. Arca campechiensis Gmelin, Hackney, Nautilus, vol. 58, No. 2, p. 56. Arca campechiensis Gmelin, van Bentham-Jutting, Geolog.-Mijnbouwk. Genootschap Nederland en Kolonian, Geol. ser., vol. 14, p. 77. Arca campechiensis Gmelin, Stewart, Nautilus, vol. 60, No. 1, p. 19. Arca campechiensis Gmelin, Jaume, Soc. Malac. “Carlos de La Torre”, Rev., vol. 4, No. 3, p. 98. Arca campechiensis americana “Gray”, Wood, Lange de Morretes, Mus. Paranaense, Arq., vol. 7, art. 1, p. 9. Arca (Argina) campechiensis Gmelin, McLean, New York Acad. Sci. Scientific Survey of Porto Rico and the Virgin Islands, vol. 17, pt. 1, pp. 17-18, pl. 3, fig. 1. Arca campechiensis Gmelin, Pulley, Texas Jour. Sci., vol. 4, No. 2, p. 179, pl. 6, figs. 1-2. Arca (Argina) campechiensis pexata Say and A. campechiensis amert- cana Wood, Haas, Fieldiana-Zoology, vol. 34, No. 20, p. 203. Anadara (Lunarca) ovalis (Bruguiére), Abbott, American Seashells, p. 345, pl. 27t. Anadara ovalis (Bruguiére), Moore, Gulf Research Repts., vol. 1, No. 1 pp: 15; 36: Anadara (Lunarca) ovalis (Bruguiére), Warmke and Abbott, Caribbean Seashells, pp. 159-150, pl. 30m. The Recent Venezuelan shell is moderately large, fairly solid, inflated, porcelaneous, longer than high, obliquely subrhomboidal or subrectangular or suboval. Anterior end rounded, base gently round- ed to subtruncate, posterior end oblique and subtruncate, the pos- terior basal end well rounded and a little produced. Posterior ridge VENEZUELAN CENOzOIC PELECYPODS: WEISBORD 75 high, somewhat rounded. Posterior dorsal area alate, more so on small shells than on large. Beaks far forward, nearly touching each other, snugged into the cardinal area. Anterior to the beak, the cardinal area is short and wide; posteriorly it is narrowly lanceolate, the ligamental tegument scored with several long and sometimes obtusely angulated resilial grooves. Hinge fairly straight medially, curved downward at the ends, the anterior curve shorter and more pronounced that the posterior. Separating the anterior teeth from the posterior there is a small deep irregular fossette, and the margin of the hinge above the anterior teeth is thinned and elevated into an auricular plate or strong septum. On an average there are 8 anterior teeth and 29 posterior ones, the anterior teeth coarse and irregular and not infrequently coalescing, the posterior small and crowded near the fossette which they override, gradually becoming larger and more widely separated distally. Muscle scars distinct, the pallial line parallel with, and well removed from the ventral margin. Margin corrugated by broad flat crenations, the rim of the basal margin thin. Surface sculptured by square, flat-topped radial ribs, averag- ing 34 in number, crossed by numerous concentric striae and lamellae, the lamellae becoming more pronounced basalward. The ribs of both valves may be feebly grooved along the middle, the grooving perhaps a little more distinct on the right valve. At the base, the ribs are a little wider than the square-cut interspaces. The color is flesh on the exterior, white within. The periostracum is black-brown and closely lamellar. The Venezuelan fossil specimens are identical with the Recent ones. The radial ribs on young valves are tubular at the margin. Dimensions —Specimen A372b, length 32.5 mm.; height 25 mm.; thickness 10 mm. Left valve, Recent. Specimen A372a, length 35 mm.; height 27 mm.; thickness 12 mm. Right valve, Recent. Specimen T384b, length 33 mm.; height 20.5 mm.; thickness 10 mm. Left valve, fossil. Specimen T384a, length 39 mm.; height 27 mm.; thickness 11 mm. Right valve, fossil. Localities —Recent, on beach of Playa Grande Yachting Club, Distrito Federal. Forty-four specimens including twenty-eight right valves and sixteen left valves. Upper Mare formation, in stream 250 meters south-southwest of the mouth of Quebrada Las Pailas. 76 BuL.etIn 204 Twenty-five specimens including fifteen right valves and ten left valves. Mare formation at W-14, on hillside above west bank of Quebrada Mare Abajo. Four specimens, two of each valve. Lower Mare formation at W-13, on hillside above west bank of Quebrada Mare Abajo. Forty-six specimens including twenty-one right valves and twenty-five left valves. Lower Mare formation, in small stream 100 meters west of Quebrada Mare Abajo. Twenty-five specimens including fifteen right valves and ten left valves. Remarks.—Bruguiére’s A. ovalis seems to have been named prior to Gmelin’s well-known campechiensis. The species, though constant otherwise, is variable in shape, and this has given rise to such names as A. ovalis [campechiensis campechiensis] and A. hol- mest for the rounded form, A. americana for the elongated porcelane- ous form, and A. pexata for the somewhat elongated earthy form. My Recent Venezuelan shells are porcelaneous and approach A. pex- ata in shape. The largest of my fossil specimens is elongated like the variant A. americana. In Brazil (Jenkins, Haas) and elsewhere, roundish forms occur together with subrectangular ones, and to-day conchologists tend to agree with Dall (1898, p. 651) who, after study of a large series of Recent specimens, ranging from Jamaica to Cape Cod, was “obliged to recognize that no sharp line of dis- crimination can be drawn between the several varieties.” The [sub]generic name of Lunarca was proposed by Reinhart (1943, p. 75) as a substitute for Argina Gray, the latter having been preoccupied by a genus of Lepidoptera. Argina Gray is antedated by Argina Hiibner circa 1822 by about 20 years. Range and distribution —The living A. ovalis and its several forms is a far-flung species ranging from Cape Cod, Massachusetts, to Brazil. As a sub-Recent or Pleistocene fossil it has been reported from southern New England, New Jersey, Georgia, South Carolina, Florida, Louisiana (in wells), Cuba, the Panama Canal Zone, Vene- zuela and Brazil (Estado Rio Grande do Norte). Guppy listed the species (as A. pexata) from the Pliocene at Cumana, Venezuela, (see Lunarca aff. ovalis Bruguiére in collection 18408 at the U.S. National Museum) and Matura, Trinidad, and from the middle Miocene of the Dominican Republic, the last being referable, how- ever, to A. tolepia Dall (1898, pp. 649-650, pl. 33, figs. 1, 8). Maury VENEZUELAN CENOzoIC PELECYPODS: WEISBORD Tih recorded the present shell as a questionable late Miocene species in well No. 29 Jennings, Louisiana, at 1960-1980 feet. Anadara (Lunarca ?) caboblanquensis, new species Pl. 6, figs. 5-8 Shell small, moderately inflated, subquadrate, broadly alate be- hind, narrowed somewhat in front. Anterior and posterior ends gently rounded, the ventral margin obliquely subtruncate, the curve at the ventral posterior margin fairly acute. Beaks low, a little anterior, nearly touching, slightly sulcate on top, the sulcation broadening into a very feeble radial depression and continuing to the basal margin where it becomes obsolescent. Cardinal area extremely nar- row, lanceolate, concave. Hinge line sharp and straight, the hinge itself obtusely angulate, forming a small, more or less edentulous embayment under the beak. Left valve with four or five anterior teeth and seven or eight posterior teeth, the distal anterior end of the hinge a little broader than the distal posterior end. Margins scalloped or fluted at the rim, corrugated within by flat-topped crenations, each crenation lying under the corresponding intercostal groove of the exterior. Surface sculptured by 26 low square-cut radial ribs which are feebly crenulate, and, at the base of the disk, about as wide as the interspaces. Faintly decussating the exterior are rather regularly spaced concentric threads which stand out more sharply in the intercostal spaces than on the ribs themselves. Dimensions—Holotype (Q394a), left valve, length 2.1 mm.; height 1.8 mm.; thickness 0.9 mm.; Paratype (T394a), left valve, length 1.8 mm.; height 1.5 mm.; thickness 0.5 mm. Type locality —Playa Grande formation (Maiquetia member) at W-4, Quebrada Las Pailas. 2 left valves, including the holotype. Other localities —Upper Mare formation, in stream 250 meters south-southwest of mouth of Quebrada Las Pailas. One left valve, the paratype. Playa Grande formation (Maiquetia member) at W-23, north flank of Punta Gorda anticline. One left valve, badly corroded. Comparisons.—This new species is not only much smaller than the upper Miocene to Recent A. ovalis (Bruguiére), but it has fewer radial ribs and fewer teeth than that, and its beak is not situated so far forward. Also the faint radial depression (at least on the left 78 BuLLeTIN 204 valve) of A. caboblanquensis, n. sp. is wanting on A. ovalis. The subgeneric position of the new species is somewhat in doubt. Anadara (Lunarca ?) mareana, new species Pl. 6, figs. 9-12 Shell small, moderately inflated, subquadrate, broadly alate be- hind, narrowed a little in front. Anterior end well rounded, the pos- terior gently so, the base slightly rounded to obliquely subtruncate, the curve at the basal posterior margin fairly acute. Beaks situated a little forward, the umbos with a slight radial depression which broadens toward, but becomes obsolescent at the base. Cardinal area narrow, lanceolate, slightly concave. Hinge line fairly sharp and straight, the hinge itself slightly arcuate, with the posterior end curved slightly downward and the anterior end nearly straight. The posterior dorsal margin of the valve is thin and sharp, and the hinge line abuts into it immediately above the third from last tooth. There are 15 or 16 uninterrupted teeth of which 7 are anterior, the distal teeth scored by minute transverse grooves or striae. Margin scalloped or fluted at the rim, corrugated within by flat-topped denticles, the denticles lying under the corresponding intercostal grooves of the exterior, the ends of both the denticles and the external ribs tubular. Posterior muscle scar larger and lower than the anterior, the pallial line connecting them well removed from the ventral margin. Surface sculptured by 30 radial ribs, the ribs of the left valve seeming to be more uniformly beaded or crenate than those of the right valve, and perhaps a trifle wider than the latter at the base. Crossing the sur- face are regularly spaced concentric threads which stand out more sharply in the interspaces than on the ribs themselves. Dimensions —Holotype (J393a), length 3.6 mm.; height 3 mm.; thickness 1.5 mm. Right valve. Paratype (J393b), length 3.7 mm.; height 3.4 mm.; thickness 1.3 mm. Left valve. Type locality—Lower Mare formation, in small stream 100 meters west of Quebrada Mare Abajo. Two specimens including one right valve (holotype) and one left valve (paratype). Other localities —Mare formation at W-25, south flank of Punta Gorda anticline. One right valve. Comparisons.—A. mareana, n. sp. is close to A. caboblanquensts, n. sp. but differs from A. caboblanquensis in having several more VENEZUELAN CENOzoIC PELECYPoDS: WEISBORD 79 radial ribs and a wider cardinal area. Also the hinge of A. caboblan- quensts has an embayed area under the beak where it is more or less edentulous, whereas the teeth are continuous across the gently and evenly arcuate hinge of the present species. The well-known upper Miocene to Recent A. ovals (Bruguiére) is larger, is more generously ribbed and toothed, has the beak more forward, and lacks, in specimens of comparable size, the faint radial depression on the umbos. Anadara (Cunearca) brasiliana (Lamarck) Pl. 6, figs. 13-16 1819. 1822. 1824. 1844. 1845. 1857. 1860. 1864. 1864. 1867. 1871. 1878. 1889. 1891. 1891. 1892. 1895. 1895. 1898. 1898. 1903. 1904. 1907. 1913. Arca brasiliana Lamarck, An. sans Vert., vol. 6, p. 44. Arca incongrua Say, Acad. Nat. Sci. Philadelphia, Jour., 1st ser., vol. 2; PD: 268- Arca incongrua Say, Acad. Nat. Sci. Philadelphia, Jour., 1st ser., vol. 4, p. 78. Arca incongrua Say, Reeve, Conch. Icon., vol. 2, Arca, pl. 8, sp. 50. Arca brasiliana Lamarck, Philippi, Abbildungen und Beschreibungen Conchylien, Arca, vol. 1, p. 44, pl. 1, fig. 3. Arca incongrua Say, Tuomey and Holmes, Pleiocene Fossils of South Carolina, p. 45, pl. 16, figs. 5, 6. Arca incongrua Say, Holmes, Post-Pleiocene Fossils of South Carolina, p. 19, pl. 4, figs. 1, la. Arca incongrua Say, Guppy, Sci. Assoc. Trinidad, Trans., p. 41. Arca brasiliana Lamarck, Krebs, The West Indian Marine Shells, p. 124. Arca incongrua Say, Guppy, Sci. Assoc. Trinidad, Proc., p. 163 (part). Arca incongrua Say, Coues, Acad. Nat. Sci. Philadelphia, Proc., vol. 23, p. 133. Arca brasiliana Lamarck, Moérch, Catalogue of West-India Shells, p. 16. Arca (Scapharca) incongrua Say, Dall, U. S. Nat. Mus., Bull. 37, p. 40. Arca incongrua Say, Baker, Acad. Nat. Sci. Philadelphia, Proc., vol. 43, - 46. Hees (Scapharca) incongrua Say, Kobelt, Syst. Conchylien-Cabinet, Arca, p. 97, pl. 26, figs. 5-6. Arca incongrua Say, Singley, Geol. Survey Texas, Fourth An. Rept. p. 325. Arca incongrua Say, Harris, Bull. Amer. Paleont., vol. 1, No. 3, pp. 87-88. Arca (Scapharca) brasiliana Lamarck, von Ihering, Jour. Conchyl., vol. 43. 213. Scapharca (Cunearca) incongrua (Say), Dall, Wagner Free Inst. Sci., Trans., vol. 3, pt. 4, pp. 618, 635, 659. Scapharca (Cunearca) braziliana (Lamarck), Dall, Wagner Free Inst. Sci., Trans., vol. 3, pt. 4, p. 635. Arca incongrua Say, Vanatta, Acad. Nat. Sci. Philadelphia, Proc., vol. 55. ps7 56: Arca brasiliana Lamarck, Lamy, Jour. Conchyl., vol. 52, p. 162, pl. 5, fig. 3. Arca (Cunearca) brasiliana Lamarck, Lamy, Jour. Conchyl., vol. 55, pp. 263-268. Arca (Scapharca) braziliana Lamarck, Jenkins, Amer. Philos. Soc., Proc., vol. 52, No. 211, p. 457. 80 BuLueTiIn 204 1916. Arca incongrua Say, Sheldon, Palaeontographica Americana, vol. 1, No. 1, pp. 59-60, pl. 14, figs. 4-7. 1916. Arca brasiliana Lamarck, Sheldon, Palaeontographica Americana, vol. 1, No. 1, pp. 59-60, pl. 14, fig. 8. 1920. Scapharca (Cunearca) incongrua (Say), Maury, Bull. Amer. Paleont., vol. 8, No. 34, pp. 50-51. 1922. Scapharca (Cunearca) brasiliana (Lamarck), Maury, Palaeontographica Americana, vol. 1, No. 4, p. 36. 1937. Arca incongrua Say, Smith, East Coast Marine Shells, p. 27, pl. 3, fig. 2. 1938. Arca incongrua Say, Richards, Geol. Soc. Amer., Bull., vol. 49, pt. 2 p. 1290. 1945. Arca brasiliana Lamarck, van Bentham Jutting, Geolog.-Mijnbouwk. Genootschap Nederland en Kolonien, Geol. ser., vol. 14, p. 77. 1946. Arca incongrua brasiliana Lamarck, Stewart, Nautilus, vol. 60, No. 1, pro: 1949. Arca brasiliana Lamarck, Lange de Morretes, Mus. Paranaense, Arq., vol. 7, art. 1; p-.9- 1952. Arca incongrua Say, Pulley, Texas Jour. Sci., vol. 4, No. 2, p. 180, pl. 6, figs. 5-6. 1954. Anadara (Cunearca) brasiliana (Lamarck), Abbott, American Seashells, p. 346, pl. 27y. 1961. Anadara brasiliana (Lamarck), Moore, Gulf Research Repts., vol. 1, No. 1, pp. 15, 36. 1961. Anadara (Cunearca) brasiliana (Lamarck), Warmke and Abbott, Carib- bean Seashells, p. 160, pl. 30n. The Recent Venezuelan shell is inflated, moderately large and thin, rhomboidal in outline, the right valve always appearing a little distorted. Anterior end rounded, the posterior end oblique, and trun- cate to subtruncate. The ventral margin of the right valve is gently rounded to subtruncate whereas that of the left valve often has a gentle subangular curve at or a little aft of the middle, this part of the inferior edge always thinner and extending a little beyond the margin of the right valve. Posterior ridge high, subangulate. Umbos elevated, regularly convex, the beaks facing each other at the center of the cardinal area. Cardinal area lozenge-shaped, bounded by a deep groove, sloping down from under the beak toward the hinge and a little concave, generally marked, beneath the thin ligamental tegument, by numerous horizontal lineations which may be crossed by closely spaced vertical ones. The hinge line proper is straight, the hinge itself slightly arcuate and somewhat wider distally than along the narrow middle. Below the beak, the lower edge of the hinge is bowed down slightly at about the middle. Teeth 34 to 38, generally, but not always, with a few more of them occurring posteriorly than anteriorly. Inner border with broad flat slightly raised corrugations, each corrugation lying below the interspace of VENEZUELAN CENOZOIC PELECYPODS: WEISBORD 81 the external ribs. Pallial line distinct, the line a little embayed an- terior to the middle. Externally, the right valve has a feeble radial depression extending from the anterior side of the umbo to the ventral margin anterior to the middle. This depression is not present on the right valve. Sculpture consisting of about 30 radial ribs of which there are 10 on the posterior dorsal area. Left valve with all ribs wider than the interspaces which are narrow on the central area of the disk. Crossing the ribs of the left valve are regularly spaced beads, elongated in the concentric direction below, the bead- ing or crenation most prominent anteriorly and becoming obsolescent toward the posterior ridge. On the posterior rostration the crenation is relatively weak above, obsolescent below. On the right valve, the ribs are smooth and narrower than the interspaces between the radial depression and the posterior ridge, the ribs of the anterior and posterior ends, however, wider than the interspaces, the anterior ones strongly beaded or crenate, the posterior ones weakly crenate as the hinge is approached. On an occasional right valve there is one inter- stitial rib on the disk in the depressed area in front of the middle. Color creamy white on the surface, white within. Periostracum thin, light brown. Dimensions.—Left valve (A373b), length 39 mm.; height 32 mm.; thickness 14 mm. Right valve (A373a), length 35 mm.; height 29 mm.; thickness 12.2 mm, Average specimen, length 26.5 mm.; height 23.5 mm.; thickness (both valves) 22 mm. Localities —Recent, on beach of Playa Grande Yachting Club, Distrito Federal. Thirty-three specimens including twenty-five left valves and eight right. Recent, on beach east of Higuerote, State of Miranda. One specimen, a right valve. Remarks.—The distinguishing characters of A. brasilana are the thin valves, the even thinner ventral margin behind the middle of the left valve, the narrowness of the ribs on the disk of the night valve contrasted with the wider ones of the left valve, the basal overhang of the posterior ventral margin of the left valve, and the feeble radial depression in front of the middle of the right valve. Dall (1889, p. p. 635) was the first to call attention to the closeness of A. incongrua (Say) to A. brasilana (Lamarck), and present-day conchologists consider them the same. As pointed out 82 BuLLETIN 204 by Abbott (1954, p. 346), the Pleistocene to Recent A. chemnitz (Philippi) (1851, vol. 8, p. 50), living from Texas, U.S.A., to Brazil, is similar to A. brasilana but is smaller, and the beaks are slightly forward of the center of the cardinal area. A. willardaustent Maury (1917, p. 343, pl. 29, figs. 6-7) from the middle Miocene of the Dominican Republic has more ribs than A. brasiliana, and on the right valve there are two faint radial depressions, one in front of the middle and the other behind. Range and distribution—Recent—North Carolina, U.S.A., to Brazil. Pleistocene—In wells, Texas and Louisiana; South Carolina; Colombia; Venezuela; in bed of Rio Ceara-Mirim, 10 kilometers northwest of Extremoz, Rio Grande do Norte, Brazil. Upper Miocene —Galveston well (2433-2920 feet), Texas. Anadara (Cunearca) chemnitzi (Philippi) Pl. 23, figs. 2-5 1784. Arca rhombea var. Chemnitz, Syst. Conchylien-Cabinet, vol. 7, p. 212, pl. 56, fig. 553b. Not of Born 1778, Index Rerum Naturalium Musei Caesarei Vindobonensis, p. 76. 1851. Arca chemnitzi Philippi, Zeitschr. f. Malakozool., vol. 8, p. 50. 1864. Scapharca Chemnitzii (Philippi), Krebs, The West Indian Marine Shells, DeelZ5: 1878. Arca rhombea Born, Morch, Catalogue of West-India Shells, p. 16. Not of Born 1778. : 1889. Arca (Noetia) Orbignyi (Kobelt), Dall, U. S. Nat. Mus., Bull. 37, p. 40. 1891. Arca d’Orbignyi Kobelt, Syst. Conchylien-Cabinet, vol. 2, p. 57, pl. 16, figs. 7-8. 1895. Arca (Anomalocardia) Chemnitzi Philippi, von Ihering, Jour. Conchyl., vol. 43, p. 213. 1898. Scapharca (Cunearca) Chemnitzi (Philippi), Dall, Wagner Free Inst. Sci., Trans., vol. 3, pt. 4, pp. 636, 659. 1901. Arca (Scapharca) chemnitzi Philippi, Dall and Simpson, U. S. Fish Com., Bull., vol. 20 for 1900, pt. 1, p. 461. 1907. Arca Chemnitzi Philippi, Lamy, Jour. Conchyl., vol. 55, pp. 272-274. 1912. Scapharca (Cunearca) chemnitzi (Philippi), Maury, Acad. Nat. Sci. Philadelphia, Jour., vol. 15, pp. 44-45. 1916. Arca chemnitzi Philippi, Sheldon, Palaeontographica Americana, p. 60, pl. 15, figs. 3-4. 1920. Scapharca (Cunearca) chemnitzi (Philippi), Maury, Bull. Amer. Paleont., vol. 8, No. 34, p. 34. 1922. Scapharca (Cunearca) chemnitzi (Philippi), Maury, Palaeontographica Americana, vol. 1, No. 4, p. 34. 1925. Scapharca (Cunearca) chemnitzi (Philippi), Maury, Bull. Amer. Paleont., vol. 10, No. 42, pp. 220-221. 1935. Arca chemnitzi Philippi, Richards, Jour. Paleont., vol. 9, No. 3, p. 256. 1936. Arca chemnitzi Philippi, McLean, Soc. Cubana Hist. Nat. “Felipe Poey’, Mem., vol. 10, No. 1, p. 39. 1937. Arca chemnitzi Philippi, Smith, East Coast Marine Shells, p. 27, pl. 3, figs. 6a, b. VENEZUELAN CENOozoIc PELECYPoDS: WEISBORD 83 1940. Arca chemnitzii Philippi, Richards, Soc. Venezolana Cienc. Nat., Bol., vol. 6, No. 46, p. 306. 1942. Arca chemnitzi Philippi, Jaume and Pérez Farfante, Soc. Cubana Hist. Nat. “Felipe Poey”, Mem., vol. 16, No. 1, p. 38. 1943. Arca chemnitzi Philippi, Richards, Jour. Paleont., vol. 17, No. 1, p. 121. 1945. Arca chemnitzi Philippi, van Bentham Jutting, Geolog.-Mijnbouwk. Genootschap Nederland en Kolonien, Geol. ser., vol. 14, p. 77. 1949. Arca chemnitzi Philippi, Lange de Morretes, Mus. Paranaense, Arq., vol. Thy eres Ale joy Op 1951. Arca (Scapharca) chemnitzi Philippi, McLean, New York Acad. Sci. Scientific Survey of Porto Rico and the Virgin Islands, vol. 17, pt. 1, Dalply 2 tion 7 1952. Arca chemnitzi Philippi, Pulley, Texas Jour. Sci., vol. 4, No. 2, p. 179. 1954. Anadara (Cunearca) chemnitzi (Philippi), Abbott, American Seashells, p. 346. 1958. Anadara chemnitzi (Philippi), Olsson and McGinty, Bull. Amer. Paleont., vol. 39, No. 177, p. 19. Shell of medium size, inflated, slightly inequivalve, interior trhomboidal, exterior of disk triangular. Anterior end gently rounded, posterior end oblique and truncate, ventral margin gently rounded anteriorly, subtruncate posteriorly. Posterior ridge high, somewhat rounded. Beaks high, swollen, slightly forward of the center of the cardinal area. Cardinal area lozenge-shaped, bounded by a deep narrow groove, marked, beneath the thin ligamental tegument, by fine horizontal and vertical lineations. Hinge line straight, the hinge itself narrow throughout its length although a trifle wider near the ends where it is also curved a little downward. Total number of teeth 36 to 46 depending on the size of the shell, with generally a few more of them posteriorly than anteriorly, the “middle” of the hinge sometimes exhibited as a small, irregular edentulous depres- sion. The larger teeth at the ends of the hinge are often scored by fine vertical grooves. Inner margin corrugated by broad flat denticles each denticle lying under the corresponding intercostal groove of the exterior, the external ribs reflected through to the interior of the valve. Surface sculptured by 28 radial ribs, those of the left valve beaded more or less uniformly on the whole of the exterior, the beading of the right valve tending to become obsolescent posteriorly from the middle of the disk to the last 3 or 4 ribs on the posterior rostration. On both valves near the base the ribs are a little wider than the flat interspaces. Color whitish. Periostracum dark brown, closely lamellar on the posterior rostration, spinose in the grooves of the anterior half, the soft spines pointing upward. 84 BuLLeETIN 204 Dimensions—Specimen A659a, right valve, length 20 mm.; height 18.6 mm.; thickness 8.4 mm. Specimen A659b, left valve, length 19 mm.; height 18.7 mm.; thickness 8 mm. Specimen A659c, right valve, length 22.9 mm.; height 22.5 mm.; thickness 10 mm. Locality.—Recent, on beach of Playa Grande Yachting Club, Distrito Federal. Four specimens including two left valves and two right. Range and distribution—The living A. chemnitzi (Philippi) ranges from Texas to Brazil. As a fossil it has been reported from the Pleistocene of Cuba and the Island of Margarita, Venezuela. Van Bentham Jutting listed the species from the Quaternary at Punta Gorda, Venezuela, but the fossiliferous sediments at this locality are probably pre-Pleistocene in age. Anadara (Cunearca) cumanensis (Dall) Pl. 7, figs. 1-6 1867. Arca incongrua Say, Guppy, Sci. Assoc. Trinidad, Proc., pt. 3, p. 163 (part). Reprinted by Harris, 1921, Bull. Amer. Paleont.,, vol. 8, No. 35, p. 190. Not of Say, 1822, Acad. Nat. Sci. Philadelphia, Jour., 1st ser., vol. 2, p. 268. 1874. Arca incongrua Say, Guppy, Geol. Mag., decade 2, vol. 1, p. 443. Not of Say. 1898. Scapharca (Cunearca) cumanensis Dall, Wagner Free Inst. Sci., Trans., vol. 3, pt. 4, pp. 633-634. 1916. Scapharca (Cunearca) cumanensis Dall, Sheldon, Palaeontographica Americana, vol. 1, No. 1, p. 61. 1917. Scapharca (Cunearca) cumanensis Dall, Maury, Bull. Amer. Paleont., vol. 5, No. 29, p. 344. 1920. Arca (Cunearca) cf. cumanensis (Dall), McLean, New York Acad. Sci. Scientific Survey of Porto Rico and the Virgin Islands, vol. 3, pt. 1, . 11-12. 1925. Srephoncs (Cunearca) cumanensis Dall, Maury, Bull. Amer. Paleont., vol. 10, No. 42, pp. 222-223. The Cabo Blanco shell referred to A. cumanensis is of medium size, inflated, squarish rhomboidal, slightly inequivalve, the ventral margin of the left valve extending a little beyond the margin of the right valve. Anterior end rounded, the basal and posterior margins truncate, the latter oblique. Posterior ridge high, somewhat rounded. Beaks elevated, full, a little anterior to the center of the cardinal area. Cardinal area moderately broad, generally concave, lozenge- shaped, bounded by a deep narrow groove, marked by fine hori- zontal striae which are crossed by vertical lineations, occasionally engraved with wavy to lunate resilial grooves, the latter discon- VENEZUELAN CENOZzOIC PELECYPODS: WEISBORD 85 tinuous. Hinge line straight, the hinge itself curved downward some- what at the ends. Teeth 25 to 37 in all, with a range of 12 to 15 anterior ones and 13 to 30 posterior ones. There are a few more pos- terior teeth than anterior ones, and on well-preserved specimens most of the teeth are scored by fine closely spaced transverse grooves. Inner margin of valves corrugated into broad flat denticles, each denticle lying under the corresponding intercostal groove of the exterior. Surface sculptured by 28 squarish radial ribs, the ribs of the left valve more or less uniformly beaded or crenate on the whole of the valve, the beading of the right valve obsolescent on the posterior half of the disk. At the base, the radial ribs of the left valve are a little wider than the interspaces, whereas on the right valve the ribs are about the same width or a trifle narrower than the interspaces. On the right valve also a feeble interstitial thread may be present in the intercostal areas but none has been observed on the left valve. Fine concentric striae and lamellae overrun the surface, the latter more pronounced toward the base. On young specimens the ends of the ribs may be tubular. Dimensions—Specimen R374a, right valve, length 28.5 mm.; height 27.5 mm.; thickness 12.4 mm. Specimen R374b, left valve, length 27.5 mm.; height 26 mm.; thickness 11.3 mm. Largest speci- men (1377a), right valve, length 35.6 mm.; height 37.6 mm.; thick- ness 18 mm. Localities —Upper Mare formation, in stream 250 meters south- southwest of mouth of Quebrada Las Pailas. Two specimens, one of each valve. Mare formation near W-14, on hillside above west bank of Quebrada Mare Abajo. Six specimens including four left valves, one right valve, and one doublet. Lower Mare formation at W-13, on hillside above west bank of Quebrada Mare Abajo. Twelve specimens including eight left valves and four right valves. Lower Mare formation in small stream 100 meters west of Quebrada Mare Abajo. Eight specimens including six left valves and two right valves. Playa Grande formation (Maiquetia member) at W-4, Quebrada Las Pailas. Two broken specimens. Playa Grande forma- tion (Maiquetia member) at W-26 in Quebrada Las Bruscas ap- proximately 125 meters upstream from junction with Quebrada Las Pailas. Six specimens including three left valves and three right 86 BULLETIN 204 valves. Playa Grande formation (Maiquetia member) at W-23, north flank of Punta Gorda anticline. One worn specimen. Remarks.—A cumanensis (Dall) is closely related to the Pleisto- cene to Recent A. chemnitz (Philippi) but is distinguished from that by its broader hinge and fewer teeth. Both A. chemmnitzi and A. cwmanensis may be discriminated from the upper Miocene to Recent A. brasiliana (Lamarck) in being more tumid and in lacking the faint radial depression on the exterior. Range and distribution—A cumanensis (Dall) has been previ- ously recorded from Cumana, Venezuela (Pliocene ?), and from an island in Lago Henriquillo, Dominican Republic (middle Miocene ?). Anadara (Cunearca) species indeterminate Pl. "7; "Hes. "toca The cast, which is composed of a highly calcareous shelly sand- stone, indicates that the shell is of medium size, inflated, and sub- thomboidal, with an elevated and subrounded posterior ridge. The beaks are high and a little forward. The cardinal area is moderately broad, somewhat concave, and lanceolate. The hinge line is straight. A faint imprint on the anterior lower half of the left valve suggests that there is an interstitial riblet between the principal radial ribs. Dimensions.—Specimen M370a, left valve, length 25.5 mm.; height 25 mm.; thickness 10.5 mm. Locality —Playa Grande formation (Catia member) at W-15, south side of Playa Grande road, 40 meters southwest of its inter- section with the Playa Grande Yachting Club road. One specimen, the cast of a left valve. Remarks.—This form, which is included for the sake of com- pleteness, might be A. cwmanensts (Dall) or a species of similar ilk. GLYCYMERIDAE Glycymeris (Glycymeris) undata (Linnaeus) Pl. 7, figs. 9-12 1758. Arca undata Linnaeus, Syst. Nat., ed. 10, p. 695, No. 149. 1767. Arca undata Linnaeus, Syst. Nat., ed. 12, pt. 2, p. 1142, No. 179. 1784. Arca undata Linnaeus, Chemnitz, Syst. Chonchylien-Cabinet, vol. 7, p. 224, pl. 57, fig. 560. 1819. Pectunculus undatus (Linnaeus), Lamarck, An. sans Vert., vol. 6, p. 50. 1843. Pectunculus lineatus Reeve, Conch. Icon., vol. 1, pl. 5, sp. 25. VENEZUELAN CENOZzOIC PELECYPODS: WEISBORD 87 1846. Pectunculus hirtus Philippi, Zeitschr. f. Malakozool., vol. 3, p. 191. 1852. Axinea undata (Linnaeus), Moérch, Catalogue Conchyliorum Comes de Yoldi, pt. 1, p. 42. 1855. Arca undata Linnaeus, Hanley, Ipsa Linnaei Conchylia, p. 97. 1864. Pectunculus undatus (Linnaeus), Krebs, The West Indian Marine Shells, Pp. 127. 1878. Pectunculus undatus (Linnaeus), Moérch, Catalogue of West-India Shells, p. 16. 1886. Pectunculus undatus (Linnaeus), Dall, Mus. Comp. Zool., Bull., vol. 12, No. 6, pp. 238-239 (part). 1889. Pectunculus undatus (Linnaeus), Dall, U. S. Nat. Mus., Bull. 37, p. 42. 1889. Pectunculus undatus (Linnaeus), Dall, U. S. Nat. Mus., Proc., vol. 12, No. 773, p. 260. 1897. Pectunculus undatus (Linnaeus), von Ihering, Mus. Paulista, Rev., vol. 2; P= 09: 1900. Pectunculus undatus (Linnaeus), Verrill and Bush, Connecticut Acad. Arts and Sci., Trans., vol. 10, art. 12, p. 517. 1905. Pectunculus undatus (Linnaeus), Verrill, Connecticut Acad. Arts and Sci.,, Drans., vol. 12, art. 2, p. 186: 1911. Pectunculus undatus (Linnaeus), Lamy, Jour. Conchyl., vol. 59, p. 116. 1936. Glycymeris lineata (Reeve), McLean, Soc. Cubana Hist. Nat. “Felipe Poey”, Mem., vol. 10, No. 1, p. 40. 1938. Glycymeris lineata (Reeve), Richards, Geol. Soc. Amer., Bull., vol. 49, pt. 2; p. 1290. 1952. Arca undata Linnaeus, Dodge, Amer. Mus. Nat. Hist. Bull., vol. 100, art. 1, pp. 155-157. 1954. Glycymeris undata (Linnaeus), Abbott, American Seashells, p. 348, pl. 27g. 1959. Glycymeris undata (Linnaeus), Nowell-Usticke, A Check List of the Marine Shells of St. Croix, pp. 1, 2. 1961. Glycymeris undatus (Linnaeus), van Regteren Altena, Koninkl. Nederl. Akad. Wetensch.-Amsterdam, Proc., ser. B, vol. 64, No. 2, p. 299. 1961. Glycymeris undata (Linnaeus), Warmke and Abbott, Caribbean Sea- shells, p. 161. Shell small, solid, suborbicular, moderately inflated. Beaks fairly high, subcentral. Dorsal margin on either side of beak straight. Car- dinal area narrow, subtriangular. Hinge evenly arcuate, provided with 15 to 17 minutely striate teeth, with one more tooth on what is taken to be the anterior series than on the posterior series. The inner teeth are bent a little whereas the outer ones are stubbier, shorter, and obliquely directed. Inner margin crenulate, the crenula- tions extending well above the ends of the hinge plate. The crenula- tions on the lateral margins are in the form of short, single, oblique denticles, but starting at about the middle of the valve and continu- ing around the base the denticles are very narrowly bifid, with the points directed downward. There are in all about 64 crenulations on 88 BuLLeTIN 204 specimens some 10 millimeters or so in diameter. Muscle scars bor- dered by a ridgelet which converges toward the umbo but plays out beneath the base of the hinge plate. Surface sculptured by faintly beaded or crenate radial riblets which are crossed by numerous, ex- ceedingly fine concentric striae. On the umbo the radial riblets are single and stand out rather sharply, and across the upper part of the valve there are about 22 of them. Below the umbonal area inter- stitial riblets appear, and both those and the primary radials flatten out and become bipartite at the base. The interspaces are minutely and regularly punctate, the punctations probably representing points of attachment of the periostracum. Dimensions —Specimen S484a, right ? valve, length 10.8 mm.,; height 10.6 mm.; thickness 3.5 mm. Specimen [484a, right ? valve, length 9.7 mm.; height 9 mm.; thickness 3.2 mm. Specimen J482a, right ? valve, length 6.5 mm.; height 6.3 mm.; thickness 2 mm. Localities —Playa Grande formation (Maiquetia member) at W-23, north flank of Punta Gorda anticline. One right ? valve. Lower Mare formation at W-13, on hillside above west bank of Que- brada Mare Abajo. One right ? valve. Lower Mare formation, in small stream 100 meters west of Quebrada Mare Abajo. One right ? valve. Remarks.—The three Venezuelan fossil specimens are young and are similar to the immature shell of G. americana (DeFrance) illus- trated by Gardner (1943, pp. 27-28, pl. 1, figs. 18, 19) from the Pliocene at Neils Eddy Landing on the Cape Fear River of North Carolina. Although the Recent G. americana has been reported as far south as Brazil. Nicol (1953, pp. 451-455) indicated that the southern limit of G. americana s. s., either living or fossil, is Florida. The adult G. americana is said to be much flatter than the adult G. undata, but the young are much alike. Tentatively this fossil is re- ferred to G. undata as that is known to extend to the tropics. Range and distribution—The living G. wndata (Linnaeus) ranges from North Carolina to the West Indies at depths generally above 65 fathoms. As a fossil it occurs in the Pleistocene of Florida, St. Kitts, and St. Eustatius, and it has been reported as far back as the Miocene by Dall (1889, p. 42). VENEZUELAN CENOzOIC PELECYPODS: WEISBORD 89 Glycymeris (Tucetona) pectinata (Gmelin) Ply 7 uhigs 13,514: 1791. 1819. 1843. 1853. 1864. 1878. 1885. 1886. 1889. 1889. 1890. 1895. 1898. 1897. 1901. 1911. 1920. 1922. 1924. 1926. 1926. 1932. 1936. 1936. 1936. 1937. 1938. 1939. Pl. 8, figs. 1-4 Arca pectinata Gmelin, Syst. Nat., vol. 6, p. 3313. Pectunculus pectinatus (Gmelin), Lamarck, An. sans Vert, ed. 2, vol. 6, p. 494. Pectunculus pectinatus (Gmelin), Reeve, Conch. Icon., vol. 1, pl. 6, sp. 28. Pectunculus pectiniformis d’Orbigny, [in] La Sagra, Hist. phys., polit. nat. l’Ile de Cuba, Mollusques, vol. 2, p. 313. Not of Lamarck 1819, East Indies. Pectunculus pectinatus (Gmelin), Krebs, The West Indian Marine Shells, p. 127. Pectunculus pectinatus (Gmelin), Mérch, Catalogue of West-India Shells, p. 16. Pectunculus pectinatus (Gmelin), Smith, Voyage of H.M.S. Challenger, Zoology, vol. 13, p. 250. Pectunculus pectinatus (Gmelin), Dall, Mus. Comp. Zool., Bull., vol. 12, p. 239. Pectunculus pectinatus (Gmelin), Dall, U. S. Nat. Mus., Bull. 37, p. 42. Pectunculus pectinatus Lamarck, Simpson, Davenport Acad. Nat. Sci., Proc., vol. 5, p. 68. Pectunculus pectinatus (Gmelin), Smith, Linnean Soc. London, Jour., vol. 20, p. 503. Pectunculus pectinatus (Gmelin), Gregory, Geol. Soc. London, Quart. our. viol: 51, p; 291: Glycymeris pectinata (Gmelin), Dall, Wagner Free Inst. Sci., Trans., vol. 3, pt. 4, pp. 612-613. Pectunculus pectinatus (Gmlein), von Ihering, Mus. Paulista, Rev., vol. ZIPs 99: Glycymeris pectinatus (Gmelin), Dall and Simpson, U. S. Fish Com., Bull., vol. 20 for 1900, pt. 1, p. 459. Pectunculus pectinatus (Gmelin), Lamy, Jour. Conchyl., vol. 59, pp. 98- OOM ple 2, fig. 5. Glycymeris pectinata (Gmelin), Maury, Bull. Amer. Paleont., vol. 8, No. 34, p. 53. Glycymeris pectinata (Gmelin), Johnson, Nautilus, vol. 36, No. 1, p. 11. Glycymeris pectinata (Gmelin), Mansfield, Florida State Geol. Sur., Fifteenth An. Rept., list following p. 28. Glycymeris pectinata (Gmelin), Gardner, U. S. Geol. Sur., Prof. Paper 142-A, p. 38, pl. 9, figs. 9-12. Glycymeris pectinata (Gmelin), Weisbord, Nautilus, vol. 39, No. 3, p. 82. Glycymeris pectinata (Gmelin), Mansfield, Florida State Geol. Sur., Bull. No. 8, pp. 38-39, pl. 3, figs. 1, 7. Glycymeris pectinata (Gmelin), McLean, Nautilus, vol. 49, No. 4, p. 116. Glycymeris pectinata (Gmelin), McLean, Soc. Cubana Hist. Nat. “Felipe Poey”, Mem., vol. 10, No. 1, p. 40. Glycymeris pectinata (Gmelin), Clench and McLean, Soc. Cubana Hist. Nat. “Felipe Poey”’, Mem., vol. 10, No. 3, p. 162. Glycymeris pectinatus (Gmelin), Smith, East Coast Marine Shells, p. 29, pl. 2, fig. 8. Glycymeris pectinata (Gmelin), Richards, Geol. Soc. Amer., Bull., vol. 49, pt. 2, p. 1290. Glycymeris pectinata (Gmelin), Mansfield, State of Florida Dept. Conserv., Geol. Bull. No. 18, pp. 12, 18, 22, 25. 90 BuLtetin 204 1944. Glycymeris pectinata (Gmelin), Hackney, vol. 58, No. 2, p. 57. 1945. Glycymeris pectinata (Lamarck), van Bentham Jutting, Geolog.-Mijn- bouwk. Genootschap Nederland en Kolonien, Geol. ser., vol. 14, p. 77. 1946. Glycymeris pectinata (Gmelin), Jaume, Soc. Malac. “Carlos de La Torre” Rev., vol. 4, No. 3, p. 98. 1949. Glycymeris pectinata (Gmelin), Lange de Morretes, Mus. Paranaense, Arg:s vol:i7,;antl. p:o10: 1951. Glycymeris (Glycymeris) pectinatus (Gmelin), McLean, New York Acad. Sci. Scientific Survey of Porto Rico and the Virgin Islands, vol. 17, pt. Ie os wb yni ks thy wares Be 1954. Glycymeris pectinata (Gmelin), Abbott, American Seashells, p. 348, pl. 271. 1955. Glycymeris pectinata (Gmelin), Perry and Schwengel, Marine Shells of the Western Coast of Florida, pp. 38-39, pl. 3, figs. 14a, b. 1956. Glycymeris (Tucetona) pectinata (Gmelin), Nicol, Nautilus, vol. 70, No. 2, Pp. 51; 52: 1958. Glycymeris (Tucetona) pectinata (Gmelin), Abbott, Acad. Nat. Sci. Philadelphia, Mon. No. 11, p. 112. 1959. Glycymeris pectinata (Gmelin), Nowell-Usticke, A Check List of the Marine Shells of St. Croix, pp. 1, 2. 1961. Glycymeris (Tucetona) pectinata (Gmelin), van Regteren Altena, Koninkl. Nederl. Akad. Wetensch.-Amsterdam, Proc., ser. B, vol. 64, No. 2, p. 299. 1961. Glycymeris pectinata (Gmelin), Warmke and Abbott, Caribbean Sea- shells, p. 161, pl. 31a. The Venezuelan fossils referred to G. pectinata are of medium size, subequivalve, equilateral to inequilateral, a little inflated, sub- trigonal to suborbicular in outline. Typically, the posterior margin is obliquely truncate to slightly concave above, the ventral margin well rounded, and the anterior end gently rounded to subtruncate. Some specimens, however, are equilateral and orbicular. Beaks mod- erately high and central. Cardinal area fairly narrow, triangular, grooved with two to five resilial carets which are more or less paral- lel with the sides of the area. Hinge line straight, lying atop and truncating the inner teeth of the hinge. Hinge plate subangularly arched. Hinge teeth 19 to 24 in number, with usually one more on the anterior series than on the posterior, the ones near the beak chevron-shaped to bent, the distal ones oblique, all of them trans- versely and minutely striate. Internal ventral margin crenulate, the crenulations paired and corresponding to the spaces between the external radial ribs. Muscle scars pronounced, the posterior one a little larger and slightly lower than the anterior, the inner border of the scars bounded by a sharp ridgelet, the ridgelets converging toward the umbo but becoming obsolescent under the hinge plate. Exterior sculptured by 22 to 27 fanlike radial ribs, the ribs squarish VENEZUELAN CENOZzOIC PELECYPODS: WEISBORD 91 or somewhat rounded or occasionally subtriangular, crossed by con- centric striae and lamellae. At the basal margin the ribs may be wider than or about the same width as the intercoastal areas. Dimensions—Specimen G48la, left valve, length 24.6 mm.; height 24.5 mm.; thickness 6.1 mm. Specimen G481b, right ? valve, length 16 mm.; height 16 mm.; thickness 4.2 mm. Specimen G48Ic, left ? valve, length 7.2 mm.; height 7 mm.; thickness 3 mm. Speci- men H48la, left ? valve, length 25 mm.; height 26 mm.; thickness 7.1 mm. Specimen H481b, left valve, length 27.5 mm.; height 30 mm.; thickness 10 mm. Localities —Upper Mare formation, in stream 250 meters south- southwest of mouth of Quebrada Las Pailas. One specimen, a right valve. Mare formation at W-14, on hillside above west bank of Quebrada Mare Abajo. Eight specimens including four right valves and four left valves. Mare formation at W-25, south flank of Punta Gorda anticline. Three specimens including two left ? valves and one right valve. Lower Mare formation at W-13, on hillside above west bank of Quebrada Mare Abajo. Two specimens including one right valve and one left. Remarks.—On equilateral examples of this species, as on others of this genus, it is often difficult to distinguish posterior from an- terior, and even with inequilateral specimens paleontologists differ in their vews of what constitutes the front and rear of a valve. In this work the posterior end of G. pectinata is the one which is usually truncate, which has the larger and lower muscle scar, and which often has a tooth or two less on the hinge. Range and distribution—The living Glycymeris pectinata (Gmelin) ranges from North Carolina, U.S.A., to Brazil, in 2 to 874 fathoms. In the Pleistocene it has been found in South Caro- lina, Louisiana (Knapp’s no. 3 well at 670, 700-780 feet and New Orleans Gymnasium well at 1200 feet), Florida, St. Kitts, St. Eusta- tius, Venezuela (Paraguana), and Barbados. In the Pliocene it has been reported from North Carolina, South Carolina, and Florida; in the upper Miocene from Virginia, North Carolina, South Carolina, and Florida; and from the middle Miocene of Florida. Glycymeris pectinata is a variable species both in shape and character of the ribbing, and some authors have placed G. arata 92 BuLLeTIN 204 (Conrad) (1841, Am. Jour. Sci., vol. 41, p. 346) in synonymy with it. However, Olsson and Harbison (1953, pp. 30-31, pl. 1, figs. 6, 6a) examined and illustrated the holotype of G. arata and believe it should be considered a distinct species on the basis of its heavier shell, trigonal outline, and widely spaced ribs. According to their information, the typical G. arata seems to be restricted to the Mio- cene, Glycymeris (Glycymerella) decussata (Linnaeus) Pl. 8, figs. 5-10; Pl" 9) figssal 1758. Arca decussata Linnaeus, Syst. Nat., ed. 10, p. 694, No. 147. 1767. Arca decussata Linnaeus, Syst. Nat., ed. 12, p. 1142, No. 177. 1784. Arca decussata Linnaeus, Chemnitz, Syst. Conchylien-Cabinet, vol. 7, p. 226, pl. 57, fig. 561. 1789. Arca decussata Linnaeus, Bruguiére, Encycl. Méth., vol. 1, p. 112, pl. 310, fig. 5. 1819. Pectunculus pennaceus Lamarck, An. sans Vert., vol. 6, p. 51. 1843. Pectunculus pennaceus Lamarck, Reeve, Conch., Icon., Pectunculus, pl. 5, sp. 24. 1855. Arca decussata Linnaeus, Hanley, Ipsa Linnaei Conchylia, p. 96. 1864. Pectunculus decussatus (Linnaeus), Krebs, The West Indian Marine Shells, p. 126. 1864. Pectunculus decussata (Chemnitz), Guppy, Sci. Assoc. Trinidad, Trans., p. 36. 1867. Pectunculus pennaceus Lamarck, Guppy, Sci. Assoc. Trinidad, Proc., pt. 3, p. 164. é 1878. Pectunculus decussatus (Linnaeus), Mérch, Catalogue of West-India Shells, p. 16. 1878. Pectunculus decussatus (Linnaeus), Arango y Molina, Contribucién a la Fauna Malacolégica Cubana, p. 260. 1889. Pectunculus pennaceus Lamarck, Lorié, Samml. Geol. Reichs-Mus. Leiden, ser. 2, vol. 1, pp. 120, 141. 1895. Pectunculus (Axinea) pennaceus Lamarck, Gregory, Geol. Soc. London, Quart. Jour., vol. 51, p. 291. 1898. Glycymeris pennacea (Lamarck), Dall, Wagner Free Inst. Sci., Trans., vol. 3, pt. 4, pp. 608-609. 1901. Glycymeris pennaceus (Lamarck), Dall and Simpson, U. S. Fish Com., Bull., vol. 20 for 1900, pt. 1, p. 459. 1911. Pectunculus decussatus (Linnaeus), and P. pennaceus Lamarck, Lamy, Jour. Conchyl., vol. 59, p. 119, pl. 3, fig. 7. 1922. Glycymeris decussatus (Linnaeus), Olsson, Bull. Amer. Paleont., vol. 9, No. 39, pp. 352-353, pl. 19, figs. 6, 7. 1925. Glycymeris (Glycymerella) pennacea (Lamark), Woodring, Carnegie Inst. Washington, Publ. No. 366, p. 26. 1925. Glycymeris decussata (Linnaeus), Maury, Bull. Amer. Paleont., vol. 10, No. 42, pp. 182-183, pl. 18, fig. 14. 1933. Pectunculus (Glycimeris) pennaceus Lamarck, Trechmann, Geol. Mag., vol. 70, No. 823, p. 35. 1936. Glycymeris pennacea (Lamarck), McLean, Soc. Cubana Hist. Nat. “Felipe Poey”, Mem., vol. 10, No. 1, p. 40. 1936. Glycymeris pennacea (Lamarck), Clench and McLean, Soc. Cubana Hist. Nat. “Felipe Poey”, Mem., vol. 10, No. 3, p. 160. VENEZUELAN CENOZOIC PELECYPODS: WEISBORD 93 1937. Glycymeris pennaceus (Lamarck), Smith, East Coast Marine Shells, p. 29, pl. 8, figs. 7a, 7b. 1946. Glycymeris pennacea (Lamarck), Jaume, Soc. Malac. “Carlos de La Torre’, Rev., vol. 4, No. 3, p. 98. 1951. Glycymeris (Glycymerella) pennaceus (Lamarck), McLean, New York Acad. Sci. Scientific Survey of Porto Rico and the Virgin Islands, vol. 7 ptleep: IZ apliel tion 5. 1952. Arca decussata Linnaeus, Dodge, Amer. Mus. Nat. Hist., Bull., vol. 100, art. 1, pp. 153-155. 1953. Glycymeris (Glycymerella) decussata (Linnaeus), Olsson and Harbison, Acad. Nat. Sci. Philadelphia, Mon. No. 8, p. 30, pl. 1, fig. 3. 1954. Glycymeris decussata (Linnaeus), Abbott, American Seashells, p. 348, pl. 27h. 1958. Glycymeris (Glycymerella) decussata (Linnaeus), Abbott, Acad. Nat. Sci. Philadelphia, Mon. No. 11, p. 112. 1959. Glycymeris decussata (Linnaeus), Nowell-Usticke, A Check List of the Marine Shells of St. Croix, pp. 1, 2. 1961. Glycymeris (Glycymeris) decussata (Linnaeus), van Regteren Altena, Koninkl. Nederl. Akad. Wetensch.-Amsterdam, Proc., ser. B, vol. 64, No. 2, p. 299. 1961. Glycymeris decussata (Linnaeus), Warmks and Abbott, Caribbean Sea- shells, p. 160, pl. 31b. Shell fairly large, moderately inflated, broadly elliptical to sub- orbicular. Anterior and ventral margins rounded, the posterior end subangulate, the upper half obliquely truncate, the lower very gently rounded to subtruncate. Umbos low, the beaks sharp, nearly touching, opisthogyrate, located at about the posterior fourth of the cardinal area. Cardinal rudely lozenge-shaped, sunken, bounded on either side by a sulcus which widens hingeward, the posterior sulcus a little more pronounced than the anterior. On some spec- imens there is a hump on the cardinal area under the beak, and on well-preserved examples there are about three asymmetrically angu- late ligamental grooves, the anterior ones the longer. Hinge line short and nearly straight, lying atop and truncating the proximal anterior teeth. The hinge itself is usually gently and subangularly arched, but on two large right valves the smooth thickened basal margin of the hinge is nearly straight. Depending more or less on the size of the shell there are 18 to 29 teeth in all, of which there are 2 to 5 more on the anterior side than on the posterior. The proximal four to seven teeth of the anterior series are nearly vertical, and due to their truncation by the hinge line are relatively short, the distal ones heavier and a little curved. The posterior teeth nearest the beak are larger than the anterior and are chevron-shaped, the an- gulation becoming less pronounced, but the thickness of the teeth 94 BuLtetin 204 greater at the end of the hinge. All of the teeth are scored with fine closely spaced transverse grooves, the grooves a little sharper on the left face of each tooth as viewed with the umbos up. Inner margin of valve denticulate, the denticles small and pustular oppo- site the ends of the hinge, but bifid and progressively longer toward the middle of the base, the apex of the bifid denticles closed and pointing downward. Anterior muscle scar longer than the posterior, both of them bounded by a slightly raised ridgelet, the ridgelets con- verging toward the umbo but playing out beneath the base of the hinge plate. Surface sculptured by broad, gently rounded, hardly raised, evenly spaced radial ribs, which, with the spaces between them, are engraved by fine evenly spaced radial grooves of which there may be as many as nine from trough to trough at the basal margin. On the anterior and posterior ends of the valve the primary ribs as such disappear and are replaced by closely spaced radial cords or threads. The radials are impressed by exceedingly fine and numer- ous slanting striae which impart a delicate, minutely crenate, lat- ticed pattern. In addition, the surface is crossed by fine concentric striae which show to better advantage in the intercostal troughs when those are corroded. On the exterior, the Recent shell has a whitish ground with subradial markings, and with splotches of chest- nut on the umbo; the interior is white except under the hinge where it is clouded with chestnut. Dimensions.—Recent specimen A480a, right valve, length 19.5 mm.; height 17 mm.; thickness 5.2 mm. Fossil specimen [480a, left valve, length 34 mm.; height 30 mm.; thickness 16 mm. Fossil specimen 1490b, left valve, length 18 mm.; height 16.7 mm.; thick- ness 5.5 mm. Fossil specimen [480c, right valve, length 18 mm.; height 16.8 mm.; thickness 5.4 mm. Fossil specimen 1483a, immature right valve, length 7 mm.; height 5.9 mm.; thickness 1.9 mm. Largest fossil specimen J480a, right valve, length 58.0 mm.; height 57.8 mm.; thickness 21 mm. Fossil specimen T480a, right valve, length 33.4 mm.; height 30 mm.; thickness 11.5 mm. Localities —Recent, on beach of Playa Grande Yachting Club, Distrito Federal. One specimen, a right valve. Upper Mare forma- tion, in stream 250 meters south-southwest of mouth of Quebrada Las Pailas. Four specimens including three right valves and one left VENEZUELAN CENOzOIC PELECYPODS: WEISBORD 95 valve. Mare formation at W-25, south flank of Punta Gorda anti- cline. Seven specimens, all of them left valves. Lower Mare forma- tion at W-13, on hillside above west bank of Quebrada Mare Abajo. Thirty-one specimens including sixteen right valves and fifteen left valves. Lower Mare formation, in small stream 100 meters west of Quebrada Mare Abajo. Twenty-three specimens including thirteen left valves and ten right valves. Playa Grande formation (Maiquetia member) at W-23, north flank of Punta Gorda anticline. Fifty-five specimens including thirty right valves and twenty-five left valves. Remarks.—Lorié was the first to record this species from the Cabo Blanco area (“Muschelbank Cabo Blanco”), and so far as I can determine the fossils are indeed identical with the Recent G. decussata. The posterior position of the beak serves to differentiate G. decussata (Linnaeus) from the Pleistocene to Recent G. wndata (Linnaeus) on which the beak is at about the middle of the liga- mental area. The Recent G. spectralis Nicol (1952, pp. 266-257, figs. 1, 2) which ranges from North Carolina to Costa Rica has narrower and more prominent radial ribs than G. decussata. The middle Mio- cene G. jamaicensis Dall (1898, p. 608) (see Woodring, 1925, pp. 24-25, pl. 2, figs. 1-3) is similar to both G. decussata and G. undata, differing from G. decussata by its medial beak, and from G. wndata by having “stronger radial ribs on the upper half of the shell” (Woodring). Range and distribution —The living Glycymerts decussata (Lin- naeus) ranges from southeast Florida to northern South America. In the Pleistocene it occurs in Barbados, St. Kitts, and St. Eustatius. In the Pliocene it occurs at Matura, Trinidad, and near Cumana, Venezuela. In the upper Miocene ? it is reported from La Belle, Florida, and in the middle Miocene from Costa Rica and Trinidad. MYTILIDAE Brachidontes (Ischadium) recurvus (Rafinesque) Pl. 8, figs. 11-14 1820. Mytilus recurvus Rafinesque, An. Gén. Sci. Phys. Bruxelles, vol. 5, p. 1822. Miilus hamatus Say, Acad. Nat. Sci. Philadelphia, Jour., 1st ser., vol. » P- . 1823. Mytilus striatus Barnes, Amer. Jour. Sci. and Arts., 1st. ser., vol. 6, p. 364. BuLLeETIN 204 . Mytilus hamatus Say, American Conchology, unpaginated text, pl. 50, figs. 1-2, . Mytilus carolinensis Conrad, Acad. Nat. Sci. Philadelphia, Jour., 1st ser., vol. 7, p. 244, pl. 20, fig. 6. . Mytilus hamatus Say, Hanley, An Illustrated and Descriptive Catalogue of Recent Bivalve Shells, p. 46. . Mytilus hamatus Say, Reeve, Conch. Icon., vol. 7, pl. 3, sp. 7. . Brachydontes hamatus (Say), Perkins, Boston Soc. Nat. Hist., Proc., vol. 13, p. 156. . Mytilus carolinensis Conrad, Coues, Acad. Nat. Sci. Philadelphia, Proc., vol. 23, p. 134. . Modiola hamatus (Say), Verrill, Amer. Jour. Sci. and Arts, ser. 3, vol. chip AE lL vA apa . Mytilus carolinensis Conrad, Tryon, American Marine Conchology, p. 187, fig. 513. . Modiola hamatus (Say), Verrill, Amer. Jour. Sci. and Arts, ser. 3, vol. 10, p. 37. . Modiola hamatus (Say), Verrill, Connecticut Acad. Arts and Sci., Trans., vol. 5, pp. 577-578, fig. 10. . Mytilus hamatus Say, Clessin, [in] Syst. Conchylien-Cabinet, 2d ed., p. 77, pl. 11, figs. 9-10. . Mytilus hamatus Say, Simpson, Davenport Acad. Nat. Sci., Proc., vol. Sp 69) . Mytilus hamatus Say, Dall, U. S. Nat. Mus., Bull. 37, p. 38. . Mytilus hamatus Say, Baker, Acad. Nat. Sci. Philadelphia, Proc., vol. 43, p. 46. . Mytilus hamatus Say, Singley, Geol. Survey Texas, Fourth An. Rept., paoZo- . Mytilus (Hormomya) hamatus Say, Dall, Wagner Free Inst. Sci., Trans., vol. 3, pt. 4, p. 789. . Mytilus (Hormomya) hamatus Say, Dall and Simpson, U. S. Fish Com., Bull., vol. 20 for 1900, pt. 1, p. 469. . Brachydontes (Ischadium) hamatus (Say), Jukes-Browne, Malac. Soc. London, Proc., vol. 6, pp. 222-223. . Mytilus hamatus Say, Clark, Maryland Geol. Sur., Pliocene and Pleisto- cene, p. 203, pl. 60, figs. 5-6. . Mytilus hamatus Say, Maury, Bull. Amer. Paleont., vol. 8, No. 34, pp. 65-66. . Mytilus hamatus Say, Clench, Nautilus, vol. 38, No. 3, p. 94. . Mytilus hamatus Say, Clench, Nautilus, vol. 43, No. 1, p. 35. . Mytilus (Hormomya) recurvus Rafinesque, Johnson, Boston Soc. Nat. Hist., Proc., vol. 40, No. 1, p. 27. . Brachydontes (Ischadium) hamatus (Say), Lamy, Jour. Conchyl., ser. 4, vol. 34(80), pp. 196-198. . Mytilus recurvus Rafinesque, Smith, East Coast Marine Shells, p. 37, pl. 10, figs. 8a, b. . Mytilus hamatus Say, Wheeler, Nautilus, vol. 51, No. 3, p. 92. . Mytilus hamatus Say, Richards, Geol. Soc. Amer., Bull., vol. 49, pt. 2, p. 1291. . Mytilus recurvus Rafinesque, Stenzel, Nautilus, vol. 54, No. 1, p. 21. . Brachidontes (Ischadium) recurvus (Rafinesque), Gardner, U. S. Geol. Sur., Prof. Paper 199-B, pp. 29-30, pl. 1, figs. 7-8. Mytilus recurvus Rafinesque, Hackney, Nautilus, vol. 58, No. 2, p. 57. . Brachydontes (Ischadium) recurvus (Rafinesque), McLean, New York Acad. Sci. Scientific Survey of Porto Rico and the Virgin Islands, vol. 17, pt. 1, pp. 44-45, pl. 9, fig. 5. VENEZUELAN CENOzoIC PELECYPODS: WEISBORD 97 1952. Brachidontes recurvus (Rafinesque), Pulley, Texas Jour. Sci. vol. 4 No. 2, p. 180, pl. 6, figs. 17-18. 1954. Brachidontes (Ischadium) recurvus (Rafinesque), Abbott, American Seashells, p. 353, pl. 35n. 1955. Ischadium recurvus (Rafinesque), Soot-Ryen, Allan Hancock Expeditions, Univ. Southern California Press, vol. 20, No. 1, p. 36, text figs. 19-20. 1955. Brachidontes recurvus (Rafinesque), Perry and Schwengel, Marine Shells of the Western Coast of Florida, p. 52, pl. 7, fig. 24. 1959. Brachidontes recurvus (Rafinesque), Nowell-Usticke, A Check List of the Marine Shells of St. Croix, p. 3. 1959. Brachidontes recurvus (Rafinesque), Parker, Amer. Assoc. Petrol. Geol., Bull., vol. 43, No. 9, pp. 2121, 2122, 2161, 2165, pl. 1, fig. 12. 1961. Brachidontes recurvus (Rafinesque), Moore, Gulf Research Repts., vol. iNos1; pp. 15, 37. 1961. Brachidontes recurvus (Rafinesque), Warmke and Abbott, Caribbean Seashells, p. 162, pl. 31g. ’ The young Venezuelan shell referred to this species is small, broadly falcate, the ventral margin a little concave, the dorsal mar- gin subangularly rounded. Byssal gape small, situated well in front of the middle. Dorsum asymmetrically humped, the hump starting at the umbo and extending arcuately to the sharp curve at the posterior basal end of the valve. Ventral slope steep, dorsal and posterior slopes gentle. Beaks low, terminal. Umbonal end with three to five fairly long irregular teeth plus several small ones at the curve with the anteroventral margin. Ligamental groove rather shallow but fairly wide, the lower edge of the groove sharp. Behind the ligament, the internal margin is finely crenulate, the crenulations continuing around the margin to the corner of the byssal gape. In- terior slightly nacreous, the color white with large areas of violet- brown. Exterior sculptured by rather coarse but finely beaded radiat- ing ribs and numerous microscopic concentric striae. Additionally, there are widely spaced concentric rifts representing hiatuses in growth. The color of the surface is predominantly light brown with areas of dark brown and, near the basal posterior margin, brownish black. Dimensions.—Specimen A556al1-2, attached valves, length 9.7 mm.; max. width 6 mm.; thickness of doublet 5.1 mm. Locality.—Recent, on beach of Playa Grande Yachting Club, Distrito Federal. One young specimen, collected with valves at- tached. Range and distribution—Recent—Cape Cod, Massachusetts, to northern South America. In temperate regions B. recurvus is often 98 BuLLeTIN 204 found associated with oysters in waters of low salinity; in southern waters it often inhabits mangrove flats. Pleistocene—Massachusetts, Maryland, Florida, Louisiana (in well samples). Pliocene — North Carolina, Florida. Upper Miocene—Virginia. Modiolus americanus Leach Pl. 9, figs. 3-6 1775. 1815. 1819. 1857. 1864. 1873. 1878. 1884. 1889. 1889. 1891. 1898. 1901. 1903. 1907. 1920. 1923. 1934. 1936. 1936. 1936. L93i7e 1944. 1945. 195% 1952. Mytilus americanus Favart d’Herbigny, Dict. hist. nat. Test., vol. 3, p. 418. wee americana Leach, The Zoological Miscellany, vol. 2, p. 32, pl. 7A, see Ie Modiola tulipa Lamarck, An. sans Vert., vol. 6, p. 111. Modiola tulipa Lamarck, Reeve, Conch. Icon., vol. 10, pl. 4, sp. 15. Modiolus americana d’Herbigny, M. americana ? Leach, and M. tulipa Lamarck, Krebs, The West Indian Marine Shells, p. 128. Modiolus tulipa (Linnaeus), Tryon, American Marine Conchology, p. 187. Modiola americana d’Herbigny, Mérch, Catalogue of West-India Shells, p. 16. Modiola tulipa (Linnaeus), Tryon, Structural and Systematic Conchology, vol. 3, p. 263, pl. 128, fig. 95. Modiola tulipa (Linnaeus), Dall, U. S. Nat. Mus., Bull. 37, p. 38. Modiola tulipa (Linnaeus), Simpson, Davenport Acad. Nat. Sci., Proc., vol. 5, p. 69. Modiola tulipa (Linnaeus), Baker, Acad. Nat. Sci. Philadelphia, Proc., vol. 43, p. 46. Modiolus tulipus Lamarck, Dall, Wagner Free Inst. Sci., Trans., vol. 3, pt4 wpa 193 Modiolus tulipus Lamarck, Dall and Simpson, U. S. Fish Com., Bull. vol. 20 for 1900, pt. 1, p. 470. Modiolus tulipus (Linnaeus), Vanatta, Acad. Nat. Sci. Philadelphia, Proc., vol. 55, p. 756. Modiola tulipa Lamarck, Verrill, Connecticut Acad. Arts and Sci., Trans., vol. 12, art. 2, p. 186, pl. 35B, fig. 5. Modiolus tulipus Lamarck, Maury, Bull. Amer. Paleont., vol. 8, No. 34, p. 66. Modiolus tulipa (Linnaeus), Clench, Nautilus, vol. 37, No. 2, p. 55. Modiolus tulipus (Linnaeus), Johnson, Boston Soc. Nat. Hist., Proc., vol. 40, No. 1, p. 28. Modiolus tulipa americana Leach, Lamy, Jour. Conchyl., ser. 4, vol. 80, pp. 278-279. Modiolus tulipus (Linnaeus), McLean, Soc. Cubana Hist. Nat. “Felipe Poey”, Mem., vol. 10, No. 1, p. 40. Modiolus tulipus (Linnaeus), Clench and McLean, Soc. Cubana Hist. Nat. “Felipe Poey”, Mem., vol. 10, No. 3, p. 164. Modiolus tulipus (Linnaeus), Smith, East Coast Marine Shells, p. 38, pl. 1d; figs. Viay7b: Modiolus tulipa Lamarck, Hackney, Nautilus, vol. 58, No. 2, 57. Volsella tulipa (Lamarck), and V. americana (Leach), Rehder, Nautilus, vol. 59, No. 2, pp. 67-68. Modiolus (Modiolus) tulipa Lamarck, McLean, New York Acad. Sci. Scientific Survey of Porto Rico and the Virgin Islands, vol. 17, pt. 1, p. 39, pl. 8, fig. 4. Modiolus tulipus (Linnaeus), Pulley, Texas Jour. Sci., vol. 4, No. 2, p. 180, pl. 6, fig. 15. VENEZUELAN CENOzOIC PELECYPODS: WEISBORD 99 1953. Modiolus (Modiolus) tulifa (Linnaeus), Haas, Fieldiana-Zoology, vol. 34, No. 20, pp. 203, 204, 205. 1954. Volsella americana (Leach), Abbott, American Seashells, p. 351, pl. 35L. 1955. Modiolus americanus Leach, Soot-Ryen, Allan Hancock Expeditions. Univ. Southern California Press, vol. 20, No. 1, pp. 67-68, pl. 6, figs. 27-28, text fig. 56. 1955. Modiolus americanus Leach, Perry and Schwengel, Marine Shells of the Western Coast of Florida, p. 53, pl. 7, fig. 36. 1958. Modiolus americanus Leach, Keen, Sea Shells of Tropical West America, pp. 54-55, fig. 100. 1958. Modiolus americanus Leach, Abbott, Acad. Nat. Sci. Philadelphia, Mon. No. 11, p. 114. 1959. Volsella americana (Leach), Nowell-Usticke, A Check List of the Marine Shells of St. Croix, p. 3. 1961. Modiolus americanus Leach, Warmke and Abbott, Caribbean Seashells, p. 162, pl. 31k. Shell moderately large, thin, subtrapezoidal, somewhat elongat- ed, the posterodorsal side alate, the dorsum proper well inflated along the middle. Anterior end attenuate, acutely rounded, with a rather broad somewhat reflected margin, the posterior end relatively wide and evenly rounded, the ventral margin embayed and gently gaping a little in front of the middle. Extending from the anterior side of the umbo to the base there is an angulate depression ter- minating at the back of the byssal gape. Beak oblique, situated a little distance back from the anterior tip of the valve, virtually touching the reflected anterodorsal margin. Interior iridescent, violet under the umbo, but with wide concentric bands of pale green toward the rear. Exterior marked with faint concentric laminae, the color a burnt red or brown on the sides, the dorsum a deep rose with a number of unequal radial stripes of deep violet and purple. Perio- stracum straw-colored, disposed as a scaly integument around the margins back of the byssal gape, the integument developing into relatively sparse but long hairs which are matted every which way, and frequently with fine grains of sand enmeshed in them. Dimensions.—Figured specimen (A555al-2), length 41 mm.; max. width 21 mm.; thickness of doublet 18 mm. Locality.—Recent, on beach of Playa Grande Yachting Club, Distrito Federal. One doublet and one left valve. Remarks.—Although the generic name Volsella of Scopoli (1777, Introductio ad Historiam Naturalem) has priority, The International Commission on Zoological Nomenclature ruled, in Opinion 325 issued 7 January 1955, to conserve the later but better-known name of 100 BuLLetiIn 204 Modiolus Lamarck (1799, Soc. Hist. nat. Paris Mém., p. 87). Modiolus tulipus Lamarck, often referred to as M. tulipus (Linnaeus), is the same as M. americanus Leach, the latter having been named in 1815, the former in 1819. M. americanus is often difficult to distinguish, particularly in the young, from M. modiolus (Linnaeus), a northern species original- ly described from the Mediterranean, and identified in the Western Atlantic from the Arctic to northern Florida, in the Eastern Pacific from the Arctic to perhaps Monterey, California, and in the Western Pacific in Japan. Generally M. modiolus is separated from M. ameri- canus by its heavier shell and thicker, black-brown periostracum. Range and distribution—lIn the Western Atlantic Modiolus americanus Leach lives in shallow water from North Carolina, U.S.A., to Brazil. In Brazil the species has been found on the beach at Ilha Grande, in the intestine of a sea cucumber, and in the stomach of a sea slug (Haas). Soot-Ryen (1955, p. 68) stated that he was unable to separate certain Eastern Pacific specimens from others collected at Clearwater, Florida, and suggested tentatively that the range of M. americanus off the west coast of the Americas may be from Baja California to Ecuador. Musculus lateralis (Say) Pl. 9, figs. 7-8 1822. Mytilus lateralis Say, Acad. Nat. Sci. Philadelphia, Jour., ser. 1, vol. 2, p. 264. 1842. Modiola elliptica H. C. Lea, Amer. Jour. Sci., vol. 43, No. 1, pt. 11, p. 106, pl. 1, fig. 2. 1870. Modiolaria lateralis (Say), Conrad, Amer. Jour. Conch., vol. 5, pt. 2, INO:7,0p108- 1874. nee lateralis (Say), American Marine Conchology, p. 190, pl. 40, ig. 523. 1881. ? Crenella (Modiolaria) translucida, Gabb, Acad. Nat. Sci. Philadelphia, Jour., ser. 2, vol. 8, p. 377, pl. 47, fig. 81. 1886. Modiolaria lateralis (Say), Dall, Mus. Comp. Zool., Bull., vol. 12, No. 6, p. 236, pl. 6, figs. 7-8. 1889. Modiolaria lateralis (Say), Dall, U. S. Nat. Mus., Bull. 37, p. 40, pl. 6, figs. 7-8. 1889. an lig lateralis (Say), Simpson, Davenport Acad. Nat. Sci., Proc., vol. 5, 69. 1898. Modiolaria lateralis (Say), Dall, Wagner Free Inst. Sci., Trans., vol. 3, pt. 4, p. 807. 1901. Modiolaria lateralis (Say), Dall and Simpson, U. S. Fish Com., Bull., vol. 20 for 1900, pt. 1, p. 471. 1909. Modiolaria lateralis (Say), Vaughan, Florida Geol. Sur., Second An. Rept., p. 149. 1916. Modiolaria lateralis (Say), Thiele, Zool., Jahrb. Suppl. 11, p. 127. VENEZUELAN CENOzOIC PELECYPODS: WEISBORD 101 1920. Modiolaria lateralis (Say), Maury, Bull. Amer. Paleont., vol. 8, No. 34, p. 68. 1934. Modiolaria lateralis (Say), Johnson, Boston Soc. Nat. Hist., Proc., vol. 40, No. 1, p. 29. 1936. Musculus lateralis (Say), McLean, Nautilus, vol. 49, No. 4, p. 117. 1936. Modiolaria lateralis (Say), Lermond, Check List of Florida Marine Shells, Gulfport, p. 14. 1937. Modiolaria lateralis (Say), Lamy, Jour. Conchyl., ser. 4, vol. 35 (81), De o2de 1937. Modiolaria lateralis (Say), Smith, East Coast Marine Shells, p. 39, pl. 11, fig. 8. 1944. Modiolaria lateralis (Say), Hackney, Nautilus, vol. 58, No. 2, p. 57. 1951. Modiolaria lateralis (Say), New York Acad. Sci. Scientific Survey of Porto Rico and the Virgin Islands, vol. 17, pt. 1, p. 45, pl. 9, fig. 7. 1954. Musculus lateralis (Say), Abbott, American Seashells, p. 355, fig. 75d. 1955. Modiolaria lateralis (Say), Perry and Schwengel, Marine Shells of the Western Coast of Florida, p. 55, pl. 8, fig. 45. 1958. Musculus lateralis (Say), Olsson and McGinty, Bull. Amer. Paleont., vol. 39, No. 177, p. 19. 1958. Modiolaria lateralis (Say), Moore, Nautilus, vol. 71, No. 4, pp. 127, 128. 1958. Musculus lateralis (Say), Abbott, Acad. Nat. Sci. Philadelphia, Mon. No. 11, p. 114. 1959. Musculus lateralis (Say), Nowell-Usticke, A Check List of the Marine Shells of St. Croix, p. 4. 1961. Musculus lateralis (Say), Moore, Gulf Research Repts., vol. 1, No. 1, pp. 15, 38. 1961. Musculus lateralis (Say), Warmke and Abbott, Caribbean Seashells, p.1163;, plen3ile: Shell small, thin, subtranslucent, elongate-rhomboidal, some- what narrowed anteriorly, broader and produced posteriorly, moder- ately inflated. Posterodorsal margin nearly horizontal, posterior end obtusely angular, ventral margin obliquely truncated, the anterior end and the anterodorsal margin rounded and evenly continuous. Disk with a low broad rounded posterior ridge, a fairly wide pos- terior end, and a hardly discernible medial depression along the base of which the margin is slightly embayed. Umbonal area full and high, the beak somewhat appressed on top, directed forward, situated near the anterior end. Externally the posterior third of the valve and the narrower anterior submargin are sculptured by radiating, faintly crenated riblets, the riblets wanting on the middle area where only the fine faint concentric growth wrinkles appear. Interior glossy, the scars not distinguishable, the radial riblets of the exterior reflected through. Inner edge crenate except at the posterodorsal margin and middle of the ventral margin. Extending in a narrow stripe or band from the umbo to the ventral margin, the shell substance of the interior is whitened. 102 BuLLeTIN 204 Dimensions.—Specimen 1514a, left valve, length 2.1 mm.; height 1.5 mm. Locality —Lower Mare formation at W-13, on hillside above west bank of Quebrada Mare Abajo. One left valve. Range and distribution—The living M. lateralis ranges from Maine to northern South America in the Western Atlantic to depths of 30 fathoms. In the Pleistocene the species occurs in South Caro- lina and Florida, and in the Pliocene it has been reported from Florida. As pointed out by Dall, M. translucida (Gabb) from the Pliocene of Costa Rica is a similar species and may well be the same as M., lateralis (Say). Crenella divaricata (d’Orbigny) Pl. 9, figs. 9-12 1842. Nuculocardia divaricata d’Orbigny, [In] La Sagra, Hist. phys., polit. nat. l’Ile de Cuba, Mollusques, vol. 2, p. 311, Atlas, pl. 27, figs. 56-59. 1862. Nuculocardia divaricata d’Orbigny, Chenu, Man. Conchyl., vol. 2, p. 154, fig. 754. 1886. Crenella divaricata (D’Orbigny), Dall. Mus. Comp. Zool., Bull., vol. 1235p 3255 spare). 1889. Crenella divaricata (Orbigny), Dall, U. S. Nat. Mus., Bull. 37, p. 40. 1898. Crenella divaricata (Orbigny), Dall, Wagner Free Inst. Sci., Trans., vol. 3, pt. 4, p. 803. 1901. Crenella divaricata (d’Orbigny), Dall and Simpson, U. S. Fish Com., Bull., vol. 20 for 1900, pt. 1, p. 471. 1908. Crenella divaricata (Orbigny), Dall, Mus. Comp. Zool., Bull., vol. 43, No. 6, p. 410. 1920. Crenella divaricata (Orbigny), Dall, U. S. Nat. Mus., Bull. 112, p. 24. 1920. Crenella divaricata (d’Orbigny), Maury, Bull. Amer. Paleont., vol. 8, No. 34, p. 69. 1925. Crenella divaricata (d’Orbigny), Maury, Bull. Amer. Paleont., vol. 10, No. 42, p. 247, pl. 18, fig. 13. 1930. Crenella divaricata (d’Orbigny), Strong and Hanna, California Acad. Sci., Proc., ser. 4, vol. 19, Nos. 1, 3, pp. 4, 15. 1937. Crenella divaricata (Orbigny), Smith, East Coast Marine Shells, p. 39. 1937. Crenella divaricata (d’Orbigny), Lamy, Jour. Conchyl., ser. 4, vol. 35(81), pp. 60-61. 1938. Crenella divaricata (d’Orbigny), Vokes, Am. Mus. Novitates, No. 988, Dass: 1939. Crenella divaricata (d’Orbigny), Cockerell, Nautilus, vol. 53, No. 1, p. 22. 1942-43. Crenella divaricata (d’Orbigny), Rutsch, Naturforschenden Gesell. Verhandl., vol. 54 (1943), p. 101. 1946. Crenella divaricata (d’Orbigny), Hertlein and Strong, Zoologica, vol. SE es Fy eh Hey ole al sopece AR ee 1951. Crenella divaricata (d’Orbigny), McLean, New York Acad. Sci. Scien- tific Survey of Porto Rico and the Virgin Islands, vol. 17, pt. 1, p. 46, pl, u9y fig: 6; 1953. Crenella divaricata (d’Orbigny), Olsson and Harbison, Acad. Nat. Sci. Philadelphia, Mon. No. 8, p. 63. 1953. Crenella (Crenella) divaricata (Orbigny), Haas, Fieldiana-Zoology, vol. 34, No. 20, p. 203. VENEZUELAN CENOZOIC PELECYPODS: WEISBORD 103 1954. Crenella divaricata (Orbigny), Abbott, American Seashells, p. 350. 1955. Crenella divaricata (Orbigny), Soot-Ryen, Allan Hancock Pacific Ex- peditions. Univ. Southern California Press, vol. 20, No. 1, pp. 80-81, pl. 8, figs. 42, 44. 1958. Crenella divaricata (Orbigny), Keen, Sea Shells of Tropical West America, p. 50, fig. 88. 1958. Crenella divaricata (d’Orbigny), DuBar, Florida Geol. Survey, Geol., Bull. No. 40, p. 210. 1958. Crenella divaricata (d’Orbigny), Olsson and McGinty, Bull. Amer. Paleont., vol. 39, No. 177, p. 19. 1961. Crenella divaricata (Orbigny), Warmke and Abbott, Caribbean Sea- shells, p. 161, text fig. 26. Shell small, thin, inflated, obliquely subelliptical to suborbicular. Umbonal region high, the prodissoconch usually well preserved, acute, pure white, smooth, and sharply defined from the disk. Liga- ment narrow, sunken, tapering and descending posteriorly. In front of the ligament the hinge process is short, thick, and fairly broad, and is provided with three to four teeth of which there is one more on the left valve than on the right. Behind the ligament and par- tially over-riding it, the hinge, or margin of the valve, is a little thickened, narrowly lenticular, bearing about 11 short straight den- ticles of which the farther ones are the more pronounced. The entire inner margin of the valve is finely and regularly crenulate, the crenu- lations continuing without interruption from the hinge. Interior of valve coated wtih a calcareous wash which is often dissolved away revealing the external radii through the translucency. Under the wash the shell substance is faintly iridescent. Exterior sculptured by 70 to 80 delicate radial ribs which divaricate a little along a medial line from the beak toward the base. On each side of the disk there is a slightly more prominent curved rib, and from that the ribs on the anterior and posterior ends of the valve are sharply di- varicate. Also traversing the surface are fine concentric threads which stand out more sharply in the intercostal areas and form a decussate pattern, especially on the umbos. Dimensions —Specimen R487a, right valve, length 3.1 mm.; width 2.7 mm.; thickness 0.75 mm. Specimen R487b, left valve, length 2.9 mm.; width 2.4 mm.; thickness 0.7 mm. Localities —Playa Grande formation (Maiquetia member) at W-26, in Quebrada Las Bruscas, about 125 meters upstream from junction with Quebrada Las Pailas. Eleven specimens including eight 104 BuLLetin 204 left valves and three right valves. Playa Grande formation (Mai- quetia member) at W-23, north flank of Punta Gorda anticline. Two specimens including one left valve and one right. Lower Mare forma- tion, in small stream 100 meters west of Quebrada Mare Abajo. One left valve. Lower Mare formation at W-13, on hillside above west bank of Quebrada Mare Abajo. One right valve. Upper Mare forma- tion, in stream 250 meters south-southwest of mouth of Quebrada Las Pailas. One left valve. Remarks.—Specimens from West America are considered by a number of authorities to be the same as C. divaricata which was originally described by D’Orbigny from Cuba. Soot-Ryen would place the west American C. inflata Carpenter (1864, An. Mag. Nat. Hist., ser. 3, vol. 13, p. 313) and the Pliocene C. ecuadoriana Pilsbry and Olsson (1941, pp. 55-56, pl. 18, figs. 2, 3) from the Canoa for- mation of Ecuador in synonymy with C. divaricata, but compared with the Venezuelan fossils herein referred to C. divaricata, the Ec- uadorian shell is more coarsely sculptured and has a broader liga- ment. The northern race of C. divaricata is the Pleistocene to Recent C. decussata (Montagu) (1808, p. 69), and C. decussata has been reported from the Eastern Atlantic, the Western Atlantic (from Greenland to North Carolina), and the Eastern Pacific (from Bering Sea to Baja California, Mexico). C. decussata is more coarsely ribbed than C. divaricata, but the toothed hingelike process behind the ligament is much less conspicuous than on C. divaricata. The middle Miocene form referred to as C. divaricata by Gabb (1873, p. 252) and Maury (1917, pp. 358-359, pl. 26, fig. 18) from the Dominican Republic is C. diuturna Pilsbry and Johnson (1917, p. 195; Pilsbry, 1921, p. 414, text fig. 37). East American fossils close to C. divaricata are C. duplinensis Dall (1898, p. 804, pl. 35, fig 6) from the upper Miocene of North Carolina, C. duplinensis waltoniana Mansfield (1932, p. 71, pl. 9, figs. 5-7) from the late Miocene in Walton County, Florida, and C. armstrongi Gardner (1936, pp. 13- 14, pl. 1, figs. 5-6) from the middle Miocene in Folk’s Creek, Florida. C. duplinensis differs from C. divaricata “by its feebler sculpture, somewhat smaller shell, and especially by its much weaker hinge, with less conspicuous and strong crenulations. The line of divarica- tion of the sculpture is also more anterior and the beaks more re- curved” (Dall). C. duplinensis waltoniana has a heavier shell than VENEZUELAN CENOZOIC PELECYPODS: WEISBORD 105 both C. duplinensis and C. divaricata. C. armstrongt is sturdier and coarser than C. divaricata. Except perhaps for its slightly narrower ligament, the Venezuelan fossil seems identical to the living Western Atlantic C. divaricata. Range and distribution—In the Western Atlantic, C. divari- cata ranges from North Carolina, U.S.A., to Rio de Janeiro, Brazil, occurring in shallow water to 100 fathoms. In the Eastern Pacific it is reported from Southern California to Peru in 2-250 fathoms. The fossil C. divaricata is reported in the Pleistocene of San Cle- mente Island, California; in the Pliocene of Florida, Costa Rica, and Trinidad; and in the upper Miocene of Trinidad. Lioberus ? marensis, new species Pl. 9, figs. 13, 14 Shell small, moderately thick, modioliform, a little inflated, gently and obliquely humped from the umbo toward the base. Hinge smooth, the hinge plate robust, the anterior end of the plate recurved upward forming a thick septum or lamella rising above and rolled a little over the beak. The ligamental groove aft of the septum is wide and fairly shallow, and in the groove there is a narrow ridgelet which splays off from the back edge of the septum, the ridgelet lying near the lower margin of the ligamental groove and extending along it to near the middle, after which the ridgelet becomes obsolescent. Interior of valve vaguely iridescent, marked with a number of feeble narrow corrugations emerging from under the umbo. The posterior adductor impression is large, oval-oblong in outline, weakly striate. The anterior adductor scar is small, whitish, subtriangular. Exterior smooth but marked with faint con- centric growth lines, the lines appearing as fine threads on the back side of the septum at the beak. Dimensions—Holotype (I51la), left valve, the margins and part of the hinge broken away, length 5 mm.; width across umbo 3 mm.; thickness 1.3 mm. Type locality—Lower Mare formation at W-13, on hillside above west bank of Quebrada Mare Abajo. One broken specimen, the holotype. Remarks.—I have seen no other species with such a pronounced 106 BuLueTin 204 shield development of the hinge plate, and it may eventuate that even the genus is new. The Recent Lioberus castaneus (Say) (Acad. Nat. Sci. Philadelphia, Jour., Ist ser., vol. 2, p. 266) which ranges from Florida to the West Indies is thinner than the Venezuelan shell and the anterior margin of the hinge plate is not produced up- ward as a shield. The Recent Eastern Pacific L. salvadoricus (Hert- lein and Strong) (1946, p. 73, pl. 1, figs. 7, 11) which ranges from Sonora, Mexico, to Costa Rica in 2-16 fathoms, also lacks the um- bonal shield of the Venezuelan fossil. ISOGNOMONIDAE Isognomon alatus (Gmelin) Pl. 10; figs. A; 2 1791. Ostrea alata Gmelin, Syst. Nat., ed. 13, vol. 1, pt. 6, No. 129, p. 3339. Chemnitz, Syst. Conchylien-Cabinet, vol. 7, pl. 59, fig. 581. 1864. Melina alata (Gmelin), Krebs, The West Indian Marine Shells, p. 132. 1878. Isognomum alatum (Gmelin), Mérch, West-Indian Marine Shells, p. 16. 1878. Isognomon alatum (Gmelin), Arango y Molina, Contribucion a la Fauna Malacolégica Cubana, p. 269. 1901. Melina alata (Gmelin), Dall and Simpson, U. S. Fish Com., Bull., vol. 20 for 1900, pt. 1, p. 462. 1934. Pedalion alata (Gmelin), Johnson, Boston Soc. Nat. Hist. Proc., vol. 40, No. 1, p. 23. 1935. Perna alata (Gmelin), Richards, Jour. Paleont., vol. 9, No. 3, p. 256. 1936. Isognoma alata (Gmelin), McLean, Soc. Cubana Hist. Nat. “Felipe Poey”, Mem., vol. 10, No. 1, p. 40. 1936. Isognoma alata (Gmelin), Clench and McLean, Soc. Cubana Hist. Nat. “Felipe Poey”’, Mem., vol. 10, No. 3, p. 162. 1936. Pedalion alata (Gmelin), McLean, Nautilus, vol. 49, No. 4, p. 117. 1937. Pedalion alata (Gmelin), Smith, East Coast Marine Shells, p. 31, pl. 5, fig. 4. 1938. pies alata (Gmelin), Richards, Geol. Soc. Amer. Bull., vol. 49, pt. 2, Zoe 1940. Pietic alata (Gmelin), Smith, World-wide Sea Shells, p. 92, fig. 1267. 1942. Perna alata (Gmelin), Jaume and Pérez Farfante, Soc. Cubana Hist. Nat. “Felipe Poey”, Mem., vol. 16, No. 1, p. 38. 1951. Isognomon alata (Gmelin), McLean, New York Acad. Sci. Scientific Survey of Porto Rico and the Virgin Islands, vol. 17, pt. 1, p. 22, pl. 4, fig. 3. 1954. Isognomon alata (Gmelin), Abbott, American Seashells, p. 358, pl. 35b. 1958. Isognomon alata (Gmelin), Moore, Nautilus, vol. 71, No. 4, p. 128. 1958. Isognomon alatus (Gmelin), Olsson and McGinty, Bull. Amer. Paleont., Vols SOs NO. 17/7, pe to 1958. Isognomon alatus (Gmelin), Abbott, Acad. Nat. Sci. Philadelphia, Mon. No. 11, p. 115. 1959. Isognomon alatus (Gmelin), Nowell-Usticke, A Check List of the Marine Shells of St. Croix, p. 4. 1961. Isognomon alatus (Gmelin), Warmke and Abbott, Caribbean Seashells, p. 165, pl. 32c. VENEZUELAN CENOZOIC PELECYPODS: WEISBORD 107 The young Venezuelan shell referred to this species is flattish and suboval, with a low posterior wing forming an angle of about 121 degrees, and a well-rounded ventral margin. The byssal gape near the beak is rather pronounced, and the border of the gape on the left valve is thickened and lamellate. Hinge with 10 oblong sockets decreasing in size more or less progressively to the posterior end. Interior nacreous, with blotches of dull brown, dull purple and drab gray. Body cavity line about a third of the distance in from the basal margin. Exterior smoothish, but built up of appressed lamellae. The color of the exterior is brown to blackish brown, with several rays of dark brown diverging from the umbo. Dimensions.—Specimen B560a, left valve, height 40 mm.; max. width 37.8 mm.; thickness 3 mm. Locality.—Beach, southeast of Higuerote, State of Miranda. One specimen, a left valve. Range and distribution—The Recent J. alatus ranges from south Florida to northern South America and is said to be edible. In the Pleistocene it has been recorded from Florida and Cuba. PINNIDAE Pinna aff. carnea Gmelin Pl. 10, fig. 3 1791. Pinna carnea Gmelin, Syst. Nat., ed. 13, vol. 1, p. 3365. Refers to Knorr 1771, vol. 2, pl. 23, fig. 1. 1807. Pinna degenera Link, Beschreibung der Naturalien-Sammlung der Uni- versitat zu Rostock. Refers to Chemnitz 1785, vol. 8, pl. 87, fig. 769. 1819. Pinna flabellum Lamarck, An. sans Vert., vol. 6, p. 130. 1836. Pinna carnea Gmelin, Deshayes, An. sans Vert., ed. 2, vol. 7, p. 61. 1864. Pinna degenera Link, Krebs, The West Indian Marine Shells, p. 131 (part). 1889. Pinna carnea Gmelin, Dall, U. S. Nat. Mus., Bull. 37, p. 36. 1889. Pinna carnea Gmelin, Simpson, Davenport Acad. Nat. Sci., Proc., vol. Dy Je Ce 1898. Pinna carnea Gmelin, Dall, Wagner Free Inst. Sci., Trans., vol. 3, pt. 4, p. 661 (part). 1934. Pinna carnea Gmelin, Johnson, Boston Soc. Nat. Hist., Proc., vol. 40, Ptr ap= 22. 1936. Pinna carnea Gmelin, McLean, Nautilus, vol. 49, No. 4, p. 117. 1936. Pinna carnea Gmelin, McLean, Soc. Cubana Hist. Nat. “Felipe Poey”, Mem., vol. 10, No. 1, p. 40. 1936. Pinna carnea Gmelin, Clench, McLean, Soc. Cubana Hist. Nat. “Felipe Poey”’, Mem., vol. 10, No. 3, p. 162. 1937. Humng carnea Gmelin, Smith, East Coast Marine Shells, pp. 29-30, pl. 5 itige ls 108 BuLuetin 204 1939. Pinna carnea Gmelin, Bartsch and Rehder, Smithsonian Misc. Collec- tions, vol. 98, No. 10, p. 18. 1940. Pinna carnea Gmelin, Smith, World-wide Sea Shells, p. 93, fig. 1271. 1950. Pinna carnea Gmelin, Dodge, Amer. Mus. Nat. Hist., Bull. vol. 100, art. I pp. 225,,,224, 225: 1954. Pinna carnea Gmelin, Abbott, American Seashells, p. 360, pl. 27w. 1958. Pinna carnea Gmelin, Turner and Rosewater, Johnsonia, vol. 3, No. 38, pp. 306-310, pl. 149; pl. 150, figs. 1-2; pls. 151, 157. 1958. Pinna carnea Gmelin, Abbott, Acad. Nat. Sci. Philadelphia, Mon. No. iS pe 16: 1959. Pinna carnea Gmelin, Nowell-Usticke, A Check List of the Marine Shells of St. Croix, p. 5. 1961. Pinna carnea Gmelin, Warmke and Abbott, Caribbean Seashells, p. 166, pl. 34i. Shell large, fairly thick, narrowly wedge-shaped, rather regular- ly enlarging, the dorsal margin nearly straight, the side of the front half of the valve angulate along the middle. The surface is worn away but the impressions on nacreous slivers indicate that the dorsal slope of the anterior half of the valves is sculptured by about four low radiating slightly wavy ribs; the number of ribs on the ventral slope cannot be discerned clearly though there seem to be about the same number as on the dorsal slope. Dimensions —Specimen G359a (broken away at the ends and base), length 145 mm. Localities —Mare formation near W-14, on hillside above west bank of Quebrada Mare Abajo. One specimen, the valves attached, and with an internal filling of calcareous silt. Abisinia formation at W-30, eastern edge of Playa Grande village. One specimen represent- ing a portion of the anterior end; the valves are attached and filled with fine-grained calcareous sandstone. Remarks.— Although it is not possible to identify the Cabo Blanco fossils authoritatively, they show an affinity to the Recent Western Atlantic P. carnea Gmelin. Range and distribution—Pinna carena Gmelin ranges from Florida to northern South America. As a fossil it occurs in the Pleistocene of Florida, and if it can be assumed that east American species referred to P. rudis Linnaeus are in truth P. carnea Gmelin, then P. carnea probably occurs also in the Pliocene of Costa Rica (see Gabb, 1881, p. 378). The Mare formation of Venezuela referred to above is probably Pliocene in age and the Abisinia formation Ple- istocene. VENEZUELAN CENOZOIC PELECYPODS: WEISBORD 109 Comparisons —There are two other medially angulate fossil Pinnas from the Caribbean region and they are Pinna refurca Wood- ring (1925, pp. 56-57, pl. 6, fig. 8) from the middle Miocene Bowden formation of Jamaica and Pinna vaugham Cooke (1919, pp. 127-128, pl. 9, figs. 4a, b) from the lower Miocene Anguilla formation of An- guilla Island. Neither those shells nor ours are complete enough to compare definitively, but the Cabo Blanco P. carnea seems to lack the conspicuous internal ridge of P. refurca; and concerning the An- guillan P. vaugham, Cooke stated that it is not unlike P. carnea Gmelin but lacks the rudimentary riblets on the lower part of the ventral area of that species. Atrina (Servatrina) seminuda (Lamarck) Pl. 10, fig. 4 1819. Pinna semi-nuda Lamarck, An. sans Vert., vol. 6, pt. 1, p. 131. 1835. Pinna alta Sowerby, Zool. Soc. London Proc., p. 84. 1843. Pinna listeri d’Orbigny, Voyage l’Amérique Méridionale, vol. 5, pt. 3, Mollusques, p. 641, pl. 85, fig. 1. 1843. Pinna patagonia d’Orbigny, Voyage l’Ameérique Méridionale, vol. 5, pt. 3, Mollusques, p. 641, pl. 85, fig. 2. 1858. Pinna alta Sowerby, Reeve, Conch. Icon., vol. 11, Pinna, pl. 6, sp. 11. 1858. Pinna subviridis Reeve, Conch. Icon., vol. 11, Pinna, pl. 17, sp. 32. 1858. Pinna d’Orbignyi Hanley, Zool. Soc. London, Proc., p. 228. 1858. Pinna d’Orbignyi ‘Hanley’, Reeve, Conch. Icon., vol. 11, Pinna, pl. 26, sp. 49. 1858. Pinna ramulosa Reeve, Conch. Icon., vol. 11, Pinna, pl. 28, sp. 52. 1871. Pinna seminuda Lamarck, Coues, Acad. Nat. Sci. Philadelphia, Proc., vol. 23, p. 133. 1881. Pinna seminuda Lamarck, Gabb, Acad. Nat. Sci. Philadelphia, Jour., ser. 2, vol. 8, p. 345. 1889. Pinna seminuda Lamarck, Simpson, Davenport Acad. Nat. Sci., Proc., volt 5; p» 70: 1889. Pinna seminuda Lamarck, Dall, U. S. Nat. Mus., Bull. 37, p. 36. 1898. Atrina rigida (Dillwyn), Dall, Wagner Free Inst. Sci., Trans., vol. 3, pt. 4, pp. 663, 664, 665 (part). Many of the synonyms listed under rigida are, according to Turner and Rosewater (1958, p. 315), referable to seminuda. 1920. Atrina seminuda (Lamarck), Maury, Bull. Amer. Paleont., vol. 8, No. 34, p. 54 (part). 1923. Pinna seminuda Lamarck, Clench, Nautilus, vol. 37, No. 2, p. 55. 1929. Pinna seminuda Lamarck, Clench, Nautilus, vol. 43, No. 1, p. 35. 1932. Pinna semi-nuda Lamarck, Lamy, Mus. Nat. Hist. nat. Paris, Bull., sér. 2, vol. 4, p. 896. 1944. Pinna listeri d’Orbigny, Carcelles, Museo de La Plata, Rev., new ser., Zoology, vol. 3, p. 278, pl. 10, fig. 77. 1944. Pinna patagonica d’Orbigny, Carcelles,; Museo de La Plata, Rev., new ser., Zoology, vol. 3, p. 278, pl. 10, fig. 78. 1958. Atrina (Servatrina) seminuda (Lamarck), Turner and Rosewater, John- sonia, vol. 3, No. 38, pp. 315-320, pl. 150, figs. 5-6; pl. 159, figs. 5-8; pls. 160-169. 110 BuLLeTIN 204 1959. Atrina seminuda (Lamarck), Parker, Amer. Assoc. Petrol. Geol., Bull., vol. 43, No. 9, pp. 2130, 2143, 2163, 2164, pl. 3, figs. 8a, 8b. 1961. Atrina (servatrina) seminuda (Lamarck), Warmke and Abbott, Carib- bean Seashells, p. 166, pl. 34k. 1961. Atrina seminuda (Lamarck), Moore, Gulf Research Repts., vol. 1, No. 1, pp. 153) 38- Venezuelan shell thin and translucent, wedge-shaped, the dorsal margin hardly concave, the posterior margin truncate and forming a near right angle with the dorsal margin, the curve of the posterior margin with that of the ventral margin angularly rounded. The nacreous wash in the interior extends about two-thirds the length of the shell, the margin of the wash visible through the exterior. The posterior adductor impression is oval in outline and lies within the nacreous wash. Surface somewhat glistening, tan in color with areas of pale purplish brown and an occasional streak of iridescent green. Surface sculptured by 16 radiating ribs on the dorsal pos- terior slope, every alternate rib much the larger, the ribs scaly to spinose, the spines occurring as arched lamellae open to the rear. The ventral slope lacks the radiating ribs except for incipient ones at the posterior but is instead subpustular in front to scabrous and then scaly behind, the passage from one end to the other transi- tional. Dimensions.—Specimen B358a, length (anterior tip broken away) 78.5 mm. Locality.—Recent, on beach southeast of Higuerote, State of Miranda. One young specimen, the valves attached. Remarks —Atrina (Servatrina) seminuda Lamarck is a vani- able species and has been confused on the one hand with Atrina (Atrina) rigida (Solander) and with Atrina (Servatrina) serrata (Sowerby) on the other. In their excellent monograph on the Wes- tern Atlantic Pinnidae, Turner and Rosewater point out that A. seminuda is less inflated, has fewer ribs, and has a thicker shell than A. serrata; that the nacreous layer of A. seminuda extends only about one-half to two-thirds the length of the valve whereas that of A. serrata extends at least three-fourths the length of the valve; and that the posterior adductor scar of A. seminuda is usually smaller, proportionally, than that of A. serrata. In A. rigida the muscle scar protrudes well beyond the posterior margin of the nacreous area or VENEZUELAN CENOzoIC PELECYPODS: WEISBORD 111 is continuous with the margin. In A. seminuda the muscle scar al- ways lies well within the nacreous area. Also A. rigida has a heavier, darker colored shell than A. seminuda, and is usually more spinose than A. seminuda, particularly on the ventral slope. Range and distribution—In the Western Atlantic A. seminuda (Lamarck) ranges from North Carolina, U.S.A., to Argentina. I do not know of its occurrence in the Pleistocene, but since A. rigida is reported from deposits of that epoch I would expect A. seminuda to extend at least that far back. Gabb (1881, p. 345) reported A. seminuda from Sapote, Costa Rica, in a brown shale of purported Miocene age. Atrina (Servatrina ?) aff. seminuda (Lamarck) Pl. 10, fig. 5 Internal mold large, wedge-shaped, the dorsal margin slightly concave, the ventral margin embayed anteriorly, fairly straight posteriorly. There are no impressions on the left valve but on the right valve there are impressions of coarse radiating ribs particularly on the posterior ventral slope. Dimensions.—Specimen M360a, mold of paired valves broken off anteriorly and posteriorly, length 137 mm.; max. width 87 mm.; thickness of doublet 43 mm. Locality.—Playa Grande formation (Catia member) at W-15, south side of Playa Grande road, 40 meters southeast of its inter- section with the Playa Grande Yachting Club road. One specimen, an internal mold of closed valves. Remarks.—It is not possible to identify this species surely, but it seems to be close to A. seminuda (Lamarck). Atrina (Servatrina) serrata ? (Sowerby) Pl. 10, figs. 6-9 1786. Pinna serrata Solander, A Catalogue of the Portland Museum, pp. 7A, KA, 1825. Pinna serrata Sowerby, A Catalogue of the Shells contained in the Collection of the late Earl of Tankerville, London, p. 23, appendix, p. v. 1841. Pinna serrata Sowerby, Reeve, Conchologica Systematica, uk ple 103: 1849. Pinna squamosissima Philippi, [in] Roemer, Texas, Bonn, 454, 1849. Pinna squamosissima Philippi, Zeitschr. f. Malakozool., yr. a p. 164. 1858. Pinna squamosissima Philippi, Hanley, Zool. Soc. London, Proc., p. 226. 1858. Pinna seminuda Lamarck, Reeve, Conch. Icon., vol. 11, Pinna, pl. 2, sp. 2. Not of Lamarck 1819. 1859. Pinna serrata Sowerby, Reeve, Conch. Icon., vol. 11, Pinna, pl. 34, fig. 65. 112 BuLLETIN 204 1860. Pinna muricata ‘Linnaeus’, Holmes, Post-Pleiocene Fossils of South Carolina, p. 15, pl. 3, fig. 3. Not of Linnaeus 1758. 1864. Pinna muricata Linnaeus, Krebs, The West Indian Marine Shells, pp. 130-131 (part). Not of Linnaeus 1758. 1898. Atrina serrata (Sowerby), Dall, Wagner Free Inst. Sci.. Trans., vol. 3, pt. 4, pp. 664-665. 1903. Atrina serrata Solander, (Sowerby), VWanatta, Acad. Nat. Sci. Phil- adelphia, Proc., vol. 55, p. 756. 1906. Pinna (Atrina) serrata Sowerby, Bése, Inst. Geol. México, Bol. 22, p. 74, pl. 9, figs. 1-2. 1920. Atrina serrata (Sowerby), Maury, Bull. Amer. Paleont., vol. 8, No. 34, pp. 54-55 (part). 1934. Atrina serrata (Sowerby), Johnson, Boston Soc. Nat. Hist., Proc., vol. 40, No. 1, 2. 1937. Atrina serrata (Sowerby), Smith, East Coast Marine Shells, p. 30, BS Seitigs 3: 1940. Atrina serrata (Sowerby), Stenzel, Nautilus, vol. 54, No. 1, p. 21. 1944. Atrina serrata (Sowerby), Hackney, Nautilus, vol. 58, No. 2, p. 57. 1952. Brine serrata (Sowerby), Pulley, Texas Jour. Sci., vol. 4, No. 2, p. 180, Dla, etigs (5: 1954. Atrina serrata (Sowerby), Abbott, American Seashells, p. 360, pl. 27v. 1955. Atrina serrata (Sowerby), Perry and Schwengel, Marine Shells of the Western Coast of Florida, p. 40, pl. 3, fig. 16. 1958. Atrina (Servatrina) serrata (Sowerby), Turner and Rosewater, John- sonia, vol. 3, No. 38, pp. 320-323, pls. 170-171. 1961. Atrina (Servatrina) serrata (Sowerby), Warmke and Abbott, Carib- bean Seashells, p. 167. 1961. Atrina serrata (Sowerby), Moore, Gulf Research Repts., vol. 1, No. 1, pp: 15, 38. The Venezuelan fossils, referred with diffidence to A. serrata, are young, thin-shelled, and moderately inflated anteriorly. The dorsal margin is straight and, as seen on the right valve of one specimen, saw-toothed. The surface is sculptured by low radiating riblets on each of which are somewhat elevated arched lamellae open toward the rear, the vaulted arches arranged in a regular concentric pattern. Dimensions.—Incomplete specimen (L361), length 54.5 mm. Anterior end of broken specimen (L361b), length 40.5 mm. Locality—Playa Grande formation (Catia member) about 220 meters west of W-15, south side of Playa Grande road, in calcareous siltstone. Three specimens, all with valves attached. Remarks.—The fragments are scarcely sufficient for definitive determination, but the resemblance to A. serrata is marked. Range and distribution—Atrina (Servatrina) serrata (Sower- by) is a shallow-water species ranging, in the Western Atlantic, from North Carolina, U.S.A., to northern South America. In the Pleisto- VENEZUELAN CENOzOIC PELECYPODS: WEISBORD 113 cene it occurs in South Carolina, U.S.A. In the Pliocene it was re- ported by Dall (1898). And in the lower Pliocene it was recorded by Bose (1906) from Santa Maria Tatetla, in the State of Vera Cruz, Mexico. PLICATULIDAE Plicatula gibbosa Lamarck Pl. 10, figs. 10-13 1702. 1781. 1801. 1819. 1822. 1832. 1836. 1845. 1847. 1856. 1864. 1873. 1874. 1878. 1878. 1884. 1885. 1886. 1889. 1889. 1891. 1898. 1900. 1901. 1903. Spondylus barbadensis Petiver, Gazophyl. Decas III, pl. 24, fig. 12. Ostrea spondyloidea Meuschen, Mus. Gronovianum, No. 3, p. 276, No. 1189. Plicatula gibbosa Lamarck, Syst. An. sans Vert., p. 132. Plicatula ramosa Lamarck, Hist. Nat. An. sans Vert., vol. 6, p. 184. Plicatula gibbosa Lamarck, Sowerby, The Genera of Recent and Fossil Shells, vol. 1, No. 3, figs. 1-2. Plicatula ramosa Lamarck, Deshayes, Encyl. Méth., p. 801. Plicatula ramosa Lamarck, Deshayes, An. sans Vert., vol. 7, p. 176. Plicatula barbadensis d’Orbigny, Voyage dans l’Amérique Méridionale. Mollusques, p. 669. Plicatula ramosa Lamarck, Sowerby, Thes. Conchyl., vol. 1, p. 435, pl. 90, figs. 1-4. Plicatula ramosa Lamarck, Hanley, An Illustrated and Descriptive Catalogue of Recent Bivalve Shells, p. 288. Plicatula ramosa Lamarck, Krebs, The West Indian Marine Shells, p. 135. Plicatula vexillata Guppy, Sci. Assoc. Trinidad, Proc. vol. 2, p. 73; pp. 86-87, pl. 2, fig. 7. Plicatula vexillata Guppy, Geol. Mag., decade 2, vol. 1, p. 444, pl. 17, fig. 7. Plicatula spondyloidea (Meuschen), Arango y Molina, Contribucién a la Fauna Malacolégica Cubana, p. 271. Plicatula spondyloidea (Meuschen), Mérch, Catalogue of West-India Shells, p. 16. Plicatula ramosa Lamarck, Tryon, Structural and Systematic Conchology, vol. 3, p. 284, pl. 131, fig. 69. Plicatula ramosa Lamarck, Smith, Voyage of H.M.S. Challenger, Zoology, vol. 13, pp. 286-287. Plicatula spondyloidea (Meuschen), Dall, Mus. Comp. Zool., Bull., vol. 12, No. 6, p. 227. Plicatula ramosa Lamarck, Dall, U. S. Nat. Mus., Bull. 37, p. 32. Plicatula ramosa Lamarck, Simpson, Davenport Acad. Nat. Sci., Proc., vol. 5, p. 70. Plicatula ramosa Lamarck, Baker, Acad. Nat. Sci. Philadelphia, Proc., vol. 43, p. 46. Plicatula gibbosa Lamarck, Dall, Wagner Free Inst. Sci., Trans., vol. 3, pt. 4, p. 763. Plicatula spondyloidea (Meuschen), Dautzenberg, Soc. Zool. France, Mém., vol. 13, p. 222. Plicatula gibbosa Lamarck, Dall and Simpson, U. S. Fish Com., Bull., vol. 20 for 1900, pt. 1, p. 467. Plicatula gibbosa Lamarck, Vanatta, Acad. Nat. Sci. Philadelphia, Proc., vol. 55, p. 756. 114 1910. 1919. 1923. 1925. 1926. 1927. 1933. 1934. 1936. 1936. EVE 1938. 1939. 1940. 1942. 1944. 1945. 1946. 1946. 1949. 1951. 1952. 1954. 1955. 1956. 1958. 1959. 1961. 1961. 1961. 1961. BULLETIN 204 Plicatula spondyloidea (Meuschen), Vaughan, Carnegie Inst. Washing- ton bubl Now 1335p. lal. Plicatula ramosa Lamarck, Lamy, Mus. Nat. Hist. nat. Paris, Bull., vol. 24 (1918), p. 511. Plicatula gibbosa Lamarck, Clench, Nautilus, vol. 37, No. 2, p. 54. Plicatula gibbosa Lamarck, Maury, Bull. Amer. Paleont., vol. 10, No. 42, pp. 243-244, pl. 11, figs. 4-5. Plicatula gibbosa Lamarck, Weisbord, Nautilus, vol. 39, No. 3, p. 83. Plicatula gibbosa Lamarck, van Bentham Jutting, Dierk. Natura Artis. Magistra Bidjr., vol. 25, p. 24. Plicatula ramosa Lamarck Trechmann, Geol. Mag., vol. 70, No. 823, paso: Plicatula gibbosa Lamarck, P. ramosa Lamarck, P. spondyloidea (Meu- schen), and P. imbricata Reeve, Johnson, Boston Soc. Nat. Hist., Proc., vol. 40, No. 1, p. 23. Plicatula gibbosa Lamarck, McLean, Soc. Cubana Hist. Nat. “Felipe Poey”, Mem., vol. 10, No. 1, p. 40. Plicatula gibbosa Lamarck, Clench and McLean, Soc. Cubana Hist. Nat. “Felipe Poey”’, Mem., vol. 10, No. 3, p. 163. Plicatula gibbosa Lamarck, Smith, East Coast Marine Shells, p. 32, pl. 6, figs. 5a, 5b. Plicatula gibbosa Lamarck, Richards, Geol. Soc. Amer., Bull., vol. 49, pteely pst2Z91: Plicatula spondyloidea (Meuschen), Lamy, Jour. Conchyl., vol. 83, No. 1, pp. 19-21. Plicatula gibbosa Lamarck, Smith, World-wide Sea Shells, p. 95, fig. 1287. Plicatula gibbosa Lamarck, Jaume and Pérez Farfante, Soc. Cubana Hist. Nat. “Felipe Poey’, Mem., vol. 16, No. 1, p. 38. Plicatula gibbosa Lamarck, Hackney, Nautilus, vol. 58, No. 2, p. 57. Plicatula spondyloidea (Meuschen), van Bentham Jutting, Geolog.-Mijn- bouwk. Genootschap Nederland en Kolonien, Geol. ser., vol. 14, p. 77. Plicatula gibbosa Lamarck, Jaume, Soc. Malac. “Carlos de La Torre’, Rev., vol. 4, No. 3, p. 99. Plicatula gibbosa Lamarck, Stewart, Nautilus, vol. 60, No. 1, p. 19. Plicatula gibbosa Lamarck, Lange de Morretes, Mus. Paranaense, Arq., voOlepmart, Ie p:) 13: Plicatula gibbosa Lamarck, McLean, New York Acad. Sci. Scientific Survey of Porto Rico and the Virgin Islands, vol. 17, pt. 1, p. 33, pl. 6, fig. 7. Plicatula gibbosa Lamarck, Pulley, Texas Jour. Sci., vol. 4, No. 2, p. 181, pl. 8, figs. 8-9. Plicatula gibbosa Lamarck, Abbott, American Seashells, p. 361, pl. 35e. Plicatula gibbosa Lamarck, Perry and Schwengel, Marine Shells of the Western Coast of Florida, pp. 45-46, pl. 5, fig. 24. Plicatula gibbosa Lamarck, Parker, Amer. Assoc. Petrol. Geol., Bull., vol. 40, No. 2, pp. 308, 317, 371. Plicatula gibbosa Lamarck, Olsson and McGinty, Bull. Amer. Paleont., vol. 39, No. 177, p. 20. Plicatula gibbosa Lamarck, Nowell-Usticke, A Check List of the Marine Shells of St. Croix, p. 5 Plicatula gibbosa Lamarck, Moore, Gulf Research Repts., vol. 1, No. WS jojo WIA RG Plicatula gibbosa Lamarck, Olsson, Panamic-Pacific Pelecypoda, p. 155. Plicatula gibbosa Lamarck, van Regteren Altena, Koninkl. Nederl. Akad. Wetensch.-Amsterdam, Proc., ser. B, vol. 64, No. 2, p. 299. Plicatula gibbosa Lamarck, Warmke and Abbott, Caribbean Seashells, p. 167, pl. 34g. VENEZUELAN CENOzOIC PELECYPODS: WEISBORD 115 The Cabo Blanco fossils referred to this species are variable in shape, thickness, and character of the ribs. The shells are of medium size, generally thick, subtrigonal to asymmetrically fan-shaped in outline, the right (lower, attached) valve deeper than the left (upper) valve. The posterior dorsal margin is usually concave to some degree, and the outer basal margin of the larger and thicker shells is built up of coalescent incremental lamellae forming a short subtruncate slope. Inner surface of valves irregular. Muscle scar prominent, rather large, broadly kidney-shaped, raised a little, the outer lateral margin of the scar situated near the edge of the body cavity, the scar surface irregularly undulatory and sometimes finely rayed on one side like a fish scale. Left valve with two pairs of slightly divergent teeth under the beak, the outer pair large and strong, sometimes rendered bipartite by a medial groove, and marked with prominent irregular striae; the inner pair of teeth is much lower and thinner but with the same angle of divergence, the lower teeth also striate, and separated from the primary ones by fairly deep straight channels. Right valve with two deep scckets to receive the primary teeth of the opposite valve, the sockets finely fluted on the distal side in consonance with striae of the nestled teeth of the left valve; the sockets are bordered inward by a strong pair of complementary teeth, and between those is a deep medial socket. Inner lateral margins provided with about seven small crenulations or denticles which may be bifid. The ventral margin is serrated within by the ends of the external ribs, and in the troughs there are several small subpustular denticles. Body cavity defined by a strong impressed groove, the groove generally well removed from the margin. The pallial line lies outside of the groove and is relatively close to the margin. Exterior sculp- tured by high coarse trigonal radiating ribs crossed by concentric lamellae. The ribs may divaricate near the basal margin where the total number varies from about 10 to 15. In addition there are several short irregular riblets on the dorsal margins. The primary ribs extend to the flattened area of attachment on the umbo. The concentric lamellae are fine to coarse, the coarse ones forming vault- ed arches which may project a little as stubby tubular spines on the crest of the ribs. Dimensions.—Specimen S433a, right valve, height 31 mm.; 116 BuL_etin 204 max. width 27 mm.; thickness (including ribs) 13 mm. Specimen T434a, left valve, height 19.5 mm.; max. width 17.3 mm.; thickness 6 mm. Localities —Upper Mare formation, in stream 250 meters south- southwest of mouth of Quebrada Las Pailas. Two left (upper) valves. Lower Mare formation at W-13, on hillside above west bank of Quebrada Mare Abajo. Two specimens including one right valve and one left. Playa Grande formation (Maiquetia member) at W- 23, north flank of Punta Gorda anticline. Two right (lower) valves. Remarks.—The living P. gibbosa, and commonly the late Ceno- zoic fossil specimens as well, are marked by irregular radiating red- brown or purplish lines on the ribs and in the intercoastal areas. None of the Cabo Blanco fossils retains any vestige of color but otherwise certain specimens are identical with Recent examples of P. gibbosa. Comparisons——East American species resembling P. gibbosa Lamarck are the Miocene P. densata Conrad (1843, Acad. Nat. Sci. Philadelphia, Proc., vol. 1, p. 311), the middle Miocene P. guppyt Woodring (1925, Carnegie Inst. Washington, Publ. No. 366, pp. 78-79, pl. 9, figs. 9-11) from Jamaica, and the middle Miocene P. gibbosa Lamarck var. Pilsbry (1921, Acad. Nat. Sci. Philadelphia, Proc., vol. 73, p. 413.) from the Dominican Republic. West American species of Plicatula to which the variable Cabo Blanco fossils ex- hibit some affinity are the upper Pliocene to Recent P. spondylopsis Rochebrune (1895, Mus. Nat. Hist. nat. Paris, Bull., vol. 1, p. 242; see Hertlein and Strong, 1946, Zoologica, pt. 2, No. 5, pp. 63-64, pl. 1, figs. 1516), and the Pleistocene P. inezana Durham (1950, Geol Soc. Amer, Mem. 43, pt. 2, pp. 68-69, pl. 13, figs. 1, 3, 6). Specimens of P. densata Conrad at the Academy of Natural Sciences of Phila- delphia, although otherwise extremely close to P. gibbosa, do not have as prominent a muscle impression as P. gibbosa, and the teeth of P. densata are more strongly fluted than on P. gibbosa. According to Woodring, “P. guppyi is smaller than P. gibbosa, and has more distinctly foliaceous ribs,” and according to Pilsbry, P. gibbosa var. (identified as P. cristata Lamarck by Gabb, 1873, Amer. Philos. Soc., Trans., vol. 15, p. 257) appears to be identical with P. gibbosa, “except that in places fine radial striation or crinkling may be seen VENEZUELAN CENOZOIC PELECYPoDS: WEISBORD 117 under the lens. No color markings are preserved.” On P. spondy- lopsts the lateral margin of the muscle impression is farther from the edge of the body cavity groove, and the ribs are less acute than on the Cabo Blanco shells. P. inezana is more spinose than P. gztb- bosa and the muscle scar is oval rather than kidney-shaped. Range and distribution.—Recent, North Carolina to Brazil. Ple- istocene—Louisiana, Florida, St. Eustatius, Cuba, Venezuela, Bar- bados. Pliocene—Yucatan Peninsula (México) and Trinidad. Plicatula venezuelana, new species Pl. 11, figs. 1-4 Shell of medium size, thin, oval-suborbicular. Hinge strong, the left valve with a pair of large outer teeth, which are rudely fluted or striate, divergent, and shallowly but broadly sulcate, and a pair of much lower teeth within the confines of the primary ones. Margin irregularly scalloped, the inner side with small, unevenly spaced pustules or denticles. Muscle impression rather large, distinct, broad- ly oval, a little impressed, the far lateral margin of the impres- sion fairly close to the edge of the body cavity. Exterior of left valve flattish, undulatory, and with a shagreened texture, sculptured by a few broad low irregular radial folds and a few small radial nblets, the whole crossed by concentric lamellae. The radial folds are more prominent near the margin, and the radial riblets are faint on the umbo but sharper toward the base. The concentric lamellae become progressively coarser toward the base and sides where they are overlapping. Dimensions —Holotype (S432a), left valve, height 16.7 mm.; max. width 20.3 mm.; thickness 2.6 mm. Paratype (R432a), im- mature right ? valve, height 1.8 mm.; max. width 1.9 mm.; thick- ness about 0.5 mm. Type locality —Playa Grande formation (Maiquetia member) at W-23, north flank of Punta Gorda anticline. One left valve, the holotype. Other localities—Playa Grande formation (Maiquetia mem- ber) at W-26, in Quebrada Las Bruscas, approximately 125 meters upstream from junction with Quebrada Las Pailas. One immature right ? valve, the paratype. Comparisons——The new Venezuelan species is reminiscent of 118 BuLLETIN 204 the Recent Eastern Pacific P. anomioides Keen (1958a, pp. 241- 242, pl. 31, figs. 4, 7, 8) found between Guaymas and Mazatlan, Mexico, and of the Recent P. penicillata Carpenter (1856, Catalogue of the Collection of Mazatlan Shells in the British Museum Collect- ed by Frederick Reigen, p. 155) ranging from southern Mexico to Panama in the Eastern Pacific and reported by Olsson and McGinty (1958, p. 20) from the Caribbean coast of Panama. Although the Venezuelan juvenile is similar to the adult P. anomioides, the adult P. venezuelana is a little more strongly ribbed and much more coarsely lamellose than P. anomioides, whereas it is less strongly ribbed than P. penicillata and is not spinose as is P. pentcillata. Plicatula caribbeana, new species Pl. 11, figs. 5-8 Shell small, triangular, the anterior dorsal margin gently em- bayed, the posterior dorsal margin undulatory, the ventral margin a little rounded. Valves compressed, the right valve slightly convex and deeper than the left, the left valve slightly concave and a trifle smaller than the right. Prodissoconch nearly flat, suborbicular, marked with faint and fine concentric lineations, the beak appressed and blunt. Hinge strong, the left valve with a pair of large asym- metrically divergent teeth; the anterior tooth is shorter and thicker than the posterior one and is not so strongly fluted; another pair of teeth lies within the confines of the primary ones and are much lower and finer than the primaries. On the right valve the posterior socket is elongate and is strongly striate or fluted in consonance with the tooth on the opposite valve; the anterior socket is shorter, and is smooth on the distal side but striate on the near side; the chondrophore between the central teeth of the right valve is tri- angular and deep, with the apex of the septum rounded. Muscle im- pression large, distinct, oval-oblong in outline, oriented parallel with the long axis of the valve. The far lateral margin of the muscle impression is well removed from the edge of the body cavity. Inner margin of left valve shelflike, provided with small, rather irregularly spaced pustules or denticles which fit into small shallow comple- mentary indentations on the opposite valve. Exterior of right valve smoothed down except at the umbonal area which is made up of coalesced concentric lamellae. Exterior of left valve rough, irregu- VENEZUELAN Cenozoic PELEcypops: WEISBORD 119 larly humped near the umbo, sculptured by thin concentric laminae and by two or three radial ribs on the lower posterior side of the disk, the larger of the ribs tubular at the end. There are also several short feeble radial rugae on the umbonal area below the prodisso- conch. Dimensions. —Holotype (H43la 1-2), paired valves. Height of right valve (A431al) 8.2 mm.; max. width 7.7 mm.; thickness of doublet 2.6 mm. Height of left valve (A431a2) 7.6 mm.; max. width 7.2 mm. Type locality—Mare formation at W-25, south flank of Punta Gorda anticline. One specimen, found with valves attached. Remarks —The holotype of Plicatula caribbeana, n. sp. 1s probably not fully grown, but I have seen no other American species of even remotely similar stamp. PECTINIDAE Pecten (Pecten) catianus, new species Pl. 11, figs. 9-13 Shell of medium size, thin, a trifle wider than high, inequivalve, nearly equilateral. Right valve moderately convex, the left valve concave, the beak of the right valve flattish, the point extending slightly beyond the hinge line. Hinge line straightish, the ventral margin of the disk well rounded, the dorsal margins slightly concave, diverging at an angle of about 94 degrees. Auricles of right valve a little unequal, the posterior ear triangular, sharply truncate at the margin which is oriented vertically or parallel with the beak-to-base axis, the anterior ear subrectangular, its margin subtruncate, gently scalloped at the edge and also parallel with the beak-to-base axis, the base of the anterior ear with a moderately prominent notch at the byssal area. Both ears are marked on the lower part by four feeble low radial folds or riblets, but on the upper part radial mark- ings are absent; the shallow fasciolar depression between the disk margin and lowest rib of the anterior ear is somewhat wider than the corresponding shallow groove of the posterior ear; the exterior of both ears on the right valve is traversed by numerous inconspicu- ous concentric lineations. Internally, the right anterior ear is weakly fluted distally, the flutings corresponding with the external riblets. 120 BuLueTiIn 204 The auricles of the left valve are sunken below the exterior sub- margins, are sculptured by two, and possibly three radial nblets, and are traversed by sharp closely spaced concentric lamellae. In- terior of right valve with a deep triangular chondrophore and a cardinal crura running along the inner margin of either ear, the posterior crura a little thicker at the distal end than the anterior. A feeble arcuate cardinal ridge is present on the posterior ear, the ridge merging with the ligamental groove a short distance in from the end. Along the ventral margin of the right valve there are 21 radial bicrenulate ribs, these internal ribs separated at the base by deep elongate triangular flutings, the flutings becoming narrow shallow interspaces upward, the ribs and interspaces dying out toward the body cavity. The exterior of the right valve is sculp- tured by 22 radial ribs, and is crossed by strong regularly spaced concentric ridgelets. The radial ribs are squarish but gently rounded at the crest, and are separated by somewhat narrower interspaces with evenly rounded bottoms. The radial rib at either margin of the disk is rendered bipartite by a faint longitudinal groove. The concentric ridgelets are strong and rounded, and pass over the top of the ribs where they are often eroded away but where normally they are nearly as pronounced-as in the interspaces; on the sub- margins, however, the concentric cords disappear. The character of the inner surface of the left valve is not known. The exterior of the left valve is sculptured by 20 or 21 radial ribs with slightly narrower interspaces, and by closely packed concentric cords which cross both the ribs and intercostal areas in equal strength; the con- centric cords are rounded but corrode into lamellae or foliations; on the shouldered submargins of the left valve the concentric cords or lamellae become obsolescent and appear as inconspicuous linea- tions. Dimensions.—Holotype (K330a), both valves attached, height 36.2 mm.; width 36.9 mm. Paratype (K332a), might valve, height 23.3 mm.; width 33.6 mm.; thickness 7.6 mm. Type locality—Playa Grande formation (Catia member), in bluff 125 meters west of the intersection of the Playa Grande Yacht- ing Club road and coast road. Three specimens including one doublet VENEZUELAN CENOZOIC PELECYPODS: WEISBORD 121 (holotype), one right valve (paratype), and one fragment of a right valve. Remarks.—The distinguishing character of this species, though not brought out well on the illustration, is the unusually coarse concentric cording. These cords are continuous over the disk and are as pronounced on the ribs as in the intercostal spaces on un- weathered examples. Comparisons.—The new species is allied to Janira soror Gabb (1873, Amer. Philos. Soc., Trans., new ser., vol. 15, p. 257) (see Pilsbry, 1921, Acad. Nat. Sci. Philadelphia, Proc., vol. 73, p. 410, pl. 44, figs. 1-2) from the middle Miocene of the Dominican Re- public; to P. barrettt Woodring (1925, Carnegie Inst. Washington, Publ. No. 366, pp. 62-63, pl. 7, figs. 6-7) from the middle Miocene of Jamaica; to P. soror urwmaconis Harris (1927, Bull. Amer. Paleont., vol. 13, No. 49, pp. 22-23, pl. 13, fig. 1; pl. 14, figs. 3-4) from the Miocene of the State of Falcon, Venezuela; and to P. ven- tonensis Cooke (1919, Carnegie Inst. Washington, Publ. No. 261, pp. 130-131, pl. 12, figs. la, b) from Cuba, in what is stated to be the Oligocene. On the left valve, the radial ribs of P. soror are nar- rower and the interspaces much wider than on P. catianus, n. sp., and the concentric markings, though crossing both the ribs and inter- spaces as they do on the Cabo Blanco left valve, are lamellar rather than cordlike. On the right valve, the auricular riblets of P. barrett are smaller, stronger, and more numerous than on P. catianus, n. sp., and the concentric markings are lamellar instead of cordlike. P. soror urumacoms is a closely related form, but the ears of the left valve are bent decidedly inward, and the one or two radial riblets are nearer the hinge line than on the Cabo Blanco shell; also, the right valve of P. soror urumaconis is much more gibbous than that of P. catianus. On the Cuban P. ventonensis, the byssal notch of the right valve is shallower than on P. catianus, and the concentric markings on the disk are much finer. Pecten (Pecten) caribeus, new species Pi 2eticssh 2: Pl. 23, figs. 6-8 The following description pertains to the right (lower, convex) valve. 122 BuLLeTIN 204 Shell large, fairly thin, nearly equilateral, inflated, somewhat wider than high, the disk fan-shaped. Hinge line straight, dorsal margins concave and diverging from the beak at an angle of about 108 degrees, ventral margin semicircular. Dorsal slopes short and steep, the margin of the disk subrounded below the ears, excavated opposite the ears which are slightly sunken. Auricles a little unequal, the anterior one subtruncate at the margin and notched at the base, the posterior ear sharply squared off at the nearly vertical margin. Both ears are radiately ribbed below, obsoletely ribbed above, the anterior ear with about five subequal ribs in all, of which the lowest one adjacent to the fasciolar groove is the strongest, the others, par- ticularly the uppermost one or two, progressively weaker; posterior ear with about four radial ribs, the upper one nearly obsolescent, the upper third of the ear smoothish. Crossing the ears are numerous sinuous concentric growth striae. The inner surface of the anterior ear is shallowly fluted in consonance with the external ribbing, and the edge is gently scalloped. Beak small, triangular, appressed, the point even with the hinge line. Chondrophore small, triangular, deep, the sides a little thickened, and merging, in a sort of dog-leg, with the low rounded cardinal crura running along the inner margin of the ears, the anterior crura more pronounced than the posterior. There is no cardinal ridge under the ligamental groove of the an- terior ear but there is a faint arcuate one on the posterior ear, the ridge curving down obliquely from the distal end of the ear to join the upper part of the cardinal crura. Ctenolium with four small teeth, these disappearing or covered in adults. Exterior sculptured by a total of 23 radial ribs of which the two at either margin of the disk are paired, the outer rib of each pair the smallest of the disk, the submargins of the valve smooth. The ribs are squarish but gently rounded at the summit, generally regular, although occa- sionally feebly grooved medially, and separated by squarish inter- spaces about half the width of the ribs. Crossing the interspaces, but smoothed off on the crest of the ribs, are regularly spaced fine concentric lamellae which become crowded at the base of the disk. Internal ribs about 20, the interspaces narrow and shallow except at the ventral margin where they become deeper flutings nearly as wide as the ribs themselves; near the base, the ribs are bicren- ulate, and the internal ribs converge toward, and become obsoles- VENEZUELAN CENOZzOIC PELECYPODS: WEISBORD 123 cent at the middle of the valve. The body cavity is well removed from the ventral margin, and the large, rudely orbicular muscle impression lies a little in from the byssal area. Dimensions —Holotype (G344a), right valve, height 43.8 mm.; width 47.9 mm.; thickness 16.5 mm. Paratype (J344b), right valve, height 30.9 mm.; width 32.9 mm.; thickness 11.1 mm. Paratype (1344c), right valve, height 27.3.; width 29.2 mm.; thickness 9.6 mm, Type locality —Mare formation at W-14, on hillside above west bank of Quebrada Mare Abajo. One broken right valve, the holotype. Other localities—Lower Mare formation at W-13, on hillside above west bank of Quebrada Mare Abajo. One right valve, a para- type. Lower Mare formation, in small stream 100 meters west of Quebrada Mare Abajo. One right valve, a paratype. Mare forma- tion at W-25, south flank of Punta Gorda anticline. One large broken right valve. Comparisons.—P. caribeus, n. sp. is not to be confused with the preceding P. catianus, n. sp.; the latter is a smaller shell than P. cartbeus, the dorsal margins diverge considerably less, and the con- centric markings are much stronger on the interspaces and ribs alike. Other allied species are P. ventonensis Cooke (1919, pp. 130-131, pl. 12, figs. la, b) from what is stated to be the Oligocene of Cuba; P. aztecus Bose (1906, pp. 72-73, pl. 7, figs. 3-4) from the Pliocene of Mexico; P. soror urwmacoms Harris (1927, pp. 22-23, pl. 13, fig. 1; pl. 14, figs. 3-4) from the Miocene of the State of Falcon, Vene- zuela; and P. soror codercola Harris (1927, pp. 23-24, pl. 13, fig. 3; pl. 14, figs. 1, 5; pl. 15, fig. 7) from the Miocene and Pliocene of Falcon. P. ventonensis has two ribs less, and they are flattened on top whereas those of P. caribeus are gently rounded. On P. aztecus the interspaces are a little narrower and the ribs a little broader than on the right valve of the Cabo Blanco shell; also, according to Bose’s description, the right posterior ear of P. aztecus is marked only by fine concentric striae whereas there are radial riblets on both ears of P. caribeus. Both P. soror urumaconis and P. s. coder- cola have one or two more radial riblets on the auricles than does P. caribeus, n. sp.; furthermore, P. s. urumacons is less fan-shaped 124 BuLLeTIN 204 and P. s. codercola more fan-shaped than P. caribeus from Cabo Blanco. Pecten (Pecten) maiquetiensis, new species Pl. 12, figs. 3-6 The description of this species pertains to the left valve. Left valve slightly concave, suborbicular, a little wider than high. Ventral margin well rounded, dorsal margins slightly concave, sharply shouldered, diverging at an angle of about 83 degrees on young specimens but up to about 107 degrees on adults. Auricles subequal, triangular, the anterior one concave in plan, the posterior nearly plane, squared off straight at the hinge line, and with sub- truncate margins. Auricles sculptured by two to four radiating riblets which produce a finely scalloped or serrated effect at the lateral margins, particularly on the posterior ear, and both ears are traversed by numerous sharp sinuous concentric laminae. In the interior, the auricles are raised a little above the level of the disk, and often there is a small nodule or two near the base of the ears, particularly the anterior one. The internal ribs of the left valve are paired crenulations near the basal margin, the crenulations extending upward for but a short distance. The flutings between the ribs at the base proper are deeper than the sulcus dividing the ribs them- selves. Muscle scar rather large, more or less orbicular. Chondro- phore triangular, the ligamental groove adjacent to the hinge line extremely narrow and rather deep, the area immediately below the groove marked with numerous vermiform striae. Outer surface of disk sculptured by 18 to 20 strong squarish radial ribs separated by interspaces with gently rounded troughs, the interspaces a trifle narrower to a trifle wider than the ribs. The ribs and interspaces are crossed by numerous fine regular concentric laminae and lamel- lae, the laminae more or less erect on the upper half of the valve but flattening down into lamellae and becoming closer toward the base; the laminae and lamellae, though minutely ragged, run straight across the ribs and interspaces without sinuosity, and are sharper in the interspaces than over the ribs; on the submargins, which are relatively narrow, the concentric lineations are faint and crowded. Dimensions.—Holotype (T329a), left valve, height 34.3 mm.; width 38.2 mm. Paratype (J329a), left valve, height 22.1 mm.; VENEZUELAN CENOozoIc PELECYPODS: WEISBORD 125 width 22.4 mm. Largest specimen, height 46 mm.; width 52 mm. Type locality—Upper Mare formation, in stream 250 meters south-southwest of mouth of Quebrada Las Pailas, Two left valves, including the holotype. Other localities Lower Mare formation at W-13, on hillside above west bank of Quebrada Mare Abajo. Two left valves. Lower Mare formation, in small stream 100 meters west of Quebrada Mare Abajo. Three left valves, including the paratype. Mare formation at W-14, on hillside above west bank of Quebrada Mare Abajo. Two fragmentary left valves. Comparisons.—The left valve of P. maiquetiensis, n. sp. re- sembles the left valve of P. bowdenensis Dall (see Woodring, 1925, p. 63, pl. 7, figs. 8-9) and P. barretti Woodring (1925, p. 62, pl. 7, figs. 6-7), both of which are from the middle Miocene Bowden for- mation of Jamaica. The principal difference between the Cabo Blanco shell and P. bowdenensis is that the intercostals of P. bow- denensis are usually slightly raised whereas those of P. maiquetiensts are not. On P. barretti the auricles have stronger radial riblets than P. maiquetiensis. On the left valve of P. soror (Gabb) (see Pilsbry, 1921, Acad. Nat. Sci. Philadelphia, Proc., vol. 73, p. 410, pl. 44, figs. 1-2) from the middle Miocene of the Dominican Republic there are 17 external ribs and those are rounder, and the interspaces wider, than on P. maiquetiensis. Also the left anterior ear on the type of P. soror does not bear the strong radial riblets of the Venezuelan species. Perhaps the nearest relative of P. maiquetiensis is P. soror urumaconis Harris (1927, Bull. Amer. Paleont., vol. 13, No. 49, p. 22, pl. 13, fig. 1; pl. 14, figs. 3-4) from the Miocene of the State of Falcon, Venezuela, but on the left valve of the Falcon shell both ears are more concave, and the external ribs of the disk more round- ed than on the Cabo Blanco shell. The Recent Western Atlantic P. chazaliet Dautzenberg (see Grau, 1955, Nautilus, vol 68, No. 4, pp. 113-115), first collected by the yacht Chazalie in 1896 at Los Testigos Island, Venezuela, and which ranges from Florida to Brazil in 10 to 75 fathoms, is a smaller, more fragile shell than the fossil P. maiquetiensis, and on the left valve the interspaces of P. chazaler are much wider. P. chazaliei was formerly known as P. tereinus Dall (1925, Nautilus, vol. 38, No. 4, p. 115). 126 BuLuLeTIn 204 Remarks.—It is not precluded that P. maiquetiensis, n. sp. is, in truth, the left valve of P. caribeus, n. sp. (represented by the right valve only), but as neither P. maiquetiensis nor P. caribeus were found with both valves attached, it seems advisable to consider them distinct for the present. Pecten (Pecten) species Pl. 12: figs. "7/78 The following description pertains to the left valve only. Left valve large and moderately thick, flattish except for the raised and broad rounded shoulders at the lateral margins of the exterior. Dorsal slopes steep and broad, the dorsal margins diverging somewhat concavely at what seems to be a little over 90 degrees, the ventral margin of the valve shallowly rounded. Auricles deeply sunken and unusually long, the posterior one measuring 19 mm. vertically from the hinge line to the point of union with the margin, compared with 53 mm. for the beak-to-base height of the valve. Fine concentric laminae may be discerned on the ears, but because of adherent calcareous sandstone the character of the radial ribs, if present, cannot be determined. The external sculpture of the disk consists of radial ribs, estimated-at 18 in number, and fine concentric laminae. The ribs are high, relatively narrow, and squarish with a gently rounded summit, and the anterior marginal rib is rendered bipartite by a strong longitudinal groove. The intercostal areas are a little wider than the ribs, and are flat-bottomed. The concentric laminae are regularly spaced to about the middle of the disk but crowded basalward, and though they cross both the interspaces and the ribs they are smoothed off on the ribs at the base; on the submargins the concentric markings are fine, closely spaced, and relatively inconspicuous. Within, the left valve is flattish, but the top of the hinge is bent somewhat toward the exterior. The area of the valve below the chondrophore is irregularly pitted in an arc extending from the posterior side of the chondrophore across the middle of the inner margin of the ear, and within the area encircled by the pits there are several small pustules. The internal ribs are flat and broad, with deep narrower flutings between them at the basal margin; the flutings, as well as the ribs themselves, become obsolescent before reaching the body cavity. VENEZUELAN CENOZOIC PELECYPoDS: WEISBORD 17. Dimensions —Specimen 0330a, posterior half of left valve, height 53 mm. Specimen K330b, lower posterior quarter of left valve, height 35 mm. Localities —Playa Grande formation (Catia member) at W-22, on dip slope 100 meters west of Costa fault. One specimen, the posterior half of a left valve. Playa Grande formation (Catia member), in bluff 125 meters west of the intersection of the Playa Grande Yachting Club road and coast road. One anterior fragment of a left valve. Remarks.—Although it resembles both, this is neither the left valve of P. catianus, n. sp. nor of P. maiquetiensis, n. sp. It lacks the coarse concentric cords of P. catianus, and has higher, more rounded shoulders on the submargins than P. maiquetiensts. It is not possible, however, to determine unequivocally whether this is or is not the left valve of P. caribeus, n. sp., but as the right valve of P. caribeus has a thinner shell and comes from a lower formation, the conjecture is that the present form may be distinct from that. Furthermore, the specimens are too fragmentary to compare defini- tively with other known species. Pecten (Pecten ?) remulus, new species Pl. 12, figs. 9, 10 The following description is based on one immature left valve. Shell small, paper-thin, subtranslucent, subsquarish in outline, nearly equilateral, flat except for slightly elevated sides, the dorsal margins diverging at an angle of about 99 degrees, the ventral margin shallowly rounded. Hinge line long and straight. Beak small, rather full, about level with the hinge line, the umbo appressed. Auricles large, a little unequal, depressed slightly below the sub- margins but merging smoothly with them. Anterior ear a little larger than the posterior, slightly embayed at the base, the margin hardly convex; posterior ear triangular, the margin seemingly subtruncate. Both ears are gently concave and smooth except for fine incon- spicuous concentric lineations. Lower half of disk sculptured by 19 nearly obsolete low broad radial ribs which are reflected as mirror counterparts in the interior; visible concentric markings are wanting, and the submagins are smooth. Within the valve, the liga- mental groove is straight and exceedingly narrow. The chondro- 128 Bu Lvetin 204 phore is shallow, and the base of the hinge plate below it is arcuate. The body cavity, as represented by a whitish calcareous veneer on the surface, is elongate oval. Dimensions—Holotype (S345a), left valve, height 8 mm., width 8.3 mm. Type locality—Playa Grande formation (Maiquetia member) at W-23, north flank of Punta Gorda anticline; one left valve, the holotype. Comparisons.—The left valve of the new species resembles, in miniature, Pecten (Pecten) refugioensis Hertlein (1925, California Acad. Sci., Proc., ser. 4, vol. 14, No. 1, p. 7, pl. 5, fig. 9) from the upper Miocene or Pliocene at Rancho Refugio, north of San José del Cabo, Baja California, México. The principal difference is that the Mexican shell, other than its much larger size, has a semi- circular basal margin. Pecten (Euvola) ziczag caboblancoensis Druckerman, n. sp. Pl. 13, figs. 1-6 The following description is based on two type specimens (with both valves attached on each) sent to me by Daniel Druckerman through the courtesy of the Museum of Paleontology, University of California, and on a number of single valves, both right and left, contained in my own collection from Cabo Blanco. The types were collected by J. A. Tong, L. W. Henry, and J. Nomland, and donated to the Museum of Paleontology at the University of California in 1931. The original description of the subspecies was made by Druck- erman in his thesis which deals with the Tertiary history of the true Pectens in the Caribbean and Eastern Pacific. Shell fairly large, a little wider than high, inequivalve, nearly equilaterial, with an evenly rounded, nearly semicircular ventral margin, and concave dorsal margins which diverge on the adult holotype at an angle of about 116 degrees. Right valve thin, evenly inflated. Auricles of right valve a little unequal, both of them normally straight at the hingle line with perhaps a slight declivity toward the beak, the anterior ear separated from the disk by a fairly deep impressed groove; adjacent to this groove, and parallel with it, the right anterior ear is narrowly convex although the larger VENEZUELAN CENOzOIC PELECYPODS: WEISBORD 129 part of the ear above the swelling is shallowly concave. The right anterior ear is gracefully notched above the ctenolium, and the lateral margin above the notch is a little arcuate; the right posterior ear is triangular, hardly concave in plan, and has a slightly arcuate to subtruncate margin. The outer surface of both ears is smooth and completely wanting in markings except for fine obsolete con- centric lineations which are sinuous on the anterior ear and parallel with the margin on the posterior ear. Within, there is a strong rounded ridge or crura extending from the beak to a little below the byssal area along the base of the anterior ear, and it is inferred that a similar but slightly smaller ridge is present along the base of the posterior ear. The chondrophore is of medium size, triangular, and moderately deep. Ligamental groove narrow, the ligamental area on both valves bearing numerous fine vertical slightly wavy striae. The exterior of the right valve is sculptured by 19 to 23 low flat radial ribs with fine shallowly impressed grooves between them. From about the middle of the valve to the base, most of the ribs are divided by a fine groove along the middle, and occasionally there are two such grooves, close together and feebly impressed, along the middle on a lateral rib or two. The submargins are smooth as are the ribs, although with a lens the ribs are seen to be traversed by numerous microscopic concentric lineations. The interior of the right valve is shallowly fluted, the flutings becoming obsolescent upward toward the beak; between the flutings, the internal ribs are narrowly bipartite, with the pairing effect more pronounced at the basal margin. Left valve moderately thin but solid, orbicular, nearly equi- lateral, slightly concave, the dorsal margins diverging at an angle of 111 to 117 degrees, the angle of divergence becoming greater, apparently, with size. Auricles subequal, sunken below the sub- margins of the disk, straight at the hinge line, the margins sub- truncate, the anterior ear strongly concave, the posterior scarcely concave to nearly plane. The ears are marked with about four flat low tenuous ribs which render the margins somewhat serrate or scalloped, and are crossed by numerous sharp concentric laminae, the laminae sinuous where they cross the few subdued radial ribs on the outer surface of the ears. Exterior of disk sculptured by 30 to 33 wide low radial ribs alternating more or less regularly in size, 130 Bu.Letin 204 with the smaller ones a trifle lower than the larger, the ribs obsolescent or wanting on the sides or submargins of the valve. Crossing the disk are rather closely spaced regular raised concentric laminae which traverse both the ribs and interspaces with little or no deviation. Internally, the left valve has a moderately deep triangular chondrophore bordered on both sides by a thickening which curves outward and then upward to join the ligamental groove near the extremities. Ligamental groove sharp and narrow, but widening gradually toward the distal ends. Ears with a faint crura along the lower margin. The internal ribs of the disk tend to be paired at the ventral margin, and extend upward toward the beak, there becoming obsolescent. Dimensions ——Holotype (Museum of Paleontology, University of California), height 73 mm.; width 80 mm.; thickness of convex valve 23 mm. Topotype (K324a), broken right valve, height 38 mm.; thickness 12 mm. Topotype (U324a), right valve somewhat compressed, height 67 mm.; width 60 mm.; thickness 25 mm. Hypo- type (H327a), left valve, height 37.6 mm.; width 37.6 mm. Hypo- type (1327a), young left valve, height 26.2 mm.; width 26.2 mm. Type locality.—The precise locality in the Cabo Blanco area of Druckerman’s holotype is not known, although judging from the type of granular limestone filling the valves, I would infer that it was found in the Catia member of the Playa Grande formation near the coast road north of the village of Playa Grande. Other Cabo Blanco localities—Playa Grande formation (Catia member), in bluff 125 meters west of the intersection of the Playa Grande Yachting Club road and coast road. Two fragmentary right valves (including topotype K324a), and one fragment of a left valve (K328a). Playa Grande formation (Catia member) at W-22, on dip slope 100 meters west of Costa fault. One right valve. Playa Grande formation (Catia member), south side of Playa Grande road about 220 meters west of W-15. One juvenile left valve. Playa Grande formation (Catia member), south side of coast road at east end of Catia La Mar. One right valve, topotype U324a. Playa Grande formation (Maiquetia member) at W-23, north flank of Punta Gorda anticline. One right valve, the identification of which VENEZUELAN CENOZOIC PELECYPODS: WEISBORD 131 is doubtful. Mare formation at W-25, south flank of Punta Gorda anticline. Two left valves, one of them the hypotype H327a. Lower Mare formation at W-13, on hillside above west bank of Quebrada Mare Abajo. Two left valves, one of them (1327a), a hypotype. Comporisans.—P. 2%. caboblancoensis Druckerman is related to the Pleistocene and Recent P. ziczac of Linnaeus (1758, Syst. Nat., ed. 10, p. 696) and may be an ancestor. It is readily discriminated from P. ziczac s. s., however, in its lack of radial ribs on the auricles of the right valve, and in having more regular al- ternating larger and smaller ribs separated by fairly wide inter- spaces, on the left valve. The right valve of P. x. caboblancoensts is also similar to the right valve of P. bowdenensis Dall (1898, p. 713, pl. 29, fig. 1) from the middle Miocene of Jamaica and Colom- bia, but as shown in the illustrations of P. bowdenensis by Wood- ring (1925, pp. 63-64, pl. 7, figs. 8-9), the hinge of the Jamaican shell is more downwarped toward the beak than it is on P. z. caboblancoensis, and the swelling on the anterior ear is narrow and near the margin of the disk on P. z. caboblancoensis whereas it is broad and more centrally situated on the ear of P. bowdenensis. The ribbing on the left valves of these two forms is dissimilar. Remarks.—I wish to express my appreciation to Daniel Druck- erman for the loan of the holotype of P. z. caboblancoensts, as in my collection from Cabo Blanco I have no specimens with both valves attached. Pecten (Amusium) papyraceus (Gabb) Pl. 13, figs. 7-9; Pl. 14, fig. 1 1873. Pleuronectia papyracea Gabb, Amer. Philos. Soc., Trans., new ser., vol. US ae Gre 1881. Pleuronectia papyracea Gabb, Acad. Nat. Sci. Philadelphia, Jour., ser. 2, vol. 8, p. 347. 1889. Pecten (Amusium) Mortoni Say, Dall, U. S. Nat. Mus., Bull. 37, p. 34. Not P. mortoni Ravenel 1844. 1898. Pecten (A reeestare Babar dcens (Gabb), Dall, Wagner Free Inst. Sci., Trans., vol. 3; pt. 4, p. 757 1903. Amusium papycraceum (Gabb), Dall, Wagner Free Inst. Sci., Trans., vol. 3, pt. 6, p. 1586. 1917. Amusium papyraceum (Gabb), Maury, Bull. Amer. Paleont., vol. 5, No. 29, p. 354, pl. 26, fig. 22. 1920. Amusium papyraceum (Gabb), Maury, New York Acad. Sci. Scientific Survey of Porto Rico and the Virgin Islands, vol. 3, pt. 1, p. 21. 132 BULLETIN 204 1920. Amusium papyraceum, (Gabb), Hubbard, New York Acad. Sci. Scientific Survey of Porto Rico and the Virgin Islands, yol!-3, pt 2sp-. 96. 1920. Amusium papyraceum (Gabb), Maury, Bull. Amer. Paleont,, vol. 8, No. 34, p. 61. 1921. Amusium papyraceum (Gabb), Pilsbry, Acad. Nat. Sci. Philadelphia, Proc., vol. 73, p. 413, pl. 43, figs. 8-9. 1925. Amusium papyraceum (Gabb), Maury, Bull. Amer. Paleont., vol. 10, No. 42, pp. 241-242. 1925. Amusium (Amusium) papyraceum (Gabb), Woodring, Carnegie Inst. Washington, Publ. No. 366, pp. 73-74, pl. 9, figs. 1-2. 1926. Amusium papyraceum (Gabb), Gardner, U. S. Geol. Sur., Prof. Paper 142-A, p. 50. 1934. Pecten (Amusium) (gees (Gabb), Johnson, Boston Soc. Nat. Hist., Proc., vol. 40, No. 1, 26. 1951. Amusium papyraceum “(Gabb), Rehder and Abbott, Soc. Malac. “ Carlos de La Torre” Rev., vol. 8, No. 2, pp. 55-56. 1954. Pecten (Amusium) papyraceus (Gabb), Abbott, American Seashells, p. 362. Shell fairly large, thin, discoidal, suborbicular, subequilateral, and somewhat inequivalve, with the ventral margin of the left valve extending slightly beyond that of the right valve. Left valve com- pressed, the disk gently sinuous, the umbonal area flat, the middle area below the umbo hardly convex, the side areas a trifle depressed. The right valve is slightly convex overall except for the dorso- lateral areas which are flattish, the anterior flattening of greater extent than the posterior. Beaks smooth, small, triangular, project- ing a little above the hinge line. Dorsal margins slightly concave on left valve, decidedly concave on right, the divergence on an adult specimen measured near the beak, about 122 degrees on the right valve and about 128 on the left; the divergence on a young right valve 19 mm. in height is 116 degrees. Auricles subequal, the an- terior ones a little the larger. Auricles of adult left valve sculptured by a few low radiating riblets crossed by subdued sinuous concentric growth lines, the margins of the ears scalloped, the hinge line straight. On immature shells, the auricles of the left valve may not be radially ribbed. The auricles of the right valve are different than their counterparts of the opposite valve: there are no radial riblets, the lateral margins are not scalloped, and the hinge line is distinctly concave; the margin of the right posterior ear is gently and evenly rounded, whereas that of the right anterior ear is gracefully incurved below; both ears of the right valve are smoothish but are traversed by very faint curved concentric growth lines. Chondrophore tri- VENEZUELAN CENOZOIC PELECYPoDS: WEISBORD 133 angular, moderately deep, narrowly ridged along the sides. Liga- mental grooves narrow. Left valve with a single cardinal crura or ridge running along the inner margin of the auricles, each crura terminating distally in a small denticle. Internally the valves bear about 24 sets of fine radiating ribs, arranged for the most part in pairs, the ribs extending from the margins to about the middle of the disk where they become obsolescent. The surface of the valves is smooth and polished although there is often revealed faintly through the shell the radial pattern of the internal ribs; usually too, there are fine, concentric, subequally spaced, concentric lineations. Dimensions.—Specimen L326a, paired valves. Left valve (mar- gins frayed away), height 71 mm.; width 76 mm. Right valve of L326a, height 69 mm.; width 77 mm.; thickness of pair 14 mm. Speci- men L326b, left valve, height 47 mm.; thickness 5 mm. Cabo Blanco localities—Playa Grande formation (Catia mem- ber), south side of Playa Grande road about 220 meters west of W-15. Six specimens including one doublet, two right valves, two left valves, and one fragment. Playa Grande formation (Catia member), in bluff 125 meters west of intersection of the Playa Grande Yachting Club road and coast road. Six specimens includ- ing one doublet, one broken right valve, and four fragments. Playa Grande formation (Catia member), south side of Playa Grande road at W-15, about 40 meters southeast of its intersection with the Playa Grande Yachting Club road. Four specimens including one young left valve, and three fragments. Remarks.—A left valve from the Dominican Republic was illustrated by Maury in 1917; the flat, or right valve of Gabb’s type from the Dominican Republic was illustrated by Pilsbry in 1921. Allowing for minor variations such as the slightly more concave hinge line and the somewhat stronger radial riblets on the ears of the left valve of the Venezuelan shell, the Cabo Blanco fossil compares closely with the type specimen of P. (A) papyraceus. Range and distribution—Pecten (Amusium) papyraceus (Gabb) is said to range from Oligocene to Recent. The Oligocene P. papyraceus is reported from the San Sebastian shale of Puerto Rico. In Trinidad the species occurs in the lower-middle Miocene Manzanilla formation. In the middle Miocene it is found in the 134 BuLLeTIN 204 Dominican Republic and Jamaica. From the Pliocene ? near Cumana, Venezuela, a form nearly identical with the Cabo Blanco P. papyraceus is contained in Collection No. 18408 at the U. S. National Museum. The living shell inhabits the Antilles up to a reported maximum depth of 60 fathoms. Comparisons —Late Cenozoic species of the subgenus Amusiwm in the eastern Americas which resemble P. (A.) papyraceus are the following: Pecten mortont Ravenel (1844, Acad. Nat. Sci. Philadelphia, Proc., vol. 2, p. 96). Late Miocene and Pliocene from Maryland to Florida, U. S. A. This is a circular, rather than suborbicular shell, with ears nearly level with the plane of the disk, and with several fewer internal ribs than P. papyraceus. P. mortom has also been reported from the Miocene and Pliocene of Mexico by Bése (1906, Inst. Geol. Mexico, Bol. No. 22, p. 24, pl. 1, figs. 3, 6, 7, 9; p. 74, pl. 8, figs. 1-2; pl. 9, fig. 3); from the Miocene and Pliocene of Venezuela by F. Hodson, H. K. Hodson, and Harris (1927, Bull. Amer. Paleont., vol. 13, No. 39, p. 38); from the middle Miocene of Colombia by Anderson (1929, California Acad. Soc., Proc., ser. 4, vol. 18, No. 4, p. 155); and from the middle Miocene of the Panama Canal Zone by Toula (1908, K.-K. Geol. Reichs. Jahrb., vol. 58, p. 714, pl. 26, figs. 8-9). Although the Caribbean fossils are closely akin to the P. mortoni of Ravenel, there is still some reserva- tion among authors of their specific identity. Pecten (Amusium) precursor Dall (1898, Wagner Free Inst. Sci., Trans., vol. 3, pt. 4, p. 755). Middle Miocene (Chipola forma- tion), of Florida. Closely related to P. mortomi Ravenel and differing from P. papyraceus in the greater convexity of the left valve and in the radial striae on the beak and submargins. Amusium mauryi Hubbard (1920, N. Y. Acad. Sci. Scientific Survey of Porto Rico and the Virgin Islands, vol. 3, pt. 2, p. 96). Oligocene of Puerto Rico. This is a small shell, much more solid than P. papyraceus (which has also been reported from the Oligo- cene of Puerto Rico), and probably with no, or very obscure in- ternal ribs. Pecten (Amusium) antiguensis Brown (1913, Acad. Nat. Sci. Philadelphia, Proc., vol. 65, pp. 613-614, pl. 18, figs. 1-3, 5). Lower VENEZUELAN CENOzOIC PELECYPODS: WEISBORD 135 Miocene of Antigua. Exterior sculptured by fine concentric laminae and about 13 radial ribs running from the beaks, where they are pronounced. The exterior of P. papyraceus is smooth. Pleuronectia lyom Gabb (1881, Acad. Nat. Sci. Philadelphia, Jour., ser. 2, vol. 8, p. 347). Lower Miocene of Costa Rica and Anguilla, and middle Miocene of Panama Canal Zone. The internal ribs are single and not arranged in pairs as they are in P. papyraceus. Amusium bocasensis Olsson (1922, Bull. Amer. Paleont., vol. 9, No. 39, p. 378, pl. 17, figs. 3-4). Middle Miocene of Costa Rica. “In- terior of shell with about thirty-four lirae, which are usually nearly evenly spaced and not in pairs”. The Venezuelan examples of P. papyraceus have about 24 paired ribs within, Pecten ( Amusiwm) sol Brown and Pilsbry (1912, Acad. Nat. Sci. Philadelphia, Proc., vol. 64, p. 513, pl. 24,17 figs. 1-2). Middle Miocene of the Panama Canal Zone. The beaks on this species have strong radial sculpture; on P. papyraceus the beaks are smooth. Pecten (Amusium) luna Brown and Pilsbry (1912, p. 514, pl. 23*, fig. 1). Middle Miocene of the Panama Canal Zone, of Colom- bia (Weisbord, 1929, pp. 245-246, pl. 3, fig. 1), of Venezuela (F. Hodson, H. K. Hodson, and Harris, 1927, pp. 37-38), and of Costa Rica (Olsson, 1922, pp. 377-378, pl. 17, fig. 1). Olsson placed P. mortom from the Miocene of Mexico in synonymy with P. luna. The right valve of P. luna is much like that of P. papyraceus from Cabo Blanco save in the character of the ears: on P. luna the ear margins are raggedly subtruncate, whereas on the Cabo Blanco P. papyraceus they are gently and evenly curved. Also the right valve of P. luna is more convex. For a supplemental description of P. luna from the Gatun Locks of the Panama Canal see Pilsbry, 1931 (Acad. Sci. Philadelphia, Proc., vol. 83, pp. 434-435, pl. 4, fig. 1). Pecten (Amusium) toulae Brown and Pilsbry (1911, Acad. Nat. Sci. Philadelphia, Proc., vol. 63, pp. 365-366, pl. 28, fig. 7). Middle Miocene, Panama Canal Zone. “The surface is marked with narrow, sharply defined rays on a white ground, the rays less than half as wide as the intervals, subequal in the median part, much 17Plates 23 and 24 are numbered erroneously; pl. 23 should read pl. 24, and pl. 24 should read pl. 23. 136 BuLLeTIN 204 narrower at the sides, where they gradually fade out, and about 17 in number”. The interior of the valves is smooth. Pecten ( Amusium) aguaclarensis F. and H. Hodson (1927, Bull. Amer. Paleont., vol. 13, No. 49, pp. 36-37, pl. 18, fig. 1; pl. 21 figs. 1-2). Oligocene-Miocene in the States of Falcon and Lara, Venezuela. This species has 10-12 paired internal ribs compared with 22-24 on P. papyraceus. Pecten (Amusium) zamorensis F. and H. Hodson (1927, pp. 38-39, pl. 22, figs. 1, 3, 4, 5, 6). Pliocene, District of Zamora, State of Falcon, Venezuela. The umbos are radially striate, and internally the disk “carries about 14 pairs of internal lirae”. On P. papyraceus the umbos are smooth, and there are 22-24 pairs of internal ribs. Amusium rex-maris Maury (1925, Bull. Amer. Paleont., vol. 10, No. 42, pp. 242-243, pl. 15, fig. 1). Upper Miocene (Springvale formation), Trinidad. Distinguished from P. papyraceus by the greater obliquity of the valves and fewer internal ribs. Pecten (Amusium) marensis, new species Pl. 14, figs. 2, 3 The following description pertains to the left valve. Shell small, thin, subtranslucent, orbicular, a little higher than wide, sub- equilateral. Ventral margin nearly semicircular, the dorsal margins diverging at an angle of about 109 degrees. Auricles subequal, both ears depressed slightly below the plane of the disk, the anterior one more so than the posterior; lateral margin of anterior ear sub- truncate, that of the posterior hardly curved, both ears marked with barely visible concentric lineations, Hinge line straight. Along the inner margin of the posterior ear there is a fairly sharp ridge or crura, but the inner margin of the anterior ear is poorly defined. Disk flattish, with a faint radial depression on either side, the pos- terior depression slightly more pronounced. Chondrophore triangu- lar, relatively shallow. Internally there are about 20 subequal to unequal sets of feeble radiating lirae or ribs, arranged generally in pairs, extending from the margins to the upper part of the disk where they become obsolescent. The exterior of the valve is smooth but marked with faint concentric lineations, and through the shell there are revealed faintly the internal lirae. Dimensions—Holotype (G326a), left valve, height 19 mm.,; VENEZUELAN CENOzOIC PELECYPODS: WEISBORD 137 width 18.1 mm.; thickness 0.8 mm. Paratype (J326a), left valve, height 13 mm.; width 12.5 mm.; thickness 0.7 mm. Type locality—Lower Mare at W-14, on hillside above west bank of Quebrada Mare Abajo. One young left valve, the holotype. Other localities—Lower Mare formation, in small stream 100 meters west of Quebrada Mare Abajo. One juvenile left valve, the paratype. Comparisons.—Of the various species of Amusium mentioned in the immediately preceding pages the ones nearest P. marensts, n. sp. are P. papyraceus (Gabb), P. mortont Ravenel, and P. luna Brown and Pilsbry. In the Cabo Blanco collection is a left valve of P. papyraceus from the Catia member of the Playa Grande forma- tion which is just about the same size as P. marensis, n. sp. from the Mare formation, and though they appear much the same the following differences may be noted: P. papyraceus is a little wider than high, P. marensis a little higher than wide; the divergence of the dorsal margins is 115 degrees on the Catia P. papyraceus, 109 degrees on the Mare P. marensis; the Catia P. papyraceus has the thicker shell, a few more internal lirae than P. marensis, and the cardinal crurae are broader. P. mortom is a circular shell, and unlike those of P. marensts which are somewhat sunken, the auricles are separated from the disk by a faintly impressed groove. In P. luna, according to Olsson (1922, p. 377), the internal ribs are in pairs and spaced at intervals nearly twice the width of the pairs of ribs them- selves, whereas in P. marensis the subequally spaced rib-pairs and interspaces are about equal in width. Chlamys (Chlamys) ornata (Lamarck) Pl. 14, figs. 4-7 1819. Pecten ornatus Lamarck, An. sans Vert., vol. 6, p. 176. Encycl. Méth., pl. 214, fig. 5, 1797. 1853. Pecten ornatus Lamarck, d’Orbigny, [in] La Sagra, Hist. Phys., polit. et nat. l’Ile de Cuba, vol. 2, Mollusques, pp. 353-354. 1853. Pecten ornatus Lamarck, Reeve, Conch. Icon., vol. 19, sp. 68. 1864. Pecten ornatus Lamarck, Krebs, The West Indian Marine Shells, p. 134. 1878. Pecten ornatus Lamarck, Morch, Catalogue of West-India Shells, p. 16. 1878. Pecten ornatus Lamarck, Arango y Molina, Contribucién a la Fauna Malacolégica Cubana, p. 270. 1886. Pecten ornatus Lamarck, Dall, Mus. Comp. Zool., Bull., vol. 12, No. 6, p. 218. 1889. Pecten (Pecten) ornatus Lamarck, Dall, U. S. Nat. Mus., Bull. 137, p. 34. 138 BuL.etin 204 1889. nate ornatus Lamarck, Simpson, Davenport Acad. Nat. Sci., Proc., vol. 5, p. 70. 1891. Pecten ornatus Lamarck, Baker, Acad. Nat. Sci. Philadelphia, Proc., vol. 43, p. 46. 1897. Chlamys ornata (Lamarck), Verrill, Connecticut Acad. Arts and Sci., rans. evolawO0.atteec, pp soo, ole 1898. Pecten (Chlamys) ornatus Lamarck, Dall, Wagner Free Inst. Sci., Trans., vol. 3, 4, pp. 715-716, 743-744. 1901. Pecten (Chlamys) ornatus Lamarck, Dall and Simpson, U. S. Fish Com., Bull., vol. 20 for 1900, pp. 465-466. 1920. Pecten (Chlamys) ornatus Lamarck, Maury, Bull. Amer. Paleont., vol. 8, No. 34, p. 59. 1924. Pecten ornatus Lamarck, Emery, Nautilus, vol. 38, No. 2, p. 61. 1925. Pecten ornatus Lamarck, Dall, Nautilus, vol. 38, No. 4, p. 118. 1926. Pecten ornatus Lamarck, Weisbord, Nautilus, vol. 39, No. 3, p. 83. 1933. Pecten ornatus Lamarck, Trechmann, Geol. Mag., vol. 70, No. 823, p. 33. 1934. Pecten (Chlamys) ornatus Lamarck, Johnson, Boston Soc. Nat. Hist., Proc., vol. 40, No. 1, p. 24. 1936. Pecten (Chlamys) ornatus Lamarck, Clench and McLean, Soc. Cubana Hist. Nat. “Felipe Poey”’, Mem., vol. 10, No. 3, p. 163. 1937. Pecten (Chlamys) ornatus Lamarck, Smith, East Coast Marine Shells, p. 33, pl. 8, fig. 4. 1944. Pecten ornatus Lamarck, Patterson, Nautilus, vol. 58, No. 2, p. 38. 1946. Pecten (Chlamys) ornatus Lamarck, Jaume, Soc. Malac. “Carlos de La Torre”, Rev., vol. 4, No. 3, p. 99. 1949. Pecten (Chlamys) ornatus Lamarck, Lange de Morretes, Mus. Paranaense, Arq., vol. 7, art. 1, p. 14. 1951. Chlamys (Chlamys) ornata (Lamarck), McLean, N. Y. Acad. Sci. Scientific Survey of Porto Rico and the Virgin Islands, vol. 17, pt. 1, ith YE ok Sy se Ce i 1954. Chlamys ornatus (Lamarck), Abbott, American Seashells, p. 363, pl. 34b. 1958. Chlamys ornata (Lamarck), Abbott, Acad. Nat. Sci. Philadelphia, Mon. No. 11, p. 116. 1959. Chlamys ornata (Lamarck), Nowell-Usticke, A Check List of the Marine Shells of St. Croix, p. 5. 1961. Chlamys ornata (Lamarck), Warmke and Abbott, Caribbean Seashells, p. 108, pl. 33a. The Venezuelan Recent shell is thin, slightly inflated, somewhat oblique, a little higher than wide, inequilateral, nearly equivalve. Anterior and posterior auricles unequal, the posterior ones hardly developed, the left anterior triangular, with the lateral margin sub- truncate and slightly oblique, the right anterior subrectangular, embayed somewhat at the byssal area. The auricles are sculptured by coarse diverse radial riblets and scabrous concentric lamellae, and below the right anterior ear there are about seven sharp pecti- nidial teeth. The inner surface of the mght anterior ear is gently fluted, that of the slightly thicker left anterior ear smoothish, the latter finely scalloped by the projecting riblets along the lateral margin. Chondrophore small, triangular, moderately deep. Interior VENEZUELAN CENOZzoIC PELECYPODS: WEISBORD 139 of valves corrugated in consonance with the external ribs from base to beak, the basal margin crenulate. Exterior of disk sculptured by up to 20 high rounded radiating ribs. On the left valve three or five of the major ribs seem a little more prominent than the others, and between the ribs there are one or two secondary mblets; crossing the left valve are numerous fine concentric laminae which are smoothed away on the crest of the major ribs on the upper part of the disk but are sharp in the interspaces; also crossing the left valve are relatively widely spaced concentric scales which occur on the major and minor radial ribs on the lower half of the disk. On the nght valve the radials are compounded of two, three, or four ribs of unequal size, and the scales and imbrications are stronger than on the left valve. Interior white, with the maculations of the exterior showing through on young or half-grown specimens. Exterior cream- yellow, with large maculations of maroon. Dimensions.—Specimen A325a, right valve, height 16.5 mm.; width 14.4 mm.; thickness 2.1 mm. Specimen A325b, left valve, height 16.3 mm.; width 14.1 mm.; thickness 2.2 mm. Largest speci- men, left valve, height 29.5 mm.; width 25.2 mm.; thickness 3.7 mm Locality.—Recent, on beach of Playa Grande Yachting Club, Distrito Federal. Five specimens including three right valves and two left valves. Range and distribution—In the Western Atlantic, the living C. ornata is said to range from North Carolina, U.S.A., to Brazil, in depths to 116 fathoms. According to Dall (1898, p. 743), the species also occurs in the Pleistocene of the Florida Keys and in raised reefs of the Antilles. Trechmann (1933) found the species in the Coral Rock formation (Pliocene?-Pleistocene) at Canefield, Barbados, at an elevation of 1000 feet, as well as at lower levels elsewhere in Barbados. Chlamys (Chlamys) benedicti Verrill and Bush Phl4.figs3tt 1897. Chlamys Benedicti Verrill and Bush, Connecticut Acad. Arts and Sci., Trans., vol. 10, art. 2, pp. 74-75. 1898. Chlamys benedicti Verrill and Bush, U. S. Nat. Mus., Proc., vol. 20, No. 1139, pp. 834-835, pl. 84, figs. 1-2 1898. Chlamys Benedicti Verrill and Bush, Dall, Wagner Free Inst. Sci., Trans., vol. 3, pt. 4, pp. 743, 744. 140 BuLLETIN 204 1934. Pecten (Chlamys) benedicti Verrill and Bush, Johnson, Boston Soc. Nat. Hist., Proc., vol. 40, No. 1, p. 24. 1954. Chlamys benedicti Verrill and Bush, Abbott, American Seashells, p. 364. 1959. Chlamys benedicti Verrill and Bush, Nowell-Usticke, A Check List of the Marine Shells of St. Croix, pp. 5, 7. 1961. Chlamys benedicti Verrill and Bush, Warmke and Abbott, Caribbean Seashells, p. 168, pl. 33b. Shell small, thin, compressed, subequivalve, subequilateral, a little higher than wide. Dorsal margins low, somewhat concave, diverging at an angle of about 85 degrees; ventral margin semi- circular. Beaks hardly projecting beyond hinge line. Hinge line of right valve bowed slightly downward at the beak, straight on the left valve. Auricles unequal, the right anterior one the longest, subrectangular, and with a large byssal notch, below which, on the ctenolium, there are five to eight teeth; right posterior ear short, broadly triangular, the margin concave, the corner sharply right- angled; left anterior ear larger than the posterior, triangular, the margin slightly convex and fimbriate; left posterior ear small, the margin hardly concave, the corner also right-angled. Anterior auricle of right valve sculptured by six low radiating ribs pro- gressively increasing in width from the fasciolar depression toward the hinge line; posterior auricle of right valve sculptured by six un- equal radiating ribs, the broadest one at the top. Anterior auricle of left valve with eight to ten subequal radiating riblets, the pos- terior with five to seven small unequal riblets. The auricles are traversed by coarse, scaly to spinose concentric lamellae, the scales projecting well above the anterior hinge line of the right valve, the projections decreasing in size toward the beak; the scales also project over the posterior half of the hinge line but less so than on the for- ward half. On the left valve the concentric markings are spiny where they cross the auricular riblets, but in the interspaces they are in the form of regular threads, imparting a decussate pattern. The outer surface of the disk is sculptured by 23 single, moderately high, scaly to spinose radiating ribs, each with one minor scaly thread in the interspaces on the lower half of the disk. The primary ribs are squarish on the upper half of the disk on both valves; on the lower half of the left valve, however, they are subtriangular, and on the lower half of the left valve they are rounded at the summit. On both valves the relatively widely spaced scales or spines are more VENEZUELAN CENOZOIC PELECYPODS: WEISBORD 141 pronounced on the lower half of the disk and at the margins, par- ticularly on the anterior side of the right valve where the short spines are erect and sharp and the posterior side of the left valve where the markings on the ribs are in the form of low erect scales. On the interior, the right anterior ear is radially fluted, and the cardinal ridges below the ligamental groove are better defined on the right valve than on the left. The weak internal ribs, which correspond to the interspaces of the exterior, continue upward to the beak, and are bicrenulate at the basal margin. Dimensions —Specimen 1L337a, right valve, height 17 mm.; width 15 mm.; thickness 2.5 mm. Specimen L337b, left valve, height 13.9 mm.; width 12.2 mm.; thickness 2.1 mm. Specimen K338a, left valve, height 13 mm.; width 11.9 mm.; thickness 1.9 mm. Locahties—Playa Grande formation (Catia member), south side of Playa Grande road, about 220 meters west of W-15. Five specimens including one right valve and four left valves. Playa Grande formation (Catia member), in bluff 125 meters west of the intersection of the Playa Grande Yachting Club road and coast road. One right valve (broken), and one left valve. Remarks.—The type of Chlamys benedicti is an immature shell, and neither the original description nor illustrations of the type indicate the presence of interstitial riblets. However, adult Recent specimens of Chlamys benedicti in the Academy of Natural Sciences of Philadelphia all possess interstitial riblets, and except for being slightly narrower, the Venezuelan fossils are identical with the living species. Comparisons Comparable but distinct species are the fol- lowing: C. hastata (Sowerby) (1843, Thes. Conchyl., vol. 1, p. 72, pl. 20, fig. 236). Late Miocene to Recent, west coast of the Americas. C. hastata is larger than C. benedicti, has several minor threads between the primary ribs, and the dorsal margins are more concave than in C. benedict. C. varius (Linnaeus) (Syst. Nat., ed. 10, p. 698, No. 168). Recent from northern Europe and the Mediterranean. This has 26 to 32 ribs compared with 23 for C. benedicti. Dautzenberg (1900, 142 BuLueTINn 204 Soc. Zool. France, Mém., vol. 13, p. 224) reported C. varius from the Gulf of Maracaibo and the Island of Tortuga, Venezuela. Pecten (Chlamys) lowei Hertlein (1935, California Acad. Sci., Proc., ser. 4, vol. 21, No. 25, pp. 308-311, pl. 19, figs. 1, 2, 7, 8). Recent from the Gulf of California to Panama in 30 to 55 fathoms. The apical angle is narrower than in C. benedicti, and the primary ribs are compound toward the base whereas in C. benedicti they are single. C. muscosa (Wood) (Index Testaceologicus, Suppl., pl. 2, fig. 2), also known as C. exasperata (Sowerby) and C. fuscopurpurea (Conrad). Pliocene to Recent, Atlantic and Caribbean provinces. This is larger and more tumid than C. benedicti and has fewer ribs and larger auricles than the Cabo Blanco fossil. C. vaginula Dall (1898, pp. 715-716). Middle Miocene of Jamaica and the Dominican Republic. As described and illustrated by Woodring (1925, p. 65, pl. 8, figs. 1-2), C. vaginula has broader and flatter ribs than C. benedicti. Pecten (Chlamys) portoricoensis Hubbard (1920, New York Acad. Sci. Scientific Survey of -Porto Rico and the Virgin Islands, vol. 3, pt. 2, pp. 87-88, pl. 11, figs. 2-3) from the Oligocene of Puerto Rico has 26 to 27 compound primary ribs compared with 23 simple primary ribs on the Venezuelan fossil here referred to C. benedictt. Range and distribution—Chlamys benedicti ranges from Florida to northern South America and has been recorded as far north as Martha’s Vineyard, Massachusetts. The present report is the first record of it as a fossil. Aequipecten muscosus (Wood) Pl. 15;cfigsmie. 1828. Pecten muscosus Wood, Index Testaceologicus Supplement, pl. 2, fig. 2. 1847. Pecten exasperatus Sowerby, Thes. Conchyl., vol. 1, p. 54, pl. 18, figs. 183, 184, 186. 1847. Pecten muscosus Wood, Sowerby, Thes. Conchyl., vol. 2, p. 66, pl. 19, fig. 225. 1849. Pecten fuscopurpureus Conrad, Acad. Nat. Sci. Philadelphia, Jour., new ser., vol. 1, pp. 209, 280, pl. 39, fig. 10. 1852. Pecten exasperatus Sowerby, Reeve, Conch. Icon., vol. 8, pl. 2, sp. 7, 8a-b. 1853. Pecten muscosus Wood, Reeve, Conch. Icon., vol. 8, pl. 16, sp. 60. 1853. 1853. 1864. 1867. 1878. 1878. 1881. 1886. 1889. 1889. 1895. 1897. 1898. 1901. 1913. 1916. 1920. 1923. 1925. 1934. 1936. Zo 1939. 1939. 1942. 1944. 1945. 1949. 1951. 1952. VENEZUELAN CENOozoIc PELECYPODS: WEISBORD 143 Pecten triradiatus Reeve, Conch. Icon., vol. 8, sp. 120. Not of Miiller, Zool. Dan., vol. 2, p. 25, 1788. Pecten cretatus Reeve, Conch. Icon., vol. 8, pl. 29, sp. 129a-b. Pecten exasperatus Sowerby, Krebs, The West Indian Marine Shells, p. 134. Pecten exasperatus Sowerby, Guppy, Sci. Assoc. Trinidad, Proc., pt. 3, p. 164 (part). Pecten exasperatus Sowerby, Mérch, Catalogue of West-India Shells, Prelo: Pecten exasperatus Sowerby, Arango y Molina, Contribucién a la Fauna Malacolégica Cubana, p. 270. Pecten exasperatus Sowerby, Gabb, Acad. Nat. Sci. Philadelphia, Jour., 2d. ser., vol. 8, p. 379. Pecten exasperatus Sowerby, Dall, Mus. Comp. Zool., Bull., vol. 12, No. 6, p. 218. Pecten exasperatus Sowerby, Dall, U. S. Nat. Mus., Bull. 37, p. 34. ade exasperatus Sowerby, Simpson, Davenport Acad. Nat. Sci., Proc., vol. 5, p. 70. Pecten exasperatus Sowerby, Gregory, Geol. Soc. London, Quart. Jour., vol. 51, p= 291. Chlamys exasperata (Sowerby), Verrill, Connecticut Acad. Arts and Sci.. Trans., vol. 10, art. 3, pp. 59, 91. Pecten (Chlamys) exasperatus Sowerby, Dall, Wagner Free Inst. Sci. Trans., vol. 3, pt. 4, pp. 742-743. Pecten (Chlamys) exasperatus Sowerby, Dall and Simpson, U. S. Fish Com., Bull., vol. 20 for 1900, pt. 1, p. 466. Pecten exasperatus Sowerby, Brown and Pilsbry, Acad. Nat. Sci. Phil- adelphia, Proc., vol. 65, p. 496. Pecten (Chlamys) exasperatus Sowerby, Thiele, Zool. Jahrb., Suppl. 11, p. 125. Pecten (Chlamys) exasperatus Sowerby, Maury, Bull. Amer. Paleont., vol. 8, No. 34, p. 59. Pecten exasperatus Sowerby, Clench, Nautilus, vol. 37, No. 2, p. 55. Pecten muscosus Wood, Dall, Nautilus, vol. 38, No. 4, p. 120. Pecten (Chlamys) exasperatus Sowerby, Johnson, Boston Soc. Nat. Hist., Proc., vol. 40, No. 1, p. 24. Pecten exasperatus Sowerby, Lermond, Check List of Florida Marine Shells, Gulfport, p. 16. Pecten exasperatus Sowerby, Smith, East Coast Marine Shells, p. 33, pl. 8, figs. 5a, 5b; pl. 9, figs. 4a, 4b. Pecten (Chlamys) muscosus Wood, Fulton, Nautilus, vol. 52, No. 3, p. 120. Pecten exasperatus Sowerby, Mansfield, State of Florida Dept. Conserv., Geol. Bull. No. 18, p. 27 Pecten exasperatus Sowerby, Jaume and Pérez Farfante, Soc. Cubana Hist. Nat. “Felipe Poey”, Mem., vol. 16, No. 1, p. 39. Pecten exasperatus Sowerby, Hackney, Nautilus, vol. 58, No. 2, p. 57. Pecten exasperatus Sowerby, van Bentham Jutting, Geol.-Mijnbouwk. Genootschap Nederland en Kolonién Verhandl., Geol. Ser., vol. 14, p. 77. Pecten (Chlamys) exasperatus Sowerby, Lange de Morretes, Mus. Para- naense, Arq., vol. 7, art. 1, p. 14. Chlamys (Chlamys) muscosa (Wood), McLean, New York Acad. Sci. Scientific Survey of Porto Rico and the Virgin Islands, vol. 17, pt. 1, Pa29,) ple 5s ales. Pecten muscosus Wood, Pulley, Texas Jour. Sci., vol. 4, No. 2, p. 180. 144 BuLLETIN 204 1953. Chlamys (Chlamys) fuscopurpureus (Conrad), Olsson and Harbison, Acad. Nat. Sci. Philadelphia, Mon. No. 8, p. 53, pl. 3, figs. 6, 6a. 1954. Aequipecten (Aequipecten) muscosus (Wood), Abbott, American Sea- shells, p. 367, pl. 34d, e. 1955. Aequipecten muscosus (Wood), Perry and Schwengel, Marine Shells of the Western Coast of Florida, p. 48, pl. 5, fig. 27. 1958. Chlamys (Chlamys) fuscopurpureus (Conrad), DuBar, Florida Geol. Sur., Geol. Bull. No. 40, p. 158. 1958. Aequipecten muscosus (Wood), Olsson and McGinty, Bull. Amer. Paleont., vol. 39, No. 177, p. 22. 1959. Pecten muscosus Wood, Grau, Allan Hancock Pacific Exped., vol. 23, pp. 157, 158. 1959. Aequipecten muscosus (Wood), Nowell-Usticke, A Check List of the Marine Shells of St. Croix, pp. 6, 7. 1961. Pecten (Aequipecten) muscosus Wood, van Regteren Altena, Konink. Neder]. Akad. Wetensch.-Amsterdam, Proc., ser. B, vol. 64, No. 2, p. 299. 1961. Aequipecten (Aequipecten) muscosus (Wood), Warmke and Abbott, Caribbean Seashells, p. 170, pl. 33e. The following description pertains to the left valve. Shell small, a little convex, nearly equilateral, the dorsal mar- gins diverging at an angle of about 87 degrees, the ventral margin semicircular. Hinge line straight, the beak extending slightly above it. Anterior auricle slightly the larger, gently embayed at the base, and fimbriate at the margin, the posterior ear triangular and hardly convex at the margin. Anterior ear sculptured by seven coarse sub- equal radiating ribs crossed by scaly concentric threads which ex- tend slightly above the hinge line as short sharp serrations; pos- terior ear also sculptured by seven subequal radiating ribs which are a little smaller than the anterior ones, but like those are coars- ened by scaly concentric threads, the latter scarcely projecting be- yond the hinge line as fine serrations. Both ears are convex out- ward at the corner leaving a small gap when the valves are in juxta- position. Exterior of disk sculptured by 19 regular, prickly and scaly radiating ribs rounded at the summit, and separated by narrower, fairly deep interspaces. The ribs are traversed by regular, scaly lamellae which are much less pronounced in the interspaces; pro- jecting from either slope of the ribs but not reaching the crest, are smaller scales alternating with the lamellae atop the ribs, the scales arrayed in a single file. The submargins or dorsal slopes are short and moderately steep, and bear two minor radiating ribs crossed by scales of the same order of magnitude as those on the disk proper. Internally, the ligamental grooves are exceedingly narrow, and be- VENEZUELAN CENOZOIC PELECYPODS: WEISBORD 145 low them, on either side of the triangular chondrophore are slightly divergent narrow cardinal sulci. Both auricles are gently fluted distally, the anterior flutings longer than the posterior. On the inner margin at the base of the anterior ear there is a short bipartite cardinal crura. Internal ribs flat and broad, the interspaces shallow and narrow except at the base where they form deeper flutings which interlock with those of the opposite valve; the internal ribs continue upward toward the beak, and there are 18 of them. Dimensions.—Specimen K339a, left valve, height 12.1 mm.; width 11.9 mm.; thickness 2 mm. Locality —Playa Grande formation (Catia member), in bluff 125 meters west of the intersection of the Playa Grande Yachting Club road and coast road. One young left valve. Remarks.—The single Cabo Blanco fossil is identical with Recent shells of the same size from Cardenas, Cuba, contained in the collection of the Academy of Natural Sciences of Philadelphia. Range and distribution—tThe living A. muscosus ranges from North Carolina, U.S.A., to Brazil. The fossil A. muscosus has been reported from the Pleistocene of South Carolina, Florida, Cuba, the Panama Canal Zone, and the Island of St. Eustatius, and from the Pliocene of Florida and Costa Rica. Van Bentham Jutting (1945) also found the species at Punta Gorda, 2 kilometers east of Cabo Blanco, Venezuela. Chlamys (Leptopecten) desultoria, new species Ply to; figs: 3:6 The following description pertains to the right valve. Shell small, thin, subcompressed to slightly inflated, nearly equilateral, the dorsal margins low, diverging at an angle of 94 to 98 degrees, the ventral margin rounded. Beak about level with hinge line, the hinge line straight. Auricles unequal, the anterior one slightly longer, subrectangular, and with a prominent byssal notch, the posterior one triangular. Separating the anterior auricle from the disk is a prominent, wedge-shaped, fasciolar sulcus, widening rather rapidly away from the beak. Anterior ear sculptured by five or six small unequal riblets which are crossed by concentric lamellae, the lamellae crowded and low near the beak, more widely spaced and a 146 BuLtetin 204 little higher toward the extermity; posterior ear marked by five or six fine radial riblets crossed by concentric threads which are more pronounced in the decussated interspaces. The radial riblets of both ears vary somewhat in size and spacing from specimen to specimen. Ctenolium bearing four or five teeth. Disk sculptured by 13 to 15 radial ribs separated by interspaces about equally as wide. In the interspaces near the base at the middle area of the valve there is a single feeble intercostal thread usually situated submedially in the interspaces but occasionally to the side. The ribs are moderately high and subsquarish, and some of them may be faintly divided. The concentric markings consist typically of rather widely spaced laminae which are generally much sharper in the interspaces; on unweathered specimens it may be seen that the laminae in ascend- ing the sides of the ribs form small vaulted arches, although they straighten out on the summit of the ribs where they are usually smoothed off; on the paratype (J342a), the concentric laminae are worn away on both the ribs and interspaces on the lower half of the valve, thus modifying the appearance of the ribs. The sub- margins may or may not bear a faint radial groove, and the con- centric lineations there are relatively inconspicuous, particularly on the anterior submargin. Within the valve, the ligamental groove is long, narrow, and shallow, and is finely scored by numerous short vermicular grooves. Chondrophore small, triangular. Both ears are shallowly and broadly fluted, the flutings longer on the anterior ear. Internal ribs strong, extending far upward in the valve, gen- erally depressed or sulcate in greater or less degree along the middle, and separated by fairly deep interspaces. Dimensions —Holotype (G342a), right valve, height 10.3 mm.; width 10.3 mm.; thickness 1.1 mm. Paratype (J342a), right valve, height 9.6 mm.; width 9.8 mm.; thickness 2 mm. Paratype (G34la), right valve, height 11.4 mm.; width 12.3 mm.; thickness 1.9 mm. Type locality —Mare formation at G-14, on hillside above west bank of Quebrada Mare Abajo. Two right valves, the holotype and a paratype (G34la). Other localities —Lower Mare formation at G-13, on hillside above west bank of Quebrada Mare Abajo. Two right valves, one of them (J342a) a paratype. Lower Mare formation, in small stream VENEZUELAN CENOZOIC PELECYPODS: WEISBORD 147 100 meters west of Quebrada Mare Abajo. One broken right valve. Comparisons.—The nearest related species from the Atlantic- Caribbean side of the Americas are Chlamys (Plagioctenium) irremotis Olsson and Harbison (1953, p. 56, pl. 3, figs. 7, 7a) from the upper Miocene and Pliocene of Florida, and Pecten (Aequi- pecten) effossus Brown and Pilsbry (1911, pp. 364-365, pl. 28, figs. 4,6) from the middle Miocene of the Isthmus of Panama. Both of these species differ from C. desultoria, n. sp. in lacking the minor radial thread in the intercostal areas, and C. effossa not only has several more ribs than the Venezuelan shell, but on the type of C. effosa the ribs are sharply tripartite. Other somewhat similar species from the Caribbean area are Pecten vaughani Cooke (1919, p. 133, pl. 8, figs. 2-4) from the lower Miocene of Anguilla; Pecten vaughani flabellum Cooke (1919, p. 134, pl. 8, figs. 6a, 6b, 7) from the reported Oligocene of Cuba; Pecten atlanticola Anderson (1929, pp. 156-157, pl. 19, figs. 2-3) from the middle Miocene of Colombia; and Pecten maturensis Maury (1925, p. 241, pl. 14, figs. 3-4) from the Matura Pliocene of Trinidad. All of the above may be distin- guished from C. desultoria in lacking radial threads on the right anterior ear. In west America, analogous forms are Pecten woodringt Spieker (1922, Johns Hopkins Univ., Studies in Geol., No. 3, p. 125, pl. 7, figs. 4-5) from the middle Miocene of Peru and Ecuador (see Marks, 1951, Bull. Amer. Paleont., vol. 33, No. 139, pp. 331-332, pl. 3, fig. 1); Pecten (Chlamys) bellilamellatus Arnold (1906, p. 41, pl. 41, figs. 6, 6a, 7, 7a) from the Pliocene of California; the Pleistocene and Recent Pecten tumbezensis d’Orbigny (1846, Voy- age Amér. Mérid., vol. 5, p. 663); and the Recent Pecten palmer Dall (1897, Nautilus, vol. 1, No. 8, p. 85) known only from the Gulf of California. On C. woodringi the radial threads on the right anterior ear are wanting or obsolete. C. bellilamellata is slightly more oblique than C. desultoria, and lacks the minor radial thread in the intercostal spaces. C. tumbezensis (see Grau, 1959, pp. 118- 120, pl. 40), living from the Gulf of California to Peru in waters just below tide to 70 fathoms, is somewhat oblique whereas C. desultoria 1s nearly equilateral. On C. palmeri (see Grau. 1959, pp. 113-114, pl. 36), a species found on rocks and on sandy or muddy bottoms to 50 fathoms, the primary ribs are longitudinally threaded whereas on C. desultoria the primary ribs are simple. 148 BuL.eTin 204 Chlamys (Argopecten) gibbus antecessor, new subspecies, Pl. 15, figs. 7-12; Pl. 16, figs. 1-4 1925. Pecten (Plagioctenium) gibbus (Linnaeus), Maury, Bull. Amer. Paleont., vol. 10, No. 42, pp. 238-239, pl. 14, fig. 2; pl. 16, fig. 1. Not of Linnaeus ? Cabo Blanco shell of moderate size and thickness, subequi- lateral, the valves a little unequal, varying in convexity from slight to full, occasionally gently humped medially. Beaks small, extending slightly beyond the hinge line. Ventral margin evenly rounded, the dorsal margins usually slightly concave, the posterior a little longer than the anterior and thus imparting a slight obliqueness to the valves, the divergence averaging about 95 degrees. Dorsal slopes short and steep, the submargins of the disk sharply defined. Hinge line of left valve sharp and straight, the hinge line of the right hardly bowed down toward the beak. Auricles of left valve rather high, a little unequal, the posterior one scarcely concave at the margin, the anterior one gently convex above, incurved below. A shallow radial furrow bisects the left anterior ear a little above the middle, and above the furrow the ear is smoothed and bears two widely spaced inconspicuous radial folds; below the furrow there are four or five closely spaced coarse radial riblets. The left pos- terior ear is also radiately ribbed but the riblets are finer than on the anterior ear. On the right, or lower valve the auricles are un- equal, the posterior one triangular, more or less truncate at the margin, and scalloped along the edge, the anterior one subrectan- gular, convex at the margin, and subtruncate at the base. On the anterior ear of the right valve there are about five low unequal radial folds, and on the posterior ear there are about six subequal riblets on the lower two-thirds and two inconspicuous riblets on the upper third. Traversing the exterior of the auricles of both valves are concentric laminae which are sharper in the interspaces of the riblets than on the riblets themselves. Internally, the hinge plate is thickened by arcuate cardinal ridges, the ridges of the right valve more robust and more downswept than those of the left valve. On the left valve there is a fairly well-developed cardinal crura along the inner margin of the anterior ear, and below that there are two irregular nodulations representing the termini of the minor crurae. Chondrophore, or resilifer triangular and deep, the sides thickened VENEZUELAN CENOzoIC PELECYPoDS: WEISBORD 149 and merging with the cardinal ridges. There are three to five pec- tinidial teeth on the byssal area below the right anterior ear, and, when well preserved, the teeth are hooked. Both valves are sculp- tured by 19 to 21 external ribs, and there are usually two ribs less in the interior than on the exterior. The external ribs are high and regular, flattened or slightly rounded at the crest, and wider than or the same width as the interspaces but occasionally slightly narrower than the interspaces. There seems to be a tendency for the ribs of the right valve to be a trifle wider than those of the left. The ex- terior is crossed by regularly spaced concentric laminae which are sharp in the interspaces of the ribs but smoothed off on the crest of the ribs. On the short steep dorsal slopes the radial ribs are faint or wanting, and the concentric markings, though crowded, are less conspicuous than on the disk proper. The internal ribs are flat low and broad, the interspaces narrow and shallow except at the ven- tral margin proper where the interspaces are in the form of short deep triangular flutings, so designed that they interlock with the termini of the ribs of the opposite valve. The internal ribs are thick- ened slightly at the sides, and they extend to the body cavity toward which they become progressively fainter. The body cavity is situ- ated well within the interior, and the muscle impression is large and rudely orbicular. Dimensions.—Holotype (T344a), left valve, height 32 mm.; width 33.5 mm., thickness 10.2 mm. Paratype (G344b), left valve, height 22.3 mm.; width 22.3 mm.; thickness 6.3 mm. Paratype (G344c), right valve, height 18.7 mm.; width 18.7 mm.; thickness 6.8 mm. Paratype (1344a) right valve, height 17.5 mm.; width 17.8 mm.; thickness 4 mm. Paratype (1344b), left valve, height 18.9 mm.; width 18.3 mm.; thickness 5.1 mm. Paratype (J344a), left valve, height 12.5 mm.; width 11.8 mm.; thickness 2.2 mm. Paratype (J343a), left valve, height 21.4 mm.; width 21 mm.; thickness 5.8 mm. Paratype (L340a), left valve, height 12.2 mm.; width 11.8 thickness 2.1 mm. Paratype (L340b), right valve, height 17 mm.; width 17 mm.; thickness 3 mm. Type locality—Upper Mare formation, in stream 250 meters south-southwest of the mouth of Quebrada Las Pailas; Two left valves, the larger (1T344a), the holotype. 150 BuLuLeTIN 204 Other localities —Mare formation at W-14, on hillside above west bank of Quebrada Mare Abajo. Six specimens including three left valves, two right valves, and one fragment. Mare formation at W-25, south flank of Punta Gorda anticline. One left valve. Lower Mare formation at W-13, on hillside above west bank of Quebrada Mare Abajo. Four specimens including two left valves and two right valves. Lower Mare formation, in small stream west of Quebrada Mare Abajo. Seven specimens including five left valves and two right valves. Playa Grande formation (Maiquetia member) at W-26, in Quebrada Las Bruscas, approximately 125 meters up- stream from junction with Quebrada Las Pailas. One right valve. Playa Grande formation (Catia member), south side of Playa Grande road about 20 meters west of W-15. Four left valves. Playa Grande formation (Catia member), in bluff 125 meters west of the intersection of the Playa Grande Yaching Club road and coast road. One left valve. Remarks.—The new subspecies so closely resembles the Miocene to Recent C. gibbus gibbus (Linneaus) that a near relationship is indicated. C. gibbus antecessor, n. subsp. is differentiated from C’.. gibbus gibbus in both its much steeper dorsal slopes and thicker, more arcuate cardinal ridges. On many examples of the Recent C. gibbus gibbus the disk and submargins merge with but little change in the convexity, whereas on C. g. antecessor the dorsal slopes steepen so abruptly that the disk proper is subcarinate at the shoulders. I have seen variants of C. gibbus, notably C. gibbus versi- color (Lermond) from New Smyrna Beach, Florida, with fairly steep dorsal slopes, but on that form the cardinal ridges are not so arcuate or so thick as on the Cabo Blanco fossil. C. g. antecessor seems to be the same as Maury’s C. gibbus from the Matura Pliocene of Trinidad, but the latter is probably not the C. gibbus of Linnaeus. Comparisons.—C. gibbus antecessor, n. subsp. exhibits affinity to the following American species: Pecten irradians irradians Lamarck (1819, An. sans Vert., vol. 6, p. 173). Pleistocene and Recent, east America. Larger and thinner than C. g. antecessor, and with fewer (17 to 18) ribs. Ostrea nucleus Born (1780, Testacea Musei Caesarei Vindo- VENEZUELAN CENOzoIc PELECYPODS: WEISBORD 151 bonensis, p. 107, pl. 7, fig. 2) (see Aequipecten gibbus nucleus (Born), Abbott, 1954, American Seashells, p. 368, pl. 34h). Recent, southeast Florida to northern South America. This is a thin form with 21 to 23 ribs and has smaller ears than C. g. antecessor. Pecten circularis Sowerby (1835, Zool. Soc. London, p. 110) (see Arnold 1906, pp. 125-126, pl. 42, figs. 3-6; pl. 44, figs. 6-7). Upper Pliocene to Recent, west America. The typical Recent form is larger, more convex, and more oblique than C. g. antecessor. Pecten (Plagioctentum) eldridgei Arnold (1906, p. 87, pl. 25, figs. 3-6). Etchegoin formation (Pliocene), California fide Grant and Gale (1931, p. 214). The interspaces are only one-half as wide as the ribs. Pecten (Chlamys) santarosanus Bose (1906, Inst. Geol. México, Bol. No. 22, pp. 23-24, pl. 1, figs. 1,4; p. 27, pl. 1, figs. 2,5; pl. 6, figs. 3-4). Pliocene, States of Veracruz and Oaxaca, México. The right anterior ear of the Mexican forms illustrated by Bose is elongate-triangular, whereas that of C. g. antecessor is subrec- tangular. Pecten levicostatus Toula (1908, K.-K. Geol. Reichs. Jahr., vol. 58, p. 713, pl. 26, figs. 4-6). Middle Miocene of the Isthmus of Panama and Costa Rica. The right anterior ear of this species is also subtriangular. It has ben suggested by Olsson (1922, pp. 371-373, pl. 16, figs. 5-7) that the Costa Rican C. levicostata may be the same as Bose’s C. santarosana (p. 73, pl. 6, figs. 3-4) from Barranca de Santa Maria de Tatetla, State of Veracruz, Mexico. Pecten circularis venezuelanus F. and H. Hodson (1927, pp. 25-26, pl. 14, fig. 6; pl. 15, figs. 2,4,5; pl. 17, fig. 1) from the Miocene and Pliocene of the State of Falcon, Venezuela, and P. circularis cornellanus F. and H. Hodson (1927, pp. 27-28, pl. 14, fig. 2; pl. 15, figs. 3, 10; pl. 16, fig. 3) from the Miocene of the State of Falcon, Venezuela. These have a somewhat smaller angle of divergence of the dorsal margins than the Cabo Blanco C. g. antecessor. Chlamys (Plagioctenium) amelea Woodring (1925, Carnegie Inst. Washington, Publ. No. 366, pp. 70-71, pl. 8, fig. 9). Middle Miocene of Jamaica. On some examples of this species a slight 152 BuLLETIN 204 groove lies on the extreme lower part of a few ribs. No such grooves have been noted on C. g. antecessor. Also the fasciolar radial cord on the right anterior ear next to the margin of the disk is more elevated and much coarser than on the new Venezuelan subspecies. Chlamys (Plagioctenium) nicholsi Gardner (1926, U. S. Geol. Sur., Prof. Paper 142-A, p. 48, pl. 12, figs. 5-6). Shoal River forma- tion (middle Miocene), Florida, U.S.A. This abundant and wide- spread form from northwest Florida has an average of 17 radial ribs contrasted with the 19 to 21 on the Venezuelan C. g. ante- cessor. Gardner was of the opinion that C. micholst may have been an ancestral type of the C. gibbus group. Recent Pectinidae of the group exemplified by C. gibbus under the subgenus Argopecten are listed by Grau (1960, Nautilus, vol. 74, No. 1, pp. 17-18). Pecten (Plagioctenium) gibbus portusregu Grau (1952, Nauti- lus, vol. 66, No. 2, p. 69), new name for P. gibbus carolinensis Grau, not Conrad (1952, Nautilus, vol. 66, No. 1, pp. 17-19, pl. 1, figs. 2-5,7). Recent, two miles off Port Royal, South Carolina, in about 13 fathoms. This species has scales on the radial riblets of the right anterior ear, and five or six pectinidial teeth on the cteno- lium. C. gibbus antecessor, n. subsp. lacks scales on the right anterior ear, and the ctenolium or byssal area below the right anterior ear bears three to five pectinidial teeth. Pecten (Plagioctenium) evergladensis Mansfield (1931, U. S. Geol. Sur., Prof. Paper 170-D, pp. 47-48, pl. 17, figs. 1,2,4,5). Tamiami limestone (upper Miocene) of southern Florida. This has a more inequilateral shell than C. gibbus antecessor, n. subsp. Chlamys (Argopecten) imitata, new species Pl. 16, figs. 5-10 Shell thin, fairly large, moderately inflated, subequivalve, inequilateral, the valves always oblique to a greater or lesser extent. Dorso-lateral margins low, hardly concave, diverging at an angle of 103 to 109 degrees, the posterior submargin longer than the anterior, the ventral margin well rounded, the rounding posterior to the middle eccentric, the eccentricity commensurate with the obliqueness of the valve. Byssal gape narrow, the ctenolium with- out dentition. Auricles of right valve unequal, the posterior one triangular, gracefully concave at the margin and slightly concave VENEZUELAN CENOZoIC PELECYPODS: WEISBORD 153 in plan, the anterior ear subrectangular, slightly convex in plan, with a small but excavated byssal notch. Both ears of the right valve are rolled over at the summit of the hinge, and the hinge line itself is slightly bowed down toward the beak. Externally the anterior ear of the right valve has a flattish to somewhat bulging fasciolar area adjacent to the disk, and above this there are three or four feeble to obsolete low radial ridges which are generally a little more apparent near the beak than distally; crossing the right anterior ear are growth striae, the striae convex upward and pro- nounced on the fasciole, rather faint near the margin of the ear but stronger inward where they form raised threads over the radial riblets and on the summit of the hinge; on the lower half of the posterior ear there are four to six radial riblets, but the upper half is relatively smooth; on some right valves, including that of the type, the radial riblets are wholly obsolete, and the entire ear is smooth except for the numerous concentric lineations; the con- centric striae of the right posterior ear may be fine or coarse, the latter occasionally forming raised threads at the summit of the hinge near the beak. On the left valve the ears are subequal, the anterior one a little more concave at the margin than the posterior; both ears are slightly concave in plan and are also rolled over at the summit of the hinge, although more narrowly so than on the right valve, and the hinge line is straight and sharp; there may be as many as six small radial riblets on each ear of the left valve but these are generally faint and are crossed by numerous fine con- centric laminae none of which forms elevated threads on the hinge summit. Umbonal areas compressed, the sides of the disk near the beak moderately sharp, the beaks extending a little beyond the hinge line. Below the umbos, the disk and submargins are evenly convex. External sculpture consisting of radial ribs and concentric laminae. There are 21 to 26 ribs on the disk, the ribs on the right valve low and broad, and with narrow shallow interspaces, the ribs on the right valve relatively high and square above, obtusely triangular toward the base, separated by interspaces a little wider than the ribs themselves. On the submargins radial ribs are generally absent, but on one right valve in the collection the posterior sub- margin bears three low broad ones. The concentric laminae are sharp and regularly spaced on the upper half of the valve but 154 BuLLeETIN 204 crowded basalward; they are sharp in the intercostal areas of the left valve but have been smoothed off the crest of the ribs of both valves. On the right valve the concentric markings are occasionally bunched as incremental lamellae which cross the ribs and interspaces in equal prominence. Internally, the ligamental grooves are long and narrow, and below them is a shallow cardinal depression on either side of the triangular chondrophore, the depressions scored by fine vertical vermicular grooves. At or below the base of the ears there is a small pustule or two. The internal ribs are paired, and extend far upward toward the beak; at the ventral margin proper the ribs are separated by flutings, and on the right valve of the holotype the termini of the internal ribs form small wedges pro- jecting downward beyond the rim of the margin. Dimensions.—Holotype, right valve (L331a1), height and width 36.9 mm.; left valve (L331a2), height and width 37.1 mm.; thick- ness of valves atached 19 mm. Paratype (L331b), young right valve, height 17 mm.;_ width 16.8 mm.; thickness 2.7 mm. Paratype (U33l1a), right valve, height and width 27.9 mm.; thickness 5.4 mm. Specimen K334a, right valve, height 43.2 mm. Specimen U335a, right valve, height 34.7 mm.; width 36.8 mm.; thickness 11 mm. Type locality. — Playa Grande formation (Catia member), south side of Playa Grande road, about 220 meters west of W-15. Nine specimens including five doublets, four right valves, and frag- ments of left valves. Other localities—Playa Grande formation (Catia member), south side of coast road at east end of Catia La Mar. Four speci- mens including two left valves and two right valves. Comparisons.—This species is allied to various forms of both the east American C. irradians group and the west American C. circularis group. The most closely related perhaps is Pecten eccen- tricus Gabb (1873, p. 256) (see Maury, 1917, p. 351, pl. 34, fig. 8; and Pilsbry, 1921, pp. 412-413, pl. 40, fig. 12) from the middle Miocene of the Dominican Republic, but among other minor dif- ferences, C. eccentrica has deeper interspaces, more prominent ribs, and smaller ears on the right valve. C. demiurgus of authors (Maury, 1925, pp. 237-238, pl. 14, fig. 5; pl. 16, fig. 6; Harris [in] Waring, VENEZUELAN CENOzoIC PELECYPoDS: WEISBORD 155 1926, p. 109, pl. 20, figs. 3-4; and Rutsch, 1943, pp. 112-113, pl. 3, fig. 5) from the middle and upper Miocene of Trinidad and the middle Miocene of Venezuela ? and Colombia is a much larger and more coarsely ribbed shell than C. imitata, n. sp., and on young specimens of C. demiurgus the right valve is more convex than the left. It may be noted that in Dall’s illustration (1898, Wagner Free Inst. Sci., Trans., vol. 3, pt. 4, p. 178, pl. 26, fig. 3) of his type C. demiurgus, the ears of the right valve are shown to be entirely wanting in radial riblets whereas in illustrations by the above- mentioned authors the ears of the right valve are prominently ribbed. The intensity of the relatively weak auricular ribs on C. imttata, n. sp. varies considerably, and on some specimens they are absent, Pecten levicostatus Toula (1908, p. 713, pl. 26, figs. 4-6) as described by Olsson (1922, pp. 371-372, pl. 16, figs. 5-7) from the Gatun (middle Miocene) formation of the Isthmus of Panama and Costa Rica is usually a little wider than high whereas on C. wmitata the height and breadth are nearly the same. On Pecten circulars venezuelanus F. and H. Hodson (1927, pp. 25-26, pl. 14, fig. 6; pl. 15, figs. 2,4,5; pl. 17, fig. 1) from the Miocene and Pliocene of north- western Venezuela the cardinal depressions below the ligamental grooves are much more pronounced than on C. imitata, the internal ribs of C. c. venezuelana do not continue far within as in C. imitata, and the external ribs of the right valve are much higher and flatter than on the Cabo Blanco form. The Pleistocene and Recent C. trradians concentrica (Say) (1822, Acad. Nat. Sci. Philadelphia, Jour., ser. 1, vol. 2, p. 259) from the Atlantic coastal plain area of the southern United States is more gibbous than C. imitata, and not so oblique. In western America the Pliocene to Recent C. circularis (Sowerby) and congeners (see Keen, 1958, p. 72, fig. 132) are much more inflated than the Venezuelan C. imitata, n. sp. On the Pliocene C. mendenhalli (Arnold) (1906, pp. 84-85, pl. 25, figs. 2, 2a, 2b) (see Hertlein, 1925, California Acad. Sci., Proc., ser. 4, vol. 14, No. 1, ps 16, plot, tig. 5; and Hanna; 1926, sbrdNo. 18> "p: 473, pl. 25, figs. 4-5) the intercostal areas on the left valve are narrower than on C. imitata but otherwise the Venezuelan and Californian shells are much alike. On C. cristobalensis (Hertlein) (1925, pp. 19-20, pl. 3, figs. 1, 2, 5) from the Pliocene of California the ribs of the 156 BuLueTin 204 right valve are higher and squarer than on C. imitata, and it is a much larger shell. Grant and Gale, (1931, p. 210) report C. cristobalensis as a living shell from the coast of Peru. The Pliocene C. subdola (Hertlein) (1925, pp. 20-21, pl. 5, figs. 2, 4, 7) from California is yet another species allied to C. wmitata, but the margin of the left posterior ear is subtruncate whereas on C. imitata it is gracefully sinuate. Lyropecten (Nodipecten) nodosus ? (Linnaeus) PL l7 fies 1758. Ostrea nodosa Linnaeus, Syst. Nat., ed. 10, p. 697, No. 164. 1767. Ostrea nodosa Linnaeus, Syst. Nat., ed. 12, p. 1145, No. 194. 1784. Pecten corallinus Chemnitz, Syst. Conchylien-Cabinet, vol. 7, p. 306, pl. 64, figs. 609-611. 1819. Pecten nodosus (Linnaeus), Lamarck, An. sans. Vert., vol. 6, p. 170. 1845. Pecten nodosus (Linnaeus), d’Orbigny, xin La Sagra, Hist. Fis., Polit. y Nat. Isla de Cuba, pt. 2, vol. 5, p. 36 1864. Pecten nodosus (Linnaeus), Krebs, a West Indian Marine Shells, p 134. 1871. Pecten nodosus Lamarck, Coues, Acad. Nat. Sci. Philadelphia, Proc., vol. 23, p. 132. 1873. Pecten magnificus Gabb, Amer. Philos. Soc., Trans., new ser., vol. 15, p. 256. Not of Sowerby, 1835, Zool. Soc. London, Proc., p. 109. 1878. Pecten nodosus (Linnaeus), Mérch, Catalogue of West-India Shells, p. 16. 1878. Pecten nodosus (Linnaeus), Arango y Molina, Contribucién a la Fauna Malacolégica Cubana, p. 270. 1884. Pecten (Lyropecten) nodosus (Linnaeus), Tryon, Structural and Syste- matic Conchology, vol. 3, p. 290, pl. 133, fig. 17. 1887. Pecten nodosus (Linnaeus), Heilprin, Wagner Free Inst. Sci., Trans., volwd.vaps 100: 1887. Pecten pernodosus Heilprin, Wagner Free Inst. Sci., Trans., vol. 1, p. 131, pl. 16b, figs. 69, 69a. 1889. Pecten (Pecten) nodosus (Linnaeus), Dall, U. S. Nat. Mus., Bull. 37, p. 34. 1889. Pecten nodosus (Linnaeus), Simpson, Davenport Acad. Nat. Sci., Proc., vol. 5, p. 63. 1897. Lyropecten nodosus (Linnaeus), Verrill, Connecticut Acad. Arts and Sci., Trans., vol. 10, art. 2, pp. 64, 91. 1898. Pecten (Nodipecten) nodosus (Linnaeus), Dall, Wagner Free Inst. Sci., Trans., vol. 3, pt. 4, pp. 695, 717, 728-729. 1900. Lyropecten nodosus (Linnaeus), Verrill and Bush, Connecticut Acad. Arts and Sci. Trans., vol. 10, art. 12, p. 516. 1901. Pecten (Nodipecten) nodosus (Linnaeus), Dall and Simpson, U. S. Fish Com., Bull., vol. 20 for 1901, pt. 1, p. 465. 1916. Pecten (Nodipecten) nodosus (Linnaeus), Thiele, Zool. Jahr., Suppl. 11, p. 125. 1917. Pecten (Nodipecten) nodosus (Linnaeus), Maury, Bull. Amer. Paleont., vol. 5, No. 29, pp. 350-351. 1920. 1920. 1921. 1921. 1925. 1931. 1934. 1936. 1937. 1939. 1944. 1945. 1946. 1949. 1949. 1951. 1951. 1952. 1952. 1953. 1954. 1955. 1959. 1961. 1961. VENEZUELAN CENOZOIC PELECYPODS: WEISBORD 157 Pecten (Nodipecten) nodosus (Linnaeus), Maury, Bull. Amer. Paleont., vol. 8, No. 34, p. 59. Pecten (Nodipecten) nodosus (Linnaeus), Hubbard, N. Y. Acad. Sci. Scientific survey of Porto Rico and the Virgin Islands, vol. 3, pt. 2, pp. 86-87, pl. 10, fig. 5. Pecten nodosus (Linnaeus), Pilsbry, Acad. Nat. Sci. Philadelphia, Proc., vol. 73, pp. 409-410. Pecten (Nodipecten) nodosus (Linnaeus), Woodring, [in] Geol. Survey Dominican Republic, Mem., vol. 1, pp. 125, 144. Pecten nodosus (Linnaeus), Clench, Nautilus, vol. 38, No. 3, p. 94. Pecten (Lyropecten) nodosus (Linnaeus), Grant and Gale, San Diego Soc. Nat. Hist., Mem., vol. 1, pp. 179-180. Pecten (Nodipecten) nodosus nodosus (Linnaeus), Johnson, Boston Soc. Nat. Hist., Proc., vol. 40, No. 1, p. 24. Pecten nodosus (Linnaeus), Mansfield, Jour. Paleont., vol. 10, No. 3, p. 183. Pecten (Lyropecten) nodosus (Linnaeus), Smith, East Coast Marine Shells, pp. 34-35, pl. 8, fig. 3; pl. 9, fig. 6; pl. 28, fig. 5. Pecten (Nodipecten) nodosus ’(Linnaeus), Mansfield, State of Florida Dept. Conserv., Geol. Bull. No. 18, pp. 19, 26, 54. Pecten nodosus (Linnaeus), Hackney, Nautilus, vol. 58, No. 2, p. 57. Pecten nodosus (Linnaeus), van Bentham Jutting, Geol.-Mijnbouwk. Genootschap Nederland en Kolonien, Verh., Geol. ser., vol. 14, p. 77. Pecten (Lyropecten) nodosus (Linnaeus), Jaume, Soc. Malac. “Carlos de La Torre’’, Rev., vol. 4, No. 3, p. 99. Pecten nodosus (Linnaeus), Platt, Natl. Geogr. Mag., vol. 96, p. 43, fig. 7. Pecten (Lyropecten) nodosus (Linnaeus), Lange de Morretes, Mus. Paranaense, Arq., vol. 7, art. 1, p. 14. Lyropecten (Nodipecten) nodosus (Linnaeus), Rogers, The Shell Book, pp. 415, 502. Chlamys (Lyropecten) nodosa (Linnaeus), McLean, N. Y. Acad. Sci. Scientific Survey of Porto Rico and the Virgin Islands, vol. 17, pt. 1, ps 30) pl. 6, figs 1. Pecten nodosus (Linnaeus), Pulley, Texas Jour. Sci., vol. 4, No. 2, p. 181, pl. 8, fig. 10. Ostrea nodosa Linnaeus, Dodge, Amer. Mus. Nat. Hist., Bull., vol. 100, art. 1, pp. 171-172. Pecten (Nodipecten) nodosus (Linnaeus), Haas, Fieldiana-Zoology, vol. 34, No. 20, p. 203. Lyropecten (Nodipecten) nodosus (Linnaeus), Abbott, American Sea- shells, p. 366, pl. 33b. Lyropecten nodosus (Linnaeus), Perry and Schwengel, Marine Shells of the Western Coast of Florida, p. 49, pl. 6, fig. 30. Lyropecten nodosus (Linnaeus), Nowell-Usticke, A Check List of the Marine Shells of St. Croix, p. 6. Pecten (Nodipecten) nodosus (Linnaeus), van Regteren Altena, Koninkl. Nederl. Akad. Wetensch.-Amsterdam, Proc., ser. B, vol. 64, No. 2, p. 299. Lyropecten (Nodipecten) nodosus (Linnaeus), Warmke and Abbott, Caribbean Seashells, pp. 169-170, pl. 4b; 33g. Shell large, suborbicular, sculptured by nine strong rounded nodose ribs which are separated by deep rounded interspaces nearly as wide as the ribs themselves; ribs and interspaces alike marked by strong radial riblets of which there are as many as nine on the 158 BuLtetin 204 largest ribs and as many as six in the widest interspaces, the latter riblets a little smaller than those on the principal ribs. The nodules occur in a few concentric rows of unequal spacing, and are much larger on the lower part of the shell; on the right ? valve of the Cabo Blanco specimen there is one node on each rib per row. The entire surface is covered with numerous equal concentric laminae, and there are concentric growth ridgelets near the base. Auricles unequal, the anterior one larger, both sculptured by radial riblets which are crossed by strong concentric lamellae. Interior fluted, the flutings converging to the beak, toward which they diminish grad- ually in depth and strength. At the base of the valve the internal ribs between the flutings are thickened slightly on the sides, and there is the suggestion that at the base the internal ribs are multi- crenulate. Dimensions —Figured specimen (N322a) right ? valve, height 103 mm. Localities—Playa Grande formation (Catia member) near W-21, in stream flowing along the strike of the north flank of the Litoral anticline. One valve (right ?) filled with fine calcareous fossiliferous standstone, found loose in bed of stream. Playa Grande formation (Catia member) at W-22, on dip slope 100 meters west of Costa fault. One clean fragment. Remarks.—The imperfect Cabo Blanco fossil so closely re- sembles L. nodosus that it may well be the same. Often, the nodes on the left valve of L. nodosus occur on every other primary rib whereas the nodes on the right valve, though not so large, are present on each primary rib. Recent Eastern Atlantic analogues of L. nodosus are L. corallinoides (d’Orbigny) and L. noduliferus (Sowerby) (see Dodge, 1952, p. 172). The east American L. fragosus (Conrad) and the west American L. subnodosus (Sowerby) were thought by Dall (1898, pp. 728-729) to be mere variants of L. nodosus nodosus, but some authors consider the seven-ribbed L. fragosus to be a subspecies of L. nodosus, and L. subnodosus to be a distinct species. Range and distribution—Lyropecten (Nodipecten) nodosus (Linnaeus) ranges from lower Miocene to Recent. The living shell is found in the Western Atlantic from North Carolina, U.S.A., to VENEZUELAN CENOZOIC PELECYPODS: WEISBORD 159 Brazil. As a Pleistocene fossil, L. nodosus is recorded from St. Kitts and St. Eustasias, doubtfully from the Dominican Republic (Pilsbry 1921, pp. 409-410), and from Paraguana, Tortuga, and Cubagua in Venezuela. In the Pliocene it is said to occur in Florida and Costa Rica. Maury (1917, pp. 350-351) collected several imperfect speci- mens of the species from the middle Miocene of the Dominican Republic, and Hubbard (1920, pp. 86-87) classified as L. nodosus a few poorly preserved specimens from the Quebradillas limestone (lower ? Miocene) of Puerto Rico. Lyropecten (Nodipecten) arnoldi Aguerrevere Pl... 18) fig.2: PL 39. fig. 1 1886. “Pecten gigas” Karsten, Géologie de l’ancienne Colombie bolivarienne, Vénézuela, Nouvelle-Grénade et Ecuador, p. 9. 1925. Pecten (Lyropecten) arnoldi Aguerrevere, Southern California Acad. Sci., Bull., vol. 24, pt. 2, pp. 51-53, pl. 5. 1956. Pecten arnoldi Aguerrevere, Rivero, Bol. de Geologia, Publ. Especial, No. 1, p. 120. 1957. Pecten arnoldi Aguerrevere, Weisbord, Bull. Amer. Paleont., vol. 38, No. 165, p. 16. The Cabo Blanco shell is large, slightly broader than high, subequilateral, subequivalve, the right valve moderately convex, the left compressed. Both valves have a fairly thick shell substance, and fit snugly at the evenly rounded basal margin, with the ribs of one valve nestled into the flutings of the other. Anterior auricle of right valve somewhat larger than the posterior, the anterior auricle obliquely truncate at the superior lateral margin, incurved below, sculptured by four subequal radiating riblets on the upper two- thirds of the ear; there are no radiating riblets on the lower third or so of the anterior auricle of the right valve, but the whole auricle is traversed by numerous raised sinuous laminae. Anterior auricle of left valve with about six radiating riblets which are finer and weaker than those of the right valve, the entire ear also crossed by numerous sharp laminae. Posterior auricles squarish, the auricle of the right valve sculptured by five or six radiating riblets which are much feebler than those on the anterior ear of the nght valve, and by numerous raised wavy laminae which are stronger than those on the anterior ear. The posterior auricle of the left valve is completely wanting in radiating riblets but is transversed by 160 BuLueTIN 204 closely spaced, raised, wavy laminae sharper than the laminae of the anterior ear. Byssal gape narrow and relatively small, the byssal area flattened and marked with concentric laminae only. Pectinidial teeth below the anterior auricle are absent, but on one adult speci- men with the ear broken at the junction of the disk there are a number of denticulations normally covered by the inner margin of the auricle. Chondrophore large, deep, wedge-shaped, internal, bounded along the posterior side by a thick ridge with a sulcus down the middle paralleling the edge of the chondrophore. On the hinge plate behind this ridge there is a triangular or ovate depression with the long axis paralleling the ligamental groove above it but extending only about half the length of the ligamental groove. The anterior side of the chondrophore is bordered by a single narrow ridge, on the forward side of which is a roughly rectangular de- pressed area bearing heavy irregular vertical rugae. Ligamental groove long and narrow, extending along the full length of the hinge line. Body cavity well removed from the margins, the border of the cavity scored with numerous short vertical grooves. Muscle scar large, suborbicular, the posterior margin coinciding with the margin of the body cavity. Inner surface of ventral margin marked by generally nine short broad raised ribs separated by wide triangular flutings, the raised ribs corresponding to the intercostal areas of the exterior, the flutings corresponding to the external costae. The internal ribs are thickened along the margins rendering them bicari- nate. The exterior of the shell is sculptured by nine or ten broad, gently rounded ribs which are themselves compounded of four sub- sidiary riblets of about equal size. At the base, the interspaces are slightly narrower than the primary ribs, and in the interspaces there are uSually one prominent riblet in the middle and a minor one on either side; the intercostal riblets are much more prominent than the subsidiary ones on the main ribs. The sides of the disk are sculptured by several secondary radiating riblets, and crossing the whole of the exterior are numerous equally spaced concentric lam- inae. Both valves are somewhat nodose in the early stages of growth, the nodes occurring on every rib in about the same prominence. Several of the right valves are colored light violet around the body cavity. VENEZUELAN CENOozoIC PELECYPoDsS: WEISBORD 161 Dimensions.—Specimen M320a, height 137 mm., width 148 mm.; length of hinge line 97 mm.; thickness (right valve) 35 mm. Largest specimen, height 205 mm.; width 220 mm.; thickness (valves attached) 90 mm. Type locality—“The type specimen of Pecten arnoldi was found 1 and % miles east of the castle of Cumana, State of Sucre, Venezuela, S.A.” (Aguerrevere). Cabo Blanco localities —Playa Grande formation (Catia mem- ber) in bluff 125 meters west of intersection of the Playa Grande Yachting Club road and coast road. Eleven specimens including three doublets and eight large fragments. Playa Grande formation (Catia member) at W-15, south side of Playa Grande road, 40 meters southeast of its intersection with Playa Grande Yachting Club road. Six right valves. Playa Grande formation (Catia mem- ber) near W-21 and in stream flowing along the strike of the north flank of the Litoral anticline. Two fragments. Remarks.—This species is probably the same as the one listed by Karsten (1886) as “Pecten gigas’ from Cabo Blanco near La Guaira. The name seems to have been coined by Karsten to indicate its size, but as there is no formal description it is a nomen nudum with no official status. However, Aguerrevere’s excellent description leaves little doubt that the large Cabo Blanco Pecten is identical with L. arnoldi from Cumana. Comparisons—The Miocene-Pliocene Pecten (aff. Nodipecten) colinensis F. and H. Hodson (1927, p. 33, pl. 18, figs. 3, 6; pl. 19, fig. 4) from the District of Colina, State of Falcon, Venezuela, is similar to L. arnoldi but has one or two more primary ribs than L. arnoldi, and the subsidary riblets on the primary ribs are stronger. Pecten (Lyropecten) pittieri Dall (1925, U.S. Nat. Mus. Proc., vol. 66, No. 2554, art. 17, p. 23, pl. 17, fig. 6) from the later Tertiary of Moin Hill, near Limon, Costa Rica, is much smaller than L. arnold1, and the intercostal riblets are all of about the same size. The lower Miocene to Recent L. nodosus (Linnaeus) (1758, Syst. Nat., ed. 10, p. 697) in the eastern Americas is characterized by strong radiat- ing riblets on both auricles of both valves. The lower Pliocene to Recent L. subnodosus (Sowerby) (see Thes. Conchyl., vol. 1, p. 65, pl. 15, figs. 97, 112) from the western Americas differs from L. 162 BuLteTIN 204 arnoldi in having more numerous secondary riblets of about equal size in the intercostal areas. Range and distribution—Lyropecten arnoldi is now known from two Venezuelan localities: Cabo Blanco in the Distrito Federal, and near Cumana on the State of Sucre, about 310 kilometers east of Cabo Blanco. Aguerrevere suggested a Miocene age for the Cumana deposit in which L. arnoldi was found. Tentatively I would consider the Catia member of the Playa Grande formation in the Cabo Blanco area to be Pliocene in age. Lyropecten (Nodipecten) species “a” Pl. 17, Higgs Illustrated are fragments of a species which is much the same as L. arnoldi Aguerrevere except in the character of the larger in- ternal ribs on the basal margin. Those ribs are quadripartite on the present shell but bipartite on L. arnoldi, Whether this is an indi- vidual variation or a specific difference cannot be determined with the material at hand. Dimensions——Specimen 1323a, height of fragment 66 mm. Specimen J323a, width of fragment 80 mm. Localities —Lower Mare formation at W-13, on hillside above west bank of Quebrada Mare Abajo. One fragment. Lower Mare for- mation, in small stream 100 meters west of Quebrada Mare Abajo. One fragment. Lyropecten (Nodipecten) species ‘“‘b” Pl) 17; figse 4S Shell attaining a large size, sculptured exteriorly by broad, flat- tish, flexuous and slightly curved radiating costae with steep sides. The costae are themselves made up of three to five strong, coarse radiating riblets more or less equal in size, the lateral riblets grooved along the middle, the inner ones single, all of them rendered nodu- lous where they are crossed by concentric growth ridges. In the intercostal areas there are one to three radial riblets, the middle one of these about the same size as the riblets on the principal costae and also nodulous, the ones on either side of that minor. On the middle of the disk, and presumedly above as well, there are widely spaced rows of large rounded nodes, with one such node per row on each costa. Crossing the whole of the disk are numerous concentric VENEZUELAN CENOZOIC PELECYPODS: WEISBORD 163 laminae, the laminae curved downward on all radial ribs and up- ward in all of the interspaces. At the basal margin of the valve the laminae are crowded and more or less coalescent. The interior of the shell is fluted from the margins to the body cavity, the flut- ings corresponding with the external costae and more deeply 1m- pressed at the margin. The flutings are bordered by raised flat ribs corresponding to the intercostal areas of the exterior. Near the base of the shell these ribs are thickened on each side rendering them bidenticulate. Dimensions —Specimen 0321la (fragment), width 59 mm.; height 52 mm. Locality —Playa Grande formation (Catia member) at W-22, on dip slope 100 meters west of Costa fault. One fragment. Remarks.—Superficially the present shell resembles L. colinen- sts (F. and H. Hodson) (1927, p. 33, pl. 18, figs. 3, 6; pl. 19, fig. 4) from Miocene-Pliocene strata at various localities in the State of Falcon, Venezuela, but on Hodson’s species the large nodes occur on every third costa whereas on the Cabo Blanco form they appear on each costa. SPONDYLIDAE Spondylus americanus Hermann Pl. 17, figs. 6-8; Pl. 20, figs.-1..2: Pl. 21, figs: 1.2 1781. Spondylus americanus Hermann, Der Naturforscher, vol. aS, Sill: 1784. Ostrea echinata Martyn, The Universal Conchologist, vol. 3, fig. 154. 1787. ? Spondylus fimbriatus Meuschen, Museum Geversianum, p. 434. 1798. Spondylus dominicensis Roding, Museum Botenianum, ed. 1, p. 193. 1798. Spondylus aurantiacus Roding, Museum Boltenianum, ed. 1, p. 195. 1819. Spondylus arachnoides Lamarck, An. sans Vert., vol. 6, p. 188. 1819. Spondylus americanus Lamarck, An. sans Vert., vol. 6, pp. 188-189. Not of Schreiber 1793. 1819. ? Spondylus longitudinalis Lamarck, An. sans Vert., vol. 6, p. 191. 1819. Spondylus crassisquama Lamarck, An. sans Vert., vol. 6, p. 191. 1832. Spondylus americanus Lamarck, Deshayes, Encycl. Méth., vol. 3, p. 978, pl. 195, figs. 1-2. 1845. ? Spondylus striato-spinosus Chenu, Illustrations Conchyliogiques, vol. 2, p. 7. 1848. Spondylus spathuliferus Sowerby, Thes. Conchyl., p. 421, pl. 89, fig. 61. 1853. Spondylus folia-brassica d’Orbigny, [in] La Sagra, Hist. phys., polit. nat. I’Ile de Cuba, Mollusques, vol. 2, p. 358. 1853. Spondylus echinatus (Martyn), d’Orbigny, [in] La Sagra, Hist. phys., polit. nat I’Ile de Cuba, Mollusques, vol. 2, p. 359. 1856. Spondylus americanus Lamarck, Reeve, Conch. Icon., vol. 9, pl. 4, sp. 17. 164 1856. 1856. 1864. 1878. 1878. 1881. 1884. 1889. 1889. 1889. 1891. 1895. 1898. 1901. 1905. 1912. 1920. 1924. 1933. 1935. 1936. 1936. 1936. 1937. 1937. 1938. 1938. 1940. 1940. BuLLetTin 204 Spondylus ictericus Reeve, Conch. Icon., vol. 9, pl. 11, sp. 40. Spondylus longitudinalis Lamarck, Reeve, Conch. Icon., vol. 9, pl. 13, sp. 46. Spondylus americanus Lamarck, Krebs, The West Indian Marine Shells, parte thy Spondylus fimbriatus Meuschen, S. spathuliferus Lamarck, S. americanus Lamarck, and S. croceus Reeve, Mérch, Catalogue of West-India Shells, p. 16. Spondylus croceus Humphrey, Arango y Molina, Contribucion a la Fauna Malacolégica Cubana, p. 271. Spondylus americanus Lamarck, Gabb, Acad. Nat. Sci. Philadelphia, Jour., ser. 2, vol. 8, p. 379. Spondylus americanus Lamarck, Tryon, Structural and Systematic Conchology, vol. 3, p. 285, pl. 131, fig. 72. Spondylus croceus Chemnitz, and S. spathuliferus Sowerby, Simpson, Davenport Acad. Nat. Sci., Proc., vol. 5, p. 70. Spondylus Americanus Lamarck, Lorie, Samml. Geol. Reichs-Mus. Leiden, ser. 2, vol. 1, pp. 114-115, 141. Spondylus spathuliferus Sowerby, Dall, U. S. Nat. Mus., Bull. 37, p. 32. Spondylus longitudinalis Lamarck, Baker, Acad. Nat. Sci. Philadelphia, Proc., vol. 43, p. 46. Spondylus ictericus Reeve, Gregory, Geol. Soc. London, Quart. Jour., vol. 51, p. 291. Spondylus echinata (Martyn), Dall, Wagner Free Inst. Sci., Trans., vol. 3, pt. 4, pp. 759-761. Spondylus echinatus (Martyn), Dall and Simpson, U. S. Fish Com., Bull., vol. 20 for 1900, pt. 1, p. 467. Spondylus americanus Lamarck, Verrill, Connecticut Acad. Arts and Sci., Trans., vol. 12 (1907), p. 186, pl. 35B, figs. 1, 1a. Spondylus americanus Hermann, Hedley and Pilsbry, Nautilus, vol. 26, No. 4, pp. 45-46. Spondylus echinatus (Martyn), Maury, Bull. Amer. Paleont., vol. 8, No. 34, pp. 62-63. Spondylus echinatus (Martyn), Emery, Nautilus, vol. 38, No. 2, p. 62. Spondylus ictericus Reeve, Trechmann, Geol. Mag., vol. 70, No. 823, p. 33. Spondylus americanus Lamarck, Richards, Jour. Paleont., vol. 9, No. 3, p. 256. Spondylus echinatus (Martyn), McLean, Nautilus, vol. 49, No. 4, p. 117. Spondylus echinatus (Martin), McLean, Soc. Cubana Hist. Nat. “Felipe Poey”’, Mem., vol. 10, No. 1, p. 40. Spondylus echinatus (Martyn), Clench and McLean, Soc. Cubana Hist. Nat. “Felipe Poey’, Mem., vol. 10, No. 3, p. 162. Spondylus dominicensis Roding, and S. ictericus Reeve, Fulton, Nautilus, vol. 51, No. 2, p. 38. Spondylus americanus Hermann, Smith, East Coast Marine Shells, p. 32, pl. 6, figs. la, 1b; pl. 54, figs. 1, 4. Spondylus americanus Hermann, Palmer, Palaeontographica Americana, vol. 2, No. 8, pp. 147, 150. Spondylus americanus Hermann, Richards, Geol. Soc. Amer., Bull., vol. 49, pt. 2, p. 1291, Spondylus echinatus echinatus (Martyn), and S. echinatus americanus Lamarck, Johnson, Boston Soc. Nat. Hist., Proc., vol. 40, No. 1, p. 23. Spondylus americanus Lamarck, Smith, World-wide Sea Shells, p. 94, figs. 1278a, b. VENEZUELAN CENOZOIC PELECYPODS: WEISBORD 165 1940. Spondylus americanus Hermann, Stenzel, Nautilus, vol. 54, No. 1, p. 21. 1942. Spondylus echinatus (Martyn), Jaume and Pérez Farfante, Soc. Cubana Hist. Nat. “Felipe Poey”, Mem., vol. 16, No. 1, p. 38. 1945. Spondylus americanus Hermann, van Bentham Jutting, Geolog.-Mijn- bouwk. Genootschap Nederland en Kolonien, Geol. ser., vol. 4, p. 77. 1946. Spondylus ictericus Reeve, Jaume, Soc. Malac. “Carlos de La Torre”, Rev., vol. 4, No. 3, p. 99. 1949. Spondylus echinatus Martyn, Lange de Morretes, Mus. Paranaense, Arq., vol. 7, art. 1, p. 15. 1951. Spondylus americanus Hermann, Rogers, The Shell Book, pp. 405, 502. 1951. Spondylus americanus Hermann, McLean, New York Acad. Sci. Scientific Survey of Porto Rico and the Virgin Islands, vol. 17, pt. 1, pp. 32-33, pl. 7a tags ale 1952. Spondylus americanus Lamarck, Pulley, Texas Jour. Sci., vol. 4, No. 2, p. 181, 1953. Spondylus echinatus (Martyn), Haas, Fieldiana-Zoology, vol. 34, No. 20, p. 203. 1954. Spondylus americanus Hermann, Abbott, American Seashells, pp. 369- 370, pl. 36b. 1955. Spondylus ictericus Reeve, Perry and Schwengel, Marine Shells of the Western Coast of Florida, pp. 44-45, pl. 5, fig. 23. 1955. Spondylus americanus Hermann, Perry and Schwengel, Marine Shells of the Western Coast of Florida, p. 45, frontispiece. 1958. Spondylus americanus Hermann, Olsson and McGinty, Bull. Amer, Paleont., vol. 39, No. 177, p. 20. 1958. Spondylus americanus Hermann, Abbott, Acad. Nat. Sci. Philadelphia, Mon. No. 11, p. 117. 1959. Spondylus americanus Hermann, Nowell-Usticke, A Check List of the Marine Shells of St. Croix, p. 7. 1961. Spondylus americanus Hermann, Warmke and Abbott, Caribbean Sea- shells, p. 170-171, pl. 4e; 34a, b. The Venezuelan fossils referred to this species are large, robust, suborbicular, and inflated. The posterior side is rounded a little more acutely than the anterior near the middle and is embayed more prominently below the posterior auricle. Interior with crenulate mar- gins, a large, fairly deep adductor impression, a simple pallial line not far from the margin, and a well-defined body cavity. Exterior diversely sculptured by spinose radial ridges and foliaceous con- centric lamellae. Our largest left valve, which is worn, has about six primary radials with short strong spines, and, on the disk, about half a dozen subequal secondary radial ribs. On the largest right ? valve, the spines are long and strong on the primary ridges, are convex on the upper surface, and are longitudinally fluted with a single groove on the under side. The exterior of other fragments is raspy and scabrous, and the spines flattened, the rasps produced by numerous small acutely vaulted lamellae. The umbo of the lower, 166 BULLETIN 204 or right valve is extended high above the upper valve and is strongly lamellate or foliaceous. The cardinal area above the hinge proper on the lower valve is high triangular, but the specimen is too im- perfect to reveal the nature of the longitudinal cartilage groove. Dimensions.—Specimen (S$354a), left valve, height 123 mm.; max. width 111 mm.; thickness approximately 45 mm. Specimen (0355a), right ? valve, height (umbo missing) 130 mm.; max. width 108 mm. Specimen 0441a (umbonal area and beak), right valve, height 42 mm. Specimen 0356a (part of the umbonal area), height 36.5 mm. Localities —Playa Grande formation (Maiquetia member) at W-23, north flank of Punta Gorda anticline. One left valve. Playa Grande formation (Catia member) at W-22, on dip slope 100 meters west of Costa fault. Two right valves, one fragment of um- bonal area, three fragments of base. Remarks.—Many present-day conchologists are of the opinion that there is but one living species of Spondylus in the Western At- lantic, and that is the one known currently as S. americanus Her- mann. The Eastern Pacific analogue is S. princeps Broderip (1833, Zool. Soc. London Proc., p. 4; see Keen, 1958, p. 76, pl. 2). These two Recent species, on opposite sides of the American continent, are much alike, although Abbott (1954, pp. 169, 170) stated that the Pacific form (as S. pictorwm Schreiber ) is usually more brilliantly colored than the Atlantic species, and that the spines are 1-1/2 inches or less in length as compared with those of S. americanus which are 2 inches or less in length. Although worn and encrusted, the Cabo Blanco fossils are believed to be the same as the Recent American shell, but whether it should be referred to the Western At- lantic S. americanus or to the Eastern Pacific S. princeps is a moot question. The Western Atlantic name has priority, and I tentatively identify the Cabo Blanco fossils with that species. Range and distribution—S. americanus Hermann is known from the Pliocene to Recent in east America, and S. princeps Brode- rip from the lower Pliocene to Recent in west America. The living S. americanus ranges from Florida to Brazil, S. princeps from the Gulf of California to Ecuador. In the Pleistocene S. americanus is re- corded from Florida, Cuba, St. Eustatius ?, Colombia, Barbados, and VENEZUELAN CENOzoIC PELECYPoDS: WEISBORD 167 Curacao, and in the Pliocene from Costa Rica. There are several Caribbean Miocene species that are similar or related to the ex- tremely variable S. americanus and among those are Spondylus species Woodring (1925, pp. 77-78, pl. 9, fig. 8) from Bowden, Ja- maica, and the middle Miocene S. colombiensis Weisbord (1929, pp. 246-247, pl. 2, figs. 10-11) from near Tubera, Colombia. LIMIDAE Lima (Limaria) pellucida C. B. Adams Pl. 18, figs. 2, 3 1846. Lima pellucida C. B. Adams, Boston Soc. Nat. Hist., Proc., vol. 2, p. 103. 1864. Lima inflata Lamarck (L. pellucida Adams), Krebs, The West Indian Marine Shells, p. 133. 1878. Lima pellucida Adams, Morch, Catalogue of West-India Shells, p. 16. 1885. Lima (Mantellum) hians (Gmelin), Smith, Voyage of H.M.S. Challenger, Zoology, vol. 13, p. 290 (part). Not of Gmelin. 1886. Lima inflata Lamarck, Dall, Mus. Comp. Zool., Bull., vol. 12, No. 6, p. 224. 1889. Lima inflata Lamarck, Dall, U. S. Nat. Mus., Bull. 37, p. 36. 1901. Lima inflata Lamarck, Dall and Simpson, U. S. Fish Com., Bull., vol. 20 for 1900, pt. 1, p. 468. 1920. Lima inflata Lamarck, Maury, Bull. Amer. Paleont., vol. 8, No. 34. 1931. Lima inflata Lamarck (L. pellucida C. B. Adams), Johnson, Nautilus, vol. 44, No. 4, p. 126. 1934. Lima (Limaria) inflata Lamarck (L. pellucida C. B. Adams), Johnson, Boston Soc. Nat. Hist., vol. 40, No. 1, p. 26. 1936. Lima (Limaria) hians (Gmelin), Clench and McLean, Soc. Cubana Hist. Nat. “Felipe Poey”, Mem., vol. 10, No. 3, p. 163. Not of Gmelin. 1937. Lima hians (Gmelin), Smith, East Coast Marine Shells, p. 36, pl. 10, figs. 3a, 3b. Not of Gmelin. 1940. Lima inflata Chemnitz, Smith, World-Wide Sea Shells, p. 97, fig. 1314. 1946. Lima (Limaria)hians (Gmelin), Jaume, Soc. Malac. “Carlos de La Torre”, Rev., vol. 4, No. 3, p. 99. Not of Gmelin. 1950. Lima pellucida C. B. Adams, Clench and Turner, Occas. Papers on Mollusks, vol. 1, No. 15, p. 324, pl. 43, figs. 8-9. 1951. Lima (Mantellum) inflata (Gmelin), McLean, New York Acad. Sci. Scientific Survey of Porto Rico and the Virgin Islands, vol. 17, pt. 1, pp. 35-36, pl. 7, fig. 5. 1954. Lima pellucida C. B. Adams, Abbott, American Seashells, p. 370. 1955. Lima (Limaria) inflata (Gmelin), Perry and Schwengel, Marine Shells of the Western Coast of Florida, p. 50, pl. 6, fig. 31. Not of Gmelin. 1958. Lima pellucida C. B. Adams, Olsson and McGinty, Bull. Amer. Paleont., vol. 39, No. 177, p. 20. 1958. Lima (Mantellum) pellucida C. B. Adams, Abbott, Acad. Nat. Sci. Philadelphia, Mon. No. 11, p. 117. 1958. Lima inflata Lamarck (pellucida C. B. Adams), Nowell-Usticke, A Check List of the Marine Shells of St. Croix, p. 8. 1961. Lima (Limaria) pellucida C. B. Adams, Warmke and Abbott, Caribbean Seashells, p. 171, pl. 34e. The worn and encrusted shell referred to Lima pellucida is represented by a right valve which is thin, subtranslucent, a little 168 BuLLETIN 204 inflated, elongate, obliquely subelliptical. Anterior side straight, with a long narrow hardly embayed gape, the ventral margin rather acutely rounded, the posterior side subangularly rounded with the greatest curvature a little above the middle, and with a short fairly pronounced gape below the posterior auricle. Interior of valve pol- ished, slightly corrugated by the sculpture of the exterior which is reflected through. Pallial line simple, a short distance in from the margins, the distinct edge of the body cavity farther removed. Beak small, smooth, pointed, appressed, projecting slightly, if at all, beyond the hinge line. Hinge line strongly inclined. Chondrophore relatively large, rounded-triangular, shallow. Just below the pos- terior auricle there is a short deep groove or sulcus. Exterior of valve sculptured by low delicate finely crenate radial riblets with finer threads between them, and widely spaced concentric lineations. The color is white within and without. Dimensions.—Specimen A559a, right valve, height from beak to ventral margin 21 mm.; width 13.5 mm.; thickness 4 mm. Locality—Beach at Playa Grande Yachting Club, Distrito Federal. One right valve. Remarks.—The Western Atlantic L. pellucida of C. B. Adams has been referred to by authors as L. inflata Lamarck (1819, An. san Vert., vol. 6, p. 156) and L. hians (Gmelin) (1791, Syst. Nat., p. 3333). According to Abbott (1958) L. pellucida is the same as L. inflata Lamarck 1819 but is not L. hians Gmelin 1791, which is from the Mediterranean. However, there is some question about the validity of Lamarck’s 1819 Lima inflata as that name was first used by him in January (?) 1807 (Mus. Nat. Hist. nat. Paris An., vol. 8, p. 463) in his “Mémoires sur les fossiles des environs de Paris.” In May 1807, Link (Beschreibung der Naturalien-Sammlung der Universitat zu Rostock, vol. 1, pt. 3, p. 157) described Limaria in- flata founded on Chemnitz 1784 (Neues systematisches Conchylien- Cabinet, vol. 7, pl. 68, fig. 649a) from “the coast of Guinea and the strands of the West Indian sugar islands.” That species was chosen as the type of the subgenus Limaria by Winckworth (1930, Malac. Soc. London, Proc., vol. 19, pt. 3, p. 116) and may well be the same as that named L. pellucida by C. B. Adams in 1846. However, Abbott (1958) stated that “If Mediterranean specimens prove to VENEZUELAN CENOzOIC PELECYPoDS: WEISBORD 169 be the same as our West Indian ones [L. pellucida], the name tu- berculata Olivi, 1792 or imbricata Risso, 1826 will have to be used.” The Venezuelan shell is identical to Clench and Turner’s illustration of the lectotype of L. pellucida from Jamaica, as well as, among others, to L. hians (Gmelin), Smith (1937) and Lima (Mantellum) inflata (Gmelin), McLean (1951) from Puerto Rico. Authoritative discussions of the subgenus Mantellum Roding versus Limaria Link are given by Winckworth (1930) and by Hertlein and Strong (1946, Zoologica, vol. 31, pt. 2, No. 55, p. 66). Range and distribution —Lima pellucida C. B. Adams has been found in the Western Atlantic from Florida to northern South Amer- ica at depths to 128 fathoms. The Eastern Pacific analogue appears to be L. hemphilli Hertlein and Strong (1946, pp. 66-67, pl. 1, figs. 3-4) from Monterey, California, to Acapulco, Mexico, in 10-50 fathoms. L. hemphilli also occurs as far back as the upper Miocene in California. The curvature of the posterior side is more pronounced on L. hemphilli than on L. pellucida. ANOMIIDAE Anomia mareana, new species PE tigs. 9 10; Pl. 18, figs. 4-9 Left valve thin and subtransparent to thin and subtranslucent, irregularly suborbicular to broadly oval in outline. In configuration the left valve is undulatingly flattish to convex, and on some adults the dorsal and ventral margins are so bent over that the lateral profile of the valve is U-shaped. On many specimens there is a broad shallow radial depression before the posterior margin which itself may be upturned. Prodissoconch orbicular, the beak small, pointed, slightly raised, and distinct. Interior of shell slightly na- creous, with a subcentral oblongish patch of calcified white extend- ing from below the ligament to about the middle of the valve where the patch widens. On the patch there are three rather prominent muscle scars, each of the scars offset from the other. The uppermost, or upper byssal scar, is the largest of the three, and is roughly circu- lar in outline, lying in the top center of the patch; the lowest scar, or adductor impression, lies in the lower posterior area of the patch and is broadly ovate, the narrow end of the scar pointing upward; 170 BULLETIN 204 the smallest scar, representing the lower byssal muscle, is subtri- gonal to ovate, with the narrow end generally pointing down, and it lies below and a little to the right of the upper byssal scar. The calcified ligamental area is narrowly triangular, with a wide gently arched base, and the fourth muscle impression of the valve at the anterior end of the area is broadly semilunar, the upper edge of the impression lying under or near the anterior basal margin of the ligamental process. The dorsal margins of the valve overhang the ligament a little and are thickened by incremental lamellae. The exterior of all young specimens and most intermediate ones is sculptured by fine concentric lamellae and low vermicular radial ribs and rugae, but on large valves the radial ribs become obso- lescent. Dimensions —Holotype (T362b), left valve, height 24.8 mm.; max. width 23.9 mm., thickness 7 mm. Paratype (T362a), left valve, height 36 mm.; max. width 40.2 mm.; thickness 15 mm. Paratype (G362b), left valve, height 25.2 mm.; max. width 26.5 mm.; thick- ness 1.7 mm. Paratype (J444a), left valve, height 6.3 mm.; max. width 7.7 mm.; thickness 1 mm. Largest specimen, a left valve, height 42 mm.; max. width 46.5-mm.; thickness 8.4 mm. Most highly bent specimen, a left valve, height 19.3 mm.; max. width 28 mm.,; thickness 8 mm. Type locality—Upper Mare formation, in stream 250 meters south-southwest of mouth of Quebrada Las Pailas. Three left valves. Other localities —Mare formation at W-14, on hillside above west bank of Quebrada Mare Abajo. Six left valves. Lower Mare formation at W-13, on hillside above west bank of Quebrada Mare Abajo. Eleven left valves. Lower Mare formation, in small stream 100 meters west of Quebrada Mare Abajo. Eight left valves. Comparisons—Some adult specimens of A. mareana, n. sp., on which the radial ribs are obsolescent, closely resemble certain vari- ants of the middle Miocene to Recent A. simplex d’Orbigny (1842, p. 367, Atlas, pl. 38, figs. 31-34), but normally A. mareana is sculp- tured by both wavy radial ribs (which are inherent and not due to the influence of situs) and concentric lamellae, whereas typically A. simplex is a smoothish form marked only by concentric lamellae. Other species to which A. mareana exhibits affinity are the follow- ing: VENEZUELAN CENOZOIC PELECYPODS: WEISBORD wl A. peruviana d’Orbigny (1846, Voyage Amérique Meridonale, vol. 5, pt. 3, Mollusques, P. 673). Recent adult specimens of this west American Pliocene to Recent form which I have seen in the Academy of Natural Sciences of Philadelphia are all marked with fairly strong vermicular radiating rugae whereas adults of the Vene- zuelan fossil A. mareana and of A. simplex d’Orbigny are smoothish. A. subcostata Conrad (see Hanna, 1926, California Acad. Sci., Proc., ser. 4, vol. 14, No. 18, pp. 460-461, pl. 23, figs. 3-5) from the Pliocene Carrizo formation of California varies in its radial sculp- ture from strongly plicate to none at all. A. venezuelana Harris ([in] F. Hodson, H. K. Hodson, and Harris, 1927, pp. 43-44, pl. 23, figs. 2-3) from the Miocene and Pliocene of the State of Falcon, Venezuela. The adult of A. venezue- lana is larger than A. mareana, n. sp., is more attentuate posteriorly, and has coarser and more prominent radial rugae. A. indecisa Woodring (1925, p. 84, pl. 10, figs. 6-9) from the middle Miocene of Jamaica and the Dominican Republic. A. indecisa is a small smooth shell which may bear very fine obscure radial threads near the ventral margin. Also the lower byssal and adduc- tor scars lie in a nearly horizontal plane whereas the lower byssal scar of A. mareana lies to the right of and higher than the adductor. A. glypta Gardner (1926, U. S. Geol. Sur., Prof. Paper 142-A, pp. 53-54, pl. 12, figs. 6-7) from the middle Miocene Chipola for- mation of Florida. The upper byssal scar and lower adductor scar are about the same size, with the former lying almost directly above the adductor. On the Venezuelan A. mareana, the upper byssal scar is larger and rounder than the adductor, and lies above and to the right of the adductor. A. suwaneensis Gardner (1926, pp. 54-55, pl. 13, fig. 5) from the middle Miocene Chipola formation of Florida. The ligamental scar is broadly conical or horshoe-shaped whereas the ligament of A. mareana is narrowly and widely triangular. Anomia catiana, new species Pl. 19, figs. 2-6; Pie 25) f199 The upper, or left valve of this species is moderately thin, sub- 172 BuLLeETIN 204 trigonal, oval, or suborbicular in outline, compressed to convex, some specimens with the umbo so full and bent over that they are gry- phaeaform. Prodissoconch orbicular, the beak small and pointed on young shells, appressed on old. Interior with a large, slightly ob- lique, more or less medial oblongish patch, the anterior edge of the patch fairly straight, the posterior edge arcuate. The muscle im- pressions on the patch are not visible. Dorsal margin of valve thickened by incremental lamellae, the lateral and ventral margins thin. Ligamental area broadly subconical, not on an elevated process, distinguished by vertical scratches on the inner surface of the valve under the overhang of the dorsal margin. On several examples a strong semilunar muscle impression may be seen touching the an- terior end of the ligamental area. The exterior of the valve is shag- reened by numerous erratically disposed short shallow grooves, superposed on the feeble concentric undulations or fine, concentric, appressed lamellae. An occasional specimen is marked with faint zigzag or vermicular rugae, and one specimen (K362d), undoubtedly belonging to this species, is sculptured by numerous microscopic crenated radial filaments of about equal size covering the whole of the disk from the umbo down;- the umbo itself is smoothish. The character of the rnght, or attached valve is not known as no ex- amples were found. Dimensions.—Holotype (K362a), left valve, height 33 mm.,; max. width 32 mm.; thickness 10 mm. Paratype (K362b), left valve, height 32.8 mm.; max. width 38.3 mm.; thickness 7.2 mm. Paratype (K362c), left valve, 31 mm.; max. width 30.2 mm.; thick- ness 5.5 mm. Paratype (K362d), left valve, height 26.6 mm.; max. width 25 mm.; thickness 4.5 mm. Type locality—Playa Grande formation (Catia member), in bluff 125 meters west of the intersection of the Playa Grande Yacht- ing Club road and coast road, about 95 meters due south of the shoreline. Eleven left valves. Other localities— Playa Grande formation (Catia member), about 220 meters west of W-15, on south side of Playa Grande road. One left valve. Comparisons.—Anomia catiana, n. sp. is reminiscent of the middle Eocene A. lisbonensis Aldrich (see Harris, 1919, Bull. Am. VENEZUELAN CENOzoIc PELECYPODS: WEISBORD 173 Paleont., vol. 6, No. 31, pp. 17-18, pl. 11, figs. 6-10) from Texas, Louisiana, and Alabama. A. lisbonensis is variable in shape, with some of the left valves having a pustular surface and others a finely lineate one. The radial lineations of A. isbonensts are in the nature of somewhat irregular hachures, whereas those of A. catiana are uninterrupted, regular, faint even under a lens, and equal in size. The surface of the majority of the left valves of A. catiana, n. sp. is faintly roughened by a maze of short linear grooves, whereas the faint roughening of A. lisbonesis is pustular in aspect. The rare lineate variant of A. catiana is reminiscent of the Miocene to Recent A. aculeata Gmelin (1791, Syst. Nat., vol. 6, p. 3346), but the linea- tions are stronger on A. aculeata. On the single lineate specimen of A. catiana, the fine radial lineations cover the disk but are wanting on the prodissoconch, Pododesmus rudis (Broderip) Pl. 19, figs. 7, 8; Pl. 23, fig. 10 1834. Placunanomia rudis Broderip, Zool. Soc. London, Proc. for 1834, p. 2. 1837. Pododesmus decipiens Philippi, [in] Wiegmann, Archiv Naturgeschichte, vol. 1, p. 386, pl. 9, figs. 1a-d. 1849. Placunanomia rudis Broderip, Gray, Zool. Soc. London, Proc. for 1849, . 120. 1849. Been ent abnormalis Gray, Zool. Soc. London, Proc. for 1849, p. 121. 1859. Placunanomia echinata Broderip, Reeve, Conch. Icon., vol. 11, Placun- anomia, pl. 1, sp. 1. 1859. Higchnanomia rudis Broderip, Reeve, Conch. Icon., vol. 11, Placunanomia, piel spe02. 1859. Placunanomia harfordi Reeve, Conch. Icon., vol. 11, Placunanomia, pl. 2, sp. 8a, 8b. 1859. Placunanomia abnormalis Gray, Reeve, Conch. Icon., vol. 11, Placun- anomia, pl. 3, sp. 14a, 14b. 1864. Placunanomia rudis Broderip, Krebs, The West Indian Marine Shells, pe 37. 1878. Placunanomia echinata Broderip and P. rudis Broderip, Morch, Cata- logue of West-India Shells, p. 16. 1884. Pododesmus rudis (Broderip), Tryon, Structural and Systematic Con- chology, vol. 3, p. 294, pl. 131, fig. 77. 1886. Pododesmus rudis (Broderip), Fischer, Manuel de Conchyliologie et de Paléontologie Conchyliologique, p. 932 (1887). 1889. Placunanomia rudis Broderip, Dall, U. S. Nat. Mus., Bull. 37, p. 32. 1898. Pododesmus rudis (Broderip), Dall, Wagner Free Inst. Sci., Trans., vol. 3, pt. 4, p. 779. 1901. Pododesmus rudis (Broderip), Dall and Simpson, U. S. Fish Com., Bull., vol. 20 for 1900, pt. 1, p. 469. 1920. Pododesmus rudis (Broderip), Maury, Bull. Amer. Paleont., vol. 8, No. 34, pp. 64-65. 174 BuLLETIN 204 1926. Pododesmus rudis ? (Broderip), (Gray), Gardner, U. S. Geol. Sur., Prof. Paper 142-A, p. 55, pl. 13, fig. 12. 1934. Pododesmus decipiens Philippi, and P. rudis (Broderip), Johnson, Boston Soc. Nat. Hist., Proc., vol. 40, No. 1, p. 27. 1937. Pododesmus decipiens Philippi, Smith, East Coast Marine Shells, p. 37, pl. 10, fig. 13. 1949. Pododesmus rudis (Broderip), Lange de Morretes, Mus. Paranaense, Arq: vol. /, att. 1, 0p: 16. 1951. Pododesmus rudis (Broderip), McLean, New York Acad. Sci. Scientific Survey of Porto Rico and the Virgin Islands, vol. 17, pt. 1, p. 38, pl. 8, fig. 1. 1954. Bodog outst rudis (Broderip), Abbott, American Seashells, pp. 372-373, pl. 38b. 1955. Pododesmus rudis (Broderip), Perry and Schwengel, Marine Shells of the Western Coast of Florida, p. 51, pl. 6, fig. 33. 1961. Pododesmus rudis (Broderip), Warmke and Abbott, Caribbean Sea- shells, pl. 34). Left, or upper valve moderately solid, broadly oval to subor- bicular, a little convex. Interior subnacreous, with a large oblong- ish patch of white enamel extending from the ligamental area to a little below the middle of the valve, the posterior margin of the patch ragged but straight, the anterior margin irregularly convex outward. The patch bears two prominent muscle impressions, the large ovate impression of the byssal muscle lying a little above the middle and near the anterior margin of the patch, the smaller adductor muscle impression lying in the lower left area of the patch. The larger impression exhibits faint rays divaricating from the long axis, the smaller marked with long faint striae running obliquely across the central area. The ligamental area is impressed into the enamel, and is semiconical in outline with the outer ends projecting downward as prongs, the horizontal basal edge of the ligamental area lying above but connected with the prongs. The dorsal margins of the left valve are built up by scabrous incremental lamellae; the lateral and ventral margins are irregularly scalloped along the edge and are faintly crenulate within. On the exterior, the beak is small, pointed, and smooth, and lies a short distance from the dorsal margin. The area of the prodissoconch below the beak is sculptured by fine, rather widely spaced crenated vermicular radial threads, these developing on the rest of the disk into irregular, fairly crowd- ed, coarse radial rugae, here and there twisted, between which there are a few minor threads. The rugae are crossed by arched or vaulted scales which are relatively sparse on most of the disk but are much more numerous and stronger toward the foliaceous ventral margin. VENEZUELAN CENozoIc PELECYPops: WEISBORD 175 What I take to be the attached, or right valve of this species is represented in the collection by a single young broken specimen. This valve is thin, hardly convex, subtransparent, more or less orbicular in outline, and with an undulating surface. The area of the byssal foramen is roundish and but partially open. The exterior of the valve is sculptured by sharp wavy crenated radiating riblets between which are a few minor radiating threadlets. From about the middle of the valve down the primary riblets bear widely spaced short vaulted lamellae or scales open toward the base. The riblets on the posterior side of the right ? valve are a little closer and more strongly crenate than the ones on the anterior side, but on the single specimen the anterior riblets seem more prone to develop the vaulted scales. Dimensions.—Specimen G362a, adult left valve, height 38.2 mm.; width 44.8 mm.; thickness 4.7 mm. Specimen G362c, immature right ? valve, height 10.8 mm.; thickness 2.2 mm. Locahties—Mare formation at W-14, on hillside above west bank of Quebrada Mare Abajo. One large left valve and one small right ? valve. Remarks.—The Venezuelan fossil is believed to be the same as the Recent east American P. rudis (Broderip) which is a variable species with respect to shape and scaliness. It is also like the Pliocene to Recent west American P. macroschisma (Deshayes) (1839, Soc. Zool. Cuvierienne, Rev., p. 359; also, see Grant and Gale, 1931, San Diego Soc. Nat. Hist., Mem., vol. 1, pp. 241-242, pl. 12, figs 3, 4a, 4b) except for the position of the byssal muscle impression which lies more or less centrally within the enamel patch on P. macroschis- ma but near the anterior margin of the patch on the Venezuelan shell. Range and distribution—The Recent P. rudis (Broderip) is re- ported as ranging from Florida to the mouth of La Plata River, South America, in less than 50 fathoms. Gardner reported P. rudis from the Pliocene Waccamaw formation of North Carolina and from the middle Miocene Chipola formation of Florida. The identification of the latter, however, is doubtful as the single valve “does not re- tain enough of its diagnostic characters to make the determination convincing.” Gardner’s illustration is of a Recent left valve from the Antilles. 176 BuLuLeTIn 204 OSTREIDAE Ostrea (Ostrea) libella, new species Pl. 20, figs. 3, 4; Pl. 21) "figs, 3-0 Shell small, rudely oval, subtriangular, or subfalcate, the valves subequal, compressed, irregularly undulate. Left, or attached valve with a small, slightly elevated opisthogyral beak, the beak of the right valve appressed. Cartilage process generally short, oblique, and shallow; on one left valve, however, the cartilage channel is narrow and sinuous, and is bordered on each side by a thickened ridge. The inner margins are normally pitted on the left valve and den- ticulate on the right, though the denticulations are usually slitted at the summit, the slits sometimes breaching the rim of the valve to form an Jsognomon-like hinge pattern. The pits and denticles are present on the dorso-lateral margins, but they may continue around the ventral margin as well. The kidney-shaped muscle scar is situ- ated posterior to the middle but its orientation depends on the shape of the valve; on most examples it lies normal to the long axis of the valve but sometimes it is parallel with it or transverse to it. The exterior is sculptured by rather coarse irregular concentric lamellae becoming incremental at the base and margins, and on a number of specimens there are gentle radial folds or plicae on the basal half of the valve. Dimensions —Holotype (C351e), left valve, height 11.5 mm.; width 10 mm.; thickness 2.2 mm. Paratype (C351d), right valve, height 13.7 mm.; width 15 mm.; thickness 2 mm. Paratype (C35la), left valve, height 11.4 mm.; width 10 mm.; thickness 2.9 mm.; Specimen C351f, left valve, height 9 mm.; width 6.5 mm.; thickness 3.2 mm. Largest specimen, right valve, height 23 mm.; width 20 mm.; thickness 4.8 mm. Type locality.—La Salina, west of Puerto Cabello, State of Cara- bobo. Twenty specimens including at least three left valves and nine right valves, the remainder indeterminate. Comparisons.—This species belongs in the category of such Ostreidae as the Recent Western Atlantic O. spreta d’Orbigny (1842, p. 365, pl. 28, fig. 30) and O. permollis Sowerby (1841, [in] Reeve, Conch Icon., vol. 28, pl. 10, fig. 18a). O. spreta, however, has a more VENEZUELAN CENOZzoIC PELECYPODS: WEISBORD 177 centrally located muscle scar, and O. permollis, which lives com- mensally in sponges, has a fuller and larger beak, much finer and closer concentric lamellae on the disk, and is wanting in the radial folds which are present on many, although not all specimens of O. libella, n. sp. The Recent Western Atlantic O. cristata Born (see Dall, 1925,,U.S..Nat..Mus., Proc.,, vol. 66, No: 2554, art. 17, p. 23; pl. 28, figs. 7-8) and O. equestris Say (see Dall, 1925, p. 23, pl. 28, Figs. 1, 3) are sometimes placed in synonymy with O. spreta d’Or- bigny, but as shown by Dall, O. cristata is a large shell with strong angular folds, and O. equestris has a deep, teardrop-shaped lower (left) valve with a relatively long, acutely tapering cartilage channel. The La Salina fossil specimens here named O. Jibella, n. sp., are close to certain Recent forms labelled O. cristata Born in the Aca- demy of Natural Sciences of Philadelphia. The La Salina fossils are also similar to the Recent O. cristata Born from Lake Worth, Flori- da, as illustrated by McLean in Notulae Naturae (page 6, pl. 4, figures 4-7, 1941). However, neither the Venezuelan fossils nor the Recent examples just referred to have the strong angular folds purportedly present on the O. cristata of Born. Lamy (1929, Jour. Conchyl., vol. 73, pp. 103-105) stated that of the species referred to O. cristata Born by various authors only the Puerto Rican form described by Dall and Simpson (1901, U.S. Fish Com., Bull., vol. 20 for 1900, pt. 1, p. 464) was the true O. cristata. On the other hand, it is stated by Warmke and Abbott (1961, Caribbean Sea- shells, p. 172) that the Puerto Rican O. cristata of Dall and Simpson is O. equestris Say. In view of these considerations it seems ad- visable to give a new name to the La Salina fossil pending clarifica- tion of the O. cristata-equestris-spreta nomenclatural problem. Ostrea cristata Born is reported living from the Gulf of Mexico and Florida as far south as Uruguay. In the Pleistocene O. cristata has been reported from Florida, and from the Paraguana Peninsula, and the Island of Tortuga, Venezuela. Ostrea (Ostrea) pannucea, new species Pl. 22) figs: 1.3 The description of this species pertains to the right (upper) valve. 178 BULLETIN 204 Shell small, irregularly flexuous and bent but more or less compressed, varying in outline from suborbicular to ovate to sub- trigonal. Beak appressed, facing the posterior, the apex of the holo- type so formed as to indicate that the prodissoconch is orbicular and that its axis is at nearly a right angle with the long axis of the grown valve. The exterior is ridged into smooth irregular corru- gations, and is marked by concentric lamellae which are obsolete on the middle of the valve but stronger and incremental at the margins. On the paratype and other specimens, the thin outer layer of shell is worn away revealing faint vermicular radial threads on and below the umbonal area. In the interior, the cartilage area is broad and fairly long, directed opisthogyrally, its resilial depression moderately deep. The lateral margins are denticulate for longer or shorter dis- tances from the apex toward the base, and there is the suggestion that the anterior series of denticles start at the top of the beak, the posterior ones at the base of the beak. The muscle scar is semi- circular to elongate-lenticular, depending on the shape of the valve. Dimensions.—Holotype (Q349a), right valve, length 13.5 mm.,; width 9 mm. Paratype (Q349b), right valve, length 15 mm.; width 12.8 mm. The paratype is the largest of four specimens. Type locality—Playa Grande formation (Maiquetia member) at W-4, Quebrada Las Pailas. Four right valves. Comparisons—In many respects this species is similar to the preceding O. libella, n. sp., from La Salina, differing, however, in lacking the radial folds or plicae which are present on the basal half of some of the specimens of O. libella. The right valve of O. libella is also more coarsely foliated by concentric lamellae, and the carti- lage process of that valve is shorter and broader than on the present O. pannucea, n. sp. There is considerable resemblance, on their respective right valves, between the nepionic area of O. pannucea and O. democraciana chiriguarana F. Hodson (1927, Bull. Amer. Paleont., vol. 13, No. 49, p. 20, pl. 10, fig. 5; pl. 11, figs. 1-3) from the Miocene and Pliocene of the State of Falcon, Venezuela, but the right valve of O. d. chiriguarana is larger and much less undulate than that of O. pannucea. VENEZUELAN CENOZzOIC PELECYPODS: WEISBORD 179 Ostrea (Ostrea) lixula, new species Pl. 22, figs. 3-8 The following description pertains to the right (upper) valve. Shell of medium size, rather thin, generally subtrigonally ovate, rarely suboval, suborbicular, or subfalcate, flat to medially de- pressed, the outer surface undulatory to plane. Exterior nonplicate, sculptured by wide, foliaceous appressed concentric lamellae often bearing faint irregular radial riblets and a few narrow obsolete folds. On the interior, the cartilage area is low, short, and broad, directed a little toward the posterior, the resilial depression proper wide and shallow, bordered on either side by a low, rather sharp ridge. The body cavity is not excavated and slopes up to the edge of the car- tilage deck, the edge of the deck sinuous and bowed down in the middle. Beak pointed to blunt or truncate. The dorsolateral margins are denticulate, pustulate, or ridged, the nodulations occasionally continuing around the entire ventral margin, although where this occurs they are fainter and more widely separated than above. The muscle scar is large and pyriform, the narrow end of the scar ex- tending high up the valve near the posterior margin. Dimensions—Holotype (0350a), right valve, length 55.4 mm.; width 37 mm. Paratype (0350b), right valve, length 33.5 mm.; width 25.8 mm. Paratype (J347a), right valve, length 32 mm.; width 24.8 mm. Largest specimen, right valve, length 63.2 mm.; width 43.4 mm. Type locality—Playa Grande formation (Catia member) at W-22, on dip slope 100 meters west of Costa fault. Eleven right valves. Other localities —Playa Grande formation (Catia member), in the vicinity of W-21. Three right valves. Lower Mare formation, in small stream 100 meters west of Quebrada Mare Abajo. One right valve. Comparisons.—There are a number of similar species from east and west America. The closest perhaps is O. freudenbergeri Hertlein and Jordan (1927, California Acad. Sci., Proc., ser. 4, vol. 16, No. 19, p. 622, pl. 17, fig. 9; pl. 18, fig. 4) (see also Loel and Corey, 1932, California Univ. Publ., Dept. Geol. Sci., vol. 22, No. 3, pp. 190-191, pl. 14, figs. la, 1b; pl. 15, figs. la, 1b) from the lower Miocene of 180 Butwetin 204 Baja California, México, and of the State of California, U.S.A. O. freudenbergeri, however, is a larger shell, and the muscle scar of the right valve is semicircular rather than pyriform as on the new Venezuelan species. O. erict Hertlein from the middle Pliocene of Baja California is also akin to O. lixula, n. sp., but as shown on the hypotype of the species by Durham (1950, Geol. Soc. Amer., Mem. 43, p. 59, pl. 4, fig. 2), the upper valve is more circular than that of O. lixula, and the radial riblets seem to be wanting. Remarks.—Ostrea lixula, n, sp., is the dominant shell making up the Ostrea bed or coquina exposed across the Litoral anticline (see Weisbord, 1957, Geologic Sketch Map and Cross Section F-F’). This bed is six feet thick and is composed nearly entirely of valves of the new species. The oyster shells are firmly cemented at the outcrop trace except at the north end where some specimens have been loosened out naturally from the hard matrix. However, all of the loose shells collected represent the right valve of O. lixula, and the species has been described from that. Ostrea (Ostrea) caraboboensis, new species Pl. 22, figs. 9, 10; Pl. 23, figs. Ti, 12 This species is described from the left (attached) valve. Shell small, deep, oval and slightly arcuate, attached on the posterior side which is flattened irregularly. Apex relatively high, built up incrementally, the beak directed opisthogyrally. External sculpture variable, consisting, however, of both irregular concentric lamellae and radial plicae. On the holotype the lamellae, which have a shagreen texture and are somewhat foliaceous, cover nearly ex- clusively the whole of the valve although there are angular plicae at the basal margin. On the paratype thin sharp radial plicae ex- tend from the umbo to the base and are traversed by closely spaced, coarse concentric lamellae which are arched over the plicae and here and there toward the margins project as spiny scales. Within, the lateral margins are rectangularly pitted, the pits on the paratype continuing feebly around the basal margin. The cartilage area is low, short, and broad, and is crossed by densely packed concentric growth laminae. The body cavity is excavated under the hinge so that the cartilage process is decklike. The muscle scar is large, VENEZUELAN CENOZOIC PELECYPoDS: WEISBORD 181 posterior, obovate, the basal margin of the scar reaching halfway down the valve, the inner margin of the scar extending to the mid-line of the valve. Dimensions —Holotype (C437a), left valve, height 21 mm.; width 12.3 mm.; thickness 9.5 mm. Paratype (C437b), left valve, height 17.2 mm.; width 11.5 mm.; thickness 8 mm. Type locality.—La Salina, west of Puerto Cabello, State of Car- abobo. Two left valves. Comparisons.—The new species is reminiscent of O. miguelensts Hertlein (1928, Jour. Paleont., vol. 2, no. 2, p. 146, pl. 23, figs. 3-6) from the lower Miocene Vaqueros formation of San Miguel Island, California, but differs from that in being radially plicate to a great- er or lesser extent. Ostrea (Crassostrea) virginica Gmelin PL. 22 figsa 11,12 1692. Ostrea virginiana Lister, Historiae Conchyl., pl. 200, fig. 5. 1785. Ostrea rostrata maxima Chemnitz, Syst. Conchylien-Cabinet, vol. 8, pp. 38-39, pl. 73, fig. 677. 1785. Ostrea crassa Chemnitz, Syst. Conchylien-Cabinet, vol. 8, pp. 40-41, pl. 74, fig. 678. 1786. Ostrea elongata Solander, A Catalogue of the Portland Museum, p. 55. Not Born, 1780, Testacea Musei Caesarei Vindobonensis, p. 86. 1791. Ostrea virginica Gmelin, Syst. Nat., ed. 13, vol. 1, pt. 6, p. 3336. 1819. Ostrea brasiliana Lamarck, An. sans vert., vol. 6, p. 205. 1819. Ostrea canadensis and Ostrea borealis Lamarck, An. sans Vert., vol. 6, Pp: 207. 1822. Ostrea semicylindrica Say, Acad. Nat. Sci. Philadelphia, Jour., 1st ser., vol. 2, p. 228. 1822. Ostrea virginiana Sowerby, The Genera of Recent and Fossil Shells, fig. Zz 1836. Ostrea borealis Lamarck, Deshayes, An. sans Vert., ed. 2, vol. 7, p. 220. 1856. Ostrea triangularis Holmes, Elliott Soc., Proc., vol. 1, p. 29. 1860. Ostrea virginiana procyon Holmes, Post-Pleiocene Fossils of South Carolina, p. 10, pl. 2, fig. 9a. 1867. Ostrea virginica Gmelin, Guppy, Sci. Assoc. Trinidad, Proc., p. 164. 1871. Ostrea virginiana Lister, Coues, Acad. Nat. Sci. Philadelphia, Proc., VOle 235, Ds, 131: 1871. Ostrea floridensis Sowerby, [in] Reeve, Conch. Icon., vol. 18, pl. 29, sp. 76a, b. 1873. Ostrea virginica Gmelin, Gabb, Amer. Philos. Soc., Trans., vol. 15, p. DSi 1876. Ostrea virginica Gmelin, Guppy, Geol. Soc. London, Quart. Jour., vol. 32, ps 532. 1881. Ostrea virginica Gmelin, Gabb. Acad. Nat. Sci. Philadelphia, Jour., ser. 2, vol. 8, p. 380. 1884. Ostrea virginica Gmelin, Tryon, Structural and Systematic Conchology, vole 3) p. 297, ple 135, 112.) 34: 182 1886. 1889. 1889. 1894. 1898. 1901. 1903. 1906. 1906. 1910. 1913. 1914. 1917. 1918. 1920. 1920. 1923. 1924. 1924. 1925. 1925. 1927. 1927 1929. 1929. 1934. 1936. 1938. 1939. 1939. 1940. 1940. 1941. BuLLeTiIn 204 Ostrea virginica Gmelin, Fischer, Manuel de Conchyliologie et de Paléontologie Conchyliologique, p. 924. Ostrea virginica Gmelin, Simpson, Davenport Acad. Nat. Sci., Proc., vol. 5, p. 71. Ostrea virginica Gmelin, Dall, U. S. Nat. Mus., Bull. 37, 32. Ostrea virginica Gmelin, Whitfield, U. S. Geol. Sur., Mia 24, pp. 27-28, pl. 2, figs. 1-7. Ostrea virginica Gmelin, Dall, Wagner Free Inst. Sci., Trans., vol. 3 pt. 4, pp. 687-688. Ostrea virginica Gmelin, Dall and Simpson, U. S. Fish Com., Bull., vol. 20 for 1901, pt. 1, p. 463 (part). Ostrea virginica Gmelin, Vanatta, Acad. Nat. Sci. Philadelphia, Proc., VOl Sup His 56. Ostrea virginica Gmelin, Clark, Maryland Geol. Sur., Pliocene and Pleistocene, pp. 204-205, pls. 61-63. Ostrea virginica Gmelin, Bose, Inst. Geol. México, Bol., No. 22, pp. 66, 69, 75. Ostrea virginica Gmelin, Guppy, Agric. Soc. Trinidad and Tobago, Soc. Paper No. 440, p. 7. Ostrea virginica Gmelin, Brown and Pilsbry, Acad. Nat. Sci. Phil- adelphia, Proc., vol. 6, pp. 96-97. Ostrea virginica Gmelin, Henderson and Bartsch, U. S. Nat. Mus., Proc., vol. 47, No. 2055, p. 412. Ostrea virginica Gmelin, Maury, Bull. Amer. Paleont., vol. 5, No. 29, p. 348. Ostrea virginica Gmelin, Mansfield, Florida State Geol. Sur., Eleventh An. Rept., p. 115. Ostrea virginica Gmelin, Maury, Bull. Amer. Paleont., vol. 8, No. 34, pp. 56-57. Ostrea virginica Gmelin, Hubbard, N. Y. Acad. Sci. Scientific Survey of Porto Rico and the Virgin Islands, vol. 3, pt. 2, p. 100. Ostrea virginica Gmelin, Clench, Nautilus, vol. 37, No. 2, pp. 53-54. Ostrea virginica Gmelin, Jacot, Nautilus, vol. 38, No. 2, p. 49. Ostrea borealis Lamarck, Lamy, Mus. Nat. Hist. nat. Paris, Bull., vol. 30, p. 94: Ostrea virginica Gmelin, Maury, Bull. Amer. Paleont., vol. 10, No. 25, pp. 232-233. — Ostrea virginica Gmelin, Dall, Nautilus, vol. 38, No. 4, p. 121. Ostrea virginica Gmelin, F. Hodson, H. K. Hodson, and Harris, Bull. Amer. Paleont., vol. 13, No. 49, pp. 21-22. Ostrea virginica Gmelin, A. Wood and H. E. Wood, Nautilus, vol. 41, No. 1, pp. 12, 14-15. Ostrea virginica Gmelin, Clench, Nautilus, vol. 43, No. 1, p. 35. Ostrea virginica Gmelin, Lamy, Jour. Conchyl., vol. 73, pp. 14, 40, 97, 264, 265, 267-272, 273, 274. j Ostrea virginica Gmelin, Johnson, Boston Soc. Nat. Hist., Proc., vol. 40, No. 1, p. 23. Ostrea virginica Gmelin, Richards, Nautilus, vol. 49, No. 4, p. 132. Ostrea virginica Gmelin, Richards, Geol. Soc. Amer., Bull, vol. 49, pt. 2, p. 1291. Ostrea virginica Gmelin, Mansfield, State of Florida Dept. Conserv., Geol. Bull. No. 18, pp. 16, 18, 19, 21, 30} Ostrea virginica Gmelin, McLean, Nautilus, vol. 52, No: 3; p. 1072 Ostrea virginica Gmelin, Stubbs, Jour. Paleont., vol. 14, No. 5, p. 511. Ostrea virginica Gmelin, Stenzel, Nautilus, vol. 54, No. 1, p. 21. Ostrea (Crassostrea) virginica ae McLean, Acad. Nat. Sci. Phil- adelphia, Notulae Naturae, No. 67, pl. 8, figs. 1-4. 1942. 1943. 1944. 1945. 1946. 1947. 1947. 1947. 1949. 1950. 1951. 1951. 1951. 1952. 1953. 1954. 1955. 1958. 1959. 1961. 1961. VENEZUELAN CENOZOIC PELECYPODS: WEISBORD 183 Ostrea virginica Gmelin, Richards, Acad. Nat. Sci. Philadelphia, Proc., vol. 94, pp. 187-188, pl. 9, fig. 4. Ostrea virginica Gmelin, Jacobson, Nautilus, vol. 6, No. 4, p. 141. Ostrea virginica Gmelin, Hackney, Nautilus, vol. 58, No. 2, p. 57. Ostrea virginica Gmelin, van Bentham Jutting, Geolog.-Mijnbouwk. Genootschap Nederland en Kolonien, Geol. ser., vol. 14, p. 77. Ostrea virginica Gmelin, Stewart, Nautilus, vol. 60, No. 1, p. 19. Ostrea virginica Gmelin, Richards, Jour. Paleont., vol. 2, No. 1, pp. 2552 Crassostrea virginica (Gmelin), Stenzel, Jour. Paleont., vol. 21, No. 2p. 172. Ostrea virginica Gmelin, Alexander, Nautilus, vol. 60, No. 3, p. 75. Ostrea (Crassostrea) virginica Gmelin, Lange de Morretes, Mus. Paranaense, Arq., vol. 7, art. 1, p. 16. Crassostrea virginica (Gmelin), Gunter, Amer. Midland Naturalist, vol. 50, No. 2, pp. 438, 440, 446. Crassostrea virginica (Gmelin), Gunter, Bull. Marine Sci. Gulf and Caribbean, vol. 1, No. 1, pp. 43, 44, 45. Ostrea (Crassostrea) virginica (Gmelin), McLean, New York Acad. Sci. Scientific Survey of Porto Rico and the Virgin Islands, vol. 17, pt. 1, pp. 24-25, pl. 4, fig. 5. Ostrea virginica Gmelin, Rogers, The Shell Book, pp. 423-424. Ostrea virginica Gmelin, Pulley, Texas Jour. Sci., vol. 4, No. 2, p. 181, pl. 8, fig. 11. Ostrea (Crassostrea) virginica Gmelin, Olsson and Harbison, Acad. Nat. Sci. Philadelphia, Mon. No. 8, p. 49, pl. 5, figs. 2, 2a. Crassostrea virginica (Gmelin), Abbott, American Seashells, p. 375, pl. 28a. Crassostrea virginica (Gmelin), Perry and Schwengel, Marine Shells of the Western Coast of Florida, pp. 43-44, pl. 4, fig. 19. Crassostrea virginica (Gmelin), DuBar, Florida Geol. Sur., Geol. Bull. No. 40, Crassostrea virginica (Gmelin), Nowell-Usticke, A Check List of the Marine Shells of St. Croix, p. 9. Crassostrea virginica (Gmelin), Moore, Gulf Research Repts., vol. 1, Nos, pp: 15,39: Crassostrea virginica (Gmelin), Jacobson and Emerson, Shells of the New York City Area, p. 76, 1 fig. The left valve referred to O. virginica Gmelin is elongated, undulatingly convex, and irregularly gnarled and roughened on the exterior from the object to which it was attached. The beak is rela- tively long and straight but bent back and twisted slightly toward the anterior at the tip. The cartilage area is broad and shallow, and along the sides of the area there is a thickened ridge. The margins are unevenly scalloped. The muscle scar lies posterior to the middle and extends to the lower third of the valve. The color is dirty white tinged with purple in the interior. Dimensions——Specimen B352b, left valve, length 47.4 mm., width 23.5 mm., thickness 13.4 mm. 184 BuLueTin 204 Locality.—On beach southeast of Higuerote, State of Miranda. One left valve. The occurrence of the shell at this particular lo- cality is fortuitous, as the beach faces the open sea. However, the species is found in some abundance not too far distant in a brackish water environment, and as the oyster is eaten locally, it is presumed that the valve I collected was dropped on the beach by a bather. Range and distribution—O. virginica Gmelin is an extremely variable species which may date back to the Oligocene. In the Wes- tern Atlantic, the living shell has been recorded from Canada to Brazil. In the Pleistocene, O. virginica is known in North America from Prince Edward Island (Canada) to Florida and the southern Coastal Plain of the United States, in Central America from the Panama Canal Zone, and in South America from the Goajira Penin- sula and the Island of Tortuga (Venezuela). In the Pliocene it is known from the eastern and southern coastal plain area of the United States, and from México, Costa Rica, Venezuela, and Trinidad. In the Miocene it occurs as far north as New Jersey, extending through Maryland and the Carolinas to Florida; farther south the species has been reported in the Miocene of Hispaniola, Venezuela, and Trinidad. The Oligocene occurrence was determined by Hubbard (1920) who described it from the upper Lares limestone in Puerto Rico. Concerning it Hubbard wrote: “The specimens show the usual great variation, but comparison with recent specimens of O. vir- gimica shows no constant differences.” Ostrea (Crassostrea) species PI 24. figs, tow The single specimen is a thin left valve, elongate-elliptical in outline, with a broad roughened and slightly concave attachment area, and a steep narrow posterior submargin. Beak appressed, the cartilage area broad, shallow, and obliquely directed toward the posterior. Muscle scar large and suboval, occupying an area a little below the middle of the valve. Inner margins smooth. Color light tan within and without. Dimensions —Specimen B352a, left valve, length 54.5 mm.; width 25.2 mm.; thickness 11 mm. Locality.—On beach, southeast of Higuerote, State of Miranda. One left valve. Like the single specimen of O. virginica Gmelin dis- VENEZUELAN CENOZOIC PELECYPODS: WEISBORD 185 cussed above, this shell is believed not to have been washed up by the waves at this particular locality but to have been brought in from some more distant area. Remarks.—The shell is too worn for definitive comparison and identification. Ostrea (Crassostrea) rhizophorae Guilding Pl. 24, figs. 3, 4 1785. Ostrea arborea Chemnitz, Syst. Conchylien-Cabinet, vol. 8, pp. 46-47, pl. 74, fig. 681. 1828. Ostrea rhizophorae Guilding, Zool. Jour., vol. 3, No. 12, p. 542. 1836. Ostrea Braziliana Lamarck, Deshayes, An. sans Vert., ed. 2, vol. 7, p. 223. 1864. Ostrea rhizophora Chemnitz, Krebs, The West Indian Marine Shells, p. 136. 1871. Ostrea iP eB Ror ae Guilding, Reeve, Conch. Icon., vol. 18, pl. 9, sp. 17a, 17b. 1878. Ostrea parasitica Gmelin, Mérch, Catalogue of West-India Shells, p. 16. Not of Gmelin. 1878. Ostrea parasitica Gmelin, Arango y Molina, Contribucion a la Fauna Malacolégica Cubana, p. 273. Not of Gmelin 1882. Ostrea parasitica Gmelin, Stahl, Imprenta Boletin Mercantil, p. 242. Not of Gmelin. 1889. Ostrea rhizophorae Guilding, Lorié, Samml. Geol. Reichs-Mus. Leiden, ser. 2, vol. 1, pp. 114, 141. 1893. Ostrea adsociata Philippi, Mus. Nat. Chile, Anal., p. 14, pl. 2, fig. 1. 1898. Ostrea rhizophorae Guilding, Dall, Wagner Free Inst. Sci., Trans., vol. 3, pt. 4, p. 687. 1901. Ostrea virginica Gmelin, Dall and Simpson, U. S. Fish Com., Bull., vol. 20 for 1900, pt. 1, p. 463. Not of Gmelin. 1907. Ostrea parasitica (non Gmelin), von Ihering, Mus. Nac. Buenos Aires, Anal., vol. 14, pp. 359, 374, 426, 450. 1935. Ostrea parasitica Gmelin, Richards, Jour. Paleont., vol. 9, No. 3, p. 256. Not of Gmelin. 1929. Ostrea rhizophorae Guilding, Lamy, Jour. Conchyl., vol. 73, pp. 95-99, 100, 108, 135, 137, 139, 271. 1941. Ostrea rhizophorae Guilding, McLean, Acad. Nat. Sci. Philadelphia, Notulae Naturae, No. 67, pp. 5, 9, pl. 1, figs. 5-7. 1942. Ostrea parasitica Gmelin, Jaume and Pérez Farfante, Soc. Cubana Hist. Nat. “Felipe Poey”’, Mem., vol. 16, No. 1, p. 38. Not of Gmelin. 1949. Ostrea arborea Chemnitz, Lange de Morretes, Mus. Paranaense, Arq., vol. 7, art 1, p. 16. 1949. Ostrea rhizophorae Guilding, Mattox, Ecol. Monogr., vol. 19, pp. 339- 356. 1950. Crassostrea rhizophorae (Guilding), Gunter, American Midland Natur- alist, vol. 43, No. 2, p. 446. 1951. Crassostrea rhizophorae (Guilding), Gunter, Bull. Marine Sci. Gulf and Caribbean, vol. 1, No. 1, pp. 44-45. 1951. Ostrea (Crassostrea) rhizophorae Guilding, McLean, New York Acad. Sci. Scientific Survey of Porto Rico and the Virgin Islands, vol. 17, pt. 1, p. 25, pl. 4, fig. 6. 186 BuLueTIN 204 1954. Gopsaliea rhizophorae (Guilding), Abbott, American Seashells, pp. 4, 375. 1958. Ostrea rhizophorae Guilding, Olsson and McGinty, Bull. Amer. Paleont., vol. 39, No. 177, p. 20. 1959. Crassostrea rhizophorae (Guilding), Nowell-Usticke, A Check List of the Marine Shells of St. Croix, p. 9. 1961. Crassostrea rhizophorae (Guilding), Warmke and Abbott, Caribbean Seashells, p. 173, pl. 35b. The left, or lower valve, is fairly large, thin, irregularly suboval, eccentrically convex, with smooth margins within. Beak low, slanted toward the posterior, the cartilage channel moderately short, shal- low, and broad, the base of the hinge plate or deck truncate. Body cavity rudely orbicular, occupying the dorsal half of the valve. Muscle scar situated posterior to the middle, oval, light brown, oriented more or less parallel with the long axis of the valve. In- terior mostly white, the margins and body cavity tinged a faded lavender-purple. Exterior of valve built up of broad foliaceous la- mellae bearing a number of short low radial folds or plicae. Project- ing from the posterior dorsal margin aft of the beak are two broad flat scales forming a broad “M”. The exterior is off-white and dull tan, with a slaty tint at the incremental anterior margin. Dimensions—Figured specinien (B353a), length 76.4 mm.; width 58.7 mm.; thickness 26.5 mm. Locality.—On beach, southeast of Higuerote, State of Miranda; one left valve, washed up, or possibly thrown on the beach by some one. Remarks.—Although the solitary valve was found on a sandy, unvegetated beach, it was originally attached to what was probably a mangrove root as the bark is still present on the large attachment area at the umbo. Range and distribution—O. rhizopohorae is an edible oyster living in the Caribbean and Western Atlantic south to Brazil. In Puerto Rico, the shell is found mainly in lagoons attached to the aerial roots of mangrove in waters having a temperature of 25°C. to 31°C., a pH reading of 7.4 to 8.2, and a salinity of 37 to 44 parts per mille (Mattox, 1949). The species has been recorded in the Pleistocene of Curacao and Cuba. The Caribbean O. rhizophorae has been referred to by authors as O. parasitica Gmelin, but that name is valid only for the Indian Ocean species. VENEZUELAN CENOzoIC PELECYPODS: WEISBORD 187 Ostrea (Alectryonia) vespertina venezuvelana, new subspecies ' Pl. 24, figs. 5-11 1957. Ostrea cf. haitensis Sowerby, Weisbord, Bull. Amer. Paleont., vol. 38, No. 165, p. 17. Not of Sowerby. Shell of medium size, coarse, moderately thick, varying in outline from triangularly ovate to subtriangular to subfalcate. Valves unequal, the lower (left) moderately convex, the upper (right) a little smaller and flattish to occasionally moderately concave. Both valves are radially plicate, the left more strongly so than the right, and the plications or folds, which are prominent on the two valves, are crossed by coarse lamellae, which, from the middle of the disk to the base, often form vaulted arches on the summit of the plicae, and become incremental toward the margins. The radial folds are high and sharply triangular, and there are usually five or six of them though there may be as few as four and as many as eight primary ones. On the left valve there are three to five smaller corrugations on the anterior submargin; the posterior submargin of the left valve may bear several obsolete wrinkles below the beak, but generally the posterior submargin of the left valve is sculptured solely by concentric lamellae. On some left valves there is a low broad fold virgating off the major plica next to the posteriormost one, but the rest of the primary folds diverge from below the um- bonal area, where the valve is attached, to the base. On the mght valve the primary folds diverge from below the beak. In profile the ventral margin is strongly saw-toothed, the plicae of one valve fit- ting tightly into the valleys of the opposite. On the interior of the left valve the cartilage channel is fairly broad and shallow and directed toward the posterior, and is bordered on each side by, typically, a fairly wide and low swelling. The body cavity is exca- vated slightly below the deck of the cartilage area, but on some specimens there is no overhang whatsoever at the edge of the deck. The dorso-lateral margins of the left valve are shallowly grooved, and in the grooves there is a series of shallow slot-like pits extending from near the beak to the ventral margin proper. The cartilage area of the right valve is lower and not so well defined as that of the right, and along the dorso-lateral margins there is a series of den- ticles which engage with the pits of the left valve. The muscle scar 188 BuLLeTIN 204 is large, posterior to the middle, and subtriangularly kidney-shaped, the base of the scar bluntly produced and pointing toward the ventral margin. Dimensions.—Holotype (N346b), valves attached, height 48 mm.; width 39 mm.; thickness (including the plications) 17 mm. Paratype (N346a), right valve, height 44 mm.; width 31 mm.; thick- ness (including the plications) 9 mm. Paratype (N346c), nght valve, height 60 mm.; width 48 mm.; thickness (including the plica- tions) 21 mm. Paratype (N346d), left valve, height 63 mm., width 57 mm.; thickness (including the plications) 20 mm. Paratype (N346e), left valve, height 39 mm.; width 31 mm.; thickness (in- cluding the plications) 11 mm. Largest specimen, a doublet, height 74 mm., width 56 mm.; thickness (including the plications) 35 mm. Smallest paired specimen (Q348a 1-2), left valve, height 23 mm.; width 13 mm.; right valve, height 21.5 mm.; width 12 mm.; thick- ness of doublet 6.7 mm. This is the most arcuate example of the species in the collection. Type locality—Playa Grande formation (Catia member) at W-21. Sixty-eight specimens including 38 right valves, 23 left valves, and 1 doublet. Other localities—Playa Grande formation (Catia member), south side of Playa Grande road, 40 meters southeast of its inter- section with the Playa Grande Yachting Club road. Twelve speci- mens including six left valves, five right valves, and one doublet. Playa Grande formation (Catia member) at W-22, on dip slope 100 meters west of Costa fault. One right valve. Playa Grande formation (Maiquetia member) at W-4, Quebrada Las Pailas. One doublet. Lower Mare formation at W-13 on hillside above west bank of Quebrada Mare Abajo. One left valve and one right valve. Comparisons.—This is the shell referred to by me (Weisbord, 1957, Bull. Amer. Paleont., vol. 38, No. 165, p. 17) to Ostrea cf. haitensis Sowerby, but although it meets Sowerby’s generalized description of the original O. haitensis from the Dominican Republic, it is not, as can be seen by comparison with the illustrations of the Dominican form by Maury (1917, pl. 31), the same species. O. VENEZUELAN CENOZOIC PELECYPODS: WEISBORD 189 haitensis Sowerby (1849, Geol. Soc. London Quart. Jour., vol. 6, p. 56) is a larger and more broadly oval shell than O. vespertina venezuelana, n. subsp., and has more numerous folds which, instead of being straightish and sharply angular, are somewhat vermicular. The Cabo Blanco subspecies does, however, closely resemble certain variants of O. vespertina Conrad (1854, Acad. Nat. Sci. Philadelphia, Jour., ser. 2, vol. 2 p. 300), particularly the O. vespertina illus- trated by Arnold (1909, U. S. Geol. Survey Bull. 396, pp. 76-79, pl. 24, figs. 4-5) from the Etchegoin formation (Pliocene) of Cali- fornia and the hypotype of O. vespertina figured by Hanna (1926, California Acad. Sci. Proc., ser. 4, vol. 14, no. 18, pp. 468-469, pl. 26, figs. 1-3) from the Pliocene of Coyote Mountain, California. O. vespertina vespertina, and the synonymous veatchu Gabb (1866, Geol. Survey California, Palaeontology, vol. 2, p. 34, pl. 11, fig. 59), ranges chronologically from the upper Miocene to the Pleistocene, and geographically from California to Baja California, Méxio. Some authors have placed O. vespertina and O. veatchii in synonymy with O. haitensis Sowerby, but, as pointed out by Arnold (1909, p. 78), after examination of the material in the U. S. National Museum, “O. vespertina is smaller, relatively much narrower, and usually more falcate in outline and carries plaits more regular in size and generally fewer in number than O. haitensis.” In the eastern United States and Caribbean area O. haitensis is reported from the Oligo- cene of Puerto Rico, the Miocene of Cuba and Peru, the middle Miocene of the Dominican Republic, Haiti, Colombia, and Vene- zuela, the upper Miocene of Florida, Venezuela, and Trinidad, and the Pliocene in the Paraguana Peninsula, Venezuela. The following are east American and Caribbean fossil species to which the new Venezuelan subspecies exhibits affinity: O. sculpturata Conrad (1840, Fossils of the Medial Teriary of the United States, p. 50, pl. 25, fig. 3). Later Miocene from Virginia to Florida; Pliocene from North Carolina to Florida. This has a more elongate and more lenticular muscle scar than O. v. venezue- lana. O. sculpturata osculum Pilsbry and Brown (1917, Acad. Nat. Sci. Philadelphia Proc., vol. 69, p. 40, pl. 6, figs. 2, 2a). Middle Miocene, Colombia. Typically, this has two deep angular plications 190 BuLtietin 204 on each valve whereas the fewest plications on O. v. venezuelana are four. O. gatunensis Brown and Pilsbry (1911, Acad. Nat. Sci. Phila- delphia, Proc., vol. 63, p. 366, pl. 29, figs. 1-2). Middle Miocene of the Isthmus of Panama. This is a larger and more oval form than O. v. venezuelana, and the plications are lower and more vermiform. O. meridionalis Heilprin (1887, Wagner Free Inst. Sci., Trans., vol. 1, p. 100, pl. 14, figs. 35, 35a). Pliocene of Florida. This is more orbicular than the Venezuelan O. v. venezuelana, the plications are not so pronounced, and the pits and denticles on the dorso-lateral margins seem to be wanting. O. tamiamiensis monroensis Mansfield (1931, U. S. Geol. Sur., Prof. Paper 170-D, pp. 46-47, pl. 14, fig. 2; pl. 15, figs. 1-4). Upper Miocene of Florida. This also lacks the pits and denticles on the dorso-lateral margins, and the muscle scar is rudely oval rather than kidney-shaped as on O. v. venezuelana. Remarks.—Ostrea vespertina venezuelana, n. subsp. is abundant at station W-21 where it occurs in a weathered, soft, fine-grained sandstone about two feet thick. This bed is underlain by a tan sandstone with irregular knobby masses of hard sandstone, and is overlain by about 15 feet of dull, soft, gray to tan siltsone contain- ing knobby masses and branch- or trunk-like cylinders of hard sandstone which are interpreted to be casts of fossil mangrove. The O. v. venezuelana bed lies 150 feet stratigraphically higher than the Ostrea bed [O. lixula, n. sp.] whose trace around the plunge of the Litoral anticline is shown on the geologic map in my paper (Weisbord, 1957) dealing with the geology of the Cabo Blanco area. Ostrea (Alectryonia ?) caboblanquensis, new species Pl. 25, figs. 1-6 The folowing description pertains to the right valve. Shell moderately large and sturdy, a little convex, rudely sub- orbicular or subtrigonally ovate. The upper part of the disk is generally irregularly undulatory and gnarly, but rarely a large area of the disk may be relatively smooth and scored with faint irregular radial grooves. The base and sides of the valves are sculptured by radial plicae arising well below the umbo and becoming progres- VENEZUELAN CENOZzoIC PELECYPODS: WEISBORD 191 sively more prominent toward the margins. The plicae or folds (of which there are about 20 on the largest specimen) are fairly high, and angular to subrounded. Crossing them are coarse concentric lamellae. In the interior, the cartilage area is short, broad, and fairly straight; the resilial depression is subcentral and exceedingly shallow, and extends a little lower than the sides of the cartilage area. The body cavity is not excavated under the deck edge of the cartilage area but is flush with it. The muscle scar is large for the size of the shell, broadly ovate, subovate or oval in outline, clearly defined, lying generally normal to the long axis of the valve, the forward end reaching the center of the valve. The dorso-lateral margins are closely corrugated, shagreened, or pitted by small ridglets, pustules or indentations, these continuing over the beak. Immature right valves are thin, undulatory and gnarled over most of the disk, but at the margins the undulations tend to develop into plicae. On the more circular specimens the posterior dorsal margin forms an obtuse angle with the side of the beak. Dimensions—Holotype (S346a), right valve, height (beak to base) 61.5 mm.; width 59.7 mm.; thickness 14 mm. Paratype (0346a), right valve, height 51 mm.; width 43 mm.; thickness 12.7 mm. Largest specimen, right valve, height 96 mm.; width 78 mm.; thickness 27 mm. Paratype (M430a), juvenile right valve, height 9 mm.; width 10 mm.; thickness 2 mm. Type locality—Playa Grande formation (Maiquetia member) at W-23, north flank of Punta Gorda anticline. Three right valves. Other localities —Playa Grande formation (Catia member) at W-22, on dip slope 100 meters west of Costa fault. One right valve. Playa Grande formation (Catia member), south side of the coast road at east end of Catia La Mar. One right valve. Playa Grande formation (Catia member) at W-15, south side of Playa Grande road, 40 meters southeast of its intersection with the Playa Grande Yachting Club road. One juvenile right valve. Mare formation at W-25, south flank of Punta Gorda anticline. Three right valves, two of them immature. Lower Mare formation at W-13, on hillside above west bank of Quebrada Mare Abajo. One right valve. Lower Mare formation, in small stream 100 meters west of Quebrada Mare Abajo. One right valve, a juvenile. 192 BuLLeETIN 204 Comparisons.—It is sometimes difficult to differentiate certain individual variants of this species from the preceding O. vespertina venezuelana n. subsp., but on right valves of the same size, the muscle scar of O. caboblanquensis is always the larger and the more cleanly outlined. As with other fossil oysters from Cabo Blanco, the nearest related species are those from west America, among them such forms as the Miocene to Recent O. fisheri Dall (1914, Nautilus, vol. 28, p. 1) (see Durham, 1950, Geol. Soc. Amer., Mem. 43, p. 59, pl. 6, figs. 1, 4; and Keen, 1958, p. 66, fig. 121) and the lower and middle Miocene O. vespertina loeli Hertlein (1928, Jour. Paleont., vol. 2, p. 144, pl. 22, figs. 2-3) (see Loel and Corey, 1934, Univ. California Publ., Dept. Geol. Sci., vol. 22, No. 3, pp. 193-194, pl. 16, figs. 1a, 1b, 2; pl. 17, figs. la, 1b, 2a, 2b, 3). In east America and the Caribbean area a related species is O. haitensis Sowerby (1849, p. 53), that ranging from Oligocene to Pliocene. On all of the above-mentioned forms, however, the radial plicae extend from the umbonal area to the base whereas on O. caboblanquensis they arise relatively near the margins. Remarks.—The juvenile right valve (M430a) tentatively refer- red to this species, is small, thin, moderately inflated, slightly oblique, a little wider than high, and broadly oval in outline, with rounded margins except immediately below the posterior side of the beak where the edge of the valve takes a right-angled turn. The beak is relatively full and nearly erect. The exterior is gently corrugated or gnarled by a few folds, and is sculptured by faint but fairly regular concentric ridges on the umbo and at the margins. In the interior, the cartilage area is hardly developed, and directed posteriorly. The dorsolateral margins at the apex are denticulate, with eight or nine denticles on the forward side and four larger ones on the posterior side; below the lowest posterior denticle, at the abrupt turn of the margin, there is a fairly pronounced depression. The muscle scar is faint, large, and orbicular, and is situated high up the posterior side. The marginal plicae characteristic of the adult are not present. Ostrea (Agerostrea ?) antecursor, new species Pl. 25, figs. 7, 8 The following description pertains to the right (upper) valve. VENEZUELAN CENOzoIC PELECYPoDs: WEISBORD 193 Shell compressed, of medium size, sturdy throughout but with the anterior margin thickened more than the posterior, the holotype gently arcuate, the paratype distinctly falcate or sickle-shaped. Beak and umbo appressed. Outer surface sculptured by six or so angular to subrounded radial folds, most of them arising near the umbo, one or two of them originating near the margin, all of them attaining their maximum amplitude at the margins. Concentric markings consisting of lamellae, these smooth, appressed and faint on much of the surface but higher and incremental near and at the margins. Internally, the flattened cartilage area is short, broad, and directed posteriorly, the resilial channel proper broad and hardly depressed. Lateral margins denticulate, the denticles on the holotype extending from the beak to near the base; on the paratype, the denticles extend about halfway down the posterior margin but only a fourth of the way down on the anterior margin. The muscle scar is fairly large, slightly impressed, pyriform, cleanly and evenly outlined, situated near the posterior margin but reaching to about the center of the valve, the posterior margin of the scar long and straight, the narrow end pointing upward. Dimensions.—Holotype (R348a), right valve, length 44.4 mm.,; width 25 mm. Paratype (R348b), right valve, length 40 mm.; width 24 mm. Type locality —Playa Grande formation (Maiquetia member) at W-26, in Quebrada Las Bruscas about 125 meters upstream from its junction with Quebrada Las Pailas. Two right valves. Comparisons.—This oyster is allied to and may be a predeces- sor of the widesperad O. megodon Hanley. It is also akin to a num- ber of other forms which themselves appear to be related to O. megodon, and these are listed below: O. megodon Hanley (1846, Zool. Soc. London Proc. for 1845, pt. 13, p. 106) (see Keen, 1958, p. 66, fig. 123). Middle Miocene of the Dominican Republic, Costa Rica, Colombia, and Venezuela; Pliocene of Venezuela, Ecuador, Baja California (México), and California; Pleistocene of Baja California; and Recent from Baja California to Sechura Bay, Peru. The plicae of O. megodon arise near the margin, whereas on the Venezuelan shell they arise at the umbo. 194 BuLLeTiIn 204 O. locklint Gardner (1945, Nautilus, vol. 59, No. 2, pp. 39-40, pl. 4, figs. 3-4; pl. 5, figs. 1-2). Upper Miocene, from dredging off Snell Island, St. Petersburg, Florida. The Venezuelan shell is so close to the Floridan oyster that I would call it the same were it not for the absence of the radial folds on the middle of the nght valve of O. locklini. It is stated by Gardner that on some individuals the marginal folds do originate on the umbonal area, but these occur on the left or lower valve. O. messor Maury (1925, Bull. Amer. Paleont., vol. 10, No. 42, pp. 233-234, pl. 10, figs. 3-4). Upper Miocene, Trinidad. Maury gave this name to megodon-like oysters from the Antilles, differ- entiating O. messor from O. megodon by the smaller shell and fewer plications of the former. The Cabo Blanco O. antecursor, n. sp. may be distinguished from O. messor by having plicae which extend toward the beak whereas much of the surface of O. messor is not corrugated. O. messor cavmitica Maury (1925, pp. 234-235, pl. 11, fig. 6; pl. 12, fig. 6). Miocene, Trinidad. This is like O. messor s. 5. but with fewer, weaker, and more rounded plications. O. messor colombiensis Weisbord (1929, Bull. Amer. Paleont., vol. 14, No. 54, pp. 244-245, pl. 2, figs. 8-9). Middle Miocene, Colombia. Only the left valve of O. m. colombiensis is available for comparison with the right valve of the Venezuelan O. antecursor. The right valve of O. antecursor is characterized by having a thicker anterior margin than the posterior. This enables the right valve to be differentiated from the right valve of falcate specimens of O. vespertina venezuelana, n. subsp. on which both margins are about the same in thickness. CRASSATELLIDAE Eucrassatella (Hybolophus) antillarum (Reeve) Pl. 25, figs. 9, 10 1841. Crassatella rostrata Delessert (non Lamarck), Recueil de coquilles décrites par Lamarck, pl. 4, figs. 2-3. 1842. Crassatella Antillarum Reeve, Zool. Soc. London, Proc., pt. 10, p. 44. 1843. Crassatella Antillarum Reeve, Hanley, An Illustrated and Descriptive Catalogue of Recent Bivalve Shells, p. 37. VENEZUELAN CENOZzoIC PELECYPoDS: WEISBORD 195 1843. Crassatella Antillarum Reeve, Conch., Icon., vol. 1, Crassatella, pl. 2, sp. 8. 1847. Crassatella Antillarum Reeve, Nyst, Acad. Roy. Belgique, Bull., vol. 14, pts 2,5p:7120: 1862. Crassatella Antillarum Reeve, Chenu, Manuel de Conchyliologie et de Paléontologie Conchyliologique, vol. 2, p. 131, fig. 623. 1864. Crassatella antillarum Reeve, Krebs, The West Indian Marine Shells, p. 122. 1872. Crassatella antillarum Reeve, Tryon, Acad. Nat. Sci. Philadelphia, Proc., vol. 24, p. 130, 249. 1872. Crassatella Adelinae Tryon, Acad. Nat. Sci. Philadelphia, Proc., vol. 24, pp. 130, 249, pl. 6, fig. 1. 1881. Crassatella antillarum Reeve, Kobelt, Syst. Conchylien-Cabinet, vol. 10, pt. 1A, pp. 7-8, pl. 3, figs. 1-2. 1884. Crassatella antillarum Reeve, Tryon, Structural and Systematic Con- chology, vol. 3, p. 224, pl. 123, fig. 64. 1886. Crassatella antillarum Reeve, Dall, Mus. Comp. Zool., vol. 12, No. 6, Pp: 257- 1890. Crassatella antillarum Reeve, Dall, Wagner Free Inst. Sci., Trans., vol. 3, pt. 3,-p. 492. 1903. Crassatellites antillarum (Reeve), Dall, Wagner Free Inst. Sci., Trans., vol. 3, pt. 6, p. 1475. 1900. Crassatella antillarum Reeve, Dautzenberg, Soc. Zool. France, Mém., vol. 13, p. 243. 1913. Crassatella Antillarum Reeve, Lamy, Mus. Nat. Hist. nat. Paris, Bull. vol. 19, No. 2, p. 104. 1916. Crassatella Antillarum Reeve, Lamy, Jour. Conchyl., vol. 62, pp. 202, 216-217, 222, figs. on p. 202. 1930. Eucrassatella (Hybolophus) antillara, Stewart, Acad. Nat. Sci. Phil- adelphia, Spec. Publ., No. 3, p. 139. 1931. Crassatellites antillarum (Reeve), Grant and Gale, San Diego Soc. Nat. Hist., Mem., vol. 1, p. 271, pl. 13, figs. 7a, 7b. 1943. Eucrassatella antillarum (Reeve), Rutsch, Naturforschenden Gesell. Basel, Verhandl., vol. 4, p. 116. 1951. Eucrassatella (Hybolophus) antillarum (Reeve), Rogers, The Shell Book, pp. 369, 501. 1961. Eucrassatella (Hybolophus) antillarum (Reeve), Olsson, Panamic- Pacific Pelecypoda, p. 180. The following description pertains to the right valve. Shell of medium size and sturdiness, subtriangular, inequi- tateral, slightly convex, somewhat attentuate posteriorly. Antero- dorsal margin hardly concave, anterior margin sharply rounded, ventral margin shallowly rounded and gracefully embayed poster- iorly, posterior margin rather short and obliquely truncate, postero- dorsal margin concave. Umbo flattened at apex. The apical region, representing the nepionic shell or prodissoconch, is smooth in a tiny area at the point of the beak, but immediately below the beak there are a number of fine, regular, concentric ridgelets followed by half a dozen or so distant concentric waves with finer striae 196 BuLLeTIN 204 between them; the remainder of the valve is relatively smooth although marked with obsolete concentric lineations. Posterior dorsal area bounded by a subangular radial ridge or keel, in front of which there is a broad shallow radial depression or sulcus narrow- ing toward, but not reaching the beak; about halfway between the ridge and the border of the escutcheon is a second radial ridge diverging from the side of the beak, and between the two ridges is a narrow sulcus extending from the apex to the posterior truncation. The escutcheon is large, sublanceolate, somewhat sunken, defined from the posterior rostration by a fine incision. The lunule is elongate, narrow, shallow, and ill-defined. Within, the anterior dor- solateral tooth bordering the anterior cardinal tooth is narrow, moderately long and deeply grooved. The cardinal process is com- posed of a large, subtriangular, posterior socket and a deep, narrow, oblique, anterior socket, the sockets lying on either side of the medial cardinal tooth. Adherent to the posterior side of the middle cardinal tooth is a thick lamina which separates from the tooth at its lower end forming a low thin wall near the tooth within the main socket. Both sides of the medial cardinal tooth, and the inner side of the anterior cardinal tooth are scored by sharp grooves. The base of the hinge plate is gently sinuous, and the valve is excavated below the edge of the plate. Muscle scars impressed, the anterior one reniform, the posterior subcircularly pyriform. Pallial line sub- parallel with the ventral margin, joining the adductor scars at the base, the line generally making a dog-leg bend just before joining the posterior scar. The inner margins of the valve are smooth, and on all specimens there is a rather pronounced pit above the superior end of the anterior adductor impression. Dimensions.—Specimen 1488a, right valve, length 41 mm.; height 28.7 mm.; thickness at umbo 6.7 mm. Specimen H488b, right valve, length 34 mm.; height 23 mm.; thickness at umbo 6.1 mm. Localities —Upper Mare formation, in stream 250 meters south- southwest of mouth of Quebrada Las Pailas. Two right valves. Mare formation at W-25, south flank of Punta Gorda anticline. Two right valves. Lower Mare formation, in small stream 100 meters west of Quebrada Mare Abajo. One hinge fragment of a large mght valve. VENEZUELAN CENOZzOIC PELECYPoDsS: WEISBORD 197 Remarks.—On Recent specimens of F. antillarum from the type locality of Margarita Island, Venezuela, the ventral margin is embayed considerably more on adolescents than on adults, and it is with the smaller Recent examples that the right valves of the Cabo Blanco fossils are identical. Also, on most of the Recent speci- mens of £. antillarum in the collection at the Academy of Natural Sciences of Philadelphia, the escutcheon of the right valve is larger than that on the left. The habitat of Tryon’s E. adelinae was un- known when that species was described in 1872, but it was sub- sequently determined to be also from Margarita Island in Venezuela. In comparing the types of E. adelinae and E. antillarum from the type locality of Margarita in the Academy’s collection I was unable to discern any significant difference, and I believe them to be the same. The west American analogue of E. antilarwm is the Pleisto- cene to Recent E. diguett (Lamy) (1917, Jour. Conchyl., vol. 62, No. 4, p. 217). Range and distribution —Eucrassatella antillarum ranges from Pliocene to Recent. The Recent shell is known from the island of Margarita, Venezuela, but will doubtless be found elsewhere along the northern coast of South America. As a fossil, £. antillarum was reported by Grant and Gale from the Pliocene or Pleistocene near Santa Rosalia on the eastern side of Baja California, México. The fossil FE. antillarum also occurs in strata of probable Pliocene age near Cumana, State of Sucre, Venezuela (Collection No. 18409, U. S. National Museum). Crassinella aduncata, new species Pl. 25, figs. 11-14 Shell small, moderately thin, somewhat inflated, subequivalve, inequilateral, subtrigonal to veneridiform in outline, the beak small, opisthogyrate, sharp, and slightly hooked. Anterior dorsal margin convex, posterior dorsal margin truncate to hardly concave, ventral margin well rounded. Escutcheon of right valve smooth, fairly long, subtriangular, slightly sunken, bounded by the subangulate rim of the disk, the inner edge of the escutcheon sharp and straight. Lunule a linear ill-defined, shallow groove. Exterior sculptured by 13 to 18 regular concentric ribs, the ribs low and smooth, rounded 198 Bu.etTin 204 over most of the disk but sometimes a little sharper at the beak and anterior submargin, and generally closer together toward the base than at the umbos. Rarely, some of the ribs are engraved by a microscopic concentric groove, but the interspaces generally are smooth. Interior of valves smooth at the margins. Hinge of might valve with two simple cardinal teeth, the anterior one larger and higher than the posterior. The narrow lateral tooth or groove of the right valve extends along the anterior dorsal margin to about opposite the middle of the anterior adductor scar, the edge of the escutcheon of the opposite valve fitting into that. On the left valve the narrow lateral tooth or groove lies along the edge of of the escutcheon, and the escutcheon itself seems a trifle narrower and less developed than on the right valve. Anterior muscle scar oval, the posterior orbicular. Pallial line simple, entire, well removed from the margin, joining the muscle scars on their inner side near the base. Dimensions.—Holotype (1485a), right valve, height 2.3 mm.,; width 2.7 mm.; approx. thickness 0.8 mm. Paratype (1485b), left valve, height 1.9 mm.; width 2.1 mm.; approx. thickness 0.6 mm. Type locality—Lower Mare formation at W-13, on hillside above west bank of Quebrada Mare Abajo. Two right valves and two left valves. Other localities——Lower Mare formation, in small stream 100 meters west of Quebrada Mare Abajo. One right valve and one left valve. Upper Mare formation, in stream 250 meters south-south- west of mouth of Quebrada Las Pailas. Two right valves and one left valve. Comparisons —The most notable character of the new species is its venerid outline. The nearest relative with respect to shape and internal morphology is C. nansemondensis Gardner (1943, U. S. Geol. Sur., Prof. Paper 199-A, p. 64, pl. 13, figs. 18, 28) from the upper Miocene in the State of Virginia, U.S.A., that species differing from C. aduncata, n. sp. in being more robust and in having a narrower, more linear escutcheon. Other species which are similar in external sculpture are the Recent C. mactracea (Linsley) (1845, Amer. Jour. Sci. and Arts., vol. 48, No. 2, art. 6, p. 275, text figs. at bottom of page); the Recent West Indian C. martinicensis VENEZUELAN CENOzoIC PELECYPops: WEISBORD 199 (d’Orbigny) (1842, [in] La Sagra, Hist. phys., polit. et nat. I’Ile de Cuba, pp. 288-289, pl. 27, figs. 21-23); C. dupliniana Dall (1903, pp. 1478-1479, pl. 50, figs. 5-6) from the upper Miocene and Pliocene from Maryland to Florida; C. xena Woodring (1925, p. 98, pl. 12, figs. 5-6) from the middle Miocene Bowden formation of Jamaica; and C. cahwitensis Palmer (1923, Bull. Amer. Paleont., vol. 10, No. 40, p. 12, pl. 2, fig. 2) from the Uscari shale (lower Miocene) encountered in the Cahuita well, 22 miles southeast of Limon, Costa Rica, between 3818 and 3861 feet. C. mactracea, C. martinicensts, and C. duplimana are higher and more trigonal than the new species; C. xena is fuller than C. aduncata and is rounded-triangular in shape; C. cahuttensis is more compressed than C. aduncata, and its posterodorsal margin is more concave. Crassinella triquetra, new species Pl 26; figs) 1) 2 This species is described from a single, well-preserved left valve. Shell small, moderately sturdy, somewhat inflated, inequilateral, subangularly trigonal in outline, the left valve with a radial posterior depression starting narrowly below the umbo and shallowly broad- ening to the base. Anterodorsal margin with a pronounced bend at the umbo, ventral margin well rounded except posteriorly where it is embayed slightly to conform with the radial depression, postero- dorsal margin subtruncate. Beak opisthogyrate, somewhat hooked. Escutcheon of left valve fairly long, semiovate, a little sunken, bounded by the low subangulate edge of the disk. Lunule long, semi- elliptical, hardly depressed. Exterior sculptured by about 18 smooth low regular concentric ribs, the ribs rather broad and gently rounded over most of the disk but narrower, sharper, and fainter at the umbo. Interior of valve smooth at the margins. Hinge of left valve with a strong elevated cardinal tooth and a deep triangular socket adjacent to it. The posterior lateral tooth is a narrow, moderately deep groove extending from near the beak along the inner edge of the escutcheon to the curve of the ventral margin. At the beak, the posterior lateral tooth and the escutcheon edge are fused into the posterior cardinal tooth. The anterior lateral tooth is represented by a faint narrow shallow sulcus along the anterior margin of the valve. Anterior muscle scar reniform, the posterior one not clear but seem- 200 BuLueTin 204 ingly roughly oval. Pallial line simple, entire, well removed from the ventral margin, joining the muscle scars on their inner side at the base. Dimensions—Holotype (1486a), left valve, height 3 mm.; width 2.9 mm.; approx. thickness 0.9 mm. Type locality——Lower Mare formation at W-13, on hillside above west bank of Quebrada Mare Abajo. One left valve, the holotype. Remarks.—The distinguishing characters of C. triquetra, n. sp. are the shallow but distinct radial depression in front of the posterior submargin, and the subangulate curve of the anterodorsal margin. The shell occurs together with the preceding-described C. aduncata, n. sp., but differs from that in its more trigonal outline as well as in the characters mentioned above. CARDITIDAE Cardita (Carditamera) gracilis Shuttleworth Pl. 26, figs. 3-17 1856. Cardita gracilis Shuttleworth, Jour. Conchyl., vol. 5, p. 173. 1864. Trapezium (Cypricardia) gracilis (Shuttleworth), Krebs, The West Indian Marine Shells, p. 123. 1888. ? Cardita (?) sp. Schepman, [in] Martin, Bericht tiber eine Reise nach Nederlandisch West-Indien und darauf gegriindete Studien, Leiden. Pt. 2. Geologische Studien, appendix. 1888. Cardita gracilis Shuttleworth, Clessin, Syst. Conchylien-Cabinet, vol. 10, pt. 1, p. 45, pl. 10, figs. 4-5, 1889. Cardita gracilis Shuttleworth, Dall, U. S. Nat. Mus., Bull. 37, p. 46. 1902. Cardita gracilis Shuttleworth, Dall, Acad. Nat. Sci. Philadelphia, Proc., vol. 54, p. 702. 1920. Cardita (Carditamera) gracilis Shuttleworth, Maury, Bull. Amer. Paleont., vol. 8, No. 34, p. 79. 1934. Cardita gracilis Shuttleworth, Johnson, Boston Soc. Nat. Hist., Proc., vol. 40, No. 1, p. 38. 1936. Cardita gracilis Shuttleworth, Lermond, Check List of Florida Marine Shells, Gulfport, p. 6. 1937. ? Cardita gracilis Shuttleworth, Smith, East Coast Marine Shells, p. 44, pl. 11, fig. 9. 1946. Cardita gracilis Shuttleworth, Hertlein and Strong, Zoologica, vol. 31, pt. 3, No. 8, p. 108. 1951. Cardita gracilis Shuttleworth, McLean, New York Acad. Sci. Scientific ned of Porto Rico and the Virgin Islands, vol. 17, pt. 1, p. 54, pl. 10) fig!""7. 1954. Cardita (Carditamera) gracilis Shuttleworth, Abbott, American Sea- shells, p. 378. 1958. Cardita gracilis Shuttleworth, Olsson and McGinty, Bull. Amer. Paleont., vol. 39, No. 177, p. 20. 1961. Cardita gracilis Shuttleworth, Warmke and Abbott, Caribbean Seashells, p. 174, pl. 35d. VENEZUELAN CENOzoIC PELECYPoDS: WEISBORD 201 This species occurs both living and fossil in the Cabo Blanco area. The rather thin shell is elongate-trapezoidal, moderately com- pressed, inequilateral, equivalve, broadly and roundly rostrate behind, slightly depressed medially, narrowish at the anterior end, subalate at the posterodorsal end. Anterior margin acutely rounded. ventral margin straight to a little embayed, posterior margin rounded below, obliquely subtruncate above. Radial ribs averaging 17 in number, crossed by concentric lamellae of varying degree of coarseness and scaliness. The anterior three or four radial ribs are strongly and regularly corded concentrically; the next three ribs are flattish, low, and relatively smooth, often rendered bipartite by a faint sulcus, with the posterior margin of these ribs a little higher than the anterior; as the posterior rostration or swelling is approached, the ribs become progressively more and more asym- metrically angulate, and are coarsely imbricated by the now incre- mental lamellae. The posterior rostration is sculptured by four large, elevated, imbricated and scaly radial ribs which are nodulous where weathered, the rostration starting at the thirteenth mb from the anterior end. The imbrications and scales are rather thick, the latter forming high vaulted projecting arches over the ribs. On the post- erior alation there is always a single low scaly minor rib followed by one or two scaly ribs of intermediate size to the posterior hinge margin. At the umbos, the radial ribs are faintly beaded. On well- preserved Recent specimens the external surface is also marked by numerous delicate microscopic radial filaments decussated by minute spines. Interior radially corrugated by the ribs except at the anterior end. Lunule deep, small, broadly cordate. Escutcheon long and narrow, the ligament external. Adductor scars broadly reniform, the anterior one definitely impressed, the posterior one not impressed. Pallial line faint, entire, and straight except at the rear where it curves up to join the base of the posterior adductor scar. The right anterior cardinal tooth fits into the broadly triangular socket of the left valve, and the posterior cardinal tooth of the left valve is sturdier than the anterior tooth of the socket. Anterior half of the exterior of the Recent shell is cream-colored with rows of light brown maculations, whereas the posterior half is drab gray. Interior of valves subnacreous and mostly white except at the posterior end which is a deep shiny purplish chocolate; the posterior lateral tooth is also stained a dark brown. 202 BuLueTin 204 Dimensions.—Specimen A540a1-2, a doublet, height 11.8 mm.; length 26 mm.; thickness (valves attached) 10 mm. Specimen A540b, a doublet, height 9.1 mm.; length 19.5 mm.; thickness (valves attached) 6.7 mm. Largest specimen, a doublet, height 15.5 mm.; length 34.8 mm.; thickness (valves attached) 14.1 mm. Speci- men D540a, right valve, height 11 mm.; length 23 mm.; thickness 5.8 mm. Specimen D540b, left valve, height 7.2 mm.; length 14.4 mm.; thickness 3.1 mm. Specimen J540a, right valve, height 8.2 mm.; length 17.4 mm.; thickness 3.2 mm. Specimen J540b, left valve, height 9.1 mm.; length 18.1 mm.; thickness 4.1 mm. Speci- men 1541a, infantile left valve, height 1.4 mm.; length 2.4 mm., approx. thickness 0.5 mm. (The identification of this specimen is somewhat in doubt.) Localities—Recent, on beach of Playa Grande Yachting Club, Distrito Federal. Seventy-nine specimens including 24 right valves, 22 left valves, and 33 doublets. Abisinia formation at W-30, eastern edge of Playa Grande village. Nine specimens including four nght valves and five left valves. Lower Mare formation at W-13, on hill- side above west bank of Quebrada Mare Abajo. One infantile left valve. Lower Mare formation, in small stream 100 meters west of Quebrada Mare Abajo. One right valve and one left valve. Range and distribution—The Recent C. gracilis ranges from southwest Florida to northern South America. Its occurrence in the Abisinia formation (Pleistocene ?) and Mare formation (Pliocene ? ) is the first record as a fossil, although this might be the species from Cabo Blanco referred to by Martin (1888) as Cardita (?) sp. Remarks.—The nearest east American relative of C. gracilis is the Miocene C. protracta-aculeata-recta tribe of Conrad (see Glenn, 1904, Maryland Geol. Sur., Miocene, pp. 343-344, pl. 91, figs. 4-6) from the State of Maryland, U. S. A. These integrading forms differ but slightly from C. gracilis in being a little more robust and in having a less truncate posterodorsal margin. Other east American counterparts are the Pliocene to Recent C. floridana Conrad (see Dall, 1903, p. 1415, pl. 56, fig. 11) which is more inflated than C. gracilis and has a crenulate inner margin, and C. arata (Conrad) (1832, Fossil Shells of the Tertiary Formations of North America, vol. 1, p. 20, pl. 5, fig. 2), occurring in the VENEZUELAN CENOZOIC PELECYPODS: WEISBORD 203 Miocene and Pliocene from New Jersey to Florida, which also has a strongly crenulate inner margin. West American analogues are the upper Pliocene to Recent C. affinis Sowerby (1833, Zool. Soc. London, Proc., p. 195) and the Pleistocene to Recent C. radiata Sowerby (1833, Zbid, p. 195). As illustrated by Keen (1958), C. affinis is a coarser shell than C. gracilis, and C. radiata is not narrowed in front as is C. gracilis. Venericardia (Glyptoactis) wendellwoodringi, new species Pl. 26, figs. 18, 19; Pl. 27, figs. 1-10 1889. Cardita ajar Bruguiére, Lorie, Samm]. Geol. Reichs-Mus. Leiden, ser. 2, vol. 1, pp. 121, 141. Not of Bruguiére. This species occurs in two variants, one of which is thick- shelled highly inflated, subrhomboidal, and with high umbos, the other slightly thinner, moderately inflated, suboval, and with rela- tively low umbos. In other respects the forms are alike and seem to represent the same species. Shell of medium size and equivalve, the beak full, sharp, prosogyrate, and a little forward of the middle. Anterior margin well rounded, ventral margin shallowly convex, posterior margin hardly curved to subtruncate. Radial ribs averaging 25 in number, the ribs elevated, squarish and nodulated, the interspaces about as wide as the ribs, and “U”-shaped to “V”-shaped in cross section. The nodules are most pronounced on the anterior and posterior sub- margins of the valves, occurring there as rounded to transverse beads. In general the nodules are somewhat fainter and more uni- form on the disk of the left valve than of the right, but on the right valve several of the ribs posterior to the middle bear fainter nodules than the ribs anterior to the middle. On both valves the umbos are more closely beaded than the disk proper. On well-preserved specimens, the interspaces and sides of the ribs are seen with a lens to be lined by crowded microscopic concentric striae. The termini of the ribs at the ventral margin are serrated and fluted, and the inner margins of the valve are strongly crenulate. The crenulations are short, flat, and broad, and coincide with the inter- spaces of the external ribs; at the ventral margin proper the crenu- lations are usually shallowly bifid, and at their base are prolonged 204 BuLueTin 204 into a short sloping ridge which unites with the end of the trough of the interspace. Anterior adductor scar elongate-lenticular, the posterior broadly pyriform. Pallial line simple, entire, joining the adductor scars at the base. Lunule small, depressed, broadly cordate, bounded by a narrow groove. Escutcheon area scythe-shaped and moderately deep. Right median cardinal tooth an expansive, flange- like process, upcurved a little at the edge and with a steep forward wall, the upper surface strongly scored with transverse grooves, the small but deep funnel-like socket, in front of the tooth lying directly below the beak; forward of the right socket, on the margin of the right valve, there is a smaller and shallower pit. The left median cardinal tooth is also strongly scored, and the socket in front of it is obliquely triangular; the left anterior cardinal tooth is upright, and the blunted tip is bent a little toward the beak. Juvenile specimens of this species are relatively compressed and lucinid in outline, with an extended, well-rounded anterior margin, a shallowly rounded ventral margin and a nearly truncate posterior margin. The closely and regularly beaded ribs are low and broad, and are separated by much narrower interspaces. These infant shells resemble certain species of the subgenus Plewromerts Conrad. This fine shell is named in honor of Wendell P. Woodring for his classical works on the paleontology and stratigraphy of the Caribbean area. Dimensions —Holotype (T493a), adult right valve, height 24.2 mm.; width 23.9 mm.; thickness 11.2 mm. Paratype (T493b), young left valve, height 11.7 mm.; width 12.1 mm.; thickness 4.1 mm, Paratype (1493b), adult left valve, height 18.2 mm.; width 20.2 mm.; thickness 7 mm. Paratype (1493a), young valve, height 11.1 mm.; width 12 mm.; thickness 4.3 mm. Specimen T494a, juvenile left valve, height 3 mm.; width 3 mm.; thickness 1.2 mm. Specimen T494a, juvenile right valve, height 4.7 mm., width 4.8 mm. Specimen 5494a, juvenile left valve, height 6.5 mm.; width 6.6 mm.; thickness 2.1 mm. Type locality—Upper Mare formation, in stream 250 meters south-southwest of mouth of Quebrada Las Pailas. Eighty-eight VENEZUELAN CENOZOIC PELECYPoDS: WEISBORD 205 specimens including forty-one right valves and forty-seven left valves. Other localities —Mare formation near W-14, on hillside above west bank of Quebrada Mare Abajo. Five specimens including four left valves and one right valve. Mare formation at W-25, south flank of Punta Gorda anticline. Five specimens including four left valves and one right valve. Lower Mare formation at W-13, on hill- side above west bank of Quebrada Mare Abajo. One hundred twenty-eight specimens including 74 left valves and 54 right valves. Lower Mare formation, in small stream 100 meters west of Quebrada Mare Abajo. One juvenile right valve. Playa Grande formation (Maiquetia member) at W-23, north flank of Punta Gorda anti- cline. Sixteen specimens including ten left valves and six right valves. Remarks—tThis is one of the more abundant species in the Mare formation of the Cabo Blanco area. The subgeneric classifica- tion under Glyptoactis is from Stewart (1930, Acad. Nat. Sci. Philadelphia, Spec. Publ. 3, pp. 151-152). Typically, shells of this subgenus have tripartite or terraced ribs, but as suggested by Verastegui (1953, Palaeontographica Americana, vol. 3, No. 25, 434-435), certain late Teriary species of Glyptoactis may show a want of this character. The Cabo Blanco shell referred to as Cardita ajar Bruguiére by Lorié is probably V. wendellwoodringi, n. sp. and not of Bruguiére as C. ajar is an Eastern Atlantic species from West Africa. Comparisons.—Venericardia wendellwoodringi, n. sp. is of the same genre as V. hadra Dall (1903, pp. 1429-1430, pl. 53, figs. 11, 13) and V. hymerta Dall (1900, pl. 40, fig. 16; 1903, p. 1430, pl. 53, fig. 12) from the middle Miocene of Florida, but both of those have fewer ribs than the Cabo Blanco shell. V. serricosta (Heil- prin) (1887, Wagner Free Inst. Sci., Trans., vol. 1, pp. 117-118, pl. 16, fig. 64) from the lower Miocene of Florida also has fewer ribs (about 16), and is more elongate than the new species. Juven- iles of V. wendellwoodringi closely resemble the young of V. granu- lata Say (1824, Acad. Nat. Sci. Philadelphia, Jour., Ist ser., vol. 4, p. 142, pl. 12, fig. 1) from the Miocene of Maryland (see Glenn, 1904, Maryland Geol. Sur., Miocene, pp. 344-345, pl. 91, fig. 10), 206 BuLLETIN 204 but is discriminated from V. granulata by the truncate posterior margin. “Venericardia” waynensis Mansfield (1940, Jour. Paleont., vol. 14, No. 3, pp. 189-190, pl. 25, figs. 9, 10, 18) from the lower Miocene Chickasawhay marl of Alabama and Mississippi differs from V. wendellwoodringi in having “a radial thread developed in the adult at the base of each rib.” V. vicksburgiana Dall (1903, p. 1428, pl. 56, fig. 6) from the Oligocene of Florida is a good deal like V. wendellwoodringt in the character of the ribs but is a more orbicular shell. Compared with Caribbean species, the juvenile C. wendellwoodring: resembles V. acaris Dall (see Woodring, 1925, p. 102, pl. 12, figs. 10-12) from the middle Miocene of Jamaica, but the Venezuelan shell has 25 ribs compared with 18 on the Jamaican shell. Among adult forms, the nearest relative of V. wendellwood- ringt is the middle Miocene V. dominica Weisbord (1929, Bull. Amer. Paleont., vol. 14, No. 54, pp. 249-250, pl. 2, fig. 12; pl. 13, figs. 10-11) from Colombia and the Dominican Republic, the latter, how- ever, having 18 to 21 ribs, as compared with 24 to 27 on V. wendell- woodringt. DREISSENSIIDAE Mytilopsis leucophaeatus ? Conrad Pl; 27, figs) Liat? 1831. Mytilus leucophaeatus Conrad, Acad. Nat. Sci. Philadelphia, Jour., 1st ser. vol., 6, pp. 263-264, pl. 11, fig. 13. 1857. Mytilopsis leucophaeatus (Conrad), Acad. Nat. Sci. Philadelphia, Proc. for 1857, p. 167. 1858. Mytilus americana (Récluz MS), Reeve, Conch. Icon., vol. 10, Mytilus, pl. 10, sp. 43. 1858. Dreissena americana (Récluz MS), Fischer, Jour. Conchyl., vol. 7, Serea.e Peo. 1858. Dreissena riisei (Dunker MS), Fischer, Jour. Conchyl., vol. 7, ser. 2, p. 133. 1864. Dreisenia Rissei ? Krebs, The West Indian Marine Shells, p. 130. 1874. Dreissena leucophaeata (Conrad), Tryon, American Marine Conchology, p. 190, pl. 40, fig. 424. 1884. Dreissensia (Mytilopsis) leucophaeata (Conrad), Tryon, Structural and Systematic Conchology, vol. 3, p. 266. 1889. Dreissensia (Mytilopsis) leucophaeata (Conrad), Dall, U. S. Nat. Mus., Bull. 37, p. 40. 1889. Dreissensia leucophaeata (Conrad), Simpson, Davenport Acad. Nat. Sclijperoc, voles, ps 69: 1898. Congeria leucophaeata (Conrad), Dall, Wagner Free Inst. Sci., Trans., vol. 3, pt. 4, pp. 808-809 (part). 1920. Congeria leucopheata (Conrad), Maury, Bull. Amer. Paleont., vol. 8, No. 34, p. 70. VENEZUELAN CENOZOIC PELECYPoDS: WEISBORD 207 1929. Congeria leucophaeata (Conrad), Bailey, Nautilus, vol. 43, No. 1, p. 34. 1934. Congeria leucopheata (Conrad), Johnson, Boston Soc. Nat. Hist., Proc., vol. 40, No. 1, p. 29. 1935. Dreissensia (Mytilopsis) leucophaeata (Conrad), Richards, Jour. Paleont., vol. 9, No. 3, p. 256. 1936. Congeria leucopheata (Conrad), McLean, Soc. Cubana Hist. Nat. “Felipe Poey”, Mem., vol. 10, No. 1, p. 40. 1937. Congeria leucophaeata (Conrad), Rehder, Nautilus, vol. 50, No. 4, p. 143. 1937. Mytilopsis leucophaeta (Conrad), Smith, East Coast Marine Shells, pp. 39-40, pl. 11, fig. 3a, 3b. 1941. Mytilopsis leucophaeata (Conrad), Andrews, Nautilus, vol. 54, No. 1, p: 25. 1942. Mytilopsis leucophaeata (Conrad), Jaume and Pérez Farfante, Soc. Cubana Hist. Nat. “Felipe Poey”, Mem., vol. 16, No. 1, p. 39. 1949. Dreissensia leucophaeata (Conrad), Hertlein and Hanna, Southern California Acad. Sci., Bull., vol. 48, pt. 1, p. 18. 1954. Congeria (Mytilopsis) leucophaeata (Conrad), Abbott, American Sea- shells, p. 382. 1958. Mytilopsis leucopheata (Conrad), Olsson and McGinty, Bull. Amer. Paleont., vol. 39, No. 177, p. 20. Venezuelan shell of medium size, thin, mytiliform, flattened and subalate dorsally, the dorsum proper inflated, the ventral slope steep. Dorsal outline subangulate a little forward of the middle, the anterodorsal margin slightly sinuous, the posterodorsal margin subtruncate to hardly concave, the posterior end angularly rounded, the ventral margin nearly straight except below the beak where it is rather sharply incurved. Beak terminal, subacute, somewhat hooked. Anterior adductor impression seated on the apical septum, the septum of medium size, its hind margin thickened and evenly arcuate. Attached to the dorsal underside of the septum, and ex- tending a short distance under the anterior dorsal margin, there is a cuneate lamina which bears the scar of the anterior retractor muscle. Internal margins are smooth, the part around the front of the septum is reflected and liplike. A shallow and rather nar- row ligamental groove extends along the anterodorsal margin of the valve from the beak to the wing. Exterior marked with a few broad concentric undulations reflected in the interior and numerous concentric laminae, and, on the inflated area of the back, there are several exceedingly vague radial riblets which seem to lie on the dorsal half, the radii extending from the umbo to a little below the middle of the valve. Of the three specimens, one is bleached a more or less uniform cream color within and without. 208 BuLLeTin 204 The other two are rudely and concentrically banded in gray-black to brown and white in the interior, the exterior of one being slate- blue on the dorsum and dull white with a little slate-blue and brown elsewhere, the other concentrically banded in dull brown and white. Dimensions —Figured specimen (B557a), right valve, length 32 mm.; max. width 14.5 mm.; thickness 6.6 mm. Locality.—Recent, on beach southeast of Higuerote, State of Miranda. Three right valves. Range and distribution—The Recent M. leucophaeatus is said to range from the lower reaches of the Hudson River in New York State to the West Indies, Central America, and northern South America. It lives in brackish, fresh, or marine water, the marine shells seeming to attain a larger size. As a fossil, M. leuco- pheatus has been reported from the Pleistocene of Louisiana (in well samples), Florida, and Cuba. Remarks.—Conrad described this species as follows: Shell incurved, white, with a very rugose epidermis; anterior side much depressed; hinge margin excavated, with the teeth obsolete; on the posterior side, under the beaks, is a pointed laniinar tooth directed inward. Cab. Academy, No. 1453. Inhabits the southern coast of the U. S. Found attached by its byssus, to the Ostrea virginica. Mr. William Riley presented me with several specimens, and informs me that he observed great numbers of them between the shells of two attached oysters. I was unable to locate the type at the Academy of Natural Sciences of Philadelphia, but in the Recent collection at the Academy there are forms labelled M. leucophaeatus from Jacmal and Aux Cayes, Haiti, with which the Venezuelan shell is identical. However, both the Haitian and Venezuelan shells are more pointed anteriorly than Conrad’s illustration of the original species. Following are other Neogene to Recent American species of Mytilopsis: Mytilopsis adamsi Morrison, 1946, Smithsonian Misc. Collec- tions, vo.l 106, No. 6, pp. 46-47, pl. 1, figs. 4, 7. Recent, San José Island, 60 miles south of Panama, Panama. The dorsal margin is evenly rounded whereas that of the Venezuelan MM. leuwcophaeatus is subangulate. Also the beak of the Venezuelan shell is a little more hooked. VENEZUELAN CENOZOIC PELECYPODS: WEISBORD 209 Mytilopsts cira Pilsbry and Olsson, 1935, Acad. Nat. Sci. Philadelphia, Proc., vol. 87, p. 19, pl. 5, fig. 2. La Cira formation (upper Oligocene-Lower Miocene), Colombia. This has a sharp umbonal ridge. Mytilus cochleatus Kickx, 1835, Acad. Roy. Sci. Bruxelles, Bull., vol. 2, p. 235. Recent; reported from the Atlantic side of the Panama Canal Zone. This may be Mytilopsis leucophacatus or a variant, as the true M. cochleatus is European. Dretssena cuminginiana (Dunker ms.) (see Fischer, 1858, Jour. Conchyl., sér. 2, vol. 7, p. 131). Recent, Mississippi River. This may be the same as Mytilopsis tenebrosus (Reeve) (1858, Conch. Icon., vol. 10, Mytilus, pl. 10, sp. 46). Dreissensia dali Joukowsky, 1906, Soc. Phys. et Hist. Nat. Genéve, Mém., vol. 35, pt. 2, p. 171, pl. 6, figs. 1-5. South of Maca- racas, Panama. Miocene or Pliocene. This is smaller, relatively broader, and more triangular in outline than the Venezuelan M. leucophaeatus? Dreissena domingensis Récluz, 1852, Jour. Conchyl., sér. 1, vol. 3, p. 255, pl. 10, fig. 8. Recent, Haiti; middle Miocene, Domini- an Republic fide Maury (1917, p. 359, pl. 39, fig. 5). Maury’s fossil is much more alate, and the dorsal margin higher and more arcuate than the Venezuelan Recent shell referred to M. leucophaeatus. Maury’s M. domingensis is probably not the same as Récluz’ M. domingensis as the latter is characterized by a strong embayment under the beak and a shallowly concave ventral margin. Praxis ecuadoriana Clessin, 1879, Malakozool. Blatter, n. F., vol. 1, pp. 180-181, pl. 15, figs. 8a, b. Recent, Cayapas River, Es- meraldas Province, Ecuador. Dreissena gundlachi Dunker, 1858, Novitates Conchologicae, Abtheilung 2, Mollusca Marina. Recent, Cuba. This is a relatively small, triangular species with a rounded keel running the length of the shell above the ventral margin. Mytilopsis gamaicensis Woodring, 1925, Carnegie Inst. Wash- ington, Publ. No. 366, pp. 86-87, pl. 10, figs. 13-14. Middle Miocene, Jamaica. Closely resembles /. leucophaeatus Conrad and M. coch- leatus (Kickx). Congeria lamellata Dall, 1898, Wagner Free Inst. Sci., Trans., 210 BuL_eTiIn 204 vol. 3, pt. 4, pp. 809-810, pl. 35, figs. 13-15. Pliocene, Florida. This has a wider and deeper ligamental groove than M. leucophaeatus. Praxis milleri Clessin, 1879, Malakozool. Blatter, n. F., vol. 1, p. 179, pl. 15, figs. 7a, b. Recent, Rio Verde, Esmeraldas Province, Ecuador. The dorsal margin is more evenly rounded than on M. leucophaeatus. Dreissena mérchiana (Dunker), [in] Fischer, 1858, Jour. Conchyl., sér. 2, vol. 7, pp. 132-133. Reeve’s illustration (1858, Conch. Icon., vol. 10, Pl. 10, sp. 51) indicates that this species is closely related to M. leucophaeatus. Dreissena pfeifferr (Dunker), [in] Fischer, 1958, Jour. Conchyl., sér. 2, vol. 7, p. 132. Recent, Cuba. Dreissena rossmassleri (Dunker) (see Fischer, 1858, Jour. Conchyl., sér. 2, vol. 7, p. 132). Recent, Florida to Brazil. “It is distinguishable from the common leucophaeata by its more tri- angular anteriorly flattened, heavier shell” (Dall, 1898, p. 809). Dreissena sallei Récluz, 1849. Rev. et Mag. Zool., sér. 2, vol. 1, p. 695° 18525Jour. “Conchyl-, ‘sér 1, -vol¥’3,"pr'255, pl 10 iia. Recent, Rio Dulce, Guatemala: The dorsal margin is well and evenly rounded, and the beak is more hooked than that of M. leuco- phaeatus. See Tryon, 1884, Structural and Systematic Conchology, p. 266, pl. 129, fig. 22. Mytilus sallet Reeve, 1858, Conch. Icon., vol. 10, pl. sp. 44. Not of Récluz. Recent, West Indies. According to Dall (1898, p. 809) Reeve’s M. sallei is Dunker’s M. rossmasslert. Dressseina (Mytiloides) scripta Conrad, 1874, Acad. Nat. Sci. Philadelphia, Proc., vol. 26, pp. 29, 83, pl. 1, figs. 12, 16. Pliocene, Pebas clay, Brazil. The dorsal margin of the adult forms an angle of about 110 degrees. Mytilopsis singewaldi Pilsbry, 1944, Acad. Nat. Sci. Philadel- phia, Proc., vol. 96, p. 147, pl. 11, figs. 35-36. Upper Oligocene- lower Miocene, Pachitea River, Peru. Septifer trautwineana Tryon, 1866, Amer. Jour. Conch., vol. 2, pt. 4, No. 5, p. 302, pl. 20, fig. 8. Recent, San Juan River, Colombia. This is more angulate than M. leucophaeatus on the dorsal margin, and it has a furrow separating the dorsum proper from the wing. Mytilopsis zeteki Hertlein and Hanna, 1949, Southern Cali- VENEZUELAN CENOZOIC PELECYPoDS: WEISBORD 211 fornia Acad. Sci., Bull., vol. 48, pt. 1, pp. 15-16, figs. 1-4. Recent, Miraflores Locks, Panama Canal Zone. The myophore under the septum is larger than on M. leucophaeatus, and the dorsal margin is more evenly rounded. Olsson and McGinty (1958, p. 20) reported M. zeteki from Colon on the Atlantic side of Panama DIPLODONTIDAE Diplodonta (Diplodonta) mareana, new species Pl. 27, figs. 13, 14 Shell small, thin, translucent, suborbicular, a little wider than high, subequilateral, the disk slightly inflated, the submargins rather strongly sloping, the anterior submargin broader than the posterior. Anterodorsal margin hardly convex, anterior end well rounded and somewhat produced at the curve with the ventral mar- gin, the ventral margin hardly rounded in front of the middle but well rounded at the posterior, the posterodorsal margin truncate, fairly long, and gently inclined from the horizontal. Umbo triangular, the beak subcentral. The upper half of the single specimen is vitre- ous, the lower half scored by fine sharp concentric grooves. Re- flected through the shell, but visible through a lens and in certain light, are ephemeral radii. The surface is also covered by numerous microscopic punctations which are eroded off much of the umbonal area but still present on the lower part of the disk, the punctations showing through to the interior. Anterior cardinal of left valve cuneate, sharply bifid, protrusive, the posterior cardinal small and platy, the socket between the cardinals triangular and deep. The laterals of the left valve are feeble and close to the cardinals. The left posterior adductor scar cannot be seen; the left anterior adductor scar is also difficult to see, but if I make it out correctly it appears to be large and ovate. The pallial line is obscure but is probably entire throughout, joining the anterior scar at the base. The inner margin of the valve is smooth. Dimenstons.—Holotype (J428a), left valve, height 3.7 mm.; width 3.8 mm.; approx. thickness 0.9 mm. Type locality—lLower Mare formation, in small stream 100 meters west of Quebrada Mare Abajo; One left valve, the holotype. Comparisons —The distinctive characters of D. mareana, n. sp. 212 BuLuetin 204 are the relatively compressed disk and what seems to be an un- usually large anterior muscle scar. Analogous species, most of them more obese than the immature Cabo Blanco shell, are the following: D. punctata (Say) (1822, Acad. Nat. Sci. Philadelphia, Jour., new ser., vol. 2, p. 308). See Dall (1900, Wagner Free Inst. Sci., Trans., vol. 3, pt. 5, p. 1187) for synonymy. Pliocene? to Recent. The living shell is reported from North Carolina, U.S.A., to Brazil. Dall placed D. venezuelensis Dunker in synonymy with D. punctata, but other authors, among them C. W. Johnson (1934, Boston Soc. Nat. Hist., Proc., vol. 40, No. 1, p. 41), considered them as separate species. D. venezuelensis is more globose than D. punctata, and both of these are more inflated than D. mareana, n. sp. D. punctulata (H. C. Lea) (1843, Amer. Philos. Soc. Trans., new ser., vol. 9, p. 240, pl. 34, fig. 18). Upper Miocene at Peters- burg, Virginia, U.S.A. This, like D. mareana, n. sp., is a diaphanous shell with a minutely punctulate surface; however, it is more convex than D. mareana, and there is no mention, in the original descrip- tion, of the presence of the ephemeral radii that can be perceived on the Cabo Blanco shell. D. gabbi Dall (see Woodring, 1925, Carnegie Inst. Washington, Publ. No. 366, p. 131, pl. 18, figs. 1-3). Lower-middle Miocene of the Dominican Republic, middle Miocene of Jamaica, Recent in the West Indies. The posterodorsal margin slopes down from the beak at a greater angle from the horizontal than on D. mareana. D. semiaspera Philippi (see McLean, 1951, New York Acad. Sci. Scientific Survey of Porto Rico and the Virgin Islands, vol. 17, pt. 1, p. 67, pl. 13, fig. 9). Recent, North Carolina, U.S.A., to Brazil. This is more tumid and more distinctly pustulose than D. mareana. D. subquadrata Carpenter (see Hertlein and Strong, 1947, Zoologica, vol. 31, pt. 4, No. 10, pp. 130-131, pl. 1, fig. 11). Upper Pliocene to Recent, west America. The living shell ranges from Baja California to the Galapagos Islands, and is found in the intertidal zone to depths of 75 fathoms. Typically, D. swbquadrata is more angular in outline than D. mareana, n. sp. D. subquadrata Carpenter was reported from the Miocene of the Dominican Republic by Gabb (1873, Amer. Philos. Soc., Trans., new ser., vol. 15, p. 252) but that shell is now known as D. gabbi Dall. VENEZUELAN CENOozoIC PELECYPODS: WEISBORD 213 Diplodonta (Phlyctiderma) semiaspera Philippi Ple23\fig:ii3 1836. 1845. 1846. 1852. 1864. 1872. 1878. 1878. 1889. 1889. 1900. 1901. 1920. 1934. 1935- 1936. 1936. 1942. 1949. 1950. 1951. 1954. 1955. 1956. 1958. 1958. 1959. 1959. Diplodonta semiaspera Philippi, Arch. f. Naturg., vol. 2, pt. 1, p. 225, pl. 7, figs. 2a-2d. Lucina granulosa C. B. Adams, Boston Soc. Nat. Hist., Proc., vol. 2 pp. 9-10. Lucina semireticulata d’Orbigny, Voyage dans L’Amérique Méridionale, vol. 5, pt. 3, Mollusques, p. 584, pl. 84, figs. 7-9. Lucina granulosa C. B. Adams, Contrib. to Conch., No. 12, 245. Diplodonto [sic] semiaspera ? Philippi, Krebs, The West Tadian Marine Shells, p. 122. ? Mysia semireticulata (d’Orbigny), Tryon, Acad. Nat. Sci. Philadel- phia, Proc., vol. 24, p. 95. Diplodonta semiaspera Philippi, Mérch, Catalogue of West-India Shells, paloe Diplodonta semiaspera Philippi, Arango y Molina, Contribucién a la Fauna Malacolégica Cubana, p. 257. Diplodonta semiaspera Philippi, Simpson, Davenport Acad. Nat. Sci., Proc., vol. 5, p. 66. Diplodonta semiaspera Philippi, Dall, U. S. Nat. Mus., Bull. 37, p. 52. Diplodonta (Phlyctiderma) semiaspera Philippi, Dall, Wagner Free Inst. Sci., Trans., vol. 3, pt. 5, p. 1188. Diplodonta (Phlyctiderma) semiaspera Philippi, Dall, U. S. Nat. Mus., Proc., vol. 23, No. 1237, p. 794. Diplodonta semiaspera Philippi, Maury, Bull. Amer. Paleont., vol. 8, No. 34, p. 92. Taras (Phlyctiderma) SOLD (Philippi), Johnson, Boston Soc. Nat. Hist., Proc., vol. 40, No. 1, p. Diplodonta semias pera Philippi, ieenarde Jour. Paleont., vol. 9, No. 2, p. 256. Taras (Phlyctiderma) semiaspera (Philippi), Clench and McLean, Soc. Cubana Hist. Nat. “Felipe Poey”, Mem., vol. 10, No. 3, p. 164. Taras semiaspera (Philippi), Lermond, Check List of Florida Marine Shells, Gulfport, p. 20. Diplodonta semiaspera Philippi, Jaume and Pérez Farfante, Soc. Cubana Hist. Nat. “Felipe Poey”, Mem., vol. 16, No. 1, p. 39. Taras (Phlyctiderma) semiaspera (Philippi), Lange de Morretes, Mus. Paranaense, Arq., vol. 7, art. 1, p. 31. Lucina granulosa C. B. Adams, Clench and Turner, Occas. Papers on Mollusks, vol. 1, No. 15, p. 289, pl. 46, figs. 3-4. Taras (Phlyctiderma) semiaspera (Philippi), McLean, New York Acad. Sci. Scientific Survey of Porto Rico and the Virgin Islands, vol. 17, pty sp: (67,.pls 135) fig. 16. Diplodonta (Phlyctiderma) semiaspera Philippi, Abbott, American Sea- shells, p. 383. Taras (Phlyctiderma) semiaspera (Philippi), Perry and Schwengel, Marine Shells of the Western Coast of Florida, p. 63, pl. 40, fig. 290. Diplodonta semiaspera Philippi, Parker, Amer. Assoc. Petrol. Geol., Bull., vol. 40, No. 2, pp. 308, 315503705) plapsemtigss isa.) Sb. Diplodonta semiaspera Philippi, Olsson and McGinty, Bull. Amer. Paleont., vol. 39, No. 177, p. 20. Diplodonta (Phlyctiderma) semiaspera Philippi, Abbott, Acad. Nat. Sci. Philadelphia, Mon. No. 11, pp. 118-119, pl. 4g, 4h. Diplodonta semiaspera Philippi, Nowell-Usticke, A Check List of the Marine Shells of St. Croix, p. 10. Diplodonta semiaspera Philippi, Parker, Amer. Assoc. Petrol. Geol., Bull., vol. 43, p. 2161. 214 BuLueTIn 204 1961. Diplodonta cf. semiaspera Philippi, van Regteren Altena, Koninkl. Nederl. Wetensch.-Amsterdam, Proc., ser. B, vol. 64, No. 2, p. 299. 1961. Diplodonta (Phlyctiderma) semiaspera Philippi, Warmke and Abbott, Caribbean Seashells, p. 175, pl. 35L. The Recent Venezuelan shell is suborbicular, thin, and well inflated. The sculpture consists of fine, irregular, concentric linea- tions and numerous concentric rows of small punctations. The ad- ductor scars are large and relatively long, the anterior one lenticular, the posterior more or less elliptical. The shell is whitish, with the interior a pale lemon yellow below. The surface is encrusted here and there by calcareous algae and bryozoa. Dimensions—Specimen A66a, left valve, height 10 mm.; width 11 mm., thickness 5 mm. Locality.—Recent, on beach of Playa Grande Yachting Club, Distrito Federal. One left valve. Range and distribution.—The living shell is found at moderate depths from North Carolina, U.S.A., to Brazil. As a fossil, D. semt- aspera Philippi has been reported from the Pleistocene of Cuba and St. Kitts, and from the Pliocene of Florida. LUCINIDAE Lucina (Cavilinga) trisulcata blanda (Dall and Simpson) Pl. 28, figs. 1-4 1901. Phacoides (Cavilucina) trisulcatus Conrad var. blandus Dall, U. S. Fish Com., Bull., vol. 20 for 1900, pt. 1, pp. 493-494, pl. 58, fig. 13. 1920. Phacoides (Cavilucina) trisulcatus blandus Dall, Maury, Bull. Amer. Paleont., vol. 8, No. 34, p. 86. 1937. Linga (Cavilinga) blanda Dall, Chavan, Jour. Conchyl., vol. 81, p. 201. 1951. Phacoides (Linga) trisulcatus blandus Dall and Simpson, McLean, New York Acad. Sci. Scientific Survey of Porto Rico and the Virgin Islands, Volol7ipts Leep64, Disa i 2-akio2 9: 1959. Phacoides trisulcatus blandus Dall and Simpson, Nowell-Usticke, A Check List of the Marine Shells of St. Croix, p. 11. 1961. Lucina (Cavilinga) blanda Dall and Simpson, Warmke and Abbott, Caribbean Seashells, p. 176, pl. 36d. Shell small, obliquely suborbicular, inflated, with a rather pro- nounced but shallow radial depression posteriorly, and with a narrow shallow anterior groove extending from well below the beak to the union of the anterodorsal and ventral margins. Anterior end VENEZUELAN CENOzoIC PELECYPoDS: WEISBORD 215 somewhat produced and rounded, the posterior end subtruncate, the ventral margin rounded. Umbo full and rather large, the beak high, a little behind the median line, pointed forward. Lunule deeply con- cave, broadly cordate, sharply defined, the inner edge of the lunule also deeply concave. Ligamental groove narrowly elliptical. Surface below prodissoconch sculptured by regular flattened concentric ribs separated by linear interspaces, the prodissoconch itself marked by evenly spaced fine concentric riblets. The disk proper is character- ized by one or more resting stages, and here and there on the ribs and in the interspaces there seem to be extremely vague radial striae under the lens and in certain light. On the prodissoconch there are roughly 30 concentric riblets, and below the prodissoconch about 38 concentric ribs. All of the concentric markings are much more feebly displayed in the posterior depression. Hinge of left valve with two rather closely spaced and slightly divergent cardinal teeth, and both the anterior and posterior lateral teeth are bifid, the anterior lateral with a faint sulcus on the upper ridge. Anterior muscle scar elongate, slightly arcuate and lozenge-shaped, the pos- terior scar somewhat more distinct and rudely ovate. Pallial line simple but raggedy, uniting with the anterior adductor scar at about the middle of the outer border, and joining the posterior one at the base. The inner margin is finely and regularly denticulate from in front of the lunule to the rear of the ligamental area. Dimensions.—Specimen 1528a, left valve, height 7.2 mm.; width 7.4 mm., thickness 2.3 mm. Specimen J427a, left valve, height 9.3 mm., width 9.2 mm.; thickness 2.6 mm. Localities —Lower Mare formation near W-13, on hillside above west bank of Quebrada Mare Abajo. One left valve. Lower Mare formation, in small stream 100 meters west of Quebrada Mare Abajo. One left valve. Remarks.—The Venezuelan fossil here referred to L. trisulcata blanda is slightly broader than the typical Recent shell from Puerto Rico but is indistinguishable from suborbicular variants of that species. Other forms to which the Venezuelan fossil exhibits affin- ity are the following: L. trisulcata trisulcata (Conrad) (see Gardner, 1926, U. S. Geol. Sur., Prof. Paper 142-C, pp. 108-109, pl. 18, figs. 11-13 and 216 BULLETIN 204 Olsson and Harbison, 1953, Acad. Nat. Sci. Philadelphia, Mon. No. 8, pp. 85-86, pl. 7, figs. 4, 4a, 4b). Miocene to Recent. The inner edge of the lunule is not so depressed as on the Venezuelan shell. L. trisulcata multistriata Conrad (see Mansfield, 1932, Florida State Geol. Sur., Bull. No. 8, pp. 96-97, pl. 20, figs. 15-16 and Gardner, 1943, U. S. Geol. Sur., Prof. Paper 199-A, pp. 76-77, pl. 13, Figs. 25-26). Upper Miocene of Virginia, the Carolinas, and Florida. The lunule is more deeply sunken, the posterior depression more pronounced, and the anterior lateral of the left valve stouter than on the Venezuelan fossil. L. parawhitfieldi (Gardner) (1926, U. S. Geol. Sur., Prof. Paper 142-C, pp. 109-110, pl. 18, figs. 14-15) is less inflated than L. t. blanda, but otherwise there is a marked similarity between the two. L. parawhitfieldi occurs in the middle Miocene of Florida. L. crenulata Conrad (1845, Fossils of the Medial Tertiary of the United States, p. 39, pl. 20, fig. 2). Middle to late Miocene from New Jersey to Florida, U.S.A. The concentric ribs are finer than on L. t. blanda, and there are distinct closely spaced radial threads. L. occurrens (Dall) (see Woodring, 1925, Carnegie Inst. Wash- ington, Publ. No. 366, pp. 122-123, pl. 16, figs. 7-8). Middle Mio- cene, Bowden, Jamaica. The Venezuelan shell is less inequilateral, and the concentric ribs are stronger. L. prolongata Carpenter (see Olsson, 1961, Panamic-Pacific Pelecypoda, p. 210, pl. 31, figs. 8, 8a, 10-10b). Recent, Mazatlan, Mexico to Ecuador. This is more strongly inequilateral than L. t. blanda. Range and distribution—The Recent Lucina (Cavilinga) tri- sulcata blanda (Dall and Simpson) has been reported only from Puerto Rico. The present notice constitutes a new record of its occurrence as a fossil in northern South America. Lucina (Callucina ?) species Pl. 28, figs. 5, 6 The single broken specimen is small and slightly inflated, with a fairly low, smooth umbo and a moderately shallow cordate lunule. The sculpture consists, below the umbo, of fine closely spaced con- centric laminae, but there are no radial markings. The right anterior VENEZUELAN CENozoIc PELECypops: WEISBORD 217 cardinal is small and rudimentary, the right posterior stout, the socket between them triangular and deep. Right anterior lateral heavy, corrugated by a sulcus on the face, the posterior lateral as well as the margins and base of the valve broken away. Ligamental groove opisthodetic, fairly deep, sublinear. Dimensions—Specimen R525a, fragment of right valve, height 1.7 mm.; width 1.5 mm. Locality—Playa Grande formation (Maiquetia member) at W-26, in Quebrada Las Bruscas, approximately 125 meters up- stream from junction with Quebrada Las Pailas: One broken right valve. Remarks—Except for its smaller size, this is reminiscent of the Recent L. bermudensis (Dall) (1901, U. S. Nat. Mus., Proc., vol. 23, No. 1237, p. 825, pl. 39, fig. 5), but there is too little to go on for a definitive comparison. Lucina (Bellucina) katherinepalmerae, new species Pl 26) Nes. 1.0 Shell small, obliquely suboval, a little inflated, but with a flattish posterior submargin. Anterodorsal margin somewhat con- cave, anterior end gently rounded, ventral margin produced and well rounded, posterior margin truncate, posterodorsal margin hardly convex. Umbo moderately full, the beak subcentral, low, directed forward. Lunule cordate, moderately concave. Primary radial costae about 13, the three or so on the anterior submargin indistinct, the ones on the disk proper low and broad, most of them doubled near the base by a faint groove. The posterior submargin is fairly wide and devoid of radial markings, but there is a bipartite costa border- ing on the posterior margin. In the shallow intercostal areas of the disk there are one or two minor radial riblets. Rather prominent concentric lirae cross the entire surface, those on the umbo lamellar and imparting a cancellate effect, the others coarse and cordlike. On the posteriormost costa and on the one bordering the posterior submargin, the lirae rise into scalelike or subspinose prominences. Right valve with two unequal cardinal teeth, the central one much the stouter and with a triangular socket on either side, the anterior socket the deeper. Lateral teeth well developed, the anterior one 218 BuLLeTin 204 higher and longer than the posterior. Inner margin obscurely un- dulatory, marked with fine, closely spaced crenulations. Anterior muscle scar of right valve elongate and lozenge-shaped, the posterior scar seemingly reniform, lying immediately below the posterior later- al. Pallial line simple, entire, joining the outer edge of the anterior adductor scar at the base, and joining the posterior scar a little in from the center of the base. Dimensions —Holotype (H526a), right valve, height 5 mm.; width 4.4 mm.; thickness 1.9 mm. Type locality —Mare formation at W-25, south flank of Punta Gorda anticline. One right valve, the holotype. Remarks.—tThis rare shell is named in honor of Dr. Katherine Van Winkle Palmer, Director of the Paleontological Research Insti- tution. Comparisons.—The nearest living relative is L. nux Verrill and Bush (1900, Connecticut Acad. Arts and Sci., Trans., vol. 10, art. 12, pp. 518-519, pl. 58, figs. 12-13) from the Bermudas. That species, however, is more regularly oval than L. katherinepalmerae, differs in details of sculpture, and is not flattened posteriorly. The Pleistocene and Recent L. amiantus Dall (1901, U. S. Nat. Mus., Proc., vol. 23, No. 1237, pp. 826-827, pl. 39, fig. 10) from east America, and the Pleistocene and Recent L. cancellaris Philippi (see Durham, 1950, Geol. Soc. Amer., Mem. 43, p. 75, pl. 18, figs. 8, 13) from west America are both wider than high, whereas L. katherine- palmerae is higher than wide. The Pliocene L. waccamawensis Dall (1903, Wagner Free Inst. Sci., Trans., vol. 3, pt. 6, p. 1386, pl. 52, fig. 2) from North and South Carolina, U.S.A., and the upper Miocene L. tuomeyi Dall (1903, pp. 1385-1386, pl. 52, fig. 1) from the Carolinas and Florida are more broadly costate than L. kather- imepalmert, and L. waccamawensis has nine or ten radial ribs, L. tuomeyt seven to nine. L. nereidideditus Maury (1910, Bull. Amer. Paleont., vol. 4, No. 21, p. 154, pl. 9, fig. 5) from the Miocene at Oak Grove, Florida, is sculptured much like L. katherinepalmerae but is a more orbicular shell, with a more concave anterodorsal margin and a more prominant posterior alation. VENEZUELAN CENOZOIC PELECYPODS: WEISBORD 219 Lucina (Parvilucina) ephraimi, new species Pl. 28, figs. 9-12; Pl. 29, figs. 1-6 Shell small, fairly plump, slightly oblique, subangularly or- bicular, moderately depressed posteriorly, feebly depressed an- teriorly. Anterodorsal margin concave, anterior end more or less rounded, ventral margin a little produced and subangularly rounded in front of the middle, posterior end truncate, posterodorsal margin hardly convex. Beak smooth, low, subcentral, directed forward, touching the top of the cardinal process. Lunule elongate-cordate, moderately concave. Surface sculptured by 23 to 28 usually entire radial ribs crossed by fine slightly elevated concentric laminae. The relatively strong ribs are low and regular, are separated by nar- rower interspaces, do not extend to the beak, and are absent on the submargins. The concentric laminae are widely spaced above but become progressively closer, though not crowded, toward the base; the laminae traverse both the ribs and interspaces, impart a cancel- late pattern on the upper half of the disk, and are generally higher and lamellose on the submargins. Hinge sturdy, the anterior car- dinal tooth a little larger than the posterior cardinal on the left valve, the posterior cardinal much stouter than the anterior on the right valve, the laterals well developed on both valves. Inner mar- gin evenly crenulate. Anterior muscle scar relatively long and ar- cuate, the posterior scar more or less oval. Pallial line simple, entire, subangulate in contour, joining the outer margin of the anterior muscle scar a short distance above the base, and joining the inner margin of the posterior muscle scar at the base. Dimensions.—Holotype (R521a), right valve, height 4.9 mm.; width 4.9 mm.; thickness 1.8 mm. Paratype (R52Ic), left valve, height 4.9 mm.; width 4.9 mm.; thickness 1.6 mm. Paratype (R521b), right valve, height 4 mm.; width 4 mm.; thickness 1.7 mm. Paratype G521b, young right valve, height 2 mm.; width 2.1 mm. Paratype G521c, young left valve, height 2.9 mm.; width 2.9 mm. Type locality—Playa Grande formation (Maiquetia member) at W-26, in Quebrada Las Bruscas, approximately 125 meters up- stream from junction with Quebrada Las Pailas. Sixteen specimens including nine right valves and seven left valves. 220 BuLLETIN 204 Other localities —Playa Grande formation (Maiquetia member) at W-23, south flank of Punta Gorda anticline; three left valves. Playa Grande formation (Maiquetia member) at W-4, Quebrada Las Pailas; Two left valves and one right valve. Mare formation at W-14 on hillside above west bank of Quebrada Mare Abajo. Twenty-six specimens including 13 right valves, 12 left valves, and one doublet. Remarks—This new species is named in honor of Dr. E[phraim] Laurence Palmer, well-known naturalist, and professor for many years at Cornell University. Comparisons.—Similar species are the following: L. multilineata Tuomey and Holmes (see Mansfield, 1932, Florida Geol. Sur., Bull. No. 8, pp. 101-102, pl. 20, figs. 6-7). Middle- upper Miocene to Recent; living from North Carolina to the West Indies, near shore to 120 fathoms. The radiating ribs are finer and the concentric threads closer than on L. ephraimi. L. pectinella C. B. Adams (see Clench and Turner, 1950, Occas. Papers on Mollusks, vol. 1, No. 15, p. 324, pl. 46, figs. 9-10; also Dall and Simpson, 1901, U. S. Fish Com. Bull., vol. 20 for 1900, pt. 1, p. 492, pl. 58, fig. 9). Recent, West Indies. The hinge line after the beak diverges at a lesser angle from the horizontal than on L. ephravms, and the Recent shell is slightly taller than the Venezue- lan fossil. L. fontis (Maury) (1920, Bull. Amer. Paleont., vol. 8, No. 34 pp. 89-90 pl. 1). Upper Miocene ?, Knapp’s No. 1 well, Terre- bone Parish, Louisiana at 2000-2150 and 2250-2450 feet. The Vene- zuelan shell is close to L. fontis but is not so sturdy nor as coarsely sculptured, and the anterodorsal margin is less concave than on the Louisiana species. Also, L. ephraimi has two unequal cardinal teeth on the right valve (with the anterior tooth much the smaller), whereas L. fontis is described as having but a single cardinal, and is so illustrated; it may be, however, that the anterior cardinal of L. fontis is vestigial, and merges with the inner edge of the lunule. L. yaquensis Gabb (see Maury, 1917, Bull. Amer. Paleont., vol. 5, No. 29, p. 370, pl. 35, fig. 8). Middle Miocene of the Dominican Republic. The sculpture of the Dominican fossil consists of delicate, VENEZUELAN CENOZOIC PELECYPODS: WEISBORD | raised concentric laminae and almost obsolete radial riblets. The radials of L. ephraimi are pronounced. L. sphaeriolus (Dall) (1903, Wagner Free Inst., Sci., Trans., vol. 3, pt. 6, p. 1382, pl. 52, fig. 15). Chipola formation (middle Mio- cene) of Florida. This is wider than L. ephraimi, and the radial sculpture is less regular. L. approximata (Dall) (1901, U.S. Nat. Mus., Proc., vol. 23, No. 1237, pp. 828-829, pl. 39, fig. 4). Upper Pliocene to Recent, southern California to Panama. The description and illustration of the type indicate that the beak is fuller and higher, and the ribs broader than on L. ephraimi. L. diktyota (Gardner) (1936, State of Florida Dept. Conserv., Geol. Bull. No. 14, pp. 26-27, pl. 5, figs. 2-3). Middle Miocene, Wal- ton County, Florida. The concentric lirae are a little stronger, the anterodorsal margin is a little less concave, and the dentition is stronger than on L. ephraimi. Lucina (Parvilucina) multilineata Tuomey and Holmes PI. 29, figs. 7, 8 1857. Lucina multilineata “Conrad”, Tuomey and Holmes, Pleiocene Fossils of South Carolina, p. 61, pl. 18, figs. 16-17. 1858. Lucina multilineata Tuomey and Holmes, Emmons, Report on the North Carolina Geological Survey, p. 291. 1860. Lucina multilineata Tuomey and Holmes, Holmes, Post-Pleiocene Fossils of South Carolina, p. 30, pl. 6, fig. 6. 1901. Phacoides (Parvilucina) crenella Dall, U. S. Nat. Mus., Proc., vol. 23, No. 1237, pp. 825-826, pl. 39, fig. 2. 1903. Phacoides (Parvilucina) multilineatus Tuomey and Holmes, Dall, Wagner Free Inst. Sci., Trans., vol. 3, pt. 6, p. 1384. 1903. Phacoides crenella Dall, Vanatta, Acad. Nat. Sci. Philadelphia, Proc., vol. 55, p. 756. 1911. Phacoides multilineatus (Tuomey and Holmes), Vaughan, Georgia Geol. Sur., Bull. 26, p. 368. 1916. Phacoides (Parvilucina) crenella Dall, [in] Matson, U. S. Geol. Sur., Prof. Paper 98-L, p. 71. 1918. Phacoides multilineatus (Tuomey and Holmes), Mansfield, Florida State Geol. Sur., Eleventh An. Rept., pp. 115, 119. 1919. Phacoides (Parvilucina) multilineatus (Tuomey and Holmes), Gardner and Aldrich, Acad. Nat. Sci. Philadelphia, Proc., vol. 71, p. 19. 1920. Phacoides (Parvilucina) multilineatus (Tuomey and Holmes), Maury, Bull. Amer. Paleont., vol. 8, No. 34, pp. 88-89. 1921. Lucina multilineata Tuomey and Holmes, Lamy, Jour. Conchyl., vol. 65, p. 210. 1924. Phacoides multilineatus (Tuomey and Holmes), Mansfield, Florida State Geol. Sur., Fifteenth An. Rept., pp. 32, 33, 36, 38, 40. 1928. Phacoides (Parvilucina) multilineatus (Tuomey and Holmes), Mansfield, U. S. Geol. Sur., Prof. Paper 150-F, p. 139. 222 BuLueTin 204 1932. Phacoides (Parvilucina) multilineatus (Tuomey and Holmes), Mansfield, Florida State Geol. Sur., Bull. No. 8, pp 101-102, pl. 20, figs. 6-7. 1934. Lucina crenella (Dall), and L. multilineata Tuomey and Holmes, John- son, Boston Soc. Nat. Hist., Proc., vol. 40, No. 1, p. 42. 1936. Phacoides crenella Dall, McLean, Nautilus, vol. 49, No. 4, p. 118. 1936. Lucina (Parvilucina) multilineata Tuomey and Holmes, Lermond, Check List of Florida Marine Shells, Gulfport, p. 12. 1937. Parvilucina multilineata (Tuomey and Holmes), Chavan, Jour. Conchyl., vol. 81, p. 210. 1937. Lucina (Parvilucina) crenella (Dall), Smith, East Coast Marine Shells, pp. 46-47, pl. 23, fig. 14. 1938. Phacoides multilineatus (Tuomey and Holmes), Richards, Geol. Soc. Amer., Bull., vol. 49, pt. 2, p. 1291. 1940. Phacoides multilineatus (Tuomey and Holmes), Stubbs, Jour. Paleont., vol. 14, No. 5, p. 511. 1943. Phacoides (Parvilucina) multilineatus (Tuomey and Holmes), Gardner, U. S. Geol. Sur., Prof. Paper 199-A, pp. 78-79, pl. 13, figs. 34-37. 1944. Lucina crenella (Dall), Hackney, Nautilus, vol. 58, No. 2, p. 58. 1945. Phacoides crenella Dall, van Bentham Jutting, Geolog.-Mijnbouwk. Genootschap Nederland en Kolonien, Geol. ser., vol. 14, p. 77. 1947. Phacoides multilineatus (Tuomey and Holmes), Richards, Jour. Paleont., vol. 21, No. 1, p. 25. 1949. Linga (Parvilucina) crenella (Dall), Lange de Morretes, Mus. Paranaense, Arq., vol. 7, art. 1, p. 32. 1952. Lucina crenella (Dall), Pulley, Texas Jour. Sci., vol. 4, No. 2, p. 181. 1953. Phacoides (Parvilucina) multilineatus (Tuomey and Holmes), Olsson and Harbison, Acad. Nat. Sci. Philadelphia, Mon. No. 8, pp. 86-87. 1954. Lucina (Parvilucina) multilineata Tuomey and Holmes, Abbott, Ameri- can Seashells, pp. 386-387, fig. 78f. 1956. Lucina crenella Dall, Parker, "Amer. Assoc. Petrol. Geol., Bull., vol. 40, No. 2, pp. 308, 315, 326, 353, 370, pl. 3, figs. 4a, 4b. 1958. Phacoides (Parvilucina) multilineatus (Tuomey and Holmes), DuBar, Florida Geol. Sur., Geol. Bull., No. 40, pp. 168, 211, 220, 222, 224, 225220 227 PleuG: tig. 2 1959. Lucina crenella (Dall), Parker, Amer. Assoc. Petroleum Geol., Bull., vol. 43, No. 9, p. 2162. 1961. Lucina multilineata Tuomey and Holmes, Moore, Gulf Research Repts., vol. 1, No. 1, pp. 15, 41. Shell small, thin, moderately inflated and somewhat humped, suborbicular, slightly depressed posteriorly, the depression defined from the disk by a feeble radial ridge. Anterodorsal margin con- cave, anterior end somewhat extended and rounded, ventral margin shallowly rounded, posterior end truncate, posterodorsal margin straight, inclined from the horizontal about 40 degrees. Umbo full, moderately high, the beak slightly aft of center. Lunule cordate, moderately concave, smooth. Ligament opisthodetic, linear, Con- centric sculpture consisting of thin, regular, closely spaced concen- tric lirae separated by scarcely wider interspaces, the lirae becoming laminar on the anterior submargin and frankly lamellose on the posterior depression. The concentric lirae override and minutely VENEZUELAN CENOZOIC PELECYPODS: WEISBORD 223 cancellate the faint regular sublinear radii of the disk, the radials obsolete on the umbo and anterior submargin, and absent on the posterior depression. Anterior cardinal tooth of right valve thin and small, the posterior tooth also relatively small but robust and cuneiform. Anterior lateral tooth of right valve relatively short but stout, and crudely corrugated on the face, the right posterior lateral tooth a little longer and thinner as well as smooth. Inner margin gently crenulate, the crenulations distinct from the anterior lateral tooth to the posterior corner of the ventral margin, but much smaller and submicroscopic on the posterior margin proper. Muscle scars indistinct, the anterior one somewhat arcuate and narrowly lozenge-shaped but not overly long, the posterior scar seemingly rudely oval. Pallial line not visible on the single specimen. Dimensions.—Specimen R524a, right valve, height 3.1 mm.,; width 3.3 mm.; approx. thickness 1.2 mm. Locality.—Playa Grande formation (Maiquetia member) at W-26, in Quebrada Las Bruscas approximately 125 meters up- stream from junction with Quebrada Las Pailas. One small right valve. Remarks.—L. multilineata varies somewhat in plumpness and strength of sculpture, and the single specimen cannot be distin- guished from the not so plump and somewhat more weakly sculp- tured variants. Range and Distribution—Upper Miocene to Recent. Living near shore to 124 fathoms in the Gulf of México from Texas to Florida, and in the Western Atlantic from North Carolina to Brazil. As a fossil it is recorded from the Pleistocene in Louisiana, Ala- bama, South Carolina, Florida, and the Island of Blanquilla, Vene- zuela; from the Pliocene of North Carolina, South Carolina, and Florida; and from the upper Miocene from Virginia to Florida. Lucina (Lucinisca) muricata (Spengler) Pl. 29, figs. 9-14 1798. Tellina muricata Spengler, Skrivt. Naturf. Selsk., vol. 4, pt. 2, p. 120, No. 62. 1795. Tellina imbricata Chemnitz, Syst. Conchylien-Cabinet, vol. 11, p. 207. 1795. Tellina muricata Spengler, Chemnitz, Syst. Conchylien-Cabinet, vol. 11, p. 209, pl. 199, figs. 1945-1946. 224 1815. 1817. 1819. 1827. 1835. 1845. 1850. 1852. 1853. 1858. 1864. 1867. 1872. 1872. 1878. 1878. 1884. 1889. 1889. 1901. 1901. 1903. 1921. 1921. 1925. 1925. 1934. 1936. 1937. 1937. 1938. 1940. BuL.etin 204 Tellina muricata Spengler, Wood, General Conchology, or a description of shells, p. 185. Tellina muricata Spengler, Dillwyn, A Descriptive Catalogue of Recent Shells, p. 98. Lucina scabra Lamarck, An. sans Vert., vol. 6, p. 542. Lucina scabra Lamarck, Encycl. Méth., vol. 2, p. 385, pl. 285, figs. 5a-Sc. Lucina scabra Lamarck, Deshayes, An. sans Vert., vol. 6, p. 227, No. 9. Lucina muricata (Spengler), d’Orbigny, [in] La Sagra, Hist. Fis., Polit. y Nat. Isla de Cuba, vol. 5, Moluscos, p. 331. Lucina scabra Lamarck, Reeve, Conch. Icon., vol. 6, Lucina, pl. 8, sp. 45. Lucina scobinata Récluz, Jour. Conchyl., vol. 3, p. 252, pl. 10, figs. 6, 6’. Lucina scabra Lamarck, Fischer, Jour. Conchyl., vol. 4, p. 414. Lucina (Myrtea) muricata (Spengler), H. and A. Adams. The Genera of Recent Mollusca, vol. 2, p. 468. Lucina scabra Lamarck, Krebs, The West Indian Marine Shells, p. 121. Lucina muricata (Chemnitz), Guppy, Sci. Assoc. Trinidad, Proc., pt. 3, p. 162. Lucina scobinata Récluz, Tryon, Acad. Nat. Sci. Philadelphia, Proc., vol. 24, p. 87. Lucina muricata (Chemnitz), Pfeiffer, Syst. Conchylien-Cabinet, vol. 11, pt. 1, pp. 276-277, pl. 42, figs. 7-8. Lucina muricata (Spengler), March, Catalogue of West-India Shells, pad: Lucina muricata (Chemnitz), Arango y Molina, Contribucién a la Fauna Malacolégica Cubana, p. 255. Myrtea scabra (Lamarck), Tryon, Structural and Systematic Conchology, vol. 3. p. 210, pl. 119, figs. 44-45. Lucina muricata (Chemnitz), Simpson, Davenport Acad. Nat. Sci., Proc., vol. 5, p. 66. Lucina (Lucinisca) scabra Lamarck, Dall. U. S. Nat. Mus., Bull. 37, p. 52: Phacoides (Lucinisca) muricatus (Spengler), Dall, U. S. Nat. Mus., Proc., vol. 23, No. 1237, p. 809. Phacoides (Lucinisca) muricatus (Spengler), Dall, and Simpson, U. S. Fish Com., Bull., vol. 20 for 1900, pt. 1, p. 494. Phacoides (Lucinisca) muricatus (Spengler), Dall, Wagner Free Inst. Sci., Trans., vol. 3, pt. 6, p. 1373. Phacoides (Lucinisca) muricatus (Spengler), Pilsbry, Acad. Nat. Sci. Philadelphia, Proc., vol. 73, p. 417. Lucina muricata (Spengler), Lamy, Jour. Conchyl., vol. 65, pp. 175, 250. ?Phacoides (Lucinisca) dag Maury, Bull. Amer. Paleont., vol. 10, No. 42. pp. 319-320, pl. 29, fig. 6 Phacoides (Lucinisca) epbicntas (Spengler), Maury, Bull. Amer. Paleont., vol. 10, No. 42, pp. 319, 320. Lucina (Lucinisca) muricata (Spengler), Johnson, Boston Soc. Nat. Hist., Proc., vol. 40, No. 1, p. 41. Lucina (Lucinisca) muricata (Spengler), Lermond, Check List of Florida Marine Shells, Gulfport, p. 12. Lucina (Lucinisca) muricata (Spengler), Smith, East Coast Marine Shells, p. 46, pl. 15, fig. 3. Lucina (Lucinisca) muricata (Spengler), Chavan, Jour. Conchyl., vol. 81, p. 240. Phacoides muricatum (Spengler), Richards, Geol. Soc. Amer., Bull., vol. 49, pt. Z, p. 1291. Lucina muricatus (Spengler), Smith, World-wide Sea Shells, p. 105, fig. 1397. VENEZUELAN CENOZzOIC PELECYPoDS: WEISBORD 295 1946. Lucina (Lucinisca) muricata (Spengler), Hertlein and Strong, Zoo- logica, vol. 31, pt. 3, No. 8, p. 114. 1951. Phacoides (Lucinisca) muricatus (Spengler), McLean, New York Acad. Sci. Scientific Survey of Porto Rico and the Virgin Islands, vol. 17, pt. 1, p. 64, pl. 13, fig. 1. 1953. Phacoides (Lucinisca) muricatus (Spengler), Haas, Fieldiana-Zoology, vol. 34, No. 20, p. 203. 1958. Phacoides muricatus (Spengler), Olsson and McGinty, Bull. Amer. Paleont., vol. 39, No. 177, p. 20. 1959. Phacoides muricatus (Spengler), Nowell-Usticke, A Check List of the Marine Shells of St. Croix, p. 11. 1961. Phacoides (Lucinisca) muricatus (Spengler), Warmke and Abbott, Car- ibbean Seashells, p. 177, pl. 36i. Shell small, suborbicular, compressed to a little inflated, de- pressed on the posterior and anterior submargins, the posterior de- pression more pronounced than the anterior. Ventral margin usually rounded, the anterior end rounded to subtruncate, the anterodorsal margin sinuous, the posterodorsal margin gently and evenly convex, the posterior margin generally truncate, the truncation vertical to slightly oblique toward the ventral margin. Beak small, pointed forward, subcentral, sculptured by a few concentric lamellae which lose their identity on the disk. Lunule sublanceolate, more pro- nounced on the right valve where it is deeper and a little longer than on the left valve. Except at the beak, the surface is sculptured by fairly close radiating ridges which are often alternately larger and smaller on the disk proper, the ridges beset with fluted to spiny scales. Mature individuals bear as many as 48 ridges, and typically, the row bordering the dorsal margins has the broadest scales. On the anterior submargin the two or three radial ribs are flat and non- scaly, are separated by narrow shallow incisions, and are crossed by numerous coarse concentric striae; on the posterior submargins there are six to eight small unequal scaly ridgelets, and on the narrow ridge between the disk and the posterior submargins the spines are a little longer and sharper than elsewhere; on the disk proper the interspaces of the larger and smaller ridges are moderately deep. Hinge with a bifid anterior lateral and a bifid posterior lateral tooth, the laterals of the left valve stronger than on the right. Margins finely denticulate. Anterior muscle scar long, slightly ar- cuate and lozenge-shaped, the posterior scar more or less reniform. Pallial line simple, entire, uniting with the anterior muscle scar at about the middle of the outer edge, and joining the posterior one at the base of the inner edge. 226 BuLLETIN 204 Dimensions.—Specimen C518a, right valve, height 10 mm.; width 10 mm.; thickness 2.1 mm. Specimen C518b, right valve, height 7 mm.; width 7 mm.; thickness 1.8 mm. Specimen C518c, left valve, height 8.1 mm.; width 7.9 mm.; thickness 2 mm. Speci- men C518d, left valve, height 7.4 mm.; width 7.5 mm.; thickness 2 mm. Specimen C523a, juvenile right valve, height 2.2 mm.; width 2 mm.; approx. thickness 0.8 mm. Specimen C529a, right valve, height 10 mm.; width 10 mm.; thickness 3 mm. Locality.—La Salina, west of Puerto Cabello, State of Cara- bobo. Forty-seven specimens including 26 left valves and 21 nght valves. Remarks.—The La Salina fossils here referred to L. muricata (Spengler) are identical with Recent West Indian forms, notably those from Santiago, Cuba (Collection No. 84523, Academy of Natural Sciences of Philadelphia). Z. roigi Maury from the Plio- cene at Matura, Trinidad, seems to be a less profusely ribbed variant of L. muricata, as in other respects (and this is brought out by Maury) they are alike. Furthermore, Guppy reported L. muricata from both the Recent and Pliocene of Trinidad. Range and distribution—The range of L. muricata (Spengler) is from Pliocene to Recent. The living shell is found from Florida to Brazil at shallow depths to 82 fathoms. As a fossil the species occurs in the Pleistocene of Florida and Barbados, and in the Plio- cene of Trinidad and of Venezuela (Collection No. 18408, U. S. National Museum). Codakia (Lentillaria) orbicularis (Linnaeus) Pl. 30, figs. 1-8 1758. Venus orbicularis Linnaeus, Syst. Nat., ed. 10, p. 688. 1767. Venus tigerina var. Linnaeus, Syst. Nat., ed. 12, p. 1134. 1818. ee tigerina (Linnaeus), Lamarck, An. sans Vert., vol. 5, p. 574 part). 1850. Lucina tigerina (Linnaeus), Reeve, Conch. Icon., vol. 6, Lucina, pl. 1, sp. 3. Not of Linnaeus 1758. 1864. Lucina tigerina (Linnaeus), Krebs, The West Indian Marine Shells, p. 121. Not of Linnaeus 1758. 1872. Lucina (Codakia) tigerina (Linnaeus), Tryon, Acad. Nat. Sci. Phila- delphia, Proc., vol. 24, p. 87 (part). Not of Linnaeus 1758. 1873. Lucina tigerina (Linnaeus), Gabb, Amer. Philos. Soc., Trans., new ser., vol. 15, p. 251. Not of Linnaeus 1758. 1876. Lucina tigrina (Linnaeus), Guppy, Geol. Soc. London, Quart. Jour., vol. 32, p. 530. Not of Linnaeus 1758. 1878. Lucina tigerina (Linnaeus), Moérch, Catalogue of West-India Shells, p. 15. Not of Linnaeus 1758. 1878. 1884. 1885. 1887. 1889. 1889. 1889. 1891. 1895. 1901. 1901. 1903. 1916. 1917. 1920. 1921. 1922. 1926. 1933% 1934. 1935. 1936. 1936. 1936. 1936. 1937. 1937. 1938. VENEZUELAN CENOzoIC PELECYPODS: WEISBORD 227 Lucina tigrina (Linnaeus), Arango y Molina, Contribucién a la Fauna Malacologica Cubana, p. 256. Not of Linnaeus 1758. Lucina tigerina (Linnaeus), Tryon, Structural and Systematic Conch- ology, vol. 3, p. 210, pl. 119, fig. 42. Not of Linnaeus 1758. Lucina (Codakia) tigerina (Linnaeus), Smith, Voyage of H.M.S. Chal- lenger, Zoology, vol. 13, p. 179 (part). Not of Linnaeus 1758. Lucina (Codokia) tigerina (Linnaeus), Fischer, Manuel Conchyliologi- que et de Paléontologie Conchyliologique, p. 1143 (part). Not of Lin- naeus 1758. Lucina tigerina (Linnaeus), Lorié, Samml. Geol. Reichs-Mus. Leiden, ser. 2, vol. 1, pp. 123, 141, pl. 1, figs. 18-19. Not of Linnaeus 1758. Lucina tigrina (Linnaeus), Dall, U. S. Nat. Mus., Bull. 37, p. 50. Not of Linnaeus 1758. Lucina tigrina (Linnaeus), Simpson, Davenport Acad. Nat. Sci., Proc., vol. 5, p. 66. Not of Linnaeus 1758. Lucina tigrina (Linnaeus), Baker, Acad. Nat. Sci. Philadelphia, Proc., vol. 43, p. 47. Not of Linnaeus 1758. Codakia tigernia (Linnaeus), Gregory, Geol. Soc. London, Quart Jour., vol. 51, p. 292. Not of Linnaeus 1758. Codakia orbicularis (Linnaeus), Dall and Simpson, U. S. Fish Com., Bull. vol. 20 for 1900, pt. 1, p. 491. Codakia orbicularis (Linnaeus), Dall, U. S. Nat. Mus., Proc., vol. 23, no. 1237, p. 799. Codakia orbicularis (Linnaeus), Dall, Wagner Free Inst. Sci., Trans., vol. 3, pt. 6, p. 1347. Codakia orbicularis (Linnaeus), Thiele, Zool. Jahr., Suppl. 11, p. 129. Codakia orbicularis (Linnaeus), Maury, Bull. Amer. Paleont., vol. 5, No. 29, p. 366, pl. 35, fig. 1. Codakia orbicularis (Linnaeus), Maury, Bull. Amer. Paleont., vol. 8, No. 34, p. 83. Codakia orbicularis (Linnaeus), Lamy, Jour. Conchyl., vol. 65, p. 234, 2 text figs. Codakia orbicularis (Linnaeus), Remington, Nautilus, vol. 35, No. 4, p. 121. Codakia orbicularis (Linnaeus), Weisbord, Nautilus, vol. 39, No. 3, p. 83. Codakia orbicularis (Linnaeus) var., Trechmann, Geol. Mag., vol. 70, p. 36, pl. 4, fig. 5. Codakia orbicularis (Linnaeus), Johnson, Boston Soc. Nat. Hist., Proc., vol. 40, No. 1, p. 42. Codakia orbicularis (Linnaeus), Richards, Jour. Paleont., vol. 9, No. 3, p. 256. Codakia orbicularis (Linnaeus), McLean, Soc. Cubana Hist. Nat. “Felipe Poey,” Mem., vol. 10, No. 1, p. 41. Codakia orbicularis (Linnaeus), McLean, Nautilus, vol. 49, No. 4, p. 118. Codakia orbicularis (Linnaeus), Clench and McLean, Soc. Cubana Hist. Nat. “Felipe Poey,’ Mem., vol. 10, No. 3, p. 165. Codakia orbicularis (Linnaeus), Lermond, Check List of Florida Marine Shells, Gulfport, p. 12. Codakia orbicularis (Linnaeus), Smith, East Coast Marine Shells, p. 47, pl. 19, fig. 5. Codakia (Lentillaria) orbicularis (Linnaeus), Chavan, Jour. Conchyl., vol. 81, No. 4, p. 280. Codakia orbicularis (Linnaeus), Perry, Schwengel, and Dranga, Nau- tilus, vol. 52, No. 1, p. 28. 228 BuLueTiIn 204 1938. Codakia orbicularis (Linnaeus), Richards, Geol. Soc. Amer., Bull., vol. 49, pt. 2, p. 129. 1942. Codakia orbicularis (Linnaeus), Jaume and Pérez Farfante, Soc. Cubana Hist. Nat. “Felipe Poey,’ Mem., vol. 16, No. 1, p. 39. 1946. Codakia orbicularis (Linnaeus), Jaume, Soc. Malac. “Carlos de La Torre,” Rev., vol. 4, No. 3, p. 100. 1946. Codakia orbicularis (Linnaeus), Hertlein and Strong, Zoologica, vol. 31, Pts, NO. S,aps dvs 1949. Codakia orbicularis (Linnaeus), Lange de Morretes, Mus. Paranaense, Arq.,, vol. 7, pt 1, p.133- 1951. Codakia orbicularis (Linnaeus), Rogers, The Shell Book, pp. 366, 500, pl. 73, fig. 2. 1952. Codakia orbicularis (Linnaeus), Pulley, Texas Jour. Sci., vol. 4, No. 2, p. 181. 1954. Codakia (Codakia) orbicularis (Linnaeus), Abbott, American Seashells, p. 390, pl. 38d. 1957. Codakia, Weisbord, Bull. Amer. Paleont., vol. 38, No. 165, p. 16. 1958. Codakia (Ctena) orbicularis (Linnaeus), DuBar, Florida Geol. Sur., Geol. Bull. No. 40, p. 166. 1958. Codakia (Codakia) orbicularis (Linnaeus), Abbott, Acad. Nat. Sci. Philadelphia, Mon. No. 11, p. 119. 1958. Codakia orbicularis (Linnaeus), Olsson and McGinty, Bull. Amer. Paleont., vol. 39, No. 177, p. 21. 1959. Codakia orbicularis (Linnaeus), Nowell-Usticke, A Check List of the Marine Shells of St. Croix, p. 11. 1961. Codakia (Codakia) orbicularis (Linnaeus), van Regteren Altena, Ko- ninkl. Nederl. Wetensch-Amsterdam, Proc., ser. B, vol. 64, No. 2, p. 300. 1961. Codakia orbicularis (Linnaeus), Warmke and Abbott, Caribbean Sea- shells, p. 178, pl. 36g. The Cabo Blanco fossils referred to C. orbicularis are com- pressed, oval when young but suborbicular when fully grown, with a faintly depressed posterior and a hardly rounded to subtruncate posterior margin. The beak is smooth, but the remainder of the disk is decussated by fine subequal to unequal radial cords crossed by concentric threads, the sculpture finer, closer and subscabrous on the posterior depression. Lunule nearly all on the right valve where it is deep and spoon-shaped, the deck of the lunule flattish on young shells but becoming more and more sulcate with age so that the lunule of old specimens is deeply V-shaped. Dimensions——Specimen S417c, entire right valve of young specimen, height 30.2 mm.; length 37.2 mm., thickness 5.2 mm. Specimen $417a, broken right valve, adult, length of fragment 53.3 mm. Specimen $417b, broken right valve, length of fragment 39.5 mm. Specimen S$417d, broken left valve, length of fragment 31.8 mm. Entire specimen of medium size, left valve, height 42 mm.; VENEZUELAN CENOZzoIC PELECYPoDS: WEISBORD 229 length 47 mm.; thickness 6.5 mm. Specimen D 417a, partially bro- ken left valve, height 9 mm.; length 10 mm.; thickness 2.7 mm. Localities —Playa Grande formation (Maiquetia member) at W-23, north flank of Punta Gorda anticline. Nine right valves, four left valves, and a number of fragments. All of the examples at this locality were collected from the Lithothamnium limestone. Abisinia formation at W-30, eastern edge of Playa Grande village. One young, broken left valve, the identification of which is not certain. Remarks.—tThere is considerable variation in the details of the surface decussation, but comparing the hinge and other morphologi- cal features with Recent specimens of C. orbicularis there seems to be no significant difference. Range and distribution—The Recent C. orbicularis (Linnaeus) is found in shallow water from Texas to Brazil. In the Pleistocene, the species has been recorded from Texas, Florida, Cuba, St. Kitts, St. Eustatius, Curacao, Aruba, and Barbados. In the Pliocene it occurs in Florida. And, in the middle Miocene it has been reported by Gabb, Guppy, and Maury from the Dominican Republic. Codakia (Jagonia) orbiculata (Montagu) Pl. 31, figs. 14 1808. Venus orbiculata Montagu, Testacea, or Natural History of British Shells, Suppl., p. 42, pl. 29, fig. 7. 1817. Venus orbiculata Montagu, Dillwyn, A Descriptive Catalogue of Recent Shells, vol. 1, p. 192. 1845. Lucina imbricatula C. B. Adams, Boston Soc. Nat. Hist., Proc., vol. 2, p. 10. 1850. Lucina occidentalis Reeve, Conch. Icon., vol. 6, Lucina, pl. 7, sp. 35, errata. 1864. Lucina pecten Lamarck, Krebs, The West Indian Marine Shells, p. 120. 1872. Lucina (Codakia) imbricatula C. B. Adams, Tryon, Acad. Nat. Sci. Philadelphia, Proc., vol. 24, p. 86. 1878. Lucina pecten Lamarck, Morch, Catalogue of West-India Shells, p. 15. 1885. Lucina (Codakia) pecten Lamarck, Smith, Voyage of H.M.S. Challenger, Zoology, vol. 13, pp. 179-180 (part). 1889. Lucina pecten Lamarck, Lorié, Samml. Geol. Reichs-Mus. Leiden, ser. 2, vol. 1, pp. 123, 141. Not of Lamarck. 1889. Lucina pecten Lamarck, Dall, U. S. Nat. Mus., Bull. 37, p. 50. 1891. Lucina imbricatula Adams, Baker, Acad. Nat. Sci. Philadelphia, Proc., vol. 43, p. 47. 1895. Codakia (Myrtea) imbricatula (C. B. Adams), Gregory, Geol. Soc. London, Quart. Jour., vol. 51, p. 292. 1901. Codakia (Jagonia) orbiculata (Montagu), Dall, U. S. Nat. Mus., Proc., vol. 23, No. 1237, p. 799, 822, 823. 1901. Codakia orbiculata (Montagu), Dall and Simpson, U. S. Fish Com., Bull., vol. 20 for 1900, pt. 1, p. 491. 230 1903. 1913. 1920. 1920. 1921. 1923. 1926. 1933. 1934. 1936. 1936. 1936. 1936. WET 1937. 1938. 1938. 1939. 1946. 1949. 1950. 1951. 1954. 1955. 1958. 1958. 1959. 1961. BULLETIN 204 Codakia (Jagonia) orbiculata (Montagu), Dall, Wagner Free Inst. Sci., Trans., vol. 3, pt. 6, pp. 1350-1351 (part). Codakia orbiculata (Montagu), Brown and Pilsbry, Acad. Nat. Sci. Philadelphia, Proc., vol. 65, p. 496. Codakia (Jagonia) imbricatula C. B. Adams, Lamy, Jour. Conchyl., vol. 65, p. 249. Codakia (Jagonia) orbiculata (Montagu), Maury, Bull. Amer. Paleont., vol. 8, No. 34, pp. 83-84. Codakia (Jagonia) orbiculata (Montagu), Lamy, Jour. Conchyl., vol. 65. pp. 246, 248, 249. Codakia orbiculata (Montagu), Clench, Nautilus, vol. 37, No. 2, p. 54. Codakia orbiculata (Montagu), Weisbord, Nautilus, vol. 39, No. 3, p. 83. Codakia imbricatula (C. B. Adams), Trechmann, Geol. Mag., vol. 70, No. 823, p. 36. Codakia (Jagonia) orbiculata (Montagu), Johnson, Boston Soc. Nat. Hist. Proc., vol. 40, No. 1, p. 42. Lucina (Jagonia) orbiculata (Montagu), Lermond, Check List of Florida Marine Shells, Gulfport, p. 12. Codakia (Jagonia) orbiculata orbiculata (Montagu), McLean, Soc. Cubana Hist. Nat. “Felipe Poey,” Mem., vol. 10, No. 1, p. 41. Codakia (Jagonia) orbiculata orbiculata (Montagu), Clench and McLean, Soc. Cubana Hist. Nat. “Felipe Poey,’ Mem., vol. 10, No. 3, p. 165. Codakia orbiculata (Montagu), McLean, Nautilus, vol. 49, No. 4, p. 118. Codakia orbiculata (Montagu), Smith, East Coast Marine Shells, p. 47, pl. 14, figs. 8a, 8b, pl. 15, fig. 6. Jagonia orbiculata (Montagu), Chavan, Jour. Conchyl., vol. 81, p. 257. Codakia orbiculata (Montagu), Richards, Geol. Soc. Amer., Bull., vol. 49, pt. 2, p. 1291. Codakia orbiculata (Montagu) Perry, Schwengel, and Dranga, Nautilus, vol. 52, No. 1, p. 28. Ctena orbiculata (Montagu), Bartsch and Rehder, Smithsonian Misc. Col- lections, vol. 98, No. 10, p. 18. Codakia (Jagonia) orbiculata (Montagu), Jaume, Soc. Malac. “Carlos de La Torre,” Rev., vol. 4, No. 3, p. 100. Codakia (Jagonia) orbiculata orbiculata (Montagu), Lange de Morretes, Mus. Paranaense, Arq., vol. 7, pt. 1, p. 33. Lucina imbricatula C. B. Adams, Clench and Turner, Occas. Papers on Mollusks, vol. 1, p. 292, pl. 46, figs. 7-8. Codakia (Jagonia) orbiculata (Montagu), McLean, N. Y. Acad. Sci. Scientific Survey of Porto Rico and the Virgin Islands, vol. 17, pt. 1, Plepl2 ties. Codakia (Ctena) orbiculata (Montagu), Abbott, American Seashells, p. 391, pl. 30L. Codakia (Ctena) orbiculata (Montagu), Perry and Schwengel, Marine Shells of the Western Coast of Florida, p. 66, pl. 11, fig. 68. Codakia orbiculata (Montagu), Olsson and McGinty, Bull. Amer. Paleont., vol. 39, No. 177, p. 20. Codakia (Ctena) orbiculata (Montagu), Abbott, Acad. Nat. Sci. Phila- delphia, Mon. No. 11, p. 120, pl. 14r. Codakia orbiculata (Montagu), Nowell-Usticke, A Check List of the Marine Shells of St. Croix, p. 11. Codakia (Jagonia) imbricatula (C. B. Adams), van Regteren Altena, Koninkl-Nederl. Akad. Wetens.-Amsterdam, Proc., ser. B, vol. 64, No. 2, p. 300. VENEZUELAN CENOZOIC PELECYPODS: WEISBORD 231 The Recent Cabo Blanco shell is fairly small, moderately com- pressed, feebly depressed posteriorly, suborbicular, with an extend- ed, nearly semicircular anterior margin, a shallowly rounded ventral margin, and a slightly curved to subtruncate posterior margin. Beak low, sharp, prosogyrate, subcentral. Lunule small, indistinct, lanceo- late, slightly wider on the right valve. Disk divided into three sec- tions by two narrow concentric rifts representing resting stages of growth. Radial ribs about 30 in all, crossed by rather thick regular concentric cords rendering the ribs transversely beaded or nodulose. The ribs are low, the main ones starting at the beak, increasing in number by division and intercalation as growth progresses. The divided and intercalated riblets are smaller than the principal ribs, and their distribution is not uniform. Some of the principal ribs are a little stouter than the others, particularly toward the posterior of the left valve and anterior of the right valve. On both valves the riblets on the posterior depression are relatively feeble. The an- terior muscle scar is long and arcuately lozenge-shaped, the posterior one reniform. The pallial line is simple and entire, uniting with the anterior muscle scar near the top, and joining the posterior one at the base. The interior is faintly corrugated by the ribs, the corruga- tions slightly more pronounced but still feeble at the margins. The color is pale lemon yellow within and without, but the inner margins are whitish. Dimensions.—Specimen A520al1-2, valves attached, height 12 mm.; width 12.9 mm.; thickness 5.2 mm. Locality.—Recent, on beach of Playa Grande Yachting Club, Distrito Federal. One specimen, a doublet. Range and distribution —The living species is found in the Wes- tern Atlantic from North Carolina to Brazil. As a fossil, C. orbicu- lata occurs in the Pleistocene of Florida, the Panama Canal Zone, St. Kitts, Curacao, Aruba, and Barbados. Olsson and Harbison (1953, p. 79) recorded a closely related form from the Pliocene of Florida. Remarks—The west American analogue of C. orbiculata is C. mexicana Dall (1901, U. S. Nat. Mus., Proc., vol. 23, No. 1237, pp. 799, 822, pl. 40, fig. 6). C. mexicana ranges from upper Pliocene to Recent, the living shell occuring intertidally to depths of 45 232 ButieTin 204 fathoms from the Gulf of California to Ecuador. The Mexican shell is larger, more delicate, and more closely ribbed than C. orbicwlata. Codakia (Jagonia) pectinata (C. B. Adams) Pl. 31, figs. 5, 6 1847. Lucina pectinata C. B. Adams, Boston Soc. Nat. Hist., Proc., vol. 2, p. 288. Nude name. 1852. Lucina pectinata C. B. Adams, Contrib. to Conch., No. 12, p. 245. Not of Gmelin, 1791. 1864. Lucina pectinata C. B. Adams, Krebs, The West Indian Marine Shells, p. 120. 1900. Lucina pectinata C. B. Adams, Verrill and Bush, Connecticut Acad. Arts and Sci., Trans., vol. 10, art. 12, p. 519. 1901. Lucina pectinata C. B. Adams, Dall, U. S. Nat. Mus., Proc., vol. 23, No. 1237, p. 799. Not of Gmelin 1791, nor Carpenter 1857. 1903. Lucina pectinata C. B. Adams, Dall, Wagner Free Inst. Sci., Trans., vol. 3, pt. 6, p. 1351. In synonymy under Codakia (Jagonia) orbiculata (Montagu). 1921. Lucina pectinata C. B. Adams, Lamy, Jour. Conchyl., vol. 65, pp. 175, 250; 252; 1950. Lucina pectinata C. B. Adams, Clench and Turner, Occas. Papers on Mollusks, vol. 1, No. 15, pp. 323-324, pl. 46, figs. 5-6. Shell small, moderately tumid, obliquely suboval, inequilateral. Submargins slightly depressed, the anterior submargin broader than the posterior. Anterodorsal margin hardly concave, anterior end produced and rounded, ventral margin shallowly rounded, posterior end moderately rounded, posterodorsal margin hardly convex. Umbo full, rather high, the tip of the beak smooth, situated a little behind the middle, touching the top of the cardinal process. Lunule of right valve not well defined, elongate-cordate, slightly depressed, the rim somewhat thickened, the deck scored by fine grooves which are a continuation of the narrow concentric grooves of the disk. Sculpture consisting, from beak to base, of numerous low radial riblets (of which there are about 105 in all) finely reticulated or beaded by closely spaced concentric threads. The riblets are sepa- arated by narrow shallow grooves, tend to become obsolescent toward the base, and, along an undefined line curving down from the beak along the anterior third of the disk, the riblets on the forward side are divaricate. On the umbo, the riblets are regular and equal, but from the umbo down they increase in number by intercalation, most of the intercalated ones attaining the same size as the primaries at the ventral margin. Occasionally the riblets are finely divided at the base, and below the prodissoconch the disk VENEZUELAN CENOozoIc PELECyPoDS: WEISBORD 233 is traversed by widely separated concentric growth grooves. Post- erior cardinal of right valve stout, cuneate faintly bipartite, the anterior cardinal much smaller and joined to the rim of the lunule under the beak. Lateral teeth of right valve a little unequal, the anterior one slightly the higher and broader. Inner margin of valve weakly denticulate. Anterior muscle scar fairly long, lozenge- shaped, and somewhat arcuate, the posterior one faint and seeming- ly ovate-lenticular. Pallial line simple, entire, uniting with the outer margin of the anterior scar at about the middle, and joining the posterior one at the base. The interior is white, the exterior off- white with a faded brownish yellow stain on the posterior submargin. Dimensions.—Specimen A426a, right valve, height 11.4 mm.; width 12 mm.; approx. thickness 3.2 mm. Locality.—Recent, on beach of Playa Grande Yachting Club, Distrito Federal, One right valve. Remarks.—The Venezuelan shell appears identical with Adams’ type Lucina pectinata from Jamaica but is entirely distinct from the pectinata of Gmelin which is a lucinid often placed by authors in the genus Lucina or Phacoides. Dall (1901) recognized that neither the C. pectinata of Adams nor the later C. pectinata of Carpenter (1857) agreed with Gmelin’s pectinata. In 1903 Dall placed C. pectinata (C. B. Adams), together with some other then recognized species, as a “variety” of C. orbiculata (Montagu) but stated that some of the well-marked varieties of C. orbiculata might eventually be raised to specific rank. In comparing Adams’ type of Lucina pectinata with authentically identified specimens of C. orbiculata (Montagu), the two do seem to me to be specifically distinct, and I consider them to be separate species. Lucina pec- tinata Carpenter is now known as Codakia (Jagonia) mexicana Dall, and this ranges from upper Pliocene to Recent. The Recent C’. mexicana is reported in the Eastern Pacific from Baja California, México to Ecuador. Range and distribution—The Recent Codakia (Jagonia) pec- tinata (C. B. Adams) ranges from the West Indies to northern South America. I have not seen any report of its occurrence as a fossil. 234 BuLLeTIN 204 Codakia (Jagonia) umbonicostata, new species Pl. 3lsfigs-s%,.8 Shell rather small, fairly plump, subquadrate- orbicular, gently depressed posteriorly, and with a slight circumlunular depression anteriorly. Anterodorsal margin concave, anterior end slightly pro- duced and subtruncate, ventral margin shallowly rounded, posterior end hardly convex, posterodorsal margin straight and moderately sloping. Umbo full and high, the beak central and rather obtuse. Lunule of right valve semicordate, not deeply impressed. Sculpture consists of closely spaced regular concentric lirae, and radial riblets which are pronounced on the umbo, feeble to obsolescent on the remainder of the disk, and absent on both submargins. On the umbo, the radial ribs are stronger than the concentric lirae, but on the rest of the disk the concentric markings are the more dom- inant. Hinge sturdy, the base of the hinge plate slightly sinuous and more or less horizontal. Cardinal process of right valve con- sists of a stout, lightly bifid central tooth, a rudimentary anterior tooth in the form of a lamina (not visible on the illustration) af- fixed under the deck of the lunule, and a low posterior ridge. On either side of the central tooth there is a triangular socket, the posterior socket relatively narrow and shallow, the anterior larger and deeper. The anterior lateral is represented by a shallow groove beneath the rim of the lunule, and the posterior lateral by a distal wedgelike thickening. Ligamental groove rather long and deep. Ventral margin crenulate, and slightly thickened at the rim. Ad- ductor scars well impressed, the right anterior elongate, bent, and lenticular, and modified by a narrow finger-like sinus entering the outer side of the lower half, the posterior scar reniform. Pallial line strong, somewhat ragged, joining the posterior muscle scar at the middle of the base. Dimensions —Holotype (1519a), right valve, height 10 mm.; width 10.5 mm.; thickness 3.2 mm. Type locality—Lower Mare formation at W-13, on hillside above west bank of Quebrada Mare Abajo. One right valve, the holotype. Comparisons—The new species is reminiscent of the middle Miocene C. vendryesi Dall (1903, Wagner Free Inst. Sci., Trans., vol. 3, pt. 6, p. 1348, pl. 52, fig. 4) from Bowden, Jamaica, differing VENEZUELAN CENOzOIC PELECYPODS: WEISBORD 235 from that, however, in the obsolescence of the radial ribs below the umbo. C. wmbonicostata, n. sp. also recalls the Bowden Pha- coides (Callucina) pawperatus oligocostatus Woodring (1925, Car- negie Inst. Washington, Publ. No. 366, p. 124, pl. 16, figs. 14-15), and the middle Miocene Phacoides perplexus Pilsbry and Johnson (1917, Acad. Nat. Sci. Philadelphia, Proc., vol. 69, pp. 197-198; and Pilsbry, 1921, zbid, vol. 73, p. 416, text fig. 41 and pl. 38, fig. 3) from the Dominican Republic. The first of those, P. p. oligocostatus, is more regularly orbicular, and less strongly costate on the umbo than the Venezuelan shell, and the second, P. perplexus, though sculp- tured in much the same manner as C. umbonicostata, is semicir- cularly rounded, instead of subtruncate, at the anterior end. Divaricella ? species Pl. 30, fig. 9 An internal mold of a slightly inflated, orbicular shell is referred with doubt to the genus Divaricella. Dimensions——Specimen L423a, right valve, height 23 mm.; width 23.7 mm. Locality.—Playa Grande formation (Catia member), south side of Playa Grande road about 220 meters west of W-15. One internal mold of a right valve. Remarks.—tThe shape is like the Miocene to Recent D. quadri- sulcata (d’Orbigny) (1842, [in] La Sagra, Hist. phys., polit. et nat. Ile de Cuba, pp. 294-295, pl. 27, figs. 34-36), as well as like that of other late Cenozoic species. In his “Essai critique de classification des Divaricella,’ André Chavan (1951) pointed out that certain American species of Divari- cella were not to be classified under the Divaricella of von Martens but under a new genus for which he proposed the name Divalinga. CHAMIDAE Chama congregata Conrad Pl. 31, figs. 11-14; Pl. 32, figs. 1-9 1833. Chama congregata Conrad, Amer. Jour. Sci., 1st ser., vol. 23, p. 341. 1838. Chama congregata Conrad, Fossils of the Medial Tertiary of the United States, p. 32, pl. 17, fig. 2. 1857. Chama congregata Conrad, Tuomey and Holmes, Pleiocene Fossils of South Carolina, p. 23, pl. 7, figs. 7-10. 236 1862. 1885. 1889. 1895. 1903. 1904. 1917. 1919. 1920. 1922. 1924. 1932. 1934. 1936. 1936. 1937. 1938. 1939. 1942. 1942. 1943. 1943. 1944. 1947. 1949. 1953. 1954. 1955. 1958. 1958. 1959. BuLLetIn 204 Chama congregata Conrad, Acad. Nat. Sci. Philadelphia, Proc., vol. 14 (1863), p. 576. Chama congregata Conrad, Bush, Connecticut Acad. Arts and Sci., Trans., vol. 6, p. 478. Chama congregata Conrad, Dall, U. S. Nat. Mus., Bull. 37, p. 52. Chama congregata Conrad, Whitfield, U. S. Geol. Sur., Mon. 24, p. 65, pl. 9, figs. 14-18. Chama congregata Conrad, Dall, Wagner Free Inst. Sci., Trans., vol. 3, pt. 6, pp. 1400-1401. Chama congregata Conrad, Glenn, Maryland Geol. Sur., Miocene, p. 342, pl. 91, figs. 1-3. Chama congregatoides Maury, Bull. Amer. Paleont., vol. 5, No. 29, p. 364, pl. 33, fig. 8. Chama congregata Conrad, Odhner, K. Svenska Vetenskapsakademien Handligar, vol. 59, No. 3, p. 82. Chama congregata Conrad, Maury, Bull. Amer. Paleont., vol. 8, No. 34, pp. 80-81. Chama congregata Conrad, Olsson, Bull. Amer. Paleont., vol. 9, No. 39, p. 390, pl. 28, fig. 11. Chama congregata Conrad, Mansfield, Florida State Geol. Sur., Fifteenth An. Rept., faunal list following p. 28, p. 33. Chama congregata Conrad, Mansfield, Florida Geol. Sur., Bull. No. 8, pp. 90-91, pl. 18, figs. 2, 5. Chama congregata Conrad, Johnson, Boston Soc. Nat. Hist., Proc., vol. 40, No. 1, p. 38. Chama congregata Conrad, Lermond, Check List of Florida Marine Shells, Gulfport, p. 8. Chama congregata Conrad, McLean, Soc. Cubana Hist. Nat. “Felipe Poey,” Mem., vol. 10, No. 1, p. 41. Chama congregata Conrad, Smith, East Coast Marine Shells, p. 44, pl. 14, fig. 4. Chama congregata Conrad, Pilsbry and McGinty, Nautilus, vol. 51, No. 3, pp. 73, 75-76, pl. 7, figs. 6, 10. Chama congregata Conrad, Oinomikado, Geol. Soc. Japan, Jour., vol. 46, No. 96, pp. 618, 628, pl. 29 (15), fig. 29. Chama congregata Conrad, Jaume and Pérez Farfante, Soc. Cubana Hist. Nat. “Felipe Poey,” Mem., vol. 16, No. 1, p. 39. Chama congregata Conrad, Richards and Harbison, Acad. Nat. Sci. Philadelphia, Proc., vol. 94, p. 193. Chama congregata Conrad, Gardner, U. S. Geol. Sur., Prof. Paper 199-A, pp. 9, 11. Chama congregata Conrad, Bayer, Nautilus, vol. 56, No. 4, pp. 117, 120, pl. 12, fig. 3. Chama congregata Conrad, Hackney, Nautilus, vol. 58, No. 2, p. 58. Chama congregata Conrad, Richards, Jour. Plaeont., vol. 21, No. 1, p. 26. Chama congregata Conrad, Lange de Morretes, Mus. Paranaense, Arq., vol. 7, art. 1, p. 34. Chama congregata Conrad, Haas, Fieldiana-Zoology, vol. 34, No. 20, p. 203. Chama congregata Conrad, Abbott, American Seashells, p. 392, pl. 37d. Chama congregata Conrad, Perry and Schwengel, Marine Shells of the Western Coast of Florida, p. 61, pl. 10, fig. 59. Chama congregata Conrad, Olsson and McGinty, Bull. Amer. Paleont., vol. 39, No. 177, p. 21. Chama congregata Conrad, Moore, Nautilus, vol. 7, No. 4, p. 128. Chama congregata Conrad, Nowell-Usticke, A Check List of the Marine Shells of St. Croix, p. 12. VENEZUELAN CENOzoIC PELECYPODS: WEISBORD 237 1961. Chama congregata Conrad, Moore, Gulf Research Repts., vol. 1, No. 1, pp. 15, 41. 1961. Chama congregata Conrad, Warmke and Abbott, Caribbean Seashells, p. 179, pl. 37d. This species is represented in the Cabo Blanco area by both Recent and fossil examples. The shell is relatively small, inequivalve, the left or attached valve deep and irregularly oval, the right or upper valve slightly convex to compressed and irregularly suborbi- cular. The beak of the left valve is full and gryphaeaform, and gyrates counterclockwise; the beak of the right valve is appressed and gyrates clockwise. Exterior of left valve sculptured by foliaceous and fluted concentric lamellae; the sculpture of the right valve consists of concentric lamellae on which are numerous axial wavy cords and flutings, the flutings scalloped to severely arched to tubular at their ends. Within, the margins of the valves are finely crenulate. The pallial line merges with the basal outer margin of the anterior muscle scar, but joins the base of the posterior scar a little in from its outer margin. The muscle scars are elongate and sublenticular, the anterior scar a little narrower, longer, and lower than the posterior. The upper side of the strong cardinal tooth on the hinge plate of the deep (left) valve bears eight to fourteen narrow parallel grooves or corrugations, and the edge of the tooth is recurved slightly upward; the cardinal tooth of the right valve is similarly scored on the under side. The Recent specimens are cream-white within and dirty white on the exterior, but on the best preserved shell the axial cords are reddish brown and dark brown. Dimensions.—Recent paired shell (A436a1-2), left valve, length 20 mm.; width 15 mm.; right valve, length 15 mm.; width 13.7 mm.; thickness of doublet 12 mm. Fossil specimen $436a, right valve, length 16.7 mm.; width 13.9 mm.; thickness 7 mm. Fossil specimen $436b, right valve, length 19.9 mm.; thickness 6 mm. Fossil specimen J436a, left valve, length 28 mm.; width 24.8 mm.; thickness 15.2 mm. Fossil specimen J436b, right valve, length 17.7 mm.; width 14.6 mm.; thickness 3.5 mm. Fossil specimen 1436a, right valve, length 20.1 mm.; width 17.1 mm.; thickness 5 mm. Fossil specimen H436b, right valve, length 15.2 mm.; width 14.9 mm.; thickness 4 mm. Fossil specimen H436a, left valve, length 25.5 mm.; width 20.4 mm.; thickness 11.5 mm. 238 BuLLeETIN 204 Cabo Blanco localities—Recent, on beach at Playa Grande Yachting Club, Distrito Federal. Ten left valves, four right valves, one doublet. Abisinia formation at W-30, eastern edge of Playa Grande village. Three right valves. Upper Mare formation, in stream 250 meters south-southwest of the mouth of Quebrada Las Pailas. One right valve. Mare formation at W-25, south flank of Punta Gorda anticline. One right valve, and one left valve, the identifica- tion of which is uncertain. Lower Mare formation at W-13, on hillside above west bank of Quebrada Mare Abajo. Six right valves. Lower Mare formation, in small stream 100 meters west of Quebrada Mare Abajo. Three right valves, one left valve. Playa Grande formation (Maiquetia member) at W-23, north flank of Punta Gorda anti- cline. Sixteen right valves. Range and distribution—The Recent Chama congregata Con- rad occurs from Cape Hatteras, North Carolina, to Brazil, living near shore to 52 fathoms. As a fossil it is reported from the Pleisto- cene of Cuba, from the Pliocene of North and South Carolina, from the late Miocene along the eastern coast of the United States from New Jersey to Florida, and from the middle Miocene of the Domini- can Republic, Costa Rica, and Colombia. Chama macerophylla Gmelin Pl. 33,figssi 1784. [Chama] Macerophylla Chemnitz, Syst. Conchylien-Cabinet, vol. 7, pp. 101, 149, pl. 52, figs. 514-515. 1791. Chama macerophylla Gmelin, Syst. Nat., vol. 6, p. 3304. 1791. Chama citrea Gmelin, Syst. Nat., vol. 6, p. 3305. 1871. Chama gryphoides (ex parte) Linnaeus, Dillwyn, A Descriptive Cata- logue of Recent Shells, p. 221. 1819. Chama lazarus Linnaeus, Lamarck, An. sans Vert., vol. 6, p. 93. Not of Linnaeus. 1835. Chama lazarus Linnaeus, Deshayes, An. sans Vert., ed. 2, vol. 6, p. 579. Not of Linnaeus. 1843. Chama macrophylla Gmelin, Hanley, An Illustrated and Descriptive Catalogue of Recent Bivalve Shells, p. 226. 1846. Chama macrophylla Gmelin, Reeve, Conch. Icon., vol. 4, Chama, pl. 2, sp. 6; pl. 8, sp. 6b. 1853. Chama macrophylla Gmelin, d’Orbigny, [in] La Sagra, Hist. phys., polit. et. nat. de ’Ile de Cuba, Mollusques, vol. 2, p. 363. 1864. Chama macrophylla Gmelin, Krebs, The West Indian Marine Shells, p. 117. 1864. Chama macrophylla Chemnitz, Guppy, Sci. Assoc. Trinidad, Trans., p. 36. 1871. Chama macrophylla Gmelin, Coues, Acad. Nat. Sci. Philadelphia, Proc., vol. 23, p. 134. 1872. 1873. 1878. 1878. 1881. 1889. 1889. 1889. 1891. 1895. 1901. 1903. 1907. 1916. 1917. 1920. 1919. 1925. 1926. 1933. 1934. 1935. 1936. 1936. 1937. 1938. 1938. 1938. 1939. VENEZUELAN CENOZOIC PELECYPODS: WEISBORD 239 Chama macrophylla Chemnitz, Tryon, Acad. Nat. Sci. Philadelphia, Proc., vol. 24, p. 118. Chama macrophylla Gmelin, Gabb, Amer. Philos. Soc., Trans., new ser., vol. 15, pp. 251, 259. Chama macrophylla Chemnitz, Arango y Molina, Contribucién a la Fauna Malacolégica Cubana, p. 272. Chama macrophylla Gmelin, Mérch, Catalogue of West-India Shells, p: 15: Chama macrophylla Gmelin, Gabb, Acad. Nat. Sci. Philadelphia, Jour., ser. 2, vol. 8, p. 375. Chama macrophylla Chemnitz, Clessin, Syst. Conchylien-Cabinet, vol. 8, pt. 5, pp. 17-18, pl. 2, figs. 1-2. Chama macrophylla Gmelin, Lorié, Samml. Geol. Reichs-Mus. Leiden, ser. 2, vol. 1, pp. 122, 141. Chama macrophylla Gmelin, Simpson, Davenport Acad. Nat. Sci., Proc., vol. 5, p. 65. Chama macrophylla Gmelin, Baker, Acad. Nat. Sci. Philadelphia, Proc., vol. 43, p. 47. Chama macrophylla Chemnitz, Gregory, Geol. Soc. London, Quart. Jour., vol. 51, p. 292. Chama macrophylla Gmelin, Dall and Simpson, U. S. Fish Com., Bull., vol. 20 for 1900, pt. 1, p. 495. Chama macerophylla Gmelin, Dall, Wagner Free Inst. Sci., Trans., vol. 3, pt. 6, pp. 1403-1404. Chama macrophylla Gmelin, Verrill, Connecticut Acad. Arts and Sci., Trans., vol. 12, p. 347, pl. 35b, figs. 4, 4a. Chama macrophylla Gmelin, Thiele, Zool. Jahrb., Suppl. 11, p. 129. Chama macerophylla Chemnitz, Lamy, Mus. Nat. Hist. nat. Paris, Bull., vol. 23, No. 3, p. 202. Chama macerophylla Gmelin, Maury, Bull. Amer. Paleont., vol. 8, No. 34, p. 81. Chama macerophylla Gmelin, Odhner, K. Svenska Vetenskapsakademien Handligar, vol. 59, No. 3, pp. 10, 78, 79, 81, pl. 4, fig. 1. Chama macerophylla Gmelin, Woodring, Carnegie Inst. Washington, Publ. No. 366, pp. 104-105, pl. 12, figs. 18-19. Chama macerophylla Gmelin, Weisbord, Nautilus, vol. 39, No. 3, p. 83. Chama macrophylla Chemnitz, Trechmann, Geol. Mag., vol. 70, No. 823, p35. Chama macerophylla Gmelin, Johnson, Boston Soc. Nat. Hist., Proc., vol. 40, No. 1, p. 38. Chama macerophylla Gmelin, Richards, Jour. Paleont., vol. 9, No. 3, p. 256. Chama macerophylla Gmelin, Lermond, Check List of Florida Marine Shells, Gulfport, p. 8. Chama macerophylla Gmelin, McLean, Soc. Cubana Hist. Nat. “Felipe Poey,” Mem., vol. 10, No. 1, p. 41. Chama macerophylla Gmelin, Smith, East Coast Marine Shells, p. 44, pl. 14, fig. 2. Chama macerophylla Gmelin, Pilsbry and McGinty, Nautilus, vol. 51, No. 3, p. 75, pl. 7, figs. 2, 8. Chama macerophylla Gmelin, Pilsbry, Nautilus, vol. 51, No. 4, p. 143. Chama macerophylla Gmelin, Richards, Geol. Soc. Amer., Bull., vol. 49, pt. 2, p. 1291. Chama macerophylla Gmelin, Bartsch and Rehder, Smithsonian Misc. Collections, vol. 98, No. 10, p. 18. 240 BuLLETIN 204 1942. Chama macerophylla Gmelin, Jaume and Pérez Farfante, Soc. Cubana Hist. Nat. “Felipe Poey,” Mem., vol. 16, No. 1, p. 39. 1943. Chama macerophylla Gmelin, Bayer, Nautilus, vol. 56, No. 4, pp. 117, 119-120, pl. 13, fig. 12. 1945. Chama macrophylla Gmelin, van Bentham Jutting, Geolog.-Mijnbouwk. Genootschap Nederland en Kolonien, Geol. ser., vol. 14, p. 77. 1946. Chama macerophylla Gmelin, Jaume, Soc. Malac. “Carlos de La Torre,” Rev., vol. 4, No. 3, p. 99. 1951. Chama macerophylla Gmelin, McLean, New York Acad. Sci. Scientific Survey of Porto Rico and the Virgin Islands, vol. 17, pt. 1, p. 55, pl. 11, fig. 1. 1954. Chama macerophylla Gmelin, Abbott, American Seashells, p. 392, pl. 37b; fig. 79b. 1955. Chama macerophylla Gmelin, Perry and Schwengel, Marine Shells of the Western Coast of Florida, p. 62, pl. 10, fig. 60. 1958. Chama macerophylla Gmelin, Olsson and McGinty, Bull. Amer. Paleont., vol. 39, No. 177, p. 21. 1959. Chama macerophylla Gmelin, Nowell-Usticke, A Check List of the Marine Shells of St. Croix, p. 12. 1959. Chama macrophylla Gmelin, Rodriguez, Bull. Marine Sci. of the Gulf and Caribbean, vol. 9, No. 3, p. 277. 1961. Chama (Chama) macerophylla Gmelin, van Retgeren Altena, Koninkl. Nederl. Wetensch.-Amsterdam, Proc., ser. B, vol. No. 2, p. 300. 1961. Chama macerophylla Gmelin, Warmke and Abbott, Caribbean Seashells, p. 179, pl. 4c; 37b. Several poorly preserved right valves, both Recent and fossil, appear to represent this species. The valves are suborbicular, com- pressed to somewhat convex, with an appressed beak gyrating clock- wise. The external sculpture consists of foliaceous concentric lamellae, the lamellae below the umbo producing broad, arched, and elongated fronds which are axially striate on the upper surface but completely smooth on the under surface. Internally, the margins are denticulate, and the pallial line seems to pass around the anterior muscle scar before joining it at the apex. The two Recent specimens are lemon-yellow on the exterior as well as on the inner margins, but the body cavity is whitish. Dimensions.—Recent specimen A436b, right valve, length 18.9 mm.; width (excluding fronds) 18 mm.; thickness 6.6 mm. Localities —Recent, on beach at Playa Grande Yachting Club, Distrito Federal. One right valve. Recent, on beach southeast of Higuerote, State of Miranda. One right valve. Abisinia formation at W-30, eastern edge of Playa Grande village. Two small night valves, weathered. Playa Grande formation (Maiquetia member) at W-23, north flank of Punta Gorda anticline. One right valve, a juvenile, with neat, fairly regular frills bearing faint axial striae. VENEZUELAN CENOZOIC PELECYPODS: WEISBORD 241 Pliocene about 6 kilometers east of Cumana, State of Sucre (in U.S. National Museum Collection No. 18410). Range and distribution —The living C. macerophylla Gmelin is found in the Western Atlantic from Cape Hatteras, North Carolina, to northern South America where it is commonly associated with C. congregata Conrad. In the Pleistocene, C. macerophylla is re- corded from Florida, Cuba, the Dominican Republic, St. Kitts, Curacao, Barbados, Aruba, and Venezuela. In the Pliocene it was reported by Guppy (1864) from Matura, Trinidad, and by Gabb (1881) from Costa Rica. In Jamaica it occurs in the middle Miocene at Bowden. Remarks.—This species resembles the widespread C. congregata Conrad, but is distinguished from that by the broader, more fron- dose, and axially striate foliations, and by the position of the pallial line which skirts the margin of the anterior muscle scar on C. macerophylla but merges with the margin at the base of the anterior muscle scar on C. congregata. Chama florida Lamarck Pl 332, figs. 3,,4 1819. Chama florida Lamarck, An. sans Vert., vol. 6, pp. 94-95. 1864. Chama florida Lamarck, Krebs, The West Indian Marine Shells, p, 117. 1872. Chama florida Lamarck, Tryon, Acad. Nat. Sci. Philadelphia, Proc., vol. 24, p. 117. 1878. Chama florida Lamarck, Mérch, Catalogue of West-India Shells, p. 15. 1878. Chama florida Lamarck, Arango y Molina, Contribucién a la Fauna Malacolégica Cubana, p. 272. 1889. Chama florida Lamarck, Clessin, Syst. Conchylien-Cabinet, vol. 8, pt. 5, pp. 12-13, pl. 2, fig. 9. 1903. Chama florida Lamarck, Dall, Wagner Free Inst. Sci., Trans., vol. 3, pt. 6, p. 1404. 1917. Chama florida Lamarck, Lamy, Mus. Nat. Hist. nat. Paris, Bull., vol. 23, No. 3, pp. 204-206. 1935. Chama florida Lamarck, Richards, Jour. Paleont., vol. 9, No. 3, p. 256. 1938. Chama florida Lamarck, Pilsbry and McGinty, Nautilus, vol. 51, No. 3, p. 74. 1942. Chama florida Lamarck, Jaume and Pérez Farfante, Soc. Cubana Hist. Nat. “Felipe Poey,” Mem., vol. 16, No. 1, p. 39. 1943. Chama florida Lamarck, Bayer, Nautilus, vol. 56, No. 4, pp. 117, 119, 123, pl. 12, fig. 6. 1945. Chama florida Lamarck, van Bentham Jutting, Geolog.-Mijnbouwk. Gen- ootschap Nederland en Kolonien, Geol. Ser., vol. 14, p. 77. 1958. Chama florida Lamarck, Olsson and McGinty, Bull. Amer. Paleont., vol. INC al7/75 janelle 1959. Chama florida Lamarck, Nowell-Usticke, A Check List of the Marine Shells of St. Croix, p. 12. 1961. Chama florida Lamarck, Warmke and Abbott, Caribbean Seashells, p. 180, pl. 37e. 242 BuLLeTIn 204 The right valves referred to this species are rather small, mod- erately thick, rudely suborbicular, moderately convex to cap-shaped, with the beak prosogyrate, and the apex sometimes bulbous. The exterior is sculptured by concentric rows of short fluted foliaceous lamellae, the flutings rarely marked with faint axial striations. The interior margins are feebly but closely crenulate near the rim, and the pallial line skirts past the margin of the anterior adductor scar, joining the scar at the top. The interior is white, on some specimens stained with pink. On the exterior, the ground is white and the apex flushed a deep pink, with several deep pink interrupted radii swirl- ing off the apex on to the disk. Dimensions—Specimen A66la, right valve, length 15 mm.; width 13 mm., thickness 5.3 mm. Locality—Recent, on beach at Playa Grande Yachting Club, Distrito Federal. Five right valves. Range and distribution—The living shell ranges from south Florida to northern South America. As a fossil, the species has been reported from the Pleistocene of Cuba, and on the islands of Blan- quilla and Cubagua, Venezuela. Remarks.—According to Bayer (1943, Nautilus, vol. 56, No. 4, p. 117), C. florida Lamarck is separable from C. sarda Reeve by the position of the pallial line. On C. florida the pallial line passes around the end of the anterior adductor scar and joins it at the superior end, whereas on C. sarda the pallial line joins the margin of the scar at the base. Chama sinuosa bermudensis Heilprin Pl. 32, figs. 10, 13 1889. Chama Bermudensis Heilprin, Acad. Nat. Sci. Philadelphia, Proc., vol. 41, p. 141, pl. 8, figs. 1, 1a. 1919. Chama sinuosa bermudensis Heilprin, Odhner, K. Svenska Vetenskap- sakademien Handligar, vol. 59, No. 3, p. 77. 1938. Chama sinuosa bermudensis Heilprin, Pilsbry and McGinty, Nautilus, vol. 51, No. 3, p. 77. 1943. Chama sinuosa bermudensis Heilprin, Bayer, Nautilus, vol. 56, No. 4, pp. 118, 122, 123, pl. 14, fig. 26. The fossil shell referred to this subspecies is large, robust, and inequivalve. Left (lower) valve deep, oblong-oval to suborbicular, with an erect cornucopia-like beak gyrating counterclockwise, the right (upper) valve convex to compressed, rudely orbicular, the VENEZUELAN CENOzoIC PELECYPODS: WEISBORD 243 beak prosogyrate, the umbo moderately full to appressed, both valves with a faint radial depression fore and aft. External sculpture consisting of foliaceous concentric lamellae arched into hood-shaped fronds or ruffles, the fronds axially striate and in places produced into vaulted scales or flutings. The sculpture is better preserved and sharper on the upper valve as the lower valve is generally encrusted with a calcareous material. In the interior, the adductor scars are large and slightly arcuate, the anterior one merging into the cardinal process, the posterior one ending below the marginal tooth of the hinge plate. The margins of the valve are completely smooth. The pallial line joins the outer margin of the anterior adductor scar near the base. Dimensions.—Specimen C438a, left valve, height 61 mm.; width 52 mm.; thickness 23 mm. Specimen C438b, right valve, height 40 mm.; width 41 mm.; thickness 9 mm. Largest specimen, left valve, beak decollate, height 78 mm.; width 57 mm.; thickness 36 mm. Locahties—La Salina, west of Puerto Cabello, State of Cara- bobo. Four left valves, two right valves. Abisinia formation at W-30, eastern edge of Playa Grande village. A worn and broken right valve is doubtfully identified as this subspecies. Range and distribution.—Living in Bermuda, south Florida, the Tortugas, and the Caribbean. Pseudochama radians (Lamarck) Pl. 33, figs. 5, 6; Pl. 34, figs. 1-6 1819. Chama radians Lamarck, An. sans Vert., vol. 6, p. 96. Refers to Chem- nitz, 1786, Syst. Conchylien-Cabinet, vol. 9, p. 145, pl. 116. 1846. Chama ferruginea Reeve, Conch. Icon., vol. 4, Chama, pl. 4, sp. 21. 1847. Chama variegata Reeve, Zool. Soc. London, Proc., vol. 14, p. 118. 1864. Chama ferruginea Reeve, C. radians Lamarck, and C. variegata Reeve, Krebs, The West Indian Marine Shells, pp. 117, 118. 1872. Chama radians Lamarck, Tryon, Acad. Nat. Sci. Philadelphia, Proc., vol. 24, p. 11g. 1878. Chama ferruginea Reeve, Mérch, Catalogue of West-India Shells, p. 15. 1889. Chama ferruginea Reeve, Clessin, Syst. Conchylien-Cabinet, vol. 8, pt. 5, pp. 22-23, pl. 9, fig. 5. 1903. Chama ferruginea Reeve and C. variegata Reeve, Dall, Wagner Free Inst. Sci., Trans., vol. 3, pt. 6, p. 1404. 1917. Chama radians Lamarck, Lamy, Mus. Nat. Hist. nat. Paris, Bull., vol. 23, No. 4, p. 266. 1919. Pseudochama ferruginea (Reeve), Odhner, K. Svenska Vetenskapsaka- demien Handligar, vol. 59, No. 3, pp. 39-42, pl. 1, figs. 7-8; pl. 4, figs. 38-39; pl. 5, figs. 40-45; also pp. 15, 16, 66, 74, 80, 81, 93. 244 BuLLeTIN 204 1936. Chama variegata Reeve, Lermond, Check List of Florida Marine Shells, Gulfport, p. 8. 1938. Pseudochama radians (Lamarck), Pilsbry and McGinty, Nautilus, vol. 51, No. 3, pp. 77-78. 1943. Pseudochama radians variegata (Reeve), Bayer, Nautilus, vol. 56, No. 4, pl. 12, fig. 4. 1951. Pseudochama radians (Lamarck), P. radians ferruginea (Reeve), and P. r. variegata (Reeve), McLean, New York Acad. Sci. Scientific Survey of Porto Rico and the Virgin Islands, vol. 17, pt. 1, p. 56, pl. 11, figs. 5-6. 1954. Pseudochama radians (Lamarck), Abbott, American Seashells, p. 393, fig. 79c, pl. 37c. 1955. Pseudochama radians variegata (Reeve), Perry and Schwengel, Marine Shells of the Western Coast of Florida, p. 62, pl, 10. fig. 61. 1958. Pseudochama radians (Lamarck), Olsson and McGinty, Bull. Amer. Paleont., vol. 39, No. 177, p. 21. 1958. Pseudochama radians (Lamarck), Moore, Nautilus, vol. 71, No. 4, p. 128. 1959. Pseudochama radians ferruginea (Reeve) and P. r. variegata (Reeve), Nowell-Usticke, A Check List of the Marine Shells of St. Croix, p. 12. 1961. Pseudochama radians (Lamarck), Warmke and Abbott, Caribbean Sea- shells, p. 180, pl. 37c. Shell of medium size, inequivalve. Right (lower) valve deep, suborbicular to subtrigonally ovate, attached by the anterior half of the shell which is flattened in greater or less degree over a cres- centic area from beak to base; left (upper) valve suborbicular or suboval, compressed. Beak of right valve gryphaeaform, gyrating clockwise; beak of left valve appressed, slightly prosogyrate. The external sculpture of the right valve is variable although all of the Playa Grande specimens are both concentrically lamellate and radially ridged on the posterior part of the shell. On three right valves the short vermiform axial ridges occur on the posterior fourth of the valve, but on another specimen these ridges are present on the posterior half of the valve, and on this specimen there are also some irregular foliations anteriorly. The concentric lamellae of the right valve are simple to frilled to fluted, and on one specimen some of the flutings project as arched spines. The external sculpture of the single left valve consists of minutely foliaceous concentric lamellae becoming incremental toward the base. On the interior, three single left valves are denticulate at the margin, but both valves of a paired specimen (A662al-2) are smooth (except for occasional tiny pustules) even though this specimen seems to belong to the same species as the denticulate ones. The pallial line joins the base of the anterior muscle scar at the outer margin, but posteriorly it swings in to join the base of the anterior muscle scar at the outer VENEZUELAN CENOzoIcC PELECYPODS: WEISBORD 245 margin. The anterior cardinal tooth of the right valve is large, curved upward a little at the edge, and is striate on the upper surface; the posterior cardinal tooth of the right valve is arcuate and is also scored by a series of short grooves. The interior of both valves is generally white with a staining of mahogany-brown at the margin, but the whole interior of one right valve is mahogany- brown with blotches of white. The exterior of the left valve is whitish with short stripes of brown on the lower half; the exterior of the right valve is dirty white, and brown or dull purplish red. Dimensions.—Specimen A662al1-2 (paired), right valve, height 31.5 mm.; width 27.3 mm.; thickness 17.1 mm.; left valve, height 23.6 mm.; width 27.5 mm.; thickness 5 mm. Specimen A662b, right valve, height 21.5 mm.; width 21.5 mm.; thickness 12 mm. Specimen A662c, right valve, height 20 mm.; width 18.3 mm.; thickness 6.8 mm. Specimen D439a, right valve, height 50 mm.; width 39.5 mm.; thickness 33 mm. Specimen D439b, left valve, height 33 mm.; width 33 mm.; thickness 10 mm. Localities —Recent, on beach at Playa Grande Yachting Club, Distrito Federal. Four specimens including three right valves and one doublet, Abisinia formation at W-30, eastern edge of Playa Grande Village. Six worn or broken specimens, including five left valves and one right valve. Range and distribution.—Living in shallow water from south Florida to northern South America. This is the first report of its occurrence as a fossil. Remarks.—The forms P. ferruginea (Reeve) and P. variegata (Reeve) are considered ecological variants of P. radians by some authors but as a subspecies of P. radians by others. The Recent Playa Grande shells, which were collected near each other on the beach, exhibit considerable variation, and partake in one way or another of the characters of P. radians radians, of P. r. ferruginea, and of P. r. variegata. Specimen D440a from the Abisinia formation represented by figures 5, 6 on Plate 34, and identified with uncertainty as P. radians Lamarck, may be yet another individual variant of the species. The details are obscure but the worn and immature speci- men is inferred to be a right valve. The shell is small, shield-shaped in outline and tentlike in cross section, with a high medial ridge 246 BULLETIN 204 from beak to base from which the sides slope steeply, the an- terior slope straightish, the posterior concave. The turn of the beak is not defined but it seems to be incipiently clockwise. The anterior slope is nondescript and gnarly, and probably was the attached sur- face. The medial ridge and posterior half of the valve are sculptured by a few coarse concentric lamellae corrugated into short vermiform radial ridgelets and flutings, the termini of the flutings near the base and along the ridge projecting in places as arched spines. In the interior there is a deep linear trough under the ridge, and the entire margin of the valve is rather strongly denticulate. The muscle scars are obscure and the hinge is badly worn. The length of speci- men D440a is 12.6 mm., the maximum width 10 mm., and the eleva- tion or thickness 7.1 mm. Pseudochama ? species PL 34; fisss 2S Illustrated is an immature left valve referred with some doubt to the genus Pseudochama. The shell is small, compressed, and obliquely ovate, with a smooth plump subcircular prodissoconch facing toward the anterior. Starting at the base of the prodissoconch and extending to the base there is a low arcuate ridge with a fairly broad and gentle depression in front of it and a narrow depression behind it. The anterior half or so of the valve is sculptured by gnarly, irregular, and rather thick concentric foliations which are cordlike to gently arched on the ridge and angulately arched on the posterior quarter of the valve. In the interior the margins are smoothed, and the anterior adductor impression is long and fairly narrow. The heavy hinge apparatus is worn, and the cardinal process, which is recurved upward, appears bilobate; underneath the cardinal lobes, the anterior socket is relatively long and narrow, the posterior socket relatively high and narrow. The pallial line and posterior adductor impression are obliterated. Dimensions.—Specimen D508a, left valve, height 8 mm.; width 6 mm.; thickness 0.8 mm. Locality.—Abisinia formation at W-30, eastern edge of Playa Grande village. One left valve. Remarks—As most fossils occurring in the Pleistocene(?) Abisinia formation have survived to the Recent, this form may be VENEZUELAN CENOzoIC PELECYPOoDS: WEISBORD 247 living to-day. There are two living species of Psewdochama in the Western Atlantic, P. radians (Lamarck), and P. inezae Bayer (1943, Nautilus, vol. 56, No. 4, pp. 118, 122-123, pl. 15), and although it is possible that the single Cabo Blanco shell is a juvenile of the former, a grading series of specimens is needed in order to make a definitive comparison. Arcinella species “a” Pl. 34, figs. 9, 10 Included in the Cabo Blanco collection are two fragments of Echinochama. One of the fragments is part of a left valve, the other the apical area of a right valve. The left valve, here described, represents the back remnant of a shell which in some curious way was split through the beak and hinge parallel with the margins of the disk, thus producing the anomalous-looking smooth decklike hinge shown in the illustration. The surface is sculptured by narrow, scaly, arcuate and wavy radial ridges. On the sole specimen, which is broken away at the margins, there are seven primary ridges re- maining, and of these the anteriormost seems the largest. Between the primaries there are one to six minor ridges alternating in size, the number of secondaries increasing anteriorward, the greatest number lying between the two anterior primary ridges where the intercostal area is considerably wider than elsewhere on the disk. The scales, which occur in fairly numerous irregular rows, are in the form of rounded to angular vaulted arches, and become longer and semitubular toward the margins. The grater-like texture of the E. arcinella race is not evident except minutely in a small area between the scales on the anteroventral portion of the valve. Dimensions —Specimen T442a, a partial left valve, height 16 mm.; width 12 mm. Locahty.—Upper Mare formation, in stream 250 meters south- southwest of mouth of Quebrada Las Pailas. One left valve, broken. Remarks.—It is impossible to classify this fragment with assur- ance. Of the American species of Echinochama discussed by Nicol (1952), it seems, in a subdued way, to resemble FE. arcinella olssoni Nicol (1952, Jour. Paleont., vol. 26, No. 5, pp. 807-808, pl. 118, fig. 6) from the Armuelles formation (Pleistocene or Pliocene) of the Burica Peninsula, Panama. 248 BuL.etTIn 204 Arcinella species ‘“‘b” Pl. 34, figs. 11-13 The following description pertains to a right valve with only the thick apical area remaining. On the apical area, the outer shell has been peeled away, but part of the hinge and lunule are intact. The beak is prosogyrate and flattened on the anterior side from attachment. A wide shallow sulcus is present aft of the beak, and this probably extends to the posteroventral margin of the valve. The lunule is large, sunken, semicircular, and coarsely nodular, the nodules crossed by fine concentric laminae which become incre- mental at the margin of the hinge. The outer layer of shell is strip- ped off the surface, but from the configuration of the intermediate layer, which is corrugated by six or seven low radial folds on the anterior two-thirds of the disk, it is inferred that a whole valve bears eight or nine, probably spiny, radial ribs. The intermediate layer of shell is traversed by subequal radial threads crossed by closely spaced microscopic concentric striae which tend to be arched upward in the interspaces between the radial threads. The ligamental groove is opisthodetic, parivincular, and deep. The cardinal tooth is large, strong, and upswept, is scored by heavy grooves on the inner surface, and bears fainter ridges and elongated pustules on the superior surface. Dimensions—Specimen G435a, apical fragment of right valve, length 14.2 mm.; width 15 mm.; thickness from umbo to cardinal tooth 10.3 mm. Locality —Mare formation near W-14, on hillside above west bank of Quebrada Mare Abajo. One fragment of a right valve. Remarks.—The hinge and lunular area are virtually identical to E. cornuta (Conrad) (see Nicol, 1952, Jour. Paleont., vol. 26, No. 5, pp. 809-810, pl. 118, fig. 2; pl. 119, fig. 7), and the postulated number of external ribs also agrees with that Miocene to Recent species. However, whether the true surface ornamentation is com- parable to that of E. cornuta is, of course, undeterminable. And, whether this specimen represents that opposite valve of the pre- ceding-described Echinochama sp. “a” is likewise unknown. ERYCINIDAE Bornia tacaguana, new species Pl. 31, figs. 9, 10 VENEZUELAN CENOzoIC PELECYPops: WEISBORD 249 Shell small, thin, subtranslucent, subequilateral, the outline rounded-subtrigonal and _ subisocelene, the anterior submargin slightly compressed. Anterior and posterior ends a little rounded, the ventral margin shallowly and regularly arcuate. Beak small, mod- erately prominent, directed forward, subcentral. Resilial pit fairly deep, narrowly triangular, the base of the resilifer arched slightly upward. Anterior lamella in hinge of right valve joined to the dorsal margin at the beak, thickened immediately below the beak, but then thinning as it swerves toward the distal end of the anterodorsal margin with which it merges just below the rim of the valve, the groove between the lamella and rim linear. The posterior lamella of the right valve is not so strong as the anterior below the beak, and the groove between it and the posterodorsal margin is a little longer, though feebler, than its anterior counterpart. External sur- face sculptured by fine subregular concentric lineations which are visible in the interior. Inner margins smooth. Adductor scars and pallial line not visible in the highly polished interior. Dimensions—Holotype (T548a), right valve, width 3.4 mm.; height 3.1 mm.; thickness 0.5 mm. Type locality —Mare formation, in stream 250 meters south- southwest of the mouth of Quebrada Las Pailas. One right valve, the holotype. Comparisons——Similar species are the following: B. triangula Dall (see Gardner, 1943, U. S. Geol. Sur., Prof. Paper 199-A, pp. 82-83, pl. 14, figs. 2-5, 10). Upper Miocene and Pliocene, Maryland to Florida, U.S.A. This is more sharply triangu- lar than B. tacaguana, n. sp. B. mactroides (Conrad) (see Glenn, 1904, Maryland Geol. Sur., Miocene, p. 330, pl. 88, figs. 9a, 9b). Later Miocene of Mary- land. This is a somewhat more rounded and sturdier shell than B. tacaguana. B. longipes (Stimpson) (see Dall, 1899, U. S. Nat. Mus., Proc., vol. 21, No. 1177, pp. 888-889, pl. 88, figs. 10, 11, 13). Recent in the Western Atlantic. The height is 70 per cent of the width, whereas in C. tacaguana the height is 80 percent. B. barbadensis Dall (1899. U. S. Nat. Mus., Proc., vol. 21, No. 1177, p. 888). This is a large, evenly ovate, and inequilateral shell, dredged in 100 fathoms at Barbados. 250 BuLLeETIN 204 B. chiclaya Olsson (1961, Panamic-Pacific Pelecypoda, 233, pl. 35, fig. 13). Recent in the Eastern Pacific on the coast of Peru. This has much the same outline as B. tacaguana, n. sp. but is a somewhat larger and slightly more inflated shell, with a truncate rather than shallowly rounded basal margin. CARDIIDAE Trachycardium (Dallocardia) muricatum (Linnaeus) Pl. 35, figs. 1-8 1758. 1767. 1782. 1792. 1798. 1818. 1843. 1844. 1845. 1854. 1860. 1864. 1867. 1871. 1874. 1878. 1878. 1881. 1884. 1886. 1889. 1889. 1889. 1891. 1892. Cardium muricatum Linnaeus, Syst. Nat. ed. 10, p. 680, No. 69. Cardium muricatum Linnaeus, Syst. Nat., ed. 12, p. 1123, No. 85. Cardium muricatum Linnaeus, Chemnitz, Syst. Conchylien-Cabinet, vol. 6, p. 186, pl. 17, fig. 178. Cardium muricatum Linnaeus, Bruguiére, Encycl. Méth., vol. 1, p. 233, pl. 297, fig. 1. Cardium campechiense Réding, Museum Boltenianum, p. 191, No. 407. Cardium muricatum Linnaeus, Lamarck, An. sans Vert., vol. 6, p. 8. Cardium muricatum Linnaeus, d’ Orbigny, Voyage dans ’PAmérique Meri- dionale, vol. 3, Mollusques, p. 591. Cardium muricatum Linnaeus, Reeve, Conch. Icon., vol. 2, Cardium, sp. 33. Cardium muricatum Linnaeus, d’Orbigny, [in] La Sagra, Hist. Fis., Polit., y Nat. Isla de Cuba, vol. 5, Moluscos, p. 335. Cardium Gossei Deshayes, Zool. Soc. London, Proc., p. 330. Cardium muricatum Linnaeus, Holmes, Post- Pleiocene Fossils of South Carolina, p. 24, pl 5, fig. 3. Cardium muricatum Linnaeus, Krebs, The West Indian Marine Shells, p. 116. Cardium muricatum Linnaeus, Guppy, Sci. Assoc. Trinidad, Proc., pt. 35 Ps 205. Cardium muricatum Linnaeus, Coues, Acad. Nat. Sci. Philadelphia, Proc., VOlnzs saps 50. Cardium muricatum Linnaeus, Guppy, Geol. Mag., decade 2, vol. 1, p. 442. Cardium muricatum Linnaeus, Morch, Catalogue of West-India Shells, De 5: Cardium muricatum Linnaeus, Arango y Molina, Contribucién al la Fauna Malacolégica Cubana, p. 259. Cardium (Trachycardium) muricatum Linnaeus, Gabb, Acad. Nat. Sci. Philadelphia, Jour., ser. 2, vol. 8, p. 374. Cardium (Trachycardium) muricatum Linnaeus, Tryon, Structural and Systematic Conchology, vol. 3, p. 193, pl. 116, figs. 72-74. Cardium muricatum Linnaeus, Dall, Mus. Comp. Zool., Bull., vol. 12, No. 6, p. 270. Cardium muricatum Linnaeus, Lorié, Samml. Geol. Reichs-Mus. Leiden, Ser. i2,uv0l ly pps l2550141 pl. 2). fiona Cardium muricatum Linnaeus, Simpson, Davenport Acad. Nat. Sci, Proc, vol. 5, p. 65. Cardium muricatum Linnaeus, Dall, U. S. Nat. Mus., Bull. 37, p. 52. Cardium muricatum Linnaeus, Baker, Acad. Nat. Sci. Philadelphia, Proc., vol. 43, p. 47. Cardium muricatum Linnaeus, Singley, Geol. Sur. Texas, Fourth An. Rept., p. 327. 1896. 1900. 1901. 1901. 1903. 1913. 1920. 1925. 1930. 1934 1934. 1935. 1936. 1936. 1936. 1936. 1937. 1938. 1939. 1939. 1940. 1942. 1943. 1944. 1944. 1945. 1946. 1946. 1946. 1949. VENEZUELAN CENozoIc PELECYPODS: WEISBORD 25 Cardium maricatum [sic] Linnaeus, Sapper, Inst. Geol. México, Bol. No. 35 pag: Cardium (Trachycardium) muricatum Linnaeus, Dall, Wagner Free Inst. Sci., Trans., vol. 3, pt. 5, pp. 1089-1090. Cardium (Trachycardium) muricatum Linnaeus, Dall and Simpson, U. S. Fish Com., Bull., vol. 20 for 1900, pt. 1, pp. 487-488. Cardium (Tachycardium) muricatum Linnaeus, Dall, U. S. Nat. Mus., Proc., vol. 23, No. 1214, pp. 385-386. Cardium muricatum Linnaeus, Vanatta, Acad. Nat. Sci. Philadelphia, Proc., vol. 55, p. 757. Cardium muricatum Linnaeus, Jenkins, Amer. Philos. Soc., Proc., vol. 52, No. 211, p. 457. Cardium (Trachycardium) muricatum Linnaeus, Maury, Bull. Amer. Paleont., vol. 8, No. 34, pp. 94-95. Cardium (Trachycardium) muricatum Linnaeus, Maury, Bull. Amer. Paleont., vol. 10, No. 42, pp. 279-280, pl. 22, fig. 9. Trachycardium (Dallocardia) muricatum (Linnaeus), Stewart, Acad. Nat. Sci. Philadelphia, Spec. Publ. No. 3, p. 264. Cardium (Trachycardium) muricatum Linnaeus, Johnson, Boston Soc. Nat. Hist., Proc., vol. 40, No. 1, p. 45. Cardium (Trachycardium) muricatum Linnaeus, Maury, Amer. Mus. Nat. Hist., Bull., vol. 67, art. 4, pp. 162-163, pl. 18, fig. 4. Cardium muricatum Linnaeus, Richards, Jour. Paleont., vol. 9, No. 3, p. 256. Cardium (Trachycardium) muricatum Linnaeus, McLean, Soc. Cubana Hist. Nat. “Felipe Poey,” Mem., vol. 10, No. 1, p. 41. Cardium muricatum Linnaeus, ‘McLean, Nautilus, vol. 49, No. 4, p. 118. Cardium muricatum Linnaeus, Richards, Nautilus, vol. 49, No. 4, p. 133. Cardium muricatum Linnaeus, Lermond, Check List of Florida Marine Shells, Gulfport, p. 6. Cardium (Trachycardium) muricatum Linnaeus, Smith, East Coast Marine Shells, p. 49, pl. 17, fig. 1. Cardium muricatum Linnaeus, Richards, Geol. Soc. Amer., Bull., vol. 49, p. 1291. Cardium muricatum Linnaeus, Mansfield, State of Florida Dept. Conserv., Geol. Bull. No. 18, pp. 38, 39. Cardium (Trachycardium) muricatum Linnaeus, McLean, Soc. Cubana Hist. Nat. “Felipe Poey,’ Mem., vol. 13, No. 3, pp. 160-161, pl. 23, figs. 5-7. Cardium muricatum Linnaeus, Stenzel, Nautilus, vol. 54, No. 1, p. 21. Cardium muricatum Linnaeus, Jaume and Pérez Farfante, Soc. Cubana Hist. Nat. “Felipe Poey,” Mem., vol. 16, No. 1, p. 39. Trachycardium muricatum (Linnaeus), Gardner, U. S. Geol. Surv., Prof. Paper 199-A, pp. 92-93, pl. 15, fig. 21. Trachycardium muricatum (Linnaeus), Hackney, Nautilus, vol. 58, No. 2, p. 58. Trachycardium (Dallocardia) muricatum (Linnaeus), Clench and Smith, Johnsonia, vol. 1, No. 13, pp. 7-9, pls. 1 and 5. Laevicardium muricatum (Linnaeus), van Bentham Jutting, Geol.-Mijn- bouwk. Genootschap Nederland en Kolonien, Geol. ser., vol. 14, p. 77. Cardium muricatum Linnaeus, Stewart, Nautilus, vol. 60, No. 1, p. 19. Trachycardium (Dallocardia) muricatum (Linnaeus), Jaume, Soc. Malac. “Carlos de La Torre,” Rev., vol. 4, No. 3, p. 100. Cardium (Dallocardia) muricatum Linnaeus, Hertlein and Strong, Zoo- logica, vol. 31, pt. 3, No. 10, p. 148. Cardium (Trachycardium) muricatum Linnaeus, Lange de Morretes, Mus. Paranaense, Arq., vol. 7, art. 1, p. 35. 252 BuLLeTIN 204 1951. Cardium (Trachycardium) muricatum Linnaeus, McLean, New York Acad. Sci. Scientific Survey of Porto Rico and the Virgin Islands, vol. 17, pt. 1, pp. 70-71, pl. 14, fig. 3. 1952. Trachycardium muricatum (Linnaeus), Pulley, Texas Jour. Sci., vol. 4, No. 2, p. 182, pl. 10, figs. 7-8. 1952. Cardium muricatum Linnaeus, Dodge, Amer. Mus. Nat. Hist., Bull., vol. 100, art. 1, pp. 60-61. 1953. Cardium (Trachycardium) muricatum Linnaeus, Olsson and Harbison, Acad. Nat. Sci. Philadelphia, Mon. No. 8, p. 101, pl. 10, fig. 4. 1953. Laevicardium (Trachycardium) muricatum (Linnaeus), Haas, Fieldi- ana-Zoology, vol. 34, No. 20, p. 203. 1954. Trachycardium muricatum (Linnaeus), Abbott, American Seashells, p. 397, pl. 39p. 1955. Trachycardium muricatum (Linnaeus), Perry and Schwengel, Marine Shells of the Western Coast of Florida, p. 67, pl. 12, fig. 72. 1956. Trachycardium muricatum (Linnaeus), Parker, Amer. Assoc. Petrol. Geol., Bull., vol. 40, No. 2, pp. 309, 316, 318, 331, 353, 371, pl. 4, figs. 15a, 15b. 1958. Trachycardium muricatum (Linnaeus), DuBar, Florida Geol. Sur., Geol. Bull. No. 40, p. 171. 1958. Trachycardium muricatum (Linnaeus), Olsson and McGinty, Bull. Amer. Paleont., vol. 39, No. 177, p. 21. 1959. Trachycardium muricatum (Linnaeus), Parker, Amer. Assoc. Petrol. Geol., Bull., vol. 43, No. 9, pp. 2125, 2129, 2162, 2165, pl. 2(VI), figs. 12a, 12b. 1959. Trachycardium muricatum (Linnaeus), Nowell-Usticke, A Check List of the Marine Shells of St. Croix, p. 13. 1961. Trachycardium muricatum (iasnaeuy) Warmke and Abbott, Caribbean Seashells, p. 182, pl. 37m. This species occurs both living and as a fossil in northern Vene- zuela. The Recent shells from Playa Grande (Distrito Federal) and Higuerote (State of Miranda) are broadly rayed in the interior from under the umbo to near the middle of the valve by generally three broad contiguous bands of color, the middle band golden yellow, the outer two violet or purplish red. There are 39 to 44 radial ribs on the Recent specimens, 38 on the largest fossil. The arrangement and pattern of the denticulate scales on adult examples are in ac- cordance with the description by Dall (1900, p. 1080) and the illus- trations by Clench and Smith (1944, pl. 5). Dimensions.—Recent specimen (A498a), right valve, height 30 mm.; width 29 mm.; thickness 11.2 mm. Recent specimen (A498b), left valve, height 28.8 mm.; width 27.9 mm.; thickness 11 mm. Fossil specimen (C503a), right valve broken away at base, width 15 mm.; thickness 5.5 mm. Fossil specimen (C504a), fragment of left valve, width of fragment 9 mm.; thickness 3.1 mm. Fossil specimen (H498a), right valve, height 48 mm., width 44 mm.; thickness 15 VENEZUELAN CENOzoIC PELECYPODS: WEISBORD 253 mm. Fossil specimen (1498a), juvenile left valve, height 4.7 mm.; width 5 mm.; thickness 1.5 mm. Localities——Recent, on beach at Playa Grande Yachting Club, Distrito Federal. Ten specimens including seven right valves and three left valves. Recent, on beach southeast of Higuerote, State of Miranda. Eight specimens including four right and four left valves. La Salina, west of Puerto Cabello, State of Carabobo. Two speci- mens, one a right valve, the other a fragment of a left. Mare forma- tion at W-25, south flank of Punta Gorda anticline. One right valve. Upper Mare formation at W-14, on hillside above west bank of Quebrada Mare Abajo. One left valve. Lower Mare formation at W-13, on hillside above west bank of Quebrada Mare Abajo. One juvenile left valve. Playa Grande formation (Maiquetia member) at W-23, north flank of Punta Gorda anticline. Two fragments, one of a young right valve, and one of an adult left valve. Remarks.—The west American counterpart of 7. muricatum is the Pleistocene to Recent T. senticostwm (Sowerby) (see Olsson, 1961, pp. 246-247, pl. 37, fig. 3), living from the Gulf of California to Peru in depths to 40 fathoms. Range and distribution.—The living T. muricatum is recorded from North Carolina, U.S.A., to Argentina, S.A., the greatest depth 187 fathoms off Havana, Cuba. Pleistocene, in South Carolina, Florida, Louisiana (in borings), Cuba, the Yucatan Peninsula, Aruba?, Curacao, Venezuela, and Brazil. Pliocene, in Florida, the Yucatan Peninsula, Costa Rica, Venezuela (near Cumana, U. S. National Museum Collection No. 18408), and Trinidad?. Trachycardium (Trachycardium) cf. isocardia (Linnaeus) PI. 35, fig. 9; Pl. 36, fig. 1 1758. Cardium isocardia Linnaeus, Syst. Nat., ed. 10, p. 679, No. 66. 1767. Cardium isocardia Linnaeus, Syst. Nat., ed. 12, p. 1122, No. 82. 1782. Cardium isocardia Linnaeus, Chemnitz, Syst. Conchylien-Cabinet, vol. 6, p. 182, pl. 17, figs. 174-176. 1817. Cardium isocardia Linnaeus, Dillwyn, A Descriptive Catalogue of Recent Shells, vol. 1, p. 18. 1845. Cardium isocardia Linnaeus, Reeve, Conch. Icon., vol. 2, Cardium, pl. 17, sp. 84. 1845. Cardium isocardia Linnaeus, d’Orbigny, [in] La Sagra, Hist. Fis., Polit., y Nat. Isla de Cuba, vol. 5, Moluscos, p. 337. 1860. 2Cardium isocardia Linnaeus, Holmes, Post-Pleiocene Fossils of South Carolina, p. 25, pl. 5, fig. 4. 254 1864. 1864. 1871. 1875. 1878. 1878. 1887. 1889. 1891. 1891. 1900. 1901. 1901. 1920. 1923. 1924. 1925. 1926. 1930. 1934. 1936. 1936. 1938. 1939. 1943. 1944. 1945. 1946. 1946. BuLLetTiIn 204 ?Cardium isocardium Linnaeus, Guppy, Sci. Assoc. Trinidad, Trans., pp. 36, 40. Cardium isocardia Linnaeus, Krebs, The West Indian Marine Shells, pp. 115-116. ?Cardium isocardia Linnaeus, Coues, Acad. Nat. Sci. Philadelphia, Proc.,vole 23), p.9135- Cardium eburniferum Guppy, Ann. Mag. Nat. Hist., ser. 4, vol. 15, p. SI plsn7, tiga. Cardium isocardia Linnaeus, Arango y Molina, Contribucién a la Fauna Malacologica Cubana, p. 258. Cardium isocardia Linnaeus, Mérch, Catalogue of West-India Shells, p. 15. Cardium (Trachycardium) isocardia Linnaeus, Fischer, Manuel de Conchyliologie et de Paléontologie Conchyliologique, p. 1037. Cardium isocardia Linnaeus, Dall, U. S. Nat. Mus., Bull. 37, p. 52. Cardium isocardia Linnaeus, Baker, Acad. Nat. Sci. Philadelphia, Proc., vol. 43, p. 47. Cardium isocardia ? Linnaeus, Heiprin, Acad. Nat. Sci. Philadelphia, Proc., vol. 43, p. 143. Cardium (Trachycardium) isocardia Linnaeus, Dall, Wagner Free Inst. Sci.. Trans., vol. 3, pt. 5, p. 1085. Cardium (Trachycardium) isocardia Linnaeus, Dall, U. S. Nat. Mus., Proc., vol. 23, No. 1214, p. 385 (part). Cardium (Trachycardium) isocardia Linnaeus, Dall and Simpson, U. S. Fish Com., Bull., vol. 20 for 1900, pt. 1, p. 488 (part). Cardium (Trachycardium) isocardia Linnaeus, Maury, Bull. Amer. Paleont., vol. 8, No. 34, p. 94 (part). 2Cardium isocardia Linnaeus, Clench, Nautilus, vol. 37, No. 2, p. 55. Cardium isocardia Linnaeus, Mansfield, Florida State Geol. Survey, Fif- teenth An. Rept., list following p. -28. Cardium (Trachycardium) isocardia Linnaeus, Maury, Bull. Amer. Paleont., vol. 10, No. 42, pp. 277-278, pl. 22, figs. 5, 7. Cardium isocardia Linnaeus, Weisbord, Nautilus, vol. 39, No. 3, p. 83. Trachycardium isocardia (Linnaeus), Stewart, Acad. Nat. Sci. Phila- delphia, Spec. Paper No. 3, p. 263. Cardium (Trachycardium) isocardia Linnaeus, Johnson, Boston Soc. Nat. Hist., Proc., vol. 40, No. 1, p. 45 (part). Cardium (Trachycardium) isocardia Linnaeus, McLean, Soc. Cubana Hist. Nat. “Felipe Poey,”’ Mem., vol. 10, No. 3, p. 165. Cardium (Trachycardium) isocardia Linnaeus, Clench and McLean, Soc. Cubana Hist. Nat. “Felipe Poey,” Mem., vol. 10, No. 3, p. 165. Cardium isocardia Linnaeus, Richards, Geol. Soc. Amer., Bull., vol. 49, p. 1291. Cardium (Trachycardium) isocardia isocardia Linnaeus, McLean, Soc. Cubana Hist. Nat. “Felipe Poey,’” Mem., vol. 13, No. 3, p. 159-160, pl. 23, figs. 1-2. Trachycardium isocardia (Linnaeus), Gardner, U. S. Geol. Sur., Prof. Paper 199-A, pp. 91-92 (part). Trachycardium isocardia (Linnaeus),.Clench and Smith, Johnsonia, vol. 1, No. 13, pp. 3-4, pl. 2. Laevicardium isocardia (Linnaeus), van Bentham Jutting, Geolog.-Mijn- bouk. Genootschap Nederland en Kolonien, Geol. ser., vol. 14, p. 77. Trachycardium isocardia (Linnaeus), Jaume, Soc. Malac. “Carlos de La Torre,” Rev., vol. 4, No. 3, p. 100. Cardium (Trachycardium) isocardia Linnaeus, Hertlein and Strong, Zoologica, vol. 31, pt. 3, No. 10, p. 147. VENEZUELAN CENOZzOIC PELECYPODS: WEISBORD 255 1951. Cardium (Trachycardium) isocardia Linnaeus, McLean, New York Acad. Sci. Scientific Survey of Porto Rico and the Virgin Islands, vol. 17tpts 1, ps 70, *ple14, tigs ae 1952. Trachycardium isocardia (Linnaeus), Pulley, Texas Jour. Sci., vol. 4, No. 2, p. 182. 1952. Cardium isocardia Linnaeus, Dodge, Amer. Mus. Nat. Hist., Bull., vol. 100; arts 15p5 59: 1953. Cardium (Trachycardium) isocardia Linnaeus, Olsson and Harbison, Acad. Nat. Sci. Philadelphia, Mon. No. 8, p. 100, pl. 10, fig. 2. 1954. Trachycardium isocardia (Linnaeus), Abbott, American Seashells, p. 397. 1958. Trachycardium isocardia (Linnaeus), DuBar, Florida Geol. Sur., Geol. Bull. No. 40, p. 170. 1958. Trachycardium (Trachycardium) isocardia (Linnaeus), Keen, Sea Shells of Tropical West America, pp. 114-115. 1959. Trachycardium isocardia (Linnaeus), Nowell-Usticke, A Check List of the Marine Shells of St. Croix, p. 13. 1961. Trachycardium isocardia (Linnaeus), van Regteren Altena, Koninkl. Nederl. Akad. Wetens.-Amsterdam, Proc., Ser. B, vol. 64, No. 2, p. 300. 1961. Trachycardium (Trachycardium) isocardia (Linnaeus), Olsson, Pan- amic-Pacific Pelecypoda, p. 245. 1961. Trachycardium isocardia (Linnaeus), Warmke and Abbott, Caribbean Seashells, p. 182, pl. 4d; 37L. A broken right valve of a Cabo Blanco fossil seems referable to this species. The shell is robust, subquadrate, and strongly ribbed, the total number of ribs estimated at 37. Crossing the crest of the ribs over the whole of the exterior are prominent arched scales, the scales asymmetrically vaulted toward the posterior of the valve, with the broad side of the scales on the posterior side of the ribs, the vaulting more symmetrical anteriorly, the arches thickened on the anterior submargin and the base, the ventrad face of the thickened arches upturned. Interspaces deep, somewhat narrower than the ribs, traversed by crowded growth incrementals. Inner margins fluted, the internal ribs lightly grooved along the middle, extending a short distance inward. Anterior adductor impression rather faint, large, high, suboval; posterior adductor not seen. Dimensions.—Specimen $500a, half of a right valve, complete height 66 mm.; thickness 24 mm. Specimen 1499a, a fragment of the base, length 41 mm. Locahties.—Playa Grande formation (Maiquetia member) at W-23, north flank of Punta Gorda anticline. Two specimens, one of them the anterior half of a right valve, the other a large fragment. Lower Mare formation at W-13, on hillside above west bank of Quebrada Mare Abajo. One fragment. Remarks.—So far as comparison can be made, the Cabo Blanco 256 BuLLeTIN 204 fossil appears to be the same as the Recent Caribbean T. tsocardia (Linnaeus). The other Recent Caribbean species of Trachycardiwm is T. egmontianum (Shuttleworth) (see Clench and Smith, 1944, pp. 4-5, pl. 3) but the species, although similar to, and sometimes mistaken for 7. isocardia, has 27 to 31 ribs compared with 31 to 37 on 7’. isocardia. The west American analogue of T. isocardia is the Pleistocene and Recent T. consors (Sowerby) (see Keen, 1958, p. 114, pl. 3), and that is distinguished from 7. isocardia by its fewer ribs (30-34) and more inflated valves. Range and distribution—tThe living T. isocardia (Linnaeus), according to Clench and Smith, is a Caribbean species extending from Hispaniola to northern South America. Other authors would extend the range to Florida and as far north as North Carolina, but in some instances at least, the form so identified must be the long- overlooked 7. egmontianum (Shuttleworth). Nevertheless, the fossil T. isocardia has been reported by competent observers from the Pliocene of North Carolina and Florida, and the Pleistocene of South Carolina, Florida, and Louisiana. In the tropics, T. isocardia was reported by Guppy from the Pliocene of Trinidad (although this has not been confirmed), and Heilprin identified the species with question from the Pliocene of the Yucatan Peninsula, México. In the Pleistocene of the Caribbean area J. tsocardia is recorded from St. Kitts, and Venezuela. Trigoniocardia (Trigoniocardia) caboblanquensis, new species Pl. 35, figs. 10-12; Pl. 36, figs. 2-6 Shell small, subrhomboidal, inflated, slightly oblique. Anterior end gently rounded, ventral margin shallowly arcuate to subtruncate, posterior margin almost vertically truncate, the corner of the base and posterior margin subangular, the angle a little more than 90 degrees. Posterior area fairly wide, strongly sloping, flattened to hardly concave, the umbonal ridge prominent and well different- iated. Umbo high, the beak evenly convex, incurved, prosogyrate, subcentral. Lunule small, subcordate, rather well defined, not de- pressed except immediately under the beak, separated from the disk by the first intercostal groove which is relatively faint, nearly smooth except for minute concentric growth lines. Escutcheon of VENEZUELAN CENOzoIC PELECYPODS: WEISBORD 257 left valve rather narrow and lanceolate, that of the right valve some- what broader, subelliptical, and also smooth. Dentition normal, the anterior cardinal of the left valve and the posterior cardinal of the right valve robust, upcurved, and separated from the smaller and higher secondary cardinal by a deep trigonal pit. Laterals prominent but obtuse, the anterior laterals nearer the beak than the posterior, those of the right valve separated from the dorsal margins by deep grooves; on the left valve there is a fairly deep pit in front of the anterior lateral, and a more elongated one under the rear of the pos- terior lateral. Adductor impressions distinct, rather large, high, the anterior one rudely and obtusely triangular, the posterior one oval to subangularly ovate. Pallial line regular, not remote from, and parallel with the margins, joining the base of the adductor impressions. Inner margins fluted. Surface sculptured by generally 19 or 20 radial ribs of which there are 7 on the posterior area and 6 extra large ones on the central area of the disk. The ribs are separated by square inter- spaces which are deep and half the width of the ribs on the disk, but shallower and narrower on the submargins. Within the interspaces are strong, regular, equally spaced concentric cords decussating the interradials on the disk into oblong pits. These cords are confined to the trough of the interspaces, but on the side and crest of the ribs there are crowded microscopic concentric growth striae which are generally worn off the crests. The rib forming the umbonal ridge is high and symmetrically rounded; the next three ribs forward of the ridge are asymmetrical, gently rounded on the broad crest, the pos- terior side with a relatively high slope; farther forward the ribs are flattened both on the disk and anterior submargin, and the inter- spaces become progressively narrower and shallower anteriorward. The two or three ribs behind the umbonal ridge are moderately high and more or less equal in size, with the one or two nearest the ridge sometimes faintly bipartite; the remainder of the ribs on the posterior area become progressively wider, lower, and flatter toward the posterior margin as they do on the anterior end. Here and there on both the disk and submargins, the crest of the ribs may bear a few small nodes or tubercles. In some places there may be a number of regularly spaced tubercles on a rib, in others they seem to be entirely random, and on most specimens they are wanting, either 258 BuLLETIN 204 because of having been worn off or because of inherint sporadic de- velopment. On the best preserved specimens from the Cabo Blanco area the tubercles are sparse and erratically distributed. Dimensions—Holotype (G496d), right valve, height 10.2 mm.; width 8.2 mm.; thickness 4.9 mm. Paratype (G496c), right valve, height 11.3 mm.; width 10.1 mm.; thickness 4.8 mm. Paratype (G496b ), left valve, height 10.9 mm.; width 9.2 mm.; thickness 5.3 mm. Paratype (G496a), left valve, height 9.1 mm.; width 8.5 mm.; thickness 3.2 mm. Type locahty.—Upper Mare formation at W-14, on hillside above west bank of Quebrada Mare Abajo. Forty-seven specimens including twenty-five left valves and twenty-two right valves. Other localties—Upper Mare formation, 115 meters south- southwest of the crossing of Quebrada Mare Abajo and the coast road. One left valve. Lower Mare formation at W-13, on hillside above west bank of Quebrada Mare Abajo. Ten specimens including six left valves and four right valves. Lower Mare formation, in small stream 100 meters west of Quebrada Mare Abajo. Four specimens including two right valves and two left valves. Playa Grande forma- tion (Maiquetia member) at W-4, Quebrada Las Pailas. Three specimens including two left valves and one night valve. Comparisons.—Trigoniocardia is abundantly represented in the late Cenozoic of the Americas, and there are a number of species to which T. caboblanquensis, n. sp. exhibits affinity although not comparing precisely with any of them. Listed below are the Tertiary and Quaternary species of Trigoniocardia from America—all of them tropical in habitat—that have come to my attention: T. antillarum (d’Orbigny), (1842 [in] La Sagra, Hist. phys., polit. et nat. ’Ile de Cuba, Atlas, pl. 27, figs. 53-55; 1853 (text), vol. 2, p. 309). According to Dall (1901, U. S. Nat. Mus., Proc., vol. 23, No. 1214, p. 387) and to Abbott (1958, Acad. Nat. Sci. Philadelphia, Mon. No. 11, pp. 123-124), T. ceramidum Dall (1886, Mus. Comp. Zool., Bull., vol. 12, No. 6, p. 269, pl. 4, fig. 6) is synonymous. Pleistocene in Barbados?, and Recent from the Bahamas to the Virgin Islands. T. antillarum has 16 to 18 ribs as compared with 19 to 20 on the Venezuelan fossil, and the interspaces VENEZUELAN CENOZOIC PELECYPODS: WEISBORD 259 of T. antillarum are wider on the disk than on T. caboblanquensis, n. sp. T. haitense haitense (Sowerby) (see Woodring, 1925, Carneige Inst. Washington, Publ. No. 366, pp. 142-143, pl. 19, figs. 8-9). Lower ? to middle Miocene. This is more oblique than 7. caboblan- quensis and has two more ribs than the Venezuelan shell. T. hattense cercadicum Maury (1917, Bull. Amer. Paleont., vol. 5, p. 376, pl. 36, fig. 6). Lower ? Miocene of Puerto Rico, and middle Miocene of the Dominican Republic and Jamaica. This has 10 ribs on the posterior area, 7. caboblanquensis 7. T. haitense areciboense Hubbard (1920, New York Acad. Sci. Scientific Survey of Porto Rico and the Virgin Islands, vol. 3, pt. 1, pp. 117-118, pl. 19, fig. 9). Upper Oligocene to lower Miocene of Puerto Rico. This is a triangularly rhomboidal shell with 17 ribs. T. thawmastwm Woodring (1925, p. 144, pl. 19, figs. 12-13). Middle Miocene, Jamaica. The posterior ridge is sharply angular at the umbo; on 7’. caboblanquensis it is rounded. T. hannat Olsson (1932, Bull. Amer. Paleont., vol. 19, No. 68, pp. 99-100, pl. 8, figs. 4, 9, 10, 11). Lower Miocene, Peru. This is slightly larger and much more sturdy than 7. caboblanquensis and is more obtuse in outline. T. spiekeri Hanna and Israelsky (see Olson, 1932, p. 100, pl. 8, figs. 3, 7). Tumbez formation (upper Miocene) of Peru, and Jama formation (Pliocene) of Ecuador. The outline is obliquely subovate, and the ribs are flatter than on 7. caboblanquensis. T. sambacum sambaicum Maury (1917, p. 376, pl. 36, fig. 7). Lower Miocene of Puerto Rico and middle Miocene of the Domini- can Republic. Twenty-seven ribs compared with 19 or 20 on T. caboblanquensts. T. sambaicum portoricoensis Hubbard (1920, p. 116, pl. 19, figs. 5-6). Lower Miocene ? of Puerto Rico. Among other differences the concentric threads in the interspaces are finer than on T. cabo- blanquensis. T. herediuwm Olsson (1922, Bull. Amer. Paleont., vol. 9, No. 39, p. 399, pl. 27, fig. 10). Middle Miocene, Costa Rica. This species is more sharply carinated on the umbonal ridge, and bears one more 260 BULLETIN 204 rib on the posterior area than T. caboblanquensis, but otherwise the two forms are similar. T. callopleurum Gabb (1881, Acad. Nat. Sci. Philadelphia, Jour., ser. 2, vol. 8, p. 375, pl. 47, fig. 77). Pliocene, Costa Rica. The umbonal ridge is not so well developed, nor the ribs so broad as on T. caboblanquensis. T. aminense Dall (1900, Wagner Free Inst. Sci., Trans., vol. 3, pt. 5, p. 1104; 1903, pl. 48, fig. 11). Middle Miocene, Dominican Republic. The posterior end bears 10 radial ribs compared with 7 on the Venezuelan shell. T. mirandense Maury (1925, Bull. Amer. Paleont., vol. 10, No. 42, p. 287, pl. 23, fig. 10). Lower Miocene, Venezuela. This is more sharply carinated than the Cabo Blanco shell, and all of the ribs, of which there are 22 (8 on the truncation), are conspicuously and evenly beaded. T. carolinae Maury (1912, Acad. Nat. Sci. Philadelphia, Jour., ser. 2, vol. 15, p. 54, pl. 9, figs. 5-6). Lower-middle Miocene and Pliocene of Trinidad. This has 17 ribs, T. caboblanquensis 19 or 20. T. castum castum (Guppy) -(1866, Geol. Soc. London Quart. Jour., vol. 22, pl. 582, pl. 26, fig. 4). Lower-middle Miocene, Trini- dad. The umbo is narrower, and the outline more oblique than on T. caboblanquensis. Also there are 22 ribs on the type of T. castwm compared with 19 or 20 on the Venezuelan species. T. castwm: brassicum (1925, p. 285, pl. 23, fig. 6). Lower-middle Miocene, Trinidad. This is an elongate-oval form in contrast with T. caboblanquensis which is subrhomboidal. T. manzanillense Maury (1925, pp. 235-236, pl. 23, fig. 4). Lower-middle Miocene, Trinidad. The Venezuelan T. caboblan- quensis, n. sp. closely resembles T. manzanillense but differs in having one less rib on the posterior area and a shorter posterodorsal margin which curves gently, rather than subangularly, into the posterior margin. T. peru-maris Maury (1925, p. 288, pl. 23, fig. 8). Pliocene, Trinidad. This species has 24 ribs (of which nine are on the trunca- tion), and there is a radial depression in front of the umbonal ridge producing an embayment of the basal margin. VENEZUELAN CENOZOIC PELECYPODS: WEISBORD 261 T. gatunense (Dall) (1900, pp. 1101-1102). Lower Tertiary ? of the Panama Canal Zone. Twenty-six ribs. T. alicula Dall (1900, p. 1103, pl. 40, fig. 12; 1903, pl. 48, fig. 5). Middle Miocene, Florida. This is obliquely diamond-shaped whereas 7. caboblanquensis is subrhomboidal. T. sumrotht Dall (1900, p. 1104; 1903, pl. 48, fig. 8). Middle Miocene, Florida. The interradial cords are finer than on 7’. cabo- blanquensis, and the rib on the umbonal ridge is flexuous instead of straight as on the Venezuelan fossil. T. willcoxt Dall (1900, p. 1106; 1903, pl. 48, fig. 9). Pliocene, Florida. Body with nine, the posterior area with eight ribs. T. apateticum Dall (1900, pp. 1105-1106; 1903, pl. 48, fig. 6). Middle Miocene, Florida. When perfectly intact this species is with- out tubercles. T. sellardst Gardner (1926, U. S. Geol. Sur., Prof. Paper 142-C, pp. 140-141, pl. 23, figs. 11-12). Chipola formation (middle Miocene), Florida. Nine ribs on the posterior area. T. deadenense Mansfield (1932, Florida State Geol. Sur., Bull. No. 8, pp. 113-114, pl. 22, figs. 2-5). Late Miocene, northwest Florida. The Venezuelan T. caboblanquensts is close to T. deaden- ense but the Floridan shell has eight beaded ribs on the posterior area. T. galvestonense (Harris) (1895, Bull. Amer. Paleont., vol. 1, No. 3, p. 91, pl. 1, figs. 3, 3a). Later Miocene in Galveston well, Texas, 2,443 to 2,871 feet. The Venezuelan shell is closely related to T. galvestonense differing slightly in having somewhat broader ribs and a shorter posterodorsal margin which curves gently into the posterior margin rather than subangularly as on the Texas species. T. maturense Dall (1900, p. 1105; 1903, pl. 48, fig. 7). Pliocene at Matura, Trinidad. The posterior area has eight or nine ribs, 7. caboblanquensts seven. T. cabopasadum Pilsbry and Olsson (1941, Acad. Nat. Sci. Philadelphia, Proc., vol. 93, p. 59, pl. 12, figs. 6-7). Pliocene, Ecua- dor. Sculptured by 23 ribs of which 7 are on the posterior slope. T. graniferum (Broderip and Sowerby) (see Keen, 1958, p. 118, fig. 256). Pliocene of Ecuador; Pleistocene of Baja California, 262 BuLLeTIN 204 Mexico; Recent, from México to Peru in depths to 14 fathoms. This is a broader shell than 7. caboblanquensis. T. obovale (Sowerby) (see Keen, 1958, p. 118, fig. 257). Pliocene of Panama and Ecuador; Pleistocene of the Tres Marias Islands, México; Recent from Baja California to Peru in depths to 40 fathoms. This is an elongately subovate form. T. panis-sacchari van Regteren Altena (1961, pp. 202-203, figs. 1-4) from the Pleistocene of Sugar Loaf, Eustatius, has 22 to 24 radial ribs compared with 19 to 20 on T. caboblanquensis, has a wider and more flaring posterior area than 7. caboblanquensis, and is larger than the Cabo Blanco species. Trigoniocardia (Americardia) media (Linnaeus) Pl. 36, figs. 7-12 1758 Cardium medium Linnaeus, Syst. Nat., ed. 10, p. 678, No. 61. 1767. Cardium medium Linnaeus, Syst. Nat., ed. 12, p. 1122, No. 77. 1782. Cardium medium Linnaeus, Chemnitz, Syst. Conchylien-Cabinet, vol. 6, p. 169, pl. 16, figs. 162-164. 1791. Cardium medium Linnaeus, Gmelin, Syst. Nat., ed. 13, p. 3246. 1792. Cardium medium Linnaeus, Bruguiére, Encycl. Méth., p. 213, pl. 295, fig. 4. 1818. Cardium medium Linnaeus, Lamarck, An. sans Vert., vol. 6, p. 15. 1823. Cardium medium Linnaeus, Mawe, The Linnaean System of Conchology, pl. 7, fig. 1. 1825. Cardium medium Linnaeus, Wood, Index Testaceologicus, pl. 5, fig. 5. 1844. Cardium medium Linnaeus, Reeve, Conch. Icon., vol. 2, Cardium, pl. 6, sp. 30. 1845. Cardium medium Linnaeus, d’Orbigny, [in] La Sagra, Hist. Fis., Polit., y Nat. Isla de Cuba, pt. 2, vol. 5, Moluscos, p. 336. 1855. Cardium medium Linnaeus, Hanley, Ipsa Linnaei Conchylia, p. 47. 1861. Cardium venustum Dunker, Malakozool. Blatter, vol. 8, p. 37. 1864. Cardium medium Linnaeus, Krebs, The West Indian Marine Shells, p. 116. 1869. Cardium medium Linnaeus, Romer, [in] Syst. Conchylien-Cabinet, Neue Ausg., p. 102, pl. 4, figs. 5-7. 1878. Cardium medium Linnaeus, Mérch, Catalogue of West-India Shells, Des: 1881. Cardium medium Linnaeus, Gabb, Acad. Nat. Sci. Philadelphia, Jour., 2d ser., vol. 8, p. 374. 1881. Cardium medium Linnaeus, Dall, Mus. Comp. Zool., Bull., vol. 9, p. 132. 1885. Cardium (Fragum) medium Linnaeus, Smith, Voyage of H.M.S. Chal- lenger, Zoology, vol. 13, p. 163. 1886. Cardium medium Linnaeus, Dall, Mus. Comp. Zool., Bull., vol. 12, No. 6, p. 269. 1887. Hemicardium columba Heilprin, Wagner Free Inst. Sci., Trans., vol. 1, p. 93, pl. 11, figs. 26, 26a. Fide Dall. Olsson and Harbison (1953, p. 104, pl. 10, figs. 3, 3a, 3b, 5) consider H. columba to be distinct from T. media. 1889. Cardium medium Linnaeus, Simpson, Davenport Acad. Nat. Sci., Proc., vol. 5, p. 65. 1889. Cardium medium Linnaeus, Dall. U. S. Nat. Mus., Bull. 37, p. 52. 1889. 1890. 1895. 1900. 1901. 1901. 1904. 1913. 1916. 1919. 1920. 1922. 1925. 1925. 1926. 1930. 1933. 1934. 1935. 1936. 1936. 1936. 1936. UIT 1938. 1939. 1939. 1942. 1942. 1943, VENEZUELAN CENOZOIC PELECYPODS: WEISBORD 263 Cardium medium Linnaeus, Lorié, Samml. Geol. Reichs-Mus. Leiden, ser. 2, vol. 1, pp. 126, 141, pl. 1, fig. 22. Cardium medium Linnaeus, Linnean Soc. London, Jour., vol. 20, p. 497. Ctenocardia (Fragum) medium (Linnaeus), Gregory, Geol. Soc. London, Quart. Jour., vol. 51, p. 292. Cardium (Fragum) medium Linnaeus, Dall, Wagner Free Inst. Sci., Trans., vol. 3, pt. 5, pp. 1101-1102. Cardium (Fragum) medium Linnaeus, Dall and Simpson, U. S. Fish Com., Bull., vol. 20 for 1900, pt. 1, p. 488. Cardium (Fragum) medium Linnaeus, Dall, U. S. Nat. Mus., Proc., vol. 23, No. 1214, p. 386. Cardium (Fragum) medium Linnaeus, Glenn, Maryland Geol. Sur., Mio- cene, p. 322, pl. 86, figs. 6a, 6b. Cardium medium Linnaeus, Brown and Pilsbry, Acad. Nat Sci. Phila- delphia, Proc., vol. 65, p. 496. Cardium medium Linnaeus, Thiele, Zool. Jahrb., Suppl. 11, p. 129. Cardium (Fragum) medium Linnaeus, Gardner and Aldrich, Acad. Nat. Sci. Philadelphia, Proc., vol. 71, p. 17. Cardium (Fragum) medium Linnaeus, Maury, Bull. Amer. Paleont., vol. 8, No. 34, p. 96. Cardium (Fragum) medium Linnaeus, Olsson, Bull. Amer. Paleont., vol. 9, No. 39, pp. 189, 194, 205, 398-399, pl. 27, fig. 6. Cardium (Fragum) medium Linnaeus, Maury, Bull. Amer. Paleont., vol. 10, No. 42, pp. 283-284, pl. 23, fig. 10. Cardium (Fragum) medium Linnaeus, Woodring, Carnegie Inst. Wash- ington, Publ. No. 366, p. 140-141, pl. 19, figs. 5-6. Cardium (Fragum) medium Linnaeus, Weisbord, Nautilus, vol. 39, No. 3, p. 83. Trigoniocardia (Americardia) medium (Linnaeus), Stewart, Acad. Nat. Sci. Philadelphia, Spec. Publ. No. 3, pp. 267-268. Cardium (Fragum) medium Linnaeus, Trechmann, Geol. Mag., vol. 70, No. 823, p. 35. Trigoniocardia (Americardia) medium (Linnaeus), Johnson, Boston Soc. Nat. Hist., Proc., vol. 40, No. 1, p. 46. Cardium medium Linnaeus, Richards, Jour. Paleont., vol. 9, No. 3, p. 256. Trigoniocardia medium (Linnaeus), McLean, Nautilus, vol. 49, No. 4, p23: Cardium (Hemicardium) medium Linnaeus, Lermond, Check List of Florida Marine Shells, Gulfport, p. 6. Trigoniocardia (Americardia) medium (Linnaeus), oe Soc. Cu- bana Hist. Nat. “Felipe Poey,” Mem., vol. 10, No. 1, Trigoniocardia (Americardia) medium (Linnaeus), cies and McLean, Soc. Cubana Hist. Nat. “Felipe Poey,’ Mem., vol. 10, No. 3, p. 166. Trigoniocardia (Americardia) medium (Linnaeus), Smith, East Coast Marine Shells, p. 50, pl. 17, figs. 5a, 5b. Trigoniocardia medium (Linnaeus), Perry, Schwengel, and Dranga, Nau- tilus, vol. 52, No. 1, p. 28. Cardium medium Linnaeus, Mansfield, State of Florida Dept. Conserv., Geol. Bull. No. 18, pp. 17, 19, 26, 29. Cardium (Americardia) medium Linnaeus, McLean, Soc. Cubana Hist. Nat., Mem., vol. 13, No. 3, p. 167, pl. 25, figs. 1-2. Cardium (Fragum) medium Linnaeus?, Haas, Jour. Paleont., vol. 16, No. 3, p. 308. Trigoniocardia medium (Linnaeus), Jaume and Pérez Farfante, Soc. Cubana Hist. Nat. “Felipe Poey,” Mem., vol. 16, No. 1, p. 39. Trigontocardia (Americardia) media (Linnaeus), Gardner, U. S. Geol. Sur., Prof. Paper 199-A, p. 93. 264 BuLLeTIN 204 1944. Trigoniocardia (Americardia) medium (Linnaeus), Clench and Smith, Johnsonia, vol. 1, No. 13, pp. 21-22, pl. 11, figs. 1-2. 1945. Corculum medium (Linnaeus), van Bentham Jutting, Geolog.-Mijnbowk Genootschap Nederland en Kolonien, Geol. ser., vol. 14, p. 77. 1946. Trigoniocardia (Americardia) media (Linnaeus), Jaume, Soc. Malac. “Carlos de La Torre,” Rev., vol. 4, No. 3, p. 100. 1949. Corculum (Fragum) medium (Linnaeus), Lange de Morretes, Mus. Para- naense, Arq., vol. 7, art, 1, p. 35. 1951. Trigoniocardia (Americardia) medium (Linnaeus), McLean, New York Acad. Sci. Scientific Survey of Porto Rico and the Virgin Islands, vol. 17 apts Pass opie. til" 16: 1952. Cardium medium Linnaeus, Dodge, Amer. Mus. Nat. Hist., Bull., vol. 100, Arto) spar 6- 1953. Trigoniocardia (Americardia) medium (Linnaeus), Olsson and Harbison, Acad. Nat. Sci. Philadelphia, Mon. No. 8, p. 104. 1954. Trigoniocardia medium (Linnaeus), Abbott, American Seashells, pp. 398-399, pl. 39m. 1955. Trigoniocardia media (Linnaeus), Perry and Schwengel, Marine Shells of the Western Coast of Florida, p. 68, pl. 41, fig. 293. 1958. Trigoniocardia (Americardia) media (Linnaeus), Keen, Sea Shells of Tropical West America, p. 119. 1958. Americardia media (Linnaeus), Abbott, Acad. Nat. Sci. Philadelphia, Mon. No. 11, p. 124. 1958. Trigoniocardia medium (Linnaeus), Olsson and McGinty, Bull. Amer. Paleont., vol. 39, No. 177, p. 21. 1959. Trigoniocardia medium (Linnaeus), Nowell-Usticke, A Check List of the Marine Shells of St. Croix, p. 14. 1961. Trigoniocardia (Americardia) media (Linnaeus), van Regteren Altena, Koninkl. Nederl. Akad. Wetensch.-Amsterdam, Proc., ser. B, vol. 64, No. 2, p. 300. 1961. Americardia media (Linnaeus), Warmke and Abbott, Caribbean Sea- shells, p. 183, pl. 38b. This species occurs both Recent and fossil in the Cabo Blanco area. The adult Recent shells are sculptured by 36 ribs of which 9 to 11 are on the posterior slope; the adult fossil specimens bear 39 to 41 ribs of which there are 9 or 10 on the posterior slope. The shell is subrhomboidal, with a prominent beak, a depressed posterior trun- cation which is indented at the margin below the middle, and a steeply descending umbonal ridge which is sharp at the umbo, angular to subangularly rounded below. The radial ribs of the disk are strong and regular, the interspaces deep and much narrower than the ribs; on the posterior truncation three or four of the ribs near the posterodorsal margin are wider than the others, and two or three of the ribs along the middle of the truncation are slightly narrower than those on the side of the umbonal ridge. The ribs and interspaces are crossed by numerous regular concentric lamellae arched upward on the crest of the ribs. The Recent shells are whitish VENEZUELAN CENOzoIC PELECYPODS: WEISBORD 265 with chestnut-brown mottlings and radial stripes externally, white within. Dimensions.—Recent specimen (A497a), left valve, height 17.9 mm.; length 16.1 mm.; thickness 6.4 mm. Fossil specimen (A497al-2), a doublet, height 29.3 mm.; length 26.1 mm.; thickness of pair 24.1 mm. Largest fossil specimen, right valve, height 36.7 mm.; length 32.9 mm.; thickness 17.8 mm. Localities—Recent, on beach at Playa Grande Yachting Club, Distrito Federal. Three left valves. Playa Grande formation (Maiquetia member) at W-23, north flank of Punta Gorda anti- cline Four specimens including two right valves, one left valve, and on doublet. Range and distribution—Recent, North Carolina to Brazil at depths of 2 to 100 fathoms. Pleistocene in Cuba, the Panama Canal Zone, St. Kitts, St. Eustatius, Curacao, Venezuela, and Barbados. Pliocene in North Carolina, Florida ?, and Costa Rica. Upper Miocene in Maryland, North Carolina, and South Carolina. Middle Miocene in Costa Rica, the Dominican Republic, and Jamaica. A west American counterpart of 7. media (Linnaeus) is T. guanacastense (Hertlein and Strong) (1947, Zoologica, vol. 31, pt. 3, No. 10, pp. 140-141) which ranges from Baja California to Peru, and which has been recorded from the Pliocene of Costa Rica and the Pleistocene of Ecuador. Laevicardium ?, species Pl. 36, figs. 13, 14 Shell small, inflated, broken, probably subquadrate when whole. Beak small, low, full, and prosogyrate. Lunule not defined. Outer layer of shell with microscopic concentric wrinkles or lineations, the underlying layer with fine, hardly discernible radiating riblets. Hinge mutilated but seems to be like that of Laevicardiwm. Interior filled with sand. Dimensions——Specimen H550a, right valve (not complete), height 1.7 mm.; length 1.5 mm.; thickness 0.9 mm. Locality—Mare formation at W-25, south flank of Punta Gorda anticline. One imperfect right valve. Remarks.—The juvenile fossil is reminiscent of the Pliocene 266 BuLtetin 204 to Recent L. mortoni (Conrad) (1829, Acad. Nat. Sci. Philadelphia, Jour., Ist ser., vol. 6, pp. 259-260, pl. 11, figs. 5-7), but it is too small and imperfect for definitive comparison. Papyridea aff. soleniformis (Bruguiére) P1.:37, fies. 412 1778. 1780. 1782. 1787. 1787. 1789. 1815. 1840. 1845. 1845. 1845. 1862. 1864. 1869. 1872. 1878. 1878. 1881. 1884. 1885. 1889. 1889. 1900. 1901. 1901. ?Cardium latum Born, Index Rerum Naturalium Caesarei Vindobonen- sis, p. 67. ?Cardium latum Born, Testacea Musei Caesarei Vindobonensis, p. 48, pl. 3, fig. 9 (in the text wrongly as fig. 8, fide Dall). Solen bullatus Linnaeus, Chemnitz, Syst. Conchylien-Cabinet, vol. 6, p. 65, pl. 6, figs. 49-50. Not of Linnaeus 1758, Syst. Nat., ed. 10, p. 673. Cardium hiatus Meuschen, Museum Geversianum, p. 442. Refers to Gualtieri 1742, Index Testarum Conchyliorum, pl. 85, fig. H. Cardium spinosum Meuschen (non Solander 1786), Museum Geversi- anum, p. 242. Refers to Lister 1685, Synopsis Methodicae Conchyliorum, pl. 342, fig. 179. Cardium soleniforme Bruguiére, Encycl. Méth., vol. 1, pt. 1, p. 235. Cardium soleniforme Bruguiére, Wood, General Conchology, N. 233, pl. 56setigzs 3: Papyridea soleniforme (Bruguiére), Swainson, A Treatise on Mala- cology, p. 374. Cardium bullatum (Linnaeus), Reeve, Conch. Icon., vol. 2, Cardium, sp. 8, Not of Linnaeus 1758. Cardium hiulcum Reeve, Conch. Icon., vol. 2, Cardium, pl. 21, sp. 123. Cardium bullatum Lamarck, d’Orbigny, Hist. Fis., Polit. y Nat. Isla de Cuba, pt. 2, vol. 5, Moluscos, p. 337. Cardium (Fulvia) bullatum (Chemnitz), Chenu, Manuel de Conchyli- ologie et de Paléontologie Conchylologique, vol. 2, p. 109, figs. 500-502. Cardium soleniforme Bruguiére, Krebs, The West Indian Marine Shells, bed ll7/s Cardium (Papyridea) bullatum (Chemnitz), Romer, Syst. Conchylien- Cabinet, ed. 2, vol. 10, pt. 2, p. 74, pl. 12, figs. 13-16. Papyridea bullata (Linnaeus), Tryon, Amer. Jour. Conch., vol. 7, pt. 4, Appendix, No. 13, p. 267. Not of Linnaeus 1758. Cardium spinosum Meuschen, Morch, Catalogue of West-India Shells, pelos Cardium spinosum Meuschen, Arango y Molina, Contribucién a la Fauna Malacologica Cubana, p. 259. Papyridea bullata (Linnaeus), Gabb, Acad. Nat. Sci. Philadelphia, Jour., ser. 2, vol. 8, p. 375. Not of Linnaeus 1758. Cardium (Fulvia) bullata (Linnaeus), Tryon, Structural and Systematic Conchology, vol 3, p. 192, pl. 116, fig. 78. Not of Linnaeus 1758. Cardium (Papyridae) bullatum (Chemnitz), Smith, Voyage H.M.S. Challenger, Zoology, vol. 13, pp. 161-162. Papyridea bullata (Linnaeus), Dall, U. S. Nat. Mus., Bull. 37, p. 54. Not of Linnaeus 1758. Cardium bullatum (Linnaeus), Simpson, Davenport Acad. Nat. Sci. Proc., vol. 5, p. 65. Cardium (Papyridea) spinosum Meuschen, Dall, Wagner Free Inst. Sci., Trans., vol. 3, pt. 5, pp. 1106-1107. Cardium (Papyridea) spinosum Meuschen, Dall, U. S. Nat. Mus., Proc., vol. 23, No. 1214, p. 387. Cardium (Papyridea) spinosum Meuschen, Dall and Simpson, U.S. Fish Com., Bull., vol. 20 for 1900, pt. 1, p. 489. 1920. 1925. 19 3i1- 1935: 1936. 1936. 1936. 1938. 1939. 1940. 1940. 1942. 1944. 1947. 1949, 1950. 1951. 1953. 1954. 1955. 1956. 1958. 1958. 1959. 1961. 1961. 1961. VENEZUELAN CENOozoIC PELECYPoDS: WEISBORD 267 Cardium (Papyridea) spinosum Meuschen, Maury, Bull. Amer. Paleont., vol. 8, No. 34, pp. 96-97. Cardium (Papyridea) spinosum Meuschen, Maury, Bull. Amer. Paleont., vol. 10, No. 42, pp. 289-290. Cardium soleniforme Bruguiére, Grant and Gale, San Diego Soc. Nat. Hist.. Mem., vol. 1, p. 311. Cardium spinosum Meuschen, Richards, Jour. Paleont., vol. 9, No. 3, p. 256. Papyridea spinosa (Meuschen), McLean, Nautilus, vol. 49, No. 4, p. 118. Papyridea spinosum (Meuschen), McLean, Soc. Cubana Hist. Nat. “Felipe Poey,’ Mem., vol. 10, No. 1, p. 41. Cardium (Papyridea) spinosum Meuschen, Lermond, Check List of Florida Marine Shells, Gulfport, p. 8. Papyridea spinosa (Meuschen), Aguayo, Soc. Cubana Hist. Nat. “Felipe Poey”, Mem., vol. 12, No. 2, p. 102. Papyridea spinosum (Meuschen), McLean, Soc. Cubana Hist. Nat. “Felipe Poey”, Mem., vol. 13, No. 3, pp. 164-165, pl. 24, figs. 3, 9. Papyridea spinosum (Meuschen), Johnson, Boston Soc. Nat. Hist., Proc., vol. 40, No. 1, p. 46. Papyridea spinosa (Meuschen), Smith, World-wide Sea Shells, p. 107, fig. 1414 Papyridea spinosum (Meuschen), Jaume and Pérez Farfante, Soc. Cubana Hist. Nat. “Felipe Poey’, Mem., vol 16, No. 1, p. 39. Papyridea hiatus (Meuschen), Clench and Smith, Johnsonia, vol. 1, No. 13, pp. 17-18, pl. 4, figs. 3-5. Cardium spinosum (Meuschen), Hertlein and Strong, Zoologica, vol. 31, No. 10, p. 139. Papyridea spinosa (Meuschen), Lange de Morretes, Mus. Paranaense, Arq., vol. 7, art. 1, p. 34 Papyridea soleniforme (Bruguiére), Durham, Geol. Soc. Amer., Mem. 43, 43, pt. 2, p. 80. Papyridea hiatus (Meuschen), McLean, New York Acad. Sci. Scientific Survey of Porto Rico and the Virgin Islands, vol. 17, pt. 1, p. 71, pl. 15, figs 1s Papyridea (Papyridea) spinosa (Meuschen), Haas, Fieldiana-Zoology, vol. 34, No. 20, p. 203. Papyridea soleniformis (Bruguiére), Abbott, American Seashells, p. 398, pl. 39n. Papyridea soleniformis (Bruguiére), Perry and Schwengel, Marine Shells of the Western Coast of Florida, p. 68, pl. 13, fig. 74. Papyridea soleniformis (Bruguiére), Parker, Amer. Assoc. Petrol. Geol., Bull., vol. 40, No. 2, p. 309. Papyridea soleniformis (Bruguiére), Keen, Sea Shells of Tropical West America, p. 118. Papyridea soleniforme (Bruguiére), Olsson and McGinity, Bull. Amer. Paleont., vol. 39, No. 177, p. 21. Papyridea soleniformis (Bruguiére), Nowell-Usticke, A Check List of the Marine Shells of St. Croix, p. 13. Papyridea hiatus (Meuschen), van Regteren Altena, Koninkl. Nederl. Akad. Wetensch.-Amsterdam, Proc., ser. B, vol. 64, No. 2, p. 300. Papyridea soleniformis (Bruguiére), Olsson, Panamic-Pacific Pelecypoda, p. 250. Papyridea soleniformis (Bruguiére), Warmke and Abbott, Caribbean Seashells, pp. 182-183, pl. 37). The Venezuelan fossil referred to P. soleniformis (Bruguiére) 268 BuLLeETIN 204 is represented by a single left valve which is worn and framentary. The hinge is unusually sturdy for the species, and the surface is traversed by about 45 radial ribs. The left anterior adductor scar is margined by a faint radial ridgelet. Dimensions—Specimen 1512a (broken away at the ends and base), length 4.7 mm.; height 3.5 mm.; thickness 1.2 mm. Locality.—Lower Mare formation at W-13, on hillside above west bank of Quebrada Mare Abajo. One imperfect left valve. Remarks.—The west American counterpart of P. soleniformis is the Pleistocene to Recent P. aspersa (Sowerby) (see Durham, 1950, p. 80, pl. 19, figs. 6, 19). According to Durham, P. aspersa may be separated from P. soleniformis “by more deeply channeled interspaces between the ribs, by the lesser posterior elongation, by the posterior lateral teeth being slightly closer to the beaks, and by the cardinal tooth sloping more anteriorly.” Range and distribution.—P. soleniformis (Bruguiére) ranges from Pliocene to Recent. The living shell ranges from North Caro- lina, U.S.A., to Brazil. The fossil shell is recorded from the Pleisto- cent of Cuba and St. Kitts, and from the Pliocene of Costa Rica. VENERIDAE Dosinia (Dosinidia) concentrica prosapia, new subspecies Pl. 37, figs. 3-10; Pl. 38, figs. 1-4; Pl. 39, figs. 1, 2; Pl. 58, figs. 10, 11 Shell attaining a large size, moderately compressed to a little inflated, subcircular and thin when young, suborbicular to suboval and with a strong hinge plate when adult. Anterodorsal margin short and concave at the lunule, the posterodorsal margin long, gently convex, rather steeply sloping, and sharp at the edge. The greatest width generally is above the middle, whence the sides, on specimens of medium size, tend to converge toward the nearly semicircular ventral margin. On a number of specimens the greatest length is from the beak to the posterior end of the ventral margin where the valve is slightly produced. Beak subcentral, low, proso- gyrate. Lunule relatively small, rather deeply depressed, cordate, marked by faint lirae which are a continuation of the concentric ribs from the umbonal area. Escutcheon absent. Exterior sculptured by flat subregular concentric ribs on the middle of the disk, the VENEZUELAN CENOzoIC PELECYPoDS: WEISBORD 269 ribs developing into raised subrounded ridges toward the extremi- ties. There are about seven ribs to the centimeter on the middle area of the disk, but on the umbo and near the base they are closer together, those on the umbo quite regular; some of the ribs are intercalated and do not reach the margins. Hinge plate sturdy, excavated underneath, the base of the plate sharply curved down- ward below the anterior lateral, shallowly arcuate upward there- after to the top of the posterior adductor scar. Ligamental platform large, flat, elongate-semielliptical, the base of the platform straight. In front of the platform, the nymph is hollowed deeply under the beak. Right valve with a small pit in front of and below the anter- iormost cardinal tooth. The two right anterior cardinal teeth are close together, subparallel, and separated by a deep sublinear slit; the forward tooth of the pair is high and laminar, the hinder tooth of the pair higher, stouter, and more or less wedge-shaped, with a flat face at the slit, and a broad curved side away from the slit. The medial socket behind the latter cardinal is obliquely ovate, and after the socket there is a broad bipartite cardinal tooth, the asym- metrical sulcus dividing the tooth broad and relatively shallow, the walls on either side of the socket rather sharp. Behind the middle cardinal there is another deep narrow cleft, that bordered by a narrow ridge representing the posterior cardinal. Left valve with three divergent cardinal teeth; the anterior of these is sharp and narrowly bifid along the face, and, on the hinge plate below it, there is a small lateral node fitting into the corresponding pit of the opposite valve; the middle cardinal of the left valve is medially sulcate, and the posterior cardinal laminar; the socket between the anterior and middle cardinals is triangular, the socket between the middle and posterior teeth rather broad and sublinear. Inner anterior margin at upper end of valve broadly and shallowly con- cave, the concavity produced by a thickening along the front mar- gin of the anterior adductor scar. Adductor scars large and distinct, the anterior one lenticularly ovate and narrowed above, the pos- terior scar broader and subpyriform. Pallial line remote from the margin and parallel with it. Pallial sinus triangular, sharply pointed at the apex on adults but blunted on juveniles, directed forward at an angle of about 45 degrees, the apex nearly reaching to the center of the valve. 270 BuLLeTIN 204 Dimensions.—Holotype (T418a), right valve, length 75.5 mm.; height 75 mm.; thickness 14.5 mm. Paratype (R419al-2), paired valves separated by a filling of calcareous sandstone, length 67 mm.; height 70.5 mm. Paratype (R419b), hinge area of left valve, height of fragment 47 mm. Paratype (1418a), hinge area of left valve, length of fragment 52 mm. Paratype (G420al-2), young broken valves of same pair, length 36 mm.; thickness of pair 14.5 mm. Specimen K414a, a doublet (illustrated), length 71.5 mm.; height 74 mm.; thickness of pair 28 mm. Largest specimen (M415a), il- lustrated, an internal mold of a doublet questionably identified as D. concentrica prosapia, n. subsp., length 98.3 mm.; height 89 mm.; thickness 33 mm. Type locality—Upper Mare formation, in stream 250 meters south-southwest of mouth of Quebrada Las Pailas. One right valve, the holotype. Other localities —Upper Mare formation at W-14, on hillside above west bank of Quebrada Mare Abajo. Three doublets, all partially broken. Mare formation, 115 meters southeast of crossing of Quebrada Mare Abajo and coast road, and 90 meters southeast of W-12. One large broken doublet. Playa Grande formation (Mai- quetia member) at W-4, Quebrada Las Pailas. Nine specimens in- cluding six poorly preserved doublets, the hinges of two right valves, and one hinge of a left valve. Playa Grande formation (Mai- quetia member), in Quebrada Las Bruscas approximately 125 meters upstream from junction with Quebrada Las Pailas. Four specimens including three doublets and the hinge of a left valve. Playa Grande formation (Catia member), in bluff 125 meters west of the inter- section of the Playa Grande Yachting Club road and coast road. One doublet, poorly preserved. Playa Grande formation (Catia member) at W-15, south side of Playa Grande road, 40 meters southeast of its intersection with the Playa Grande Yachting Club road. Nine internal molds of paired valves. Comparisons.—This form is close to D. concentrica concentrica (Born) (1780, Testacea Musei Caesarei Vindobonensis, p, 71, pl. 5, fig. 5) and to D. elegans elegans Conrad (see Clench, 1942, John- sonia, vol. 1, No. 3, pp. 1-2, pl. 1). According to Clench, D. con- centrica concentrica is consistently thicker than D. elegans elegans in proportion to height and length and is also not so high as D. VENEZUELAN CENOZOIC PELECYPODS: WEISBORD 271 e. elegans. A consistent ratio of thickness to height or length cannot be established for the few Cabo Blanco specimens, but the measure- ments more nearly approach those of D. c. concentrica. Furthermore D. concentrica is the older name, and I therefore relate the present Venezuelan fossil to that species rather than to D. elegans. Whether or not the Cabo Blanco shell is identical with D. concentrica con- centrica is difficult to determine, but as most of the Cabo Blanco examples are a little higher than long, and D. concentrica a little longer than high, the subspecific name of D. concentrica prosapia is proposed for the Venezuelan shell here described. Species which Dosinia concentrica prosapia, n. subsp. resembles are the following: D., elegans Conrad (see Clench, 1942, Johnsonia, vol. 2, No. 3, pp. 1-2, pl. 1). Upper Miocene to Recent, east America. D. elegans is a little longer than high, D. c. prosapia a little higher than long. D. elegans venezuelana H. K. Hodson (1927, Bull. Amer. Paleont., vol. 13, No. 49, p. 52). Widespread in the Miocene, State of Falcon, Venezuela. Adults of D. e. venezwelana are nearly circular and slightly longer than high, whereas adults of D. c. prosapia are suborbicular, and a little higher than long. D. acetabulum Conrad (1832, Fossil Shells of the Tertiary formations of North America, p. 20, pl. 6, fig. 1). Miocene of New Jersey, Maryland, Virginia, and Florida; also reported from the middle Miocene of Panama and Costa Rica, and from the Pliocene at Santa Maria Tatetla, México. As shown by Glenn (1904, Mary- land Geol. Sur., Miocene, p. 315, pl. 84, fig. 1) in his illustration of a left valve, the pallial sinus of D. acetabulum is not so acutely tri- angular as that of the Cabo Blanco fossil, and is less oblique than on D. c. prosapia. D. ponderosa (Gray) (see Grant and Gale, 1931, pp. 351-352, pl. 15, figs. la, 1b, 1c). Recent from Baja California to Peru; Pleisto- cene from southern California to Ecuador. The pallial sinus is not as sharply pointed as in D. c. prosapia. D. ponderosa jacalitosana Arnold (1910, U. S. Geol. Sur., Bull. 396, p. 67, pl. 16, fig. 5). Miocene and Pliocene of California, U.S.A., and Baja California, México. The beak is much more prominent than on the Cabo Blanco species. D. grandis Nelson (1870, p. 201). Upper Miocene of Peru and 272 BULLETIN 204 Trinidad (as D. titan Maury), and the Pliocene of Peru (see Spie- ker, 1922, pp. 138-140, pl. 8, fig. 4). On shells of equivalent size the concentric ribs of D. grandis are wider than those of the Cabo Blanco fossil. D. desca Olsson (1932, Bull. Amer. Paleont., vol. 19, No. 68, pp. 104-105, pl. 9, figs. 1-2) from the lower Miocene Montera forma- tion of Peru is a plumper form than D. c. prosapia. D. delicatissima Brown and Pilsbry (1912, p. 516, pl. 26, fig. 1). Lower Miocene of Peru and Ecuador; middle Miocene of Panama, Colombia, Venezuela, and Ecuador. The concentric ribs are finer than on the Cabo Blanco shell, and, according to Olsson (1932, p. 103), the lunule is smooth whereas on D. c. prosapia it is marked by striae continuing from the disk. Anomalocardia brasiliana (Gmelin) Pl. 38, figs. 5-8 1780. Venus flexuosa Born, Testacea Musei Caesarei Vindobonensis, p. 62, pl. 4, fig. 10. Not of Linnaeus, Syst. Nat., ed. 12, p. 1131, No. 121, 1767. 1791. Venus brasiliana Gmelin, Syst. Nat., ed. 13, p. 3289. 1818. Cytherea macrodon Lamarck, An. sans Vert., vol. 5, p. 580. 1818. Cytherea lunularis Lamarck, An. sans Vert., vol. 5, p. 580. 1834. Venus macrodon (Lamarck), Deshayes, An. sans Vert., vol. 6, p. 327. 1834. Venus lunularis (Lamarck), Deshayes, An. sans Vert., vol. 6, p. 327. 1843. Venus macrodon (Lamarck), Hanley, An Illustrated and Descriptive Catalogue of Recent Bivalve Shells, p. 116, pl 9, fig. 7. 1844. Venus lunularis (Lamarck), Philippi, Abbildungen und Beschreibungen neuer oder wenig gekannter Conchylien, vol. 1, p. 177, pl. 3, fig. 10. 1845. Venus flexuosa d’Orbigny, [in] La Sagra, Hist. Fis., Polit. y Nat. Isla de Cuba, vol. 5, Moluscos, pp. 314-315. 1853. Anomalocardia flexuosa (Born), Deshayes, Catalogue of the Conchifera or Bivalve Shells in the British Muesum, pt. 1, p. 116. 1855. Venus macrodon (Lamarck), Sowerby, Thes. Conchyl., vol. 2, p. 717, pl. 156, fig. 88.. 1863. Venus macrodon (Lamarck), Reeve, Conch. Icon., vol. 14, pl. 21, sp. 98b-d. 1864. Venus flexuosa Linnaeus, Krebs, The West Indian Marine Shells, p. 96. Not of Linnaeus. 1864. Venus macrodon Deshayes, Guppy, Sci. Assoc. Trinidad, Trans., p. 36. 1867. Venus flexuosa Linnaeus, Guppy, Sci. Assoc. Trinidad, Proc., pt. 3, p. 162. Not of Linnaeus. 1873. Venus flexuosa Linnaeus, Guppy, Sci. Assoc. Trinidad, Proc., vol. 2, p. 91. Not of Linnaeus. 1878. Cytherea flexuosa Lamarck, Mérch, Catalogue of West-India Shells, p. 15 1883. Venus flexuosa Born, Dall, U.S. Nat. Mus. Proc., vol. 6, p. 344. 1884. Venus (Cryptogramma) macrodon (Lamarck), Tryon, Structural and Systematic Conchology, vol. 3, p. 176, pl. 113, fig. 13. 1886. Venus flexuosa Linnaeus, Karsten, Géologie de l’anciene Colombie bolivarienne, Vénézuéla, Nouvelle Grénade et Ecuador, p. 10. Not of Linnaeus. 1889. 1901. 1902. 1903. 1913. 1920. 1925. 1926. 1927. 1933. 1934. 1934. 1936. 1936. 1937. 1938. 1946. 1946. 1949. 19515 1953: 1958. 1959. 1961. VENEZUELAN CENOZzOIC PELECYPODS: WEISBORD 273 ?Venus flexuosus Linnaeus, Simpson, Davenport Acad. Nat. Sci., Proc., vol. 5, p. 64. Not of Linnaeus. Venus (Anomalocardia) flexuosa Linnaeus, Dall and Simpson, U. S. Fish Com., Bull., vol. 20 for 1900, pt. 1, p. 484. Not of Linnaeus. Anomalocardia brasiliana (Gmelin), Dall, U. S. Nat. Mus., Proc., vol. 26, No. 1312, p. 375. Anomalocardia brasiliana (Gmelin), Dall, Wagner Free Inst. Sci., Trans., vol. 3, pt. 6, p. 1306. Anomalocardia brasiliana (Gmelin), Jenkins, Amer. Philos. Soc., Proc., vol. 52, No. 211, p. 457. Anomalocardia brasiliana (Gmelin), Maury, Bull. Amer. Paleont., vol. 8, No. 34, p. 107. Anomalocardia brasiliana (Gmelin), Maury, Bull. Amer. Paleont., vol. 10, No. 42, pp. 317-318, pl. 29, figs. 10-11. Anomalocardia brasiliana (Gmelin), Weisbord, Nautilus, vol. 39, No. 3, p. 84. Chione (Anomalocardia) brasiliana (Gmelin), Palmer, Palaeonto- graphica Americana, vol. 1, No. 5, p. 375 (1927), pl. 36, figs. 5-8, 15-18d, (1929). Anomalocardia braziliana (Gmelin), Trechmann, Geol. Mag., vol. 70, No. 823, p. 36. Anomalocardia brasiliana (Gmelin), Johnson, Boston Soc. Nat. Hist., Proc., vol 40, No. 1, p. 49. Anomalocardia brasiliana (Gmelin), Maury, Amer. Mus. Nat. Hist., Bull., vol. 67, art. 4, pp. 157-158, 164, pl. 18, fig. 6. 2 Anomalocardia brasiliana (Gmelin), Lermond, Check List of Florida Marine Shells, Gulfport, p. 4 Cytherea macrodon Lamarck, Lamy and Fischer-Piette, Mus. Nat. Hist. nat. Paris Bull., vol. 10, No. 2, p. 174. Anomalocardia brasiliana (Gmelin), Smith, East Coast Marine Shells, p. 55, pl. 21, figs. 8a, 8b. 2?Anomalocardia brasiliana (Gmelin), Richards, Geol. Soc. Amer., Bull., vol. 49, pt. 2, p. 1291. Anomalocardia brasiliana (Gmelin), Jaume, Soc. Malac. “Carlos de La Torre”, Rev., vol 4, No. 3, p. 101. Anomalocardia brasiliana (Gmelin), Stewart, Nautilus, vol. 60, No. 1, p19. Anomalocardia brasiliana (Gmelin), Lange de Morretes, Mus. Para- naense, Arq., vol. 7, art. 1, p. 35. Anomalocardia brasiliana (Gmelin), McLean, New York Acad. Sci. Scientific Survey of Porto Rico and the Virgin Islands, vol. 17, pt. 1, p. 86, pl. 17, fig. 10. Anomalocardia brasiliana (Gmelin), Olsson and Harbison, Acad. Nat. Sci. Philadelphia, Mon. No. 8, p. 114. Anomalocardia brasiliana (Gmelin), Olsson and McGinty, Bull. Amer. Paleont., vol. 39, No. 177, p. 21. Anomalocardia brasiliana (Gmelin), Nowell-Usticke, A Check List of the Marine Shells of St. Croix, p. 15. Anomalocardia brasiliana (Gmelin), Warmke and Abbott, Caribbean Seashells, p. 187, pl. 38g. The La Salina fossils referred to this species are cuneiform, with a prominent posterior ridge which broadens toward the base to form a subangular submargin, and with a radial depression or sulcus in front of the ridge. The lunule is relatively smooth, cordate, 274 BuLLeETIN 204 and hardly depressed, the escutcheon also smoothish, lanceolate, and defined by the weak ridge of the submargin. Surface more or less covered with strong subregular concentric ribs, the mbs ir- regular and interrupted in the depressed area, but becoming promin- ent again as they extend over the posterior ridge to the submargin where they play out at the edge of the escutcheon. The interspaces are wider than the concentric ribs and are traversed by low broad subregular radial cords which are particularly pronounced on one of the two specimens collected. Dimensions —Specimen C539a, left valve, length 12.7 mm.,; height 8.9 mm.; thickness 3.3 mm. Specimen C539b, right valve, length 10.8 mm.; height 8.8 mm.; thickness 3 mm. Locality—La Salina, west of Puerto Cabello, State of Cara- bobo. Two specimens including one left valve and one night valve. Range and distribution —According to Abbott (1954), the Re- cent A. brasiliana (Gmelin) ranges from the West Indies to Brazil, though earlier authors have reported it as far north as North Caro- lina, possibly confusing it with A. cunermerts (Conrad) which is similar but more elongated. The fossil A. brasiliana has been re- corded from the Pleistocene of Florida, Barbados, and Brazil; from the Pliocene of Florida, Venezuela (near Cumana), and Trinidad; and, according to Maury (1925, p. 318), from the upper Miocene of Trinidad on Freeport-Todd’s road. Anomalocardia venezuelana, new species Pl. 39, figs. 3-6 Shell small, subrostrate behind, subequilaterally triangular in outline, the posterior end slightly produced, the valve inflated ex- cept after the middle where it is flattened. Lunular area gently con- cave, the anterior end acutely rounded, the basal margin arcuate in front, subtruncate behind, the posterior end bluntly cuneate, the posterodorsal margin hardly convex, with a slope of about 45 degrees. Umbonal region swollen, the beak fairly high, situated a little in front of the middle, prosogyrate. Lunule elongate-cordate, slightly depressed, vaguely defined by the edge of the disk. Escut- cheon elongate-elliptical, flattened, weakly delimited by the slight angulation at the margin of the disk, marked by faint growth striae. Surface sculpture consisting of fine subregular concentric mblets VENEZUELAN CENOZzOIC PELECYPODS: WEISBORD 275 on the umbo, succeeded below by widely spaced concentric laminae which become farther apart toward the base. There are approximate- ly 15 riblets and 10 laminae, the latter extending to, but not over the margins of the lunule and the escutcheon, and forming a rather acute angle at the posterior rostration. The spaces between the laminae are flat and shallow, and are marked by faint microscopic striae. Hinge of right valve with three discrete cardinal teeth, the anterior one a minor lamina, the middle one small but stubbily cuneate, the posterior one relatively long and platy. Along the posterodorsal margin of the right valve there is a long groove which receives the edge of the opposite valve. Adductor scars faint, the anterior scar high and ovate, the posterior low and broadly suboval. Pallial line remote from the margin and parallel with it. Pallial sinus small, nearly erect, and bluntly triangular, the apex lying a short distance from the posterior adductor scar and embayed to about the mid-line of the scar. Ventral margin crenulate, the margins of the lunule and escutcheon more finely so. Dimensions.—Holotype (C399a), right valve, length 2.5 mm.,; height 2.1 mm.; approx. thickness 0.8 mm. Paratype (C399b), right valve, length 2 mm.; height 1.75 mm.; approx. thickness 0.7 mm. Type locality—tLa Salina, west of Puerto Cabello, State of Carabobo. Three right valves. Comparisons.—This species is characterized by its high triangu- lar outline, laminar ribs, and subtruncate basal margin. In general appearance it is like the Recent A. auberiana (d’Orbigny) from Cuba, like the short high variation of the upper Miocene to Recent A. brasihana (Gmelin), and like the species referred to as Astarte meridionalis by Gabb (1881, p. 376, pl. 47, fig. 78) from the Plio- cene near Limon, Costa Rica. All three of those species, however, are depressed in front of the posterior rostration, and their basal margin is embayed in varying degree at the depression. According toy Dall.( 1902532. S.. Nat. Mus,, Proes, vol’ 26,°No:. 1312, ps 3.76) A. auberiana (d’Orbigny) (1842, Atlas, pl. 26, figs. 35-37; 1853, p. 277) is the same as A. puella (Pfeiffer) (1847, [in] Philippi, Abbildungen und Beschreibungen neuer oder wenig gekannter Con- chylien, vol. 2, pt. 4, p. 108), and if this is so, as also suggested by McLean (1951, p. 87, pl. 17, fig. 6), the name awberiana has priority. Recent specimens of A. auberiana from Cuba are more inflated and 276 BULLETIN 204 more attenuate posteriorly than A. venezuelana, n. sp. The type of A. meridionalis (Gabb) has broader concentric ribs than A. vene- zwelana, and the type of the Recent A. nesiotica Pilsbry (1930, Academy Nat. Sci. Philadelphia, Proc., vol. 82, p. 302) from the Bahamas is much more elongated than the Venezuelan fossil. Tivela (Tivela) mactroides (Born) Pl. 39, figs. 7-13 1681. [In] Buonanni, Ricreatione dell’ochio e della mente, pte. seconda, fig. 66. 1685. [In] Lister, Historiae sive synopsis methodicae Conchyliorum et Tabu- larum Anatomicarum, pl. 251, fig. 85. 1778. Venus mactroides Born, Index Rerum Naturalium Musei Caesarei Vindo- bonensis, pt. 1, p. 52. 1782. Venus mactroides Born, Chemnitz, Syst. Conchylien-Cabinet, vol. 6, pp. 624-625, pl. 31, fig. 326. 1786. Venus turgens Solander, A Catalogue of the Portland Museum, pp. 52, 68, 103, 152 (z.n.) 1791. Venus corbicula Gmelin, Syst. Nat., ed. 13, p. 3278, No. 39. 1807. Tivela vulgaris Link, Beschreibung der Naturalien-Sammlung der Uni- versitat zu Rostock, pt. 3, p. 152, [Fide Dall 1902]. 1811. Trigona radiata Megerle von Mihlfeld, Berlin Gesell. Naturf. Freunde Mag,., vol. 5, No. 1, p. 55. 1817. Trigona fasciata Schumacher, Essais d’un systéme des habitations des vers testacés, p. 153. [Fide Dall 1902]. 1817. Venus mactroides Born, Dillwyn, A Descriptive Catalogue of Recent Shells, vol. 1, p. 172, No. 33. : 1818. Cytherea corbicula (Gmelin), Lamarck, An. sans Vert., vol. 5, p. 563. 1825. Venus mactroides Born, Wood, Index Testaceologicus, p. 35, No. 33. 1838. Cytherea corbicula Lamarck, Gray, Analyst, vol. 8, p. 304. 1847. Cytherea corbicula Lamarck, Chenu, Illustrations Conchyliologiques, vol. 2, p. 70, pl. 2, figs. 6, 6a, 6b. 1853. Venus mactroides Born, d’Orbigny, [In] La Sagra, Hist. phys., polit. et nat. l’Ile de Cuba, vol. 2, pp. 266-267. 1853. Trigona mactroides (Born), Deshayes, Catalogue of the Conchifera or Bivalve Shells in the British Museum, pt. 1, p. 51. 1855. Cytherea corbicula Lamarck, Sowerby, Thesaurus Conchyliorum, vol. 2, p. 614, pl. 128, figs. 37-39. 1864. Tivela mactroides (Born), Romer, Novitates Conchologicae, ser. 2, vol. 1, suppl. 3, pp. 12-13, pl. 4, figs. 2, 2a, 2b. 1864. Cytherea mactroides (Born), Reeve, Conch. Icon., vol. 14, Cytherea, pl. Swspalsa,1sb) tse 1864. Venus mactroides Born, Krebs, The West Indian Marine Shells, p. 97. 1868. Cytherea mactroides (Born), Pfeiffer, Syst. Conchylien-Cabinet, vol. 11, p. 46, pl. 17, fig. 3. 1878. Cytherea mactroides (Born), Mérch, Catalogue of West-India Shells, ps 19; 1878. Venus mactroides Born, Arango y Molina, Contribucién a la Fauna Mala- col6gica Cubana, p. 250. 1889. Tivela mactroides (Born), Dall, U. S. Nat. Mus., Bull. 37, p. 56. 1900. Meretrix (Tivela) mactroides (Born), Dautzenberg, Soc. Zool. France, Mém., vol. 13, p. 248. 1902. Tivela mactroides (Born), Dall, U. S. Nat. Mus., Proc., vol. 26, No. 1312, pp. 349, 367-368. VENEZUELAN CENOzoIC PELECYPODS: WEISBORD 277 1903. Tivela corbicula (Gmelin), Dall, Wagner Free Inst. Sci., Trans., vol. 3, pt. 6, p. 1221. 1912. Tivela mactroides (Born), Jukes-Browne, Malac. Soc. London, Proc., vol. 10, p. 269, fig. 2. 1925. Tivela mactroides (Born), Maury, Bull. Amer. Paleont., vol. 25, No. 42, pp. 295-296, pl. 26, fig. 8; pl. 27, fig. 3. 1927. Tivela mactroides (Born), Palmer, Palaeontographica Americana, vol. 1, No. 5, pp. 319-320, pl. 22, figs. 1, 4, 6, 15, 20, 21, (1929). ' 1934. Tivela mactroides (Born), Johnson, Boston Soc. Nat. Hist., Proc., vol. 40, No. 1, p. 47. 1934. Tivela mactroides (Born), Maury, Amer. Mus. Nat. Hist., Bull., vol. 68, art. 4, pp. 163-164, pl. 19, fig. 3. 1937. Tivela mactroides (Born), Smith, East Coast Marine Shells, p. 52, pl. 18, fig. 1. 1937. Cytherea corbicula (Gmelin), Lamy and Fisher-Piette, Mus. Nat. Hist. nat. Paris, Bull., vol. 9, No. 1, p. 78. 1940. Tivela mactroides (Born), Smith, World-wide Sea Shells, p. 108, fig. 1430. 1942. Tivela mactroides (Born), Fischer-Piette and Fischer, Jour. Conchyl., vol. 85, pp. 41-43. 1945. Tivela mactroides (Born), van Bentham Jutting, Geolog.-Mijnbouwk. Genootschap Nederland en Kolonien, Geol. ser., vol. 14, p. 78. 1946. Tivela mactroides (Born), Stewart, Nautilus, vol. 60, No. 1, p. 19. 1948. Tivela mactroides (Born), Hertlein and Strong, Zoologica, vol. 33, pt. 4, No. 13, p. 166. 1949. Tivela mactroides (Born), Lange de Morretes, Mus. Paranaense, Arq,., vol. 7, art. 1, p. 36. 1951. Tivela mactroides (Born), McLean, New York Acad. Sci. Scientific Survey of Porto Rico and the Virgin Islands, vol. 17, pt. 1, p. 78, pl. 15, fig. 9. 1958. Tivela mactroides (Born), Olsson and McGinty, Bull. Amer. Paleont., vol. 39, No. 177, p. 21. 1961. Tivela (Tivela) mactroides (Born), Olsson, Panamic-Pacific Pelecypoda, p. 268. 1961. Tivela mactroides (Born), Warmke and Abbott, Caribbean Seashells, p. 188, pl. 39e. The Recent Higuerote shells are robust, gibbous, tightly closed, trigonal in outline, subequilateral, with the posterior end a little narrowed and produced, and with the posterodorsal margin slightly steeper and somewhat longer than the anterodorsal margin. Umbo high and full, the beak slightly forward of the median line and strongly bent over the hinge. Lunular area broadly cordate, hardly depressed, faintly defined at the margin, often cream-colored, with a swath of chestnut near the hinge margin. Escutcheonal area not defined, elongate-cordate, often dark brown in color. Exterior smooth but with numerous concentric lineations. Interior shiny. Hinge strong, with a stout anterior lateral. Along the posterodorsal 278 BULLETIN 204 margin there is a long groove on the right valve, and a lesser groove on the anterodorsal margin of the left valve. There are two sets of divided cardinal teeth, the posterior set coarsely serrated and more oblique than the anterior, the socket between the sets narrowly triangular. The right anterior lateral is a deep, somewhat elongate pit, the left anterior lateral an erect triangular tooth which fits into the pit of the opposite valve. Anterior muscle scar ovate, the posterior suborbicular. Pallial sinus short, oblique, “U”-shaped, well rounded at the forward end. Interior whitish but often stained a deep purple at the ends; on some specimens there are purplish hands in the umbonal cavity and a purplish tinge on part of the hinge. Exterior with alternating unequal rays of straw and chestnut, the rays of the right valve often more pronounced than those of the left valve on an individual pair. Dimensions—Specimen B543b, paired valves, height 41 mm.; length 48 mm.; thickness 29 mm. Specimen B543al, right valve of doublet, height 37 mm.; length 42.5 mm.; thickness 12.8 mm. Speci- men B543a2, left valve of same doublet, height 37.2 mm.; length 43 mm.; thickness 12.5 mm. Largest Recent specimen, left valve, height 44 mm.; length 52 mm.; thickness 15 mm. Specimen D546a, left valve, height 8 mm.; length 9.9 mm.; thickness 3.3 mm. This is badly worn. Localities —On beach, southeast of Higuerote, State of Miranda. One hundred nineteen specimens including eight doublets, forty- three right valves, and sixty-eight left valves. Abisinia formation at W-30, eastern edge of Playa Grande village. One left valve, the identification of which is not certain. Remarks.—The Pliocene to Recent 7. byronensis (Gray) (see Olsson, 1961, pp. 267-268, pl. 44, figs. 3, 6, 6a, 7, 8, 8a) from west America is a closely related species, and it is stated by Olsson that some specimens cannot be separated effectively if the locality is unknown. Range and distribution—Tivela mactroides (Born) is living in the Western Atlantic from the Florida Keys to Brazil. The fossil from the Abisinia formation (Pleistocene) referred to this species is not quite as tall as the typical Recent form but this may be due to wear. Another Pleistocene occurrence in Venezuela is recorded by van Bentham Jutting (1945, p. 78) from the Island of Margarita. VENEZUELAN CENOzoIC PELECYpopDS: WEISBORD 279 Tivela (Planitivela) venezuelana, new species Pl233;, fig: 7; Pl. 40, figs. 1-4 Shell small, scarcely inflated, somewhat inequilateral, subtri- gonally ovate, the anterior end somewhat narrowed and a little produced. Anterodorsal margin straight, anterior end sharply round- _ed, basal margin shallowly arcuate, posterior end well rounded, posterodorsal margin slightly convex. Beak low, situated a little behind the middle. Lunule hardly depressed, long, subelliptical, faintly defined by a narrow crease. Escutcheonal area small, narrow, arcuate, undefined. Surface smooth, marked, below the subhyaline prodissoconch, by fine concentric lineations. Hinge of right valve with a long anterior lateral groove bordered above by another fine groove along the anterodorsal margin, the two grooves separated by a thin lamina; at the base of the main lateral groove is another lamina, this connected with the anterior cardinal; the middle cardinal of the right valve is rather sturdy and narrowly wedge- shaped, and is separated from the posterior cardinal by a narrowly triangular socket; the right posterior cardinal is the largest of the triad and is shallowly sulcate. Hinge of left valve with a long an- terior lateral groove similar to that of the right valve, the lamina at the base of the groove joining the left anterior cardinal which’ is also laminar; atop the lateral groove is another delicate groove extending along the anterodorsal margin to near the anterior end of the valve; behind the left anterior cardinal are two slightly di- vergent cardinal teeth, and joining the hinder one of those is a posterior lamina which borders the fine groove at the posterodorsal margin. Adductor scars faint, the anterior moderately elongate and a little arcuate, the posterior scar broadly oval. Pallial sinus dimly lined, but under proper light it can be seen to arise at the base of the posterior adductor scar, extend obliquely forward in a U- shaped outline for about a third the length of the valve, and to be well rounded at the apex. Inner edge of ventral margin smooth, slightly beveled. Dimensions—Holotype (J451la), right valve, height 4.1 mm.,; length 5 mm.; thickness 1.3 mm. Paratype (1457a), right valve, height 6 mm.; length 8 mm.; thickness 1.8 mm. Paratype (T45la), left valve, height 3.9 mm.; length 4.8 mm.; length 4.8 mm.; thick- ness 1.2 mm. 280 BuLLeETIN 204 Type locality—Lower Mare formation, in small stream 100 meters west of Quebrada Mare Abajo. One right valve. Other localities—Lower Mare formation at W-13, on hillside above west bank of Quebrada Mare Abajo. One right valve. Upper Mare formation, in stream 250 meters south-southwest of mouth of Quebrada Las Pailas. Two left valves. Comparisons —Tivela venezuelana, n. sp., as represented by four young shells, is characterized by its slightly produced anterior end and its scarcely inflated valves. It is reminiscent of the Recent Eastern Pacific T. planulata (Broderip and Sowerby) (see Olsson, 1961, Panamic-Pacific Pelecypoda, pp. 269-270, pl. 44, figs. 5, 5a) but is less sharply trigonal than that. Gouldia venezuelana, new species Pl. 40, figs. 5-15 Shell small, somewhat compressed, subequilateral, rounded-sub- quadrate. Anterodorsal margin nearly straight, the ends of the valve well rounded, the ventral margin nearly semicircular, the postero- dorsal margin straight to hardly convex. Umbonal region a little inflated, the beak subcentral, rather low, prosogyrate. Lunule large, long, and elliptical, bounded by a fine impressed line, marked by fine growth striae. Escutcheon wanting. Surface sculptured by low regular concentric riblets reticulated, particularly on the posterior half and anterior quarter of the valve, by subregular radial threads, the radii obsolescent on the middle-anterior half of the disk, the spaces enclosed by the concentric and radial elements in the form of square or rectangular pits. Base of hinge plate bowed down under the anterior lateral, more or less horizontal under the middle and posterior cardinals. Anterior lateral of right valve a small, some- what elongated pit, with a minor lamina above and a thickened border below, the pit connected, via a shallower sulcus, with the deep interspace between the anterior and middle cardinals. Right anterior cardinal tooth platy, united above with the posterior tooth which is relatively thick and elongated; the right middle cardinal is separate, cuneate, and intermediate in size. Along the postero- dorsal margin of the nght valve, extending from the rear of the ligament to the curve of the posterior end, there is a narrow groove which receives the edge of the opposite valve. Hinge of left valve VENEZUELAN CENOzoIC PELECYPODS: WEISBORD 281 with a prominent anterior lateral tooth, the groove above it strong and continuing to the top of the left anterior cardinal. The anterior and middle cardinals of the left valve are united above to form a caret, the anterior tooth sublaminar and smaller than the stout medial tooth; the left posterior cardinal is the largest of the triad, and is narrowly wedge-shaped. The anterodorsal margin of the left valve also bears a fine groove extending from near the beak along the inner edge of the lunule to the curve of the anterior end. Anterior adductor scar ovate, scarcely impressed, the posterior scar faintly visible and seemingly suboval. Pallial line well removed from the margin, embayed slightly in front of the posterior adductor scar. Margin smooth within, somewhat beveled. Dimensions.—Holotype (S533b), right valve, length 1.6 mm.; width 1.4 mm. Paratype ($533a), estimated length 1.7 mm.; height 1.5 mm. (This specimen was broken after it was photographed). Paratype (S532a), right valve, length 2.1 mm.; height 1.9 mm. Paratype (S422a), right valve, length 3.2 mm.; height 2.8 mm. Paratype (H42la), broken left valve, length 5 mm. Paratype (H527a,) hinge area of left valve, length 4.7 mm. Type locality—Playa Grande formation (Maiquetia member) at W-23, north flank of Punta Gorda anticline. Four right valves. Other localities —Mare formation at W-25, south flank of Punta Gorda anticline. Two left valves. Comparisons.—The nearest related species is the middle Mio- cene G. limonensis Olsson (1922, pp. 405-406, pl. 32, fig. 18) from Port Limon, Costa Rica, that, however, having a more orbicular outline and a more convex posterodorsal margin. The Recent G. cerina (C. B. Adams) (see Clench and Turner, 1950, Occas. Papers on Mollusks, vol. 1, No. 15, p. 265, pl. 44, figs. 7-8), which ranges from North Carolina, U. S. A., to Brazil, in depths of 1 to 95 fathoms, is a more trigonal shell than G. venezuelana, n. sp. The west American G. californica Dall (see Olsson, 1961, Panamic- Pacific Pelecypoda, p. 271, pl. 39, fig. 9) is strongly reticulated over the whole of the disk, whereas on the Venezuelan fossil the radial sculpture is obsolete on the middle anterior area of the disk. The Recent G. californica ranges from the Gulf of California to Ecuador, and occurs in the Pleistocene (as G. stephensae E. K. Jordan) at Magdalena Bay, Baja California, México. Circe (pro- 282 Bu..etin 204 bably Gouldia) bermudensis Smith (1885, Voyage H.M.S. Challeng- er, Zoology, vol. 13, pp. 143-144, pl. 2, figs. 1-1b), dredged in coral mud off Bermuda at a depth of 435 fathoms, is much more deli- cately reticulated than G. venezwelana. The late Tertiary G. meta- striata (Conrad) (see Mansfield, 1932, Florida State Geol. Sur., Bull., No. 8, pp. 119-120, pl. 23, figs. 1-2), which is known from the upper Miocene and Pliocene from Virginia to Florida, is, like G. cerina (C. B. Adams), a more trigonal shell than the new Vene- zuelan fossil. Gouldia ? diffidentia, new species Pl. 40, figs. 16, 17 Shell minute, hyaline, subtranslucent, suboval, moderately com- pressed, slightly oblique, inequilateral, the anterior end produced. Anterodorsal margin long and straight, sloping at an angle of about 20 degrees from the horizontal, anterior end well rounded and a little narrowed, ventral margin arcuate, posterior end shallowly rounded, posterodorsal margin short and straight, sloping about 30 degrees from the horizontal. Umbonal region somewhat swollen, the beak directed forward, situated at about the posterior third. Lunule not defined, the escutcheon wanting. Surface sculptured by small, faint, subregular concentric riblets, but there are no radial markings. Hinge of left valve with anterior lateral and three car- dinal teeth. The lateral tooth is low and laminar, the groove above it extending to the top of the anterior cardinal. The anterior and middle cardinals are united above to form a rounded apex, the anterior cardinal flaring out below and continuing along the lower margin of the groove to join the lateral lamina. Looking down to the top of the hinge, the flare of the anterior cardinal is seen to produce a spoon-shaped process. The left posterior cardinal is slightly arcuate and narrowly cuneate, the groove of the nymph behind it narrow and shallow. Adductor scars dimly outlined, the anterior one slightly arcuate and suboval, the posterior scar sub- angularly ovate. Pallial line arcuate, shallowly and broadly embayed in front of the posterior adductor scar. Inner margin smooth. Dimensions —Holotype (1510a), left valve, length 1.7 mm.; height 1.2 mm. Type locality—Lower Mare formation at W-13, on hillside VENEZUELAN CENOzOIC PELECYPODS: WEISBORD 283 above west bank of Quebrada Mare Abajo. One juvenile left valve, the holotype. Remarks.—The long anterior end, and the absence of radial striae differentiate this shell from other American species. The character of the hinge and the slight pallial sinus suggest that it pertains to the genus Gouwldia. Transennella caboblanquensis, new species Pl. 41, figs. 1-8 Shell small, porcelaneous, moderately inflated, oval-subtrigonal, subequilateral to inequilateral. Lunular margin slightly undulatory and bowed down slightly just before the curve of the anterior end, anterior end broadly rounded, ventral margin shallowly rounded, posterior end acutely rounded, posterodorsal margin hardly convex to slightly humped. Umbo fairly plump, the beak prosogyrate, situ- ated a little forward of the middle. Lunule large, cordate, circum- scribed by a fine shallow sulcus, and marked by microscopic con- centric striae. Escutcheon not defined. Surface polished and smooth, traversed by minute, nearly obsolete concentric wrinkles. On one well-preserved specimen there are also closely spaced microscopic radial filaments here and there on the surface, but these radii have not been observed on other examples. Hinge of right valve with an elevated platy posterior cardinal and two laminar anterior cardinals separated by a deep narrow slit; in front of the right anterior set of cardinals is a binary lateral, the lower tooth fairly thick, the upper one more or less laminar, with a moderately elongate pit between them, the pit receiving the strong anterior lateral tooth of the left valve. Hinge of left valve with a laminar posterior cardinal, a mod- erately stout cuneate medial cardinal, and a smaller anterior cardinal, the latter two converging to unite immediately under the beak, the socket between them triangular. The muscle scars are hardly visible, the anterior one high and ovate, the posterior scar exceedingly faint and seemingly pyriform. Pallial line remote from the margin, uniting with the basal limb of the pallial sinus to form an acute angulation. Pallial sinus broad, U-shaped, the embayment slightly ascending to nearly horizontal, the limbs subparallel, the apex bluntly rounded and reaching to about the center of the valve. Inner margin some- what beveled, bearing the grooves characteristic of the genus. These 284 BuLteTIn 204 marginal grooves are fairly coarse, two or three in number along the base, subparallel with the edge of the valve, discontinuous, with their ends overlapping, occurring from immediately in front of the beak around the margin to the rear of the nymph. Dimensions——Holotype (1516c), right valve, length 4.5 mm.; height 3.6 mm.; thickness 1.8 mm. Paratype (1516b), right valve, length 5.5 mm.; height 4.8 mm.; thickness 2 mm. Paratype (1516a), left valve, length 3 mm.; height 2.5 mm.; thickness 1 mm. Paratype (T517a), left valve, length of fragment 1.9 mm. Paratype (T517b), right valve, height of fragment 2.5 mm.; thickness of valve 0.9 mm. Largest specimen, left valve, not figured, length 7.7 mm.; height 6.2 mm.; thickness 2 mm. Type locality—Lower Mare formation at W-13, on hillside above west bank of Quebrada Mare Abajo. Four specimens includ- ing two right valves and two left valves. Other localities—Lower Mare formation, in small stream 100 meters west of Quebrada Mare Abajo. Ten specimens including five right valves and five left valves. Upper Mare formation at W-14, on hillside above west bank of Quebrada Mare Abajo. One left valve. Upper mare formation, in stream 250 meters south-southwest of mouth of Quebrada Las Pailas. Two specimens including one right and one left valve. Playa Grande formation (Maiquetfa member) at W-23, north flank of Punta Gorda anticline. Four specimens in- cluding three juvenile left valves and one adult right valve. Comparisons ——The nearest related species is the Recent 7. culebrana (Dall and Simpson) (1901, U. S. Fish Com., Bull., vol. 20 for 1900, pt. 1, p. 486, pl. 55, fig. 5), but compared with the type of T. culebrana (No. 160064, U. S. National Museum), the Venezuelan fossil is not so sturdy, and is oval-subtrigonal in outline rather than subtrigonal. Also, the posterodorsal margin is slightly convex on T. caboblanquensis, n. sp. whereas T. culebrana has a longer and straighter posterodorsal margin and a slightly sharper posterior end. Other east American species with which the Venezuelan fossil exhibits affinity are the following: T. cubaniana (d’Orbigny) (1842, [in] La Sagra, Hist. phys., polit. et nat. ’Ile de Cuba, vol. 2, p. 278 (1853), Atlas, pl. 26, figs. 44-46). Recent from Florida to the West Indies. The concentric VENEZUELAN CENOZOIC PELECYPODS: WEISBORD 285 lineations of the surface are stronger and more regular than on 7. caboblanquensts. T. gerrardi Abbott (1958, Acad. Nat. Sci. Philadelphia, Mon. No. 11, pp. 130-131, text fig. 7, pl. 4a-c). Recent, Grand Cayman Island. The union of the pallial line and pallial sinus is narrowly and acutely rounded; on 7. caboblanquensis it is sharply angulate. T. stimpsom (Dall) (see Abbott, 1954, American Seashells, pp. 412-413, figs. 83a, b). Recent, North Carolina to the Bahamas; Pleistocene, Florida. The marginal grooves are more numerous and more tangential to the anterior edge of the shell than they are on T. caboblanquensis. Also the pallial sinus is narrower on T. stimp- SOn1. T. conradina (Dall) (see Dall, 1902, U. S. Nat. Mus., Proc., vol. 26, No. 1312, pp. 348, 367, 379, pl. 13, fig. 6). Pleistocene to Recent. This is more acuminate posteriorly than the Venezuelan fossil. T. caloosana Dall (1903, Wagner Free Inst. Sci., Trans., vol. 3, pt. 6, pp. 1242-1243, pl. 57, fig. 2). Upper Miocene to Pleistocene in Florida. The shape is more oval than that of T. caboblanquensis. T. carolinensis Dall (1903, p. 1242, pl. 55, fig. 4). Upper Mio- cene in Virginia, North Carolina, and South Carolina; Pliocene in North Carolina. The outline is nearly equilateral whereas the Cabo Blanco shell is subequilateral to inequilateral. Transennella venezuelana, new species Pl. 41, figs. 9, 10 Shell small, moderately solid, high and obtusely trigonal, strongly inflated, subequilateral, the posterior submargin flattened. Anterodorsal margin short, straight, and steeply sloping, anterior end well rounded, ventral margin hardly arcuate, posterior end slightly narrowed and rounded, posterodorsal margin obliquely sub- truncate below, convex above. Umbonal area swollen, the beak high, subcentral, prosogyrate. Lunule large, broadly elliptical, not depressed, bounded by a fine hardly impressed line, marked by faint obsolete growth lineations. Escutcheon wanting. Surface smooth but scored by faint microscopic concentric grooves and by occasional narrow sulci along lines of arrested growth. Hinge strong, the base of the hinge plate rather angulately undulatory. Left an- terior lateral a high platy triangular tooth with a rounded apex, 286 BuLtetTin 204 the tooth separated from the margin by a narrow groove. The three cardinal teeth of the left valve are divergent, the anterior one thin, sharp, and slightly curved, the middle tooth high, asymmetrically wedge-shaped, and slightly sulcate, the posterior tooth laminar and affixed to the side of the nymph. Ligamental groove behind nymph narrow and moderately deep. Adductor scars dimly outlined, pyri- form, the posterior scar a little broader than the anterior. Pallial line remote from and parallel with the ventral margin. Pallial sinus broad and deeply embayed, the upper line of the sinus subangulate, the apex rounded, projected nearly horizontally to a little beyond the middle of the interior, Inner margins with one to two long fine transennellid grooves, the grooves nearly parallel with the ventral margin, somewhat tangential with the lateral margins. Dimensions—Holotype (S552a), left valve, length 6.2 mm.; height 5.5 mm.; thickness 1.7 mm. Type locality.—Playa Grande formation (Maiquetia member) at W-23, north flank of Punta Gorda anticline. One left valve, the holotype. Comparisons.—This is a high, obtusely trigonal, strongly in- flated shell, with a broad, deep pallial sinus. Among the American species of Transennella listed on the preceding page, T. venezuelana, n. sp., is most closely related to T. carolinensis Dall, differing from that, however, by its higher beak, larger pallial sinus, and more tumid valves. Macrocallista maculata (Linnaeus) Pl. 41, figs. 11-15 Pl. 42, figs. 1-6 1758. Venus maculata Linnaeus, Syst. Nat., ed. 10, p. 686, No. 101. 1767. Venus maculata Linnaeus, Syst. Nat., ed. 12, p. 1132, No. 126. 1782. Venus maculata Linnaeus, Chemnitz, Syst. Conchylien-Cabinet, vol. 6, p. 347, pl. 33, fig. 345. 1818. Cytherea maculata (Linnaeus), Lamarck, An. sans Vert., vol. 5, p. 566, 1838. Chione maculata (Linnaeus), Gray, Analyst, vol. 8, p. 306. 1851. Cytherea maculata (Linnaeus), Sowerby, Thes. Conchyl., vol. 2, p. 629, pl. 131, fig. 97. 1853. Dione maculata (Linnaeus), Deshayes, Catalogue of the Conchifera or Bivalve Shells in the British Museum, pt. 1, Veneridae, p. 57. 1853. Callista maculata (Linnaeus), Mérch, Catalogus Conchyliorum Comes de Yoldi, pt. 2, p. 28. 1853. Venus maculata Linnaeus, d’Orbigny. [In] La Sagra, Hist. phys., polit. et. nat. I’Ile de Cuba, vol. 2, pp. 269-270. 1863. Dione maculata (Linnaeus), Reeve, Conch. Icon., vol. 15, pl. 3, sp. 11. 1864. Venus maculata Linnaeus, Krebs, The West Indian Marine Shells, p. 97. 1878. 1878. 1881. 1888. 1889. 1889. 1889. 1889. 1892. 1901. 1902. 1903. 1911. 1916. 1920. 1921. 1922. 1923. 1925. 1925. 1926. 1926. 1927. 1927. 1929. 1934. 1936. 1936. VENEZUELAN CENOZOIC PELECYPODS: WEISBORD 287 Cytherea maculata (Linnaeus), Mérch, Catalogue of West-India Shells, ps 15: Venus maculata Linnaeus, Arango y Molina, Contribucién a la Fauna Malacoldégica Cubana, p. 250. Callista maculata (Linnaeus), Gabb, Acad. Nat. Sci. Philadelphia, Jour., ser. 2, vol. 8, pp. 344, 372. Cytherea maculata (Linnaeus), Schepman, [in] Martin, Bericht tber eine Reise nach Nederlandisch West-Indien und darauf gegriindete Studien, Leiden: II-Geologische Studien, Appendix. Callista maculata (Linnaeus), Dall, U. S. Nat. Mus., Proc., vol. 12, No. Mdasap. 2lae Cytherea maculata (Linnaeus), Lorié, Samm]. Geol. Reichs-Mus. Leiden, ser. 2, vol. 1, pp. 127, 141. Cytherea (Callista) maculata (Linnaeus), Dall, U. S. Nat. Mus., Bull. 37) Dp 56: Cytherea maculata (Linnaeus), Simpson, Davenport Acad. Nat. Sci., Proc., vol. 5, p. 64. Callista maculata (Linnaeus), Singley, Geol. Survey Texas, Fourth An. Rept., p. 327. Meretrix maculata (Linnaeus), Dall and Simpson, U. S. Fish Com., Bull., vol. 20 for 1900, pt. 1, p. 485. Macrocallista (Chionella) maculata (Linnaeus), Dall, U. S. Nat. Mus., Proc., vol. 26, No. 1312, p. 369. Macrocallista (Chionella) maculata (Linnaeus), Dall, Wagner Free Inst. Sci.. Trans., vol. 3, pt. 6, pp. 1256-1257. Macrocallista maculata (Linnaeus), Brown and Pilsbry, Acad. Nat. Sci. Philadelphia, Proc., vol. 63, p. 370. Macrocallista maculata (Linnaeus), Mansfield, U. S. Nat. Mus., Proc., vol. 51, No. 2169, p. 602. Macrocallista (Paradione) maculata (Linnaeus), Maury, Bull. Amer. Paleont., vol. 8, No. 34, p. 100. Macrocallista maculata (Linnaeus), Pilsbry, Acad. Nat. Sci. Philadelphia, Proc., vol. 73, p. 422. Macrocallista (Chionella) maculata (Linnaeus), Olsson, Bull. Amer. Pa- leont., vol. 9, No. 39, pp. 406-407, pl. 31, figs. 6-7. Macrocallista maculata (Linnaeus), Clench, Nautilus, vol. 37, No. 2, p. 55. Macrocallista (Chionella) maculata (Linnaeus), Maury, Bull. Amer. Paleont., vol. 10, No. 42, pp. 297-298, pl. 25, figs. 1, 4, 5. Macrocallista (Paradione) maculata (Linnaeus), Maury, Serv. Geol. Min. Brazil, Mon. No. 4, p. 321, pl. 18, figs. 8-9. Macrocallista (Paradione) maculata (Linnaeus), Gardner, U. S. Geol. Sur., Prof. Paper 142-D, pp. 160-161. Macrocallista maculata (Linnaeus), Weisbord, Nautilus, vol. 39, No. 3, p. 86. Macrocallista maculata (Linnaeus), F. Hodson, H. K. Hodson, and Harris, Bull. Amer. Paleont., vol. 13, No. 49, p. 54, pl. 32, fig. 6. Callista (Callista) maculata (Linnaeus), Palmer, Palaeontographica Americana, vol. 1, No. 5, pp. 77-78 (1927), pl. 10, fig. 11; pl. 12, figs. 1-3, 8-9 (1929). Macrocallista (Chionella) maculata (Linnaeus), Anderson, California Acad. Sci., Proc., ser. 4, vol. 18, No. 4, p. 170. Macrocallista (Chionella) maculata (Linnaeus), Johnson, Boston Soc. Nat. Hist., Proc., vol. 40, No. 1, p. 47. Macrocallista (Paradione) maculata (Linnaeus), McLean, Soc. Cubana Hist. Nat. “Felipe Poey,’ Mem., vol. 10, No. 1, p. 41. Macrocallista maculata (Linnaeus), McLean, Nautilus, vol. 49, No. 4, p. 118. 288 1937. 1938. 1938. 1939. 1939. 1940. 1942. 1943. 1945. 1946. 1949. 1951. 1952. 1952. 1953. 1953. 1954. 1955° 1956. 1957 1958. 1958. 1959. 1961. 1961. 1961. Bu.Ltetin 204 Macrocallista maculata (Linnaeus), Smith, East Coast Marine Shells, p. 52, pl. 52, pl. 20, fig. 1. Macrocallista (Paradione) maculata (Linnaeus), Vokes, Amer. Mus. Novitates, No. 988, p. 3. Macrocallista maculata (Linnaeus), Richards, Geol. Soc. Amer., Bull., vol. 49, pt. 2, p. 1291. Macrocallista maculata (Linnaeus), Mansfield, State of Florida Dept. Conserv., Geol. Bull. No. 18, pp. 19, 23, 26, 39. Macrocallista maculata (Linnaeus), Woodring, [in] Kehrer, Amer. Assoc. Petrol. Geol., Bull., vol. 39, No. 12, p. 1853. Peea ts maculata (Linnaeus), Smith, World-wide Sea Shells, p. 109, ig. 1440. ees maculata (Linnaeus), Clench, Johnsonia, vol. 1, No. 3, pp. 6-7, pl. 5. Macrocallista (Chionella) maculata (Linneaus), Rutsch, Naturforsch. Gesell. Basel, Verhandl., vol. 54, p. 102. Pitaria maculata (Linnaeus), van Bentham Jutting, Geolog.-Mijnbouwk. Genootschap Nederland en Kolonien, Geol. ser., vol. 14, p. 78. Macrocallista (Chionella) maculata (Linnaeus), Jaume, Soc. Malac. “Carlos de La Torre” Rev., vol. 4, No. 3, p. 101. Macrocallista maculata (Linnaeus), Lange de Morretes, Mus. Para- naense, Arq., vol. 7, pt. 1, p. 36. Macrocallista maculata (Linnaeus), McLean, New York Acad. Sci. Sci- entific Survey of Porto Rico and the Virgin Islands, vol. 17, pt. 1, p. 79, pl. 16, fig. 1. Macrocallista maculata (Linnaeus), Pulley, Texas Jour. Sci., vol. 4, No. 2, p. 183. Venus maculata Linnaeus, Dodge, Amer. Mus. Nat. Hist., Bull., vol. 100, art. 1, p. 100. Macrocallista (Macrocallista) maculata (Linnaeus), Olsson and Har- bison, Acad. Nat. Sci. Philadelphia, Mon. No. 8, p. 109. Pitar (Paradione) maculatus (Linnaeus), Haas, Fieldiana-Zoology, vol. 34, No. 20, p. 203. Macrocallista maculata (Linnaeus), Abbott, American Seashells, p. 416, pls. 1b, 39e. Macrocallista maculata (Linnaeus), Perry and Schwengel, Marine Shells of the Western Coast of Florida, p. 72, pl. 13, fig. 82. Macrocallista maculata (Linnaeus), Parker, Amer. Assoc. Petrol. Geol., Bull., vol. 40, No. 2, pp. 309, 317, 318, 367, 371. Macrocallista maculata (Linnaeus), Weisbord, Bull. Amer. Paleont., vol. 38, No. 165, p. 19. Macrocallista maculata (Linnaeus), Olsson and McGinty, Bull. Amer. Paleont., vol. 39, No. 177, p. 21. Macrocallista (Paradione) maculata (Linnaeus), DuBar, Florida Geol. Sur., Geol. Bull. No. 40, pp. 172-173. Macrocallista maculata (Linnaeus), Nowell-Usticke, A Check List of the Marine Shells of St. Croix, p. 16. Macrocallista maculata (Linnaeus), van Regteren Altena, Koninkl. Akad. Wetensch.-Amsterdam, Proc., Ser. B, vol. 64, No. 2, p. 300. Macrocallista maculata (Linnaeus), Olsson, Panamic-Pacific Pelecypoda, p. 273. Macrocallista maculata (Linnaeus), Warmke and Abbott, Carribean Sea- shells, pp. 189-190, pl. 39f. The Cabo Blanco fossil referred to this species is porcelaneous and white, large, fairly thin, moderately compressed, flattened pos- VENEZUELAN CENOzoIC PELECYPoDS: WEISBORD 289 teriorly, the flattening generally delimited rather sharply from the disk. The majority of specimens are transversely ovate-trigonal, with some relatively broader than others, but there are a few young shells that are nearly oval in outline. On the former, the dorsal margin is humped in greater or lesser degree, and the posterior end is subangular at the curve with the basal margin. The oval form is rather regularly rounded at the ends, and the posterior flattening is very gentle. The hinge and other characteristics of the two forms are identical, and there is little question that they both pertain to the same species. Umbo moderately convex, the beak acute, proso- gyrate, situated at the anterior third. Lunule elongate-cordate, hardly depressed, defined by a faintly impressed line, the right half of the lunule a little wider than the left half, marked by fine striae continuing from the disk. Escutcheon not defined. External sur- face smooth except for minute concentric lineations which become pronounced on the weathered surface. Ligamental platform elongate- lanceolate, the inner edge at the border of the nymph closely and finely corrugated. Dentition typical of the genus, the anterior left lateral tooth large, upright, triangular, fitting into the correspond- ing socket of the opposite valve. Right valve with a long faint groove starting at the angle of the posterodorsal margin and extend- ing more than half way along the posterior margin, the edge of the left valve fitting into this groove. Anterior adductor scar high, rather strongly impressed, broadly ovate and with a fairly straight inner margin, the posterior scar inconspicuous, slightly larger than the anterior, the base of the scar acutely rounded. Pallial sinus wide, convergent in front, the sides subparallel, the apex acute, embayed nearly horizontally to the median line of the valve a little below the center. The surface layer of the shell flakes off readily and only rarely is the layer intact. Dimensions —Specimen G295a, left valve, length 64 mm.; height 50 mm.; thickness 14 mm. Specimen G295b, right valve, length 72.5 mm.; height 54 mm.; thickness 12 mm. Specimen G295c, left valve, length 33 mm.; height 25.7 mm.; thickness 6.8 mm. Specimen G295d, right valve, length 41.5 mm.; height 32 mm.; thickness 10 mm. Specimen G295e, left valve, length 13.9 mm.; height 10.1 mm.; thickness 2.8 mm. Specimen G295f, right valve, length 14.6 mm.; height 11.4 mm.; thickness 3.3 mm. Specimen 290 BULLETIN 204 G295g (immature oval form), left valve, length 3 mm.; height 2.2 mm.; thickness 1.1 mm. Specimen G295h (immature oval form), length 5.8 mm.; height 4.4 mm.; thickness 1.2 mm. Specimen E295a, doublet, length 71 mm.; height 54 mm.; thickness 31.5 mm. Speci- men 1295a, right valve, length 33.2 mm.; height 28.4 mm.; thick- ness 6.6 mm. Specimen M295a, internal mold of attached pair, length 65 mm.; height 48 mm.; thickness 26 mm. Localities—Upper Mare formation at and near W-14, on hill- side above west bank of Quebrada Mare Abajo. Three hundred forty-six specimens including sixteen doublets, one hundred fifty- seven left valves, and one hundred seventy-three right valves. Upper Mare formation, in stream 250 meters south-southwest of mouth of Quebrada Las Pailas. Twenty specimens including thirteen left valves, six right valves, and one doublet. Upper Mare formation, 115 meters south-southeast of crossing of Quebrada Mare Abajo and coast road and 90 meters southeast of W-12. Nine specimens including four left valves, four right valves, and one doublet. Mare formation at W-25, south flank of Punta Gorda anticline. Fifteen specimens including nine right valves and six left valves. Lower Mare formation at W-13, on hillside above west bank of Quebrada Mare Abajo. Forty-eight specimens (mostly young) including twenty-nine right valves and nineteen left valves. Lower Mare for- mation, in small stream 100 meters west of Quebrada Mare Abajo. One right valve. Playa Grande formation (Maiquetia member) at W-23, north flank of Punta Gorda anticline. Two specimens including one right valve and one left valve. Playa Grande formation at W-26, in Quebrada Las Bruscas approximately 125 meters upstream from junction with Quebrada Las Pailas. Thirteen specimens (mostly young) including seven left valves and six right valves. Playa Grande formation (Catia member), in bluff 125 meters west of the intersec- tion of the Playa Grande Yachting Club road and coast road. One in- ternal mold of a paired specimen. Playa Grande formation (Catia member) at W-15, south side of Playa Grande road about 40 meters southeast of its intersection with the Playa Grande Yachting Club road. Eleven doublets, all of them internal molds. La Salina, west of Puerto Cabello, State of Carabobo. Four specimens including three left valves and one right valve. All of these specimens are immature and worn, and the identification is somewhat in doubt. VENEZUELAN CENOzoIC PELECYPoDS: WEISBORD 291 Remarks.—This fossil occurs in great numbers in the Cabo Blanco area, especially in the upper Mare formation where all sizes are found. Large specimens are rare in the lower Mare formation and in the Maiquetia member of the Playa Grande formation but are present again in abundance as molds in the Catia member of the Playa Grande formation. The posterior flattening on the Cabo Blanco fossils is a little more pronounced than on Recent specimens of M. maculata macu- lata but otherwise the shells are identical. Range and distribution—Lower Miocene to Recent. Living from North Carolina, U. S. A., to Brazil, in depths to 40 fathoms. Pleistocene in South Carolina, Florida, St. Kitts, St. Eustatius, Aruba, Curacao, and on the Island of Cubagua, Venezuela. Pliocene in Florida, Costa Rica, and Venezuela (near Cumana, in Collection No. 18408 of the U. S. National Museum). Upper Miocene in Florida ? and Trinidad. Middle Miocene in Alabama ?, Florida, Dominican Republic, Costa Rica, Panama, Colombia, and Vene- zuela. Lower Miocene in Venezuela. Miocene, Brazil. Pitar (Pitar) albida (Gmelin) Pl. 42, figs. 7, 8 1791. Venus albida Gmelin, Syst. Nat., ed. 13, p. 3287. 1853. Dione albida (Gmelin), Deshayes, Catalogue of the Conchifera or Bivalve Shells in the British Museum, pt. 1, Veneridae, p. 68. 1863. Dione albida (Gmelin), Reeve, Conch. Icon., vol. 14, pl. 10, sp. 39. 1864. Venus albida Gmelin, Krebs, The West Indian Marine Shells, p. 95. 1867. Caryatis albida (Gmelin), Rémer, Novitates Conchologicae, Suppl. 3, vol. 1, p. 91, pl. 14, fig. 4. 1885. Cytherea albida (Gmelin), Dall, U. S. Geol. Sur., Bull. No. 24, p. 102. 1886. Cytherea albida ? (Gmelin), Dall, Mus. Comp. Zool., Bull., vol. 12, No. 65. 276: 1889. Cytherea albida (Gmelin), Dall, U. S. Nat. Mus., Bull. 37, p. 56. 1901. Meretrix albida (Gmelin), Dall and Simpson, U. S. Fish Com., Bull., vol. 20 for 1900, pt. 1, p. 485. 1902. Pitaria albida (Gmelin), Dall, U. S. Nat. Mus., Proc., vol. 26, No. 1312, pp. 370-371. 1925. Pitaria albida (Gmelin), Maury, Bull. Amer. Paleont., vol. 10, No. 42, p. 299. 1927. Pitaria (Pitaria) albida (Gmelin), Palmer, Palaeontographica Ameri- cana, vol. 1, No. 5, pp. 25-26, pl. 6, figs. 17, 18, 20 (1929). 1933. Cytherea (Dione) albida (Gmelin), Trechmann, Geol. Mag., vol. 70, No. 823, p. 35. 1934. Pitar albida (Gmelin), Johnson, Boston Soc. Nat. Hist., Proc., vol. 40, No. 1, p. 47. 1936. Cytherea albida (Gmelin), Lermond, Check List of Florida Marine Shells, Gulfport, p. 8. 292 BuLLeETIN 204 1949. Pitar (Pitar) albidum (Gmelin), Lange de Morretes, Mus. Paranaense, ATO aVOl. 7, Arts ly Ds 356 1951. Pitar (Pitar) albida (Gmelin), McLean, New York Acad. Sci. Scientific puree of Porto Rico and the Virgin Islands, vol. 17, pt. 1, p. 80, pl. 16, ig. 3. 1954. Pitar (Pitar) albida (Gmelin), Abbott, American Seashells, p. 414. 1959. Pitar albida (Gmelin), Nowell-Usticke, A Check List of the Marine Shells of St. Croix, pp. 15, 16. 1961. Pitar (Pitar) albida (Gmelin), Warmke and Abbott, Caribbean Sea- shells, p. 188, pl. 39n. The immature shell referred to this species is small, sturdy, moderately inflated, oval-subtrigonal, subequilateral. Lunular mar- gin slightly undulatory, anterior end a little attenuated and rather sharply rounded, ventral margin arcuate, posterior end shallowly rounded, posterodorsal margin hardly convex. Lunule elongate- cordate, outlined by the merest suggestion of an impressed line, nearly smooth except for scarcely discernible concentric growth striae. Escutcheon narrowly subelliptical, not well defined, bordered by the low subrounded edge of the disk, also nearly smooth. Um- bonal region rather prominent, the beak subcentral, prosogyrate. Surface obsoletely marked by minute concentric wrinkles and scored here and there by exceedingly faint microscopic lineations. Hinge of right valve with a moderately stout, vaguely sulcate posterior cardinal, that united above to the much smaller and laminar anterior cardinal, the arch underlain by the central cardinal which is inter- mediate in size. The right anterior lateral is represented by a nar- rowish pit which receives the anterior lateral tooth of the opposite valve. Along the posterodorsal margin of the right valve there is an elongated groove into which nestles the edge of the left valve. Ad- ductor scars scarcely visible, the anterior one seemingly ovate, the posterior seemingly oval. Pallial sinus V-shaped, projected obliquely, the blunt apex not quite reaching the median line of the valve and terminating against a faint linear crease in the interior, the crease extending from the umbonal cavity to the apex of the sinus. Ventral margin slightly and smoothly beveled within. Dimensions.—Specimen C407a, juvenile right valve, length 1.9 mm.; height 1.7 mm. Locality.—La Salina, west of Puerto Cabello, State of Carabobo. One juvenile right valve. VENEZUELAN CENOZzOIC PELECYPODS: WEISBORD 293 Remarks.—The identification is not certain as it 1s based on a single immature valve. Range and distribution—Recent, from Florida to Brazil, 4-25 fathoms. Pleistocene, Barbados. Pliocene, near Cumana, Venezuela (Collection No. 18408, U. S. National Museum). Pitar (Pitar) maiquetiensis, new species Pl. 42, figs. 9, 10 Shell small, subtranslucent, moderately inflated, oval-subtri- gonal, a little inequilateral, the front end scarcely narrowed. Antero- dorsal margin shallowly but evenly convex, anterior end well round- ed, ventral margin arcuate, posterior end broadly rounded, post- erodorsal margin slightly convex. Lunule relatively large, not de- pressed, cordate, bounded by a fine impressed line, microscopically striate. No escutcheon. Beak full, somewhat elevated, prosogyrate, situated a little forward of the middle. Surface somewhat glassy, marked by obsolete concentric lineations and an occasional fine concentric sulcus. Interior shiny. The right anterior lateral process of the hinge is a short pit bearing a minor denticle above and below, the lower denticle slightly the larger. Right anterior cardinal tooth narrowly wedge-shaped, united above with the posterior cardinal which is also cuneate but much larger and vaguely divided on the face; the middle cardinal of the right valve is separate, of inter- mediate size, and somewhat divergent with the anterior cardinal. Base of hinge plate bowed down at the anterior lateral, bowed up between the middle and posterior cardinals. Behind the posterior cardinal the nymph groove is narrow, deep, and somewhat irregular. Anterodorsal and posterodorsal margins bearing a fine groove, the posterior one longer and somewhat more prominent than the an- terior. Anterior adductor scar lenticular, the posterior one not dis- cernible. Pallial line well removed from the margin. Pallial sinus asymmetrically U-shaped, the upper limb of the sinus slightly ascending, the lower limb joining the end of the pallial line ob- tusely, the apex of the sinus rounded, reaching to near the center of the valve. Inner margin smooth, slightly beveled. Dimensions.—Holotype (T515a), right valve, length 1.9 mm.; height 1.7 mm. Type locality—Upper Mare formation, in stream 250 meters 294 BULLETIN 204 south-southwest of mouth of Quebrada Las Pailas. One immature right valve, the holotype. Comparisons.—The distinguishing character of the new species is the gently and evenly convex anterodorsal margin. This serves to differentiate it from the east American P. fulminata (Menke) (1828, Synopsis Methodica Molluscorum . . . Museo Menkeano, ed. 2, p. 150) and from the west American P. fluctuatus (Sowerby) (see Olsson, 1961, Panamic-Pacific Pelecypoda, pp. 275-276, pl. 43, figs. 7, 7a; pl. 45, figs. 5, 7). The Recent P. fulminata (Menke) (see Abbott, 1958, Acad. Nat. Sci. Philadelphia, Mon. No. 11, p. 131, pl. 4e, f) ranges from North Carolina, U. S. A., to Brazil, in depths of 1 to 170 fathoms, and the species has been recorded from the Pleistocene of Cuba. P. fluctwatus (Sowerby) is living from the Perlas Islands in the Gulf of Panama southward to Santa Elena, Ecuador, in depths to 8 fathoms. Pitar (Pitar ?) antillensis, new species Pl3a lesion Shell small, moderately inflated, obtusely subtrigonal, some- what inequilateral, the anterior end slightly produced and a little narrowed. Anterodorsal margin slightly and regularly convex, anterior end rather acutely rounded, ventral margin gently arcuate, posterior end broadly rounded, posterodorsal margin somewhat humped. Umbonal region full, the beak subcentral, moderately high, directed forward. Lunule large, not impressed, elliptical-cordate, hardly defined. Escutcheon narrow, not developed. Surface sculptur- ed by small faint narrow concentric riblets on the umbonal region, the riblets becoming obsolescent below where the shell is nearly smooth. Left valve with a small low laminar anterior lateral, this merging with the higher anterior cardinal tooth but defined from it by a small notch; anterior and middle cardinals united above, the anterior cardinal slightly flared below, the middle cardinal small and cuneate; left posterior cardinal thinly lamellar. Anterior ad- ductor scar slightly curved and lozenge-shaped, the posterior scar lenticular. Pallial line shallowly arcuate, subparallel with the ven- tral margin from which it is well removed. The dimly discernible pallial sinus is broadly U-shaped and slightly ascending, with a well- rounded apex which reaches to a little beyond the middle of the VENEZUELAN CENOZzOIC PELECYPODS: WEISBORD 295 interior, the lower limb of the sinus not quite parallel with the pallial line, the union of the limb and the line subrounded. Inner margin smooth, although because of corrosion it has a pseudo-transennellid appearance. Dimensions.—Holotype (1666a), left valve, length 2.7 mm.; height 2.2 mm. Type locality—Upper Mare formation, in stream 250 meters south-southwest of mouth of Quebrada Las Pailas; one young left valve, the holotype. Comparisons.—Although much smaller, P. antilensts, n. sp. is somewhat reminiscent of P. elenensts Olsson (1961, p. 275, pl. 45, figs. 1-1b), a Recent Eastern Pacific form ranging from Panama to northern Peru. However, the posterodorsal margin of the Ven- ezuelan fossil is a little more arched than that of P. elenensis, and the lower limb of the pallial sinus is nearer the pallial line than it is on P. elenensis. The hinge dentition of P. antilensis is similar to that of the left valve of Gouldia ? diffidentia, n. sp. described else- where in this monograph, but in outline and other characters the two forms are distinct. Pitar (Nanopitar ?) marensis, new species Pl. 42, figs. 11-14 Shell glassy, subtranslucent, oval-subtrigonal, a little inflated. Anterodorsal margin hardly convex, anterior end well rounded, ventral margin arcuate, posterior end shallowly rounded, postero- dorsal margin gently and evenly convex. Lunule large, broadly elliptical, outlined by a feeble incised line, marked by faint concen- tric growth striae. Escutcheonal area narrow, not defined, finely striated. Umbo full, the beak moderately high, subcentral, proso- gyrate. External surface faintly scored by obsolete concentric linea- tions and marked by an occasional stronger concentric thread. In- terior shiny. In the right valve the base of the hinge plate is bowed down under the anterior lateral, bowed up at the middle cardinal. Right anterior lateral represented by a pit which is thickened below and bears a small laminar tooth above. The pit is connected with the first cardinal interspace by an arcuate channel at the base of the anterior cardinal. Right anterior cardinal thin, united tenuously under the beak to the elongate posterior cardinal which is narrowly wedge-shaped and sulcate on the face; the middle cardinal of the 296 BuLLeETIN 204 right valve is separate, subparallel with the anterior cardinal, and intermediate in size. Dorsal margins of right valve with a fine elon- gate groove, the posterior groove longer and a little stronger than the anterior. Anterior adductor scar fairly large, ovate and high, the posterior scar seemingly broadly pyriform. Pallial line well removed from the margin. Pallial sinus a broad embayment, the apex well rounded and projecting to near the center of the valve, the upper limb of the sinus nearly horizontal, the lower limb joining the end of the pallial line at an obtuse angle. Internal ventral margin smooth and beveled. Dimensions—Holotype (1515b), right valve, length 1.8 mm.; height 1.5 mm. Paratype (1515a), might valve, length 1.3 mm.; height 1.15 mm. Type locality—Lower Mare formation at W-13, on hillside above west bank of Quebrada Mare Abajo. Two right valves. Comparisons—The type of the subgenus Nanopitar is the Recent P. (N.) pilula Rehder (1943, U. S. Nat. Mus., Proc., vol. 93, No. 3161, pp. 188-189, pl. 19, figs. 5-10) from Lake Worth, Florida, and that is a suborbicular shell in contrast with the Ven- ezuelan fossil P. (N.) marensis, n. sp., which is oval-subtrigonal in outline. The types of P. marensis are small and immature, and it is surmised that the adult also is a relatively small shell. Pitar (Pitarella ?) scutellaris, new species PL. 33, fica); Pl. 42, figs. 15, 16 Shell moderately inflated, inequilateral, subtrigonally oval, the posterior submargin somewhat flattened, the posterodorsal margin long and straight with a slope of about 40 degrees from the hori- zontal. Umbonal area full and rounded, the beak fairly high, proso- gyrate, situated a little forward of the middle. Lunule large, diamond-shaped, bounded by a fine feebly impressed line, marked by extremely faint concentric growth striae. Escutcheon absent. Surface sculptured by close fine concentric riblets, the riblets of the inner layer of the shell sharper and more laminate. Hinge strong, consisting of an anterior lateral, three cardinals and a long, large, somewhat sunken and flattened ligamental area. The right anterior lateral consists of two low denticles separated by a small pit; the VENEZUELAN CENOZOoIC PELECYPODS: WEISBORD 297 right anterior cardinal and the posterior cardinal are united above in an arch, the arch underlain by the separate middle cardinal tooth which is asymmetrically wedge-shaped; the right anterior cardinal of the holotype is broken but it seems to be parallel with, and sep- arated from the middle cardinal by a deep narrow cleft; the socket between the middle and right posterior cardinals is narrowly and obliquely triangular; the right posterior cardinal is bilaminar and virgated by a slit at the inner side. The character of the rest of the interior is not known. Dimensions —Holotype (G416a), umbonal area of a right valve, length of fragment 4.7 mm.; thickness at umbo (excluding teeth) 1.3 mm. Type locality.—Mare formation at W-14, on hillside above west bank of Quebrada Mare Abajo. One broken right valve, the holotype. Comparisons.—Although much of the single specimen is broken away, the straight slope of the posterodorsal margin, the diamond- shaped lunule, the large ligamental area, and the split posterior cardinal of the mght valve, set this shell apart from other known pitarids. Somewhat similar forms are the west American P. mexi- canus Hertlein and Strong (1948, Zoologica, vol. 33, No. 4, pp. 171- 172, pl. 1, figs. 3, 8) and the Western Atlantic P. penistonae}™ (Heilprin) (1889, Acad. Nat. Sci. Philadelphia, Proc., vol. 41, p. 142, pl. 8, figs. 4, 4a) from Bermuda. Among other differences, the Pleistocene to Recent P. mexicanus has an evenly convex postero- dorsal margin, and P. penistonae has an evenly cordate lunule. Callocardia ammondea Woodring (1925, pp. 151-152, pl. 20, figs. 11-12) and Callocardia elethusa Woodring (1925, p. 152, pl. 20, figs. 13-14) from the middle Miocene of Jamaica are more strongly inflated than P. scwtellaris, n. sp. The Peruvian P. tumbezana Olsson (1932, Bull. Amer. Paleont., vol. 19, No. 68, pl. 10, figs. 1, 3) from the middle Miocene Cardalitos shale has a gently convex postero- dorsal margin as has the middle Miocene Callocardia gatunensis Dall (1903, Wagner Free Inst. Sci., Trans., vol. 3, pt. 6, pp. 1260-1261, pl. 54, fig. 1) from the Panama Canal Zone. MOriginally named Cytherea Penistoni after Miss A. Peniston. To accord with the feminine gender, I take the liberty of amending the specific name to penistonae. 298 BuLLeTIN 204 Pitar (Hysteroconcha) dione (Linnaeus) Pl. 42, figs. 17-19; Pl. 48, figs. 1-6 1758. Venus dione Linnaeus, Syst. Nat., ed. 10, p. 684, No. 91. 1767. Venus dione Linnaeus, Syst. Nat., ed. 12, p. 1128, No. 112. 1782. Venus dione Linnaeus, Chemnitz, Syst. Conchylien-Cabinet, vol. 6, p. 282, pl. 27, figs. 271-272. 1797. Venus dione Linnaeus, Bruguiére, Encycl. Méth., vol. 2, pl. 275, figs. 1a, b, 1818. Cytherea dione (Linnaeus), Lamarck, An. sans Vert., vol. 5, p. 570. 1845. Venus dione Linnaeus, d’Orbigny, [in] La Sagra, Hist. Fis., Polit. y Nat. Isla de Cuba, vol. 5, Moluscos, p. 317. 1852. Cytherea dione (Linnaeus), Jay, A Catalogue of the Shells, p. 36. 1853. Venus dione Linnaeus, d’Orbigny, [In] La Sagra, Hist. phys., polit. et nat. l’Ile de Cuba, vol. 2, pp. 274-275. 1853. Dione veneris Deshayes, Catalogue of the Conchifera or Bivalve Shells in the British Museum, pt. 1, p. 75. 1857. Dione dione (Linnaeus), H. and A. Adams, The Genera of Recent Mol- lusca, pl. 108, figs. 1a, b. 1858. Cytherea dione (Linnaeus), Beau, Ext. Rev. Coloniale, p. 24. 1863. Dione veneris Deshayes, Reeve, Conch. Icon., vol. 15, Dione, pl. 6, sp. 23. 1864. Venus Dione Linnaeus, Krebs, The West Indian Marine Shells, p. 96. 1868. Dione dione (Linnaeus), Rémer, Novitates Conchologicae, Suppl. 3, vol. 1, p. 129, pl. 34, figs. 1a, b. 1878. Cytherea dione (Linnaeus), Mérch, Catalogue of West-India Shells, p. 15. 1880. Cytherea dione (Linnaeus), Woodward, Manual of Mollusca, 4th ed., p. 474, pl. 20, fig. 8. 1887. Meretrix (Dione) dione (Linnaeus), Fischer, Manuel de Conchyliologie et de Paléontologie Conchyliologique, pp. 1079-1080, pl. 20, fig. 8. 1889. Dione dione (Linnaeus), Dall, U. S. Nat. Mus., Bull. 37, p. 56. 1889. Cytherea dione (Linnaeus), Simpson, Davenport Acad. Nat. Sci., Proc., vol. 5, p. 64. 1892. Cytherea dione (Linnaeus), Singley, Geol. Sur. Texas, Fourth An. Rept., p. 328. 1901. Meretrix dione (Linnaeus), Dall and Simpson, U. S. Fish Com., Bull., vol. 20 for 1900, pt. 1, pp. 485-486, pl. 56, figs. 3, 10. 1902. Pitaria (Hysteroconcha) dione (Linnaeus), Dall, U. S. Nat. Mus., Proc., vol. 26, No. 1312, pp. 354, 371-372. 1903. Pitaria (Hysteroconcha) dione (Linnaeus), Dall, Wagner Free Inst. Sci., Trans., vol. 3, pt. 6, pp. 1219, 1221, 1222, 1223, 1264, 1265, 1306. 1920. Pitaria (Hysteroconcha) dione (Linnaeus), Maury, Bull. Amer. Paleont., vol. 8, No. 34, pp. 102-103. 1925. Pitaria (Hysteroconcha) dione (Linnaeus), Maury, Bull. Amer. Paleont., vol. 10, No. 42, p. 301, pl. 27, fig. 8. 1927. Pitaria (Lamelliconcha) dione (Linnaeus), Palmer, Palaeontographica Americana, vol. 1, No. 5, pp. 261-262, pl. 9, figs. 1, 2, 17, 20 (1929). 1934. Pitar (Hysteroconcha) dione (Linnaeus), Johnson, Boston Soc. Nat. Hist., Proc., vol. 40, No. 1, p. 48. 1937. Pitar (Hysteroconcha) dione (Linnaeus), Smith, East Coast Marine Shells, p. 53, pl. 18, figs. 4a, 4b. 1937. Cytherea dione (Linnaeus), Lamy and Fischer-Piette, Mus. Nat. Hist. nat. Paris, Bull., 2d. ser., vol. 9, No. 4, pp. 270-271. 1940. Pitar dione (Linnaeus), Smith, World-wide Sea Shells, p. 109, fig. 1442. 1946. Pitar (Hysteroconcha) dione (Linnaeus), Jaume, Soc. Malac. “Carlos de La Torre,” Rev., vol. 4, No. 3, p. 101. 1948. Pitar (Hysteroconcha) dione (Linnaeus), Hertlein and Strong, Zoologica, vol. 33, pt. 4, p. 174. VENEZUELAN CENOZOIC PELECYPODS: WEISBORD 299 1949. Pitar (Hysteroconcha) dione (Linnaeus), Lange de Morretes, Mus. Para- naense, Arq., vol. 7, art. 1, p. 36. 1951. Pitar (Hysteroconcha) dione (Linnaeus), McLean, New York Acad. Sci. Scientific Survey of Porto Rico and the Virgin Islands, vol. 17, pt. 1, p. 81, pl. 16, fig. 6. 1952. Pitar dione (Linnaeus), Pulley, Texas Jour. Sci., vol. 4, No. 2, p. 183. 1952. Venus dione Linnaeus, Dodge, Amer. Mus. Nat. Hist., Bull., vol. 100, art. 1, pp. 87-88. 1954. Pitar (Hysteroconcha) dione (Linnaeus), Abbott, American Seashells, p. 415, pl. 39f. 1958. Pitar (Hysteroconcha) dione (Linnaeus), Keen, Sea Shells of Tropical West America, p. 130, fig. 292. 1958. Pitar dione (Linnaeus), Olsson and McGinty, Bull. Amer. Paleont., vol. 39, No. 177, p. 21. 1961. Hysteroconcha dione (Linnaeus), Olsson, Panamic-Pacific Pelecypoda, p. 284. 1961. Pitar (Hysteroconcha) dione (Linnaeus), Warmke and Abbott, Carib- bean Seashells, p. 189, pl. 39k. Shell triangularly ovate, moderately inflated, subsolid. Beak anterior to the middle, prosogyrate. Lunule cordate, depressed, delimited by a faintly impressed line, marked with fine threads. Ligament lodged within a large lanceolate escutcheon which is nar- rowly lipped at the ligamental gape but flattish to slightly convex distally forming a posterior rostration. External sculpture con- sisting of narrow, elevated, widely spaced concentric ribs which are higher and lamellose in front, smooth and slightly recurved on the disk, and greatly reduced on the posterior slope and escutcheon; in the interspaces there are fine faint ridglets which become more prominent on the posterior slope. At the rear edge of the disk there is a radial ridge bearing a column of spines which project outward and backward, and behind that, on a second fainter ridge, there is another column of spines, the latter generally fewer in number than on the first ridge; the spines project from the end of every second or third primary concentric rib. Left valve with three cardi- nal teeth, the central one heavy and shallowly bifid, and with a stout erect anterior lateral tooth which fits into a corresponding socket on the opposite valve. Right valve with three cardinal teeth, the posterior one long, arcuate and bifid, the anterior ones separated by a deep slit. Pallial sinus angulately U-shaped, embayed nearly horizontally to about the median line of the valve below the center, the apex of the sinus gently rounded to blunt. Color violet and white on the disk, violet-brown on the escutcheon, and white in the interior except at the hinge which is a pale purple. 300 BULLETIN 204 Dimensions.—Recent specimen B397a, right valve, length 31.2 mm.; height 25 mm.; thickness 7.6 mm. Recent specimen B397b, left valve, length 36 mm.; height 28.1 mm.; thickness 7.5 mm. Largest Recent specimen, right valve, length 46.9 mm.; height 38.5 mm.; thickness 11.5 mm. Fossil specimen D403a, umbonal fragment of right valve, length 18.4 mm.; thickness 7.3 mm. Fossil specimen J397a, rear fragment of right valve, height 18.5 mm.; thickness 6 mm. Fossil specimen 1413a, anterior fragment of left valve, height 17.4 mm. Localities —Recent, on beach southeast of Higuerote, State of Miranda. Twelve valves including nine right and three left. Abisinia formation at W-30, eastern edge of Playa Grande village. One frag- ment of a right valve. Lower Mare formation, in small stream 100 meters west of Quebrada Mare Abajo. One fragment of a right valve. Lower Mare formation at W-13, on hillside above west bank of Quebrada Mare Abajo. One fragment of a left valve. Remarks——The west American analogues are P. lupanaria (Lesson) (see Keen, 1958, p. 130, fig. 292; and Olsson, 1961, p. 283, pl. 47, figs. 1-lc) and P. multispinosa (Sowerby). P. lupanaria ranges from Baja California to northern Peru, occurring along shore to depths of 13 fathoms, and has been reported in the Pleistocene of Oaxaca, México by Palmer and Hertlein (1936, Southern Cali- fornia Acad. Sci., Bull., vol. 35, pt. 2, p. 73). P. multispinosa (see Olsson, 1961, p. 284, pl. 47, figs. 2-2d) which also ranges from México to Peru, is more slender than either P. lupanaria or P. dione, and P. lupanaria has vague radial markings that are not present on the Venezuelan specimens of P. dione. Range and distribution—The Recent P. dione ranges from the Gulf of México to Brazil. It has not been previously reported as a fossil, but in addition to the present notice of its occurrence in the Abisinia and Mare formations at Cabo Blanco, Venezuela, it is also contained in Collection No. 18408 of the U. S. National Museum, which was obtained from the Pliocene near Cumana, State of Sucre, Venezuela. Periglypta aff. listeri (Gray) Pl. 43% figs: ieee 1838. Dosina Listeri Gray, The Analyst, vol. 8, p. 1853. Venus Listeri (Gray), Deshayes, Catalogue of sie Conchifera or Bivalve Shells in the British Museum, pt. 1, p. 106. 1863. 1864. 1878. 1885. 1889. 1891. 1902. 1903. 1920. 1926. 1927. 1933. 1934. 1935. 1936. 1936. 1936. 1937. 1939. 1940. 1942. 1945. 1946. 1948. 1951. 1954. 1958. 1959. 1961. VENEZUELAN CENOZOIC PELECYPops: WEISBORD 301 Venus Listeri (Gray), Reeve, Conch. Icon., vol. 12, pl. 5, sp. 14. Venus Listeri (Gray), Krebs, The West Indian Marine Shells, p. 97. Venus Listeri (Gray), Mérch, Catalogue of the West-India Shells, p. 15. Venus listeri (Gray), Smith, Voyage H. M. S. Challenger, Zoology, vol. 13, pp. 120, 121. Venus listeri (Gray), Simpson, Davenport Acad. Nat. Sci., Proc., vol. 5, p. 64. Venus listeri (Gray), Baker, Acad. Nat. Sci. Philadelphia, Proc., vol. 43, p. 47. Cytherea (Cytherea) listeri (Gray), Dall, U. S. Nat. Mus., Proc., vol. 26, No. 1312, pp. 372, 390. Cytherea listert (Gray), Dall, Wagner Free Inst. Sci., Trans., vol. 3, pt. 6, pp. 1275, 1276, 1279. Cytherea listeri (Gray), Maury, Bull. Amer. Paleont., vol. 8, No. 34, p. 103. Antigona listeri (Gray), Weisbord, Nautilus, vol. 39, No. 3, p. 83. Antigona (Dosina) listeri (Gray), Palmer, Palaeontographica Ameri- cana, vol. 1, No. 5, p. 337, pl. 28, figs. 2, 11 (1929). Chione multicostata Sowerby var., Trechmann, Geol. Mag., vol. 70, No. 823, pp. 35-36, pl. 4, fig. 6. Antigona listeri (Gray), Johnson, Boston Soc. Nat. Hist., Proc., vol. 40, No. 1, p. 48. Venus listeri (Gray), Richards, Jour. Paleont., vol. 9, No. 3, p. 256. Antigona listeri (Gray), Lermond, Check List of Florida Marine Shells, Gulfport, p. 6. Antigona listeri (Gray), McLean, Soc. Cubana Hist. Nat. “Felipe Poey,” Mem., vol. 10, No. 1, p. 41. Antigona listeri (Gray), Clench and McLean, Soc. Cubana Hist. Nat. “Felipe Poey,’ Mem., vol. 10, No. 3, p. 166. Antigona listeri (Gray), Smith, East Coast Marine Shells, p. 53, pl. 21, fig. 11. Venus listeri (Gray), McLean, Nautilus, vol. 49, No. 4, p. 119. Antigona listeri (Gray), Smith, World-wide Sea Shells, p. 110, fig. 1445. Antigona listeri (Gray), Jaume and Pérez Farfante, Soc. Cubana Hist. Nat. “Felipe Poey,” Mem., vol. 16, No. 1, p. 39. Venus listeri (Gray), van Bentham Jutting, Geolog.-Mijnbouwk. Genoot- schap Nederland en Kolonien, Geol. ser., vol. 14, p. 78. Antigona listeri (Gray), Jaume, Soc. Malac. “Carlos de La Torre,” Rev., vol. 4, No. 3, p. 101. Antigona listeri (Gray), Hertlein and Strong, Zoologica, vol. 33, pt. 4, p. 178. Antigona (Antigona) listeri (Gray), McLean, New York Acad. Sci. Sci- entific Survey of Porto Rico and the Virgin Islands, vol. 17, pt. 1, p. 82, pl. 16, fig. 5. Antigona (Dosina) listeri (Gray), Abbott, American Seashells, p. 404, pl. 32m. Antigona (Dosina) listeri (Gray), Abbott, Acad. Nat. Sci. Philadelphia, Mon., No. 11, p. 129. Antigona listeri (Gray), Nowell-Usticke, A Check List of the Marine Shells of St. Croix, p. 14. Antigona (Periglypta) listeri (Gray), Warmke and Abbott, Caribbean Seashells, p. 185, pl. 38L. Several fragments indicate that the adult species is of moderate fullness and has a truncate posterior end. The sculpture consists of subequally spaced, elevated, finely scalloped concentric laminae 302 BuLLeTIn 204 crenulated by radial ribs, and separated by deep squarish inter- spaces which are a little wider than the laminae except at the base where crowding occurs. The concentric laminae are platy on the middle of the disk but lamellose on the front and rear. The scallops are arched toward the umbo, the arches of the scallops more pro- nounced and somewhat closer on the anterior and posterior ends. On the dorsal face of the laminae there are broad low rounded radial ribs, and on the under, or ventrad side of the laminae, there are cor- responding flutings; the flutings are bounded by strong narrow mblets which continue on the interspace proper although with less sharp- ness, and between the latter there may be locally a minor inter- mediate riblet. The ventral margin is crenate within. Both adductor scars are high and relatively faint. The pallial sinus is not observable on any of the fragments. Dimensions—1410a, fragment of anterior end of left valve, height 27.5 mm. J443a, fragment of posterior end of right valve, height 26 mm. Localities —Lower Mare formation at W-13, on hillside above west bank of Quebrada Mare Abajo. Three fragments. Lower Mare formation, in small stream 100 meters west of Quebrada Mare Abajo. One fragment. Remarks.—It is not possible to identify the Cabo Blanco frag- ments with certainty though there is little question of the affinity with the east American P. listeri (Gray). In turn P. listert is the ana- logue of the Pleistocene to Recent P. multicostata (Sowerby) (see Olsson, 1961, Panamic-Pacific Pelecypoda, p. 293, pl. 50, figs. 3-3b), the slight difference lying in the outline of the posterior end of the valve which is vertical and truncated on P. listert, subtruncated on P. multicostata. The posterior end of the Cabo Blanco fossil is more closely akin to P. listeri. A possible progenitor is the upper Miocene P. mauryae (Vokes) (Amer. Mus. Novitates, No. 988, p. 12, fig. 10) from Springvale, Trinidad, but the concentric ribs are farther apart than on either P. listeri or P. multicostata. Range and distribution—tThe living P. listerc ranges from Florida to northern South America. The fossil species has been re- ported from the Pleistocene of Cuba, Barbados, and the Island of Tortuga, Venezuela. VENEZUELAN CENOzoIC PELECYPODS: WEISBORD 303 Antigona (Ventricolaria) aff. rigida (Dillwyn) Pl. 43, figs. 9-11 1791. Venus rugosa Gmelin, Syst. Nat., ed. 13, p. 3276. Not of Linnaeus, 1758. 1817. Venus rigida Dillwyn, A Descriptive Catalogue of Recent Shells, vol. 1, p. 164. 1818. Venus rugosa Lamarck, An. sans Vert., vol. 5, p. 587. Not of Linnaeus. 1845. Venus rugosa Chemnitz, d’Orbigny, [in] La Sagra, Hist. Fis., Polit. y Nat. Isla de Cuba, vol. 5, Moluscos, p. 316. 1863. Venus rugosa Gmelin, Reeve, Conch. Icon., vol. 11, pl. 7, fig. 23. 1864. Venus rugosa Gmelin (Chemnitz) = V. rigida (Solander) Dillwyn, Krebs, The West Indian Marine Shells, p. 98. 1867. (ae rugosa Chemnitz, Guppy, Sci. Assoc. Trinidad, Proc., pt. 3, p. 162 part). 1870. Venus rugosa Gmelin, Verrill, Amer. Jour. Sci., ser. 2, vol. 49, p. 221. 1878. Venus rugosa Gmelin, Arango, Contribucidn a la Fauna Cubana, p. 251. Not of Linnaeus. 1878. Venus rugosa Chemnitz, Morch, Catalogue of West-India Shells, p. 15. 1881. Venus rugosa Gmelin, Gabb, Acad. Nat. Sci. Philadelphia, Jour., ser. 2, vol. 8, p. 372. Not of Linnaeus. 1889. Venus cf. rugosa Linnaeus, Lorié, Samml. Geol. Reichs-Mus. Leiden, ser. 2, vol. 1, pp. 126-127, 141. Not of Linnaeus, 1758. 1895. Chione (Ventricola) rugosa (Gmelin), Gregory, Geol. Soc. London, Quart. Jour., vol. 51, p. 292. Not of Linnaeus. 1901. ? Venus rugosa Gmelin, Dall and Simpson, U. S. Fish Com., Bull., vol. 20 for 1901, pt. 1, p. 483. 1902. Cytherea (Ventricola) rigida (Dillwyn), Dall, U. S. Nat. Mus., Proc., vol. 26, No. 1312, p. 372. 1927. Antigona (Circomphalus) rigida (Dillwyn), Palmer, Palaeontographica Americana, vol. 1, No. 5, p. 341, pl. 30, figs. 3, 7; pl. 31, figs. 13-14, 1929. 1934. Antigona (Circomphalus) rigida (Dillwyn), Johnson, Boston Soc. Nat. Hist., Proc., vol. 40, No. 1, p. 48. 1936. Antigona rigida (Dillwyn), McLean, Soc. Cubana Hist. Nat. “Felipe Poey,” Mem., vol. 10, No. 1, p. 40. 1936. Antigona rigida (Dillwyn), Lermond, Check List of Florida Marine Shells, Gulfport, p. 6. 1948. Antigona rigida (Dillwyn), Hertlein and Strong, Zoologica, vol. 33, pt. 4, p. 179. 1949. Venus (Ventricola) rigida Dillwyn, Lange de Morretes, Mus. Parana- ense, Arq., vol. 7, art. 1, p. 37. 1950. Venus rigida Dillwyn, Durham, Geol. Soc. Amer., Mem. 43, p. 81. 1951. Antigona (Ventricola) rigida (Dillwyn), McLean, New York Acad. Sci. Scientific Survey of Porto Rico and the Virgin Islands, vol. 17, pt. 1, Prssnepl. 7, ties). 1954. Antigona (Circomphalus) rigida (Dillwyn), Abbott, American Seashells, p. 405. 1958. Ventricolaria rigida (Dillwyn), Keen, Sea Shells of Tropical West America, p. 124. 1959. Antigona rigida (Dillwyn), Nowell-Usticke, A Check List of the Marine Shells of St. Croix, p. 14. 1961. Venus (Ventricola) rugosa Gmelin, van Retgeren Altena, Koninkl. Nederl. Akad. Wetensch.-Amsterdam, Proc., ser. B, vol. 64, p. 300. 1961. Antigona (Ventricolaria) rigida (Dillwyn), Olsson, Panamic-Pacific Pelecypoda, p. 292. 1961. Antigona rigida (Dillwyn), Warmke and Abbott, Caribbean Seashells, p. 185, pl. 38m. The form from Cabo Blanco is an internal mold of the attached 304 BULLETIN 204 valves. The specimen is rounded-subquadrate and well inflated, with a subtruncate posterior end, a deeply arcuate lunular area, and crenulate margins. The impression of the muscle scars and pallial sinus cannot be seen. Dimensions—Specimen M411a, length 79 mm.; height 75 mm.; thickness of doublet 53 mm. Locality.—Playa Grande formation (Catia member) at W-15, south side of Playa Grande road 40 meters southeast of its inter- section with the Playa Grande Yachting Club road. One internal mold of a doublet. Remarks.—tThe kinship of this mold to A. rigida (Dillwyn) is, of course, open to doubt. It is not even certain that the specimen in question is not the same species as that represented by the shell fragments which I have referred to as Periglypta aff. listerc (Gray), although the present form with its obese valves and deeply impressed lunule would seem to be more closely allied to A. rigida than to P. listert. The west American analogue of A. rigida is the Pleistocene to Recent A. isocardia (Verrill) (see Keen, 1958, p. 124, fig. 268), but according to Verrill (1870, p. 221) it has a different and stronger hinge. Also related to A. rigida is the fragment of shell illustrated as figure 11 on Plate 43. This fragment (H312a) measures 27.4 mm. in height, and was collected in the Mare formation at W-25 on the south flank of the Punta Gorda anticline. The sculpture of the frag- ment consists of strong subequally spaced laminar concentric ribs with deep interspaces. In the interspaces are smaller elevated con- centric lamellae, the number of lamellae between the primary ribs usually three but occasionally two or four. The shell material is thick and came from a rather large adult specimen. Range and distribution—The present-day range of A. rgida (Dillwyn) is from Florida to Brazil. In the Pleistocene it has been found in St. Eustatius, Curacao, Aruba, and Barbados. In the Pliocene it was reported by Gabb from Costa Rica. The species re- ferred to as A. rugosa (Gmelin) by Olsson (1922, Bull. Amer. Paleont., vol. 9, No. 39, pp. 412-413, pl. 30, fig. 4) from the middle Miocene of Costa Rica is probably not the same as the Caribbean A. rigida (Dillwyn) or the west American A. tsocardia (Verrill). VENEZUELAN CENOZOIC PELECYPODS: WEISBORD 305 Antigona (Ventricolaria) rugatina (Heilprin) Pl. 43, figs. 12, 13 1887. Venus rugatina Heilprin, Wagner Free Inst. Sci., Trans., vol. 1, p. 92, pl. 11, fig. 24. 1889. Venus rugosa Gmelin var. rugatina Heilprin, Dall, U. S. Nat. Mus., Bull. 37, p. 54. 1901. Venus rugatina Heilprin, Dall and Simpson, U. S. Fish Com., Bull., vol. 20 for 1900, pt. 1, p. 483. 1902. Cytherea (Ventricola) rugatina (Heilprin), Dall, U. S. Nat. Mus., Proc., vol. 26, No. 1312, p. 372. 1903. Cytherea (Ventricola) rugatina (Heilprin), Dall, Wagner Free Inst. Sci., ‘Drans:,, voles, pt. 6, ps 12772 1920. Antigona (Ventricola) rugatina (Heilprin), Maury, Bull. Amer. Paleont., vol. 8, No. 34, p. 103. 1927. Antigona (Circomphalus) rugatina (Heilprin), Palmer, Palaeontogra- phica Americana, vol. 1, No. 5, pp. 341-342, pl. 31, fig. 4 (1929). 1934. Antigona (Circomphalus) rugatina (Heilprin), Johnson, Boston Soc. Nat. Hist., Proc., vol. 40, No. 1, p. 48. 1936. Venus rugatina Heilprin, Lermond, Check List of Florida Marine Shells, Gulfport, p. 24. 1939. Cytherea rugatina (Heilprin), Mansfield, State of Florida Dept. Con- serv., Geol. Bull. No. 18, pp. 13, 19, 26, 29. 1951. Antigona (Ventricola) rugatina (Heilprin), McLean, New York Acad. Sci. Scientific Survey of Porto Rico and the Virgin Islands, vol. 17, pt) p.083." plinil6,, figs .7% 1953. Venus (Antigona) rugatina Haas, Fieldiana-Zoology, vol. 34, No. 20, p. 203. 1953. Antigona (Ventricola) rugatina (Heilprin), Olsson and Harbison, Acad. Nat. Sci. Philadelphia, Mon. No. 8, p. 111. 1954. Antigona (Circomphalus) rugatina (Heilprin), Abbott, American Sea- shells, p. 405, pls. 32n; 38m. 1958. Antigona (Ventricola) rugatina (Heilprin), DuBar, Florida Geol. Sur., Bull. No. 40, p. 173. Not pl. 7, fig. 4, nor pl. 10, fig. 3 which are illustra- tions of Antigona willcoxi (Dall). 1961. Antigona (Ventricolaria) rugatina (Heilprin), Warmke and Abbott, Caribbean Seashells, p. 185. The worn left valve referred to this species is moderately in- flated, orbicular, slightly depressed posteriorly. The posterodorsal margin is hardly convex, the posterior end subtruncate, the ventral margin semicircular, and the anterodorsal margin at the lunular groove concave with the forward end produced and nearly horizontal. The lunule is broadly cordate, sunken, circumscribed by a narrow groove but with the inner margin elevated, sculptured by concentric lamellae. There is no escutcheon to speak of on the left valve, the area represented by a narrow feeble sulcus. The beak is moderately high, prosogyrate, subcentral. The surface sculpture consists of sub- equally spaced concentric lirae recurved toward the umbo, and be- tween these there are minor concentric lamellar ridgelets number- ing as many as six near the base. Vague radial threads are present locally but these probably appear from the inner layer of shell where 306 BULLETIN 204 the outer layer has been worn off. The posterior cardinal of the left valve is arcuate and platy, the middle one stout, subrectangular, and shallowly sulcate, the anterior cardinal tooth obliquely cuneate, broadening toward the base; in front of that there is a low but fairly large tubercle. The adductor scars and pallial sinus are obliterated, but the fine crenulations of the ventral and lunular margins may still be observed. Dimensions—Specimen A402a, left valve, length 19.7 mm.; height 18.3 mm.; thickness 6 mm. Locality—Recent, on beach of Playa Grande Yachting Club, Distrito Federal. One worn left valve. Remarks.—A. rugatina was first described by Heilprin in 1887 from the Pliocene “Floridian” formation exposed in the Caloos- hatchee River below Fort Thompson, Florida. There, according to Dall and Simpson (1901), the adult fossil may be as much as 90 cms. long, whereas adult Recent specimens are 25 to 35 mm. in length and are more orbicular than the fossil type. Among Recent examples of the species, the worn Venezuelan shell is identical to the worn Puerto Rican form illustrated by McLean (1951). Range and distribution.—Pliocene to Recent. Living from North Carolina to Brazil at depths of 85 fathoms; Pliocene, Florida. Chione (Chione) cancellata (Linnaeus) Pl. 44, figs. 1-8 1767. Venus cancellata Linnaeus, Syst. Nat., ed. 12, p. 1130. No. 118. 1782. Venus dysera Linnaeus, Chemnitz, Syst. Conchylien-Cabinet, vol. 6, p. 294, pl. 28, figs. 287-290. 1797. fey cancellata Linnaeus, Bruguiére, Encycl. Méth., vol. 2, pl. 268, figs. la, b. 1817. Venus cingenda Dillwyn, A Descriptive Catalogue of Recent Shells, vol. 1, p. 161. 1818. Venus cancellata Linnaeus, Lamarck, An sans Vert., vol. 5, p. 588. 1822. Venus elevata Say, Acad. Nat. Sci. Philadelphia, Jour., ser. 1, vol. 2, p. 272. 1828. fens cingenda Dillwyn, Wood, Supplement to the Index Testaceologicus, pl. 7, fig. 6. 1832. Venus cancellata Linnaeus, Deshayes, Encyclopédie Méthodique, pl. 1115, pl. 268, fig. 1. 1842. Venus cancellata Linnaeus, d’Orbigny, Voyage dans |’Amérique Méri- dionale, vol. 5, pt. 3, p. 588. 1853. Chione cancellata (Linnaeus), Deshayes, Catalogue of the Conchifera or Bivalve Shells in the British Museum, pt. 1, p. 134. 1853. Venus cancellata Linnaeus, Sowerby, Thes. Conchyl., vol. 2, p. 710, pl. 54. figs. 28-31. 1857. Venus cancellata Linnaeus, Tuomey and Holmes, Pleiocene Fossils of South Carolina, p. 84, pl. 21, fig. 11. 1860. 1863. 1864. 1864. 1864. 1867. 1871. 1878. 1886. 1886. 1888. 1889. 1889. 1889. 1891. 1891. 1892. 1895. 1895. 1896. 1901. 1902. 1903. 1903. 1913. 1914. 1916. 1920. 1922. 1923. 1924. VENEZUELAN CENOzOIC PELECYPODS: WEISBORD 307 Chione cancellata (Linnaeus), Holmes, Post-Pleiocene Fossils of South Carolina, p. 35, pl. 6, fig. 14. Venus cancellata Linnaeus, Reeve, Conch. Icon., vol. 14, Venus, pl. 19, sp. 88. Venus ziczac Linnaeus, Krebs, The West Indian Marine Shells, p 98. Not of Linnaeus. Venus cingenda Dillwyn, Guppy, Sci. Assoc. Trinidad, Proc., p. 36. Dione (Chamelea) cancellata (Linnaeus), Meek, Smithsonian Misc. Collections, vol. 7, No. 83, p. 10. Venus cancellata Linnaeus, Guppy, Sci. Assoc. Trinidad, Trans., p. 162. Chione cancellata (Linnaeus), Coues, Acad. Nat. Sci. Philadelphia, Proc., vol. 23, p. 126. Venus ziczac Linnaeus, Moérch, Catalogue of West-India Shells, p. 15. Not of Linnaeus. Venus (Chione) cancellata Linnaeus, Dall, Mus. Comp. Zool., Bull., vol. 12, No. 6, p. 276. Venus cancellata Linnaeus, Karsten, Géologie de lancienne Colombie bolivarienne, Vénézuéla, Nouvelle Grénade et Ecuador, p. 10. Venus cancellata Linnaeus, Schepman, [in] Martin, Bericht tiber eine Reise nach Nederlandisch West Indien und darauf gegriindete Studien, Leiden: II-Geologische Studien, Appendix. Venus cancellata Linnaeus, Lorié, Samml. Geol. Reichs-Mus. Leiden, ser. 2, vol. 1, pp. 126, 141, pl. 2, figs. 24-26. Venus cancellata Linnaeus, Dall, U. S. Nat. Mus., Bull. 37, p. 54. Chione cancellata (Linnaeus), Dall, U. S. Nat. Mus., Proc., vol. 12, No. 773, p. 271. Venus cancellata Linnaeus, Baker, Acad. Nat. Sci. Philadelphia, Proc., vol. 43, p. 47. Venus cancellata Linnaeus, Heilprin, Acad. Nat. Sci. Philadelphia, Proc., vol. 43, p. 142. Venus cancellata Linnaeus, Singley, Geol. Sur. Texas, Fourth An. Rept., Dp: 32/7. Chione cancellata (Linnaeus), Harris, Bull. Amer. Paleont., vol. 1, No. 43; Jos CE Chione (Omphaloclathrum) cancellata (Linnaeus), Gregory. Geol. Soc. London, Quart. Jour., vol. 51, p. 292. Venus cancellata Linnaeus, Sapper, Inst. Geol. México, Bol. No. 3, p. 9. Venus cancellata Linnaeus, Dall and Simpson, U. S. Fish Com., Bull., vol. 20 for 1900, pt. 1, pp. 483-484. Chione cancellata (Linnaeus), Dall, U. S. Nat. Mus., Proc., vol. 26, No. 1312, pp. 355, 373, 383, 392. Chione (Chione) cancellata (Linnaeus), Dall, Wagner Free Inst. Sci., Trans., vol. 3, pt. 6, pp. 1287, 1288, 1289. 1290-1291. Venus cancellata Linnaeus, Vanatta, Acad. Nat Sci. Philadelphia, Proc., Wels DS, 105 W57- Chione cancellata (Linnaeus), Brown and Pilsbry, Acad. Nat. Sci. Philadelphia, Proc., vol. 65, p. 497. Chione cancellata (Linnaeus), Henderson and Bartsch, U. S. Nat. Mus., Proc., vol. 47, No. 2055, p. 413. Venus cancellata Linnaeus, Thiele, Zool. Jahrb., Suppl. 11, p. 130. Chione cancellata (Linnaeus), Maury, Bull. Amer. Paleont., vol. 8, No. 34, pp. 104-105. Chione cancellata (Linnaeus), Johnson, Nautilus, vol. 36, No. 1, p. 11. Chione cancellata (Linnaeus), Clench, Nautilus, vol. 37, No. 2, p. 55. Chione cancellata (Linnaeus), Mansfield, Florida State Geol. Sur., Fif- teenth An. Rept., Faunal List following p. 28. 308 1925. 1926. 1927. 1927. 1933. 1934. 1935. 1936. 1936. 1936. 1937. 1938. 1938. 1939. 1940. 1940. 1942. 1944. 1945. 1946. 1949. 1951. 1952. 1952. 1953. 1954. 1955. 1956. 1958. BuLLeETIN 204 Chione (Chione) cancellata (Linnaeus), Maury, Bull. Amer. Paleont., vol. 10, No. 42, pp. 305-306, pl. 28, figs. 1, 5. Chione cancellata (Linnaeus), Weisbord, Nautilus, vol. 39, No. 3, pp. 81, 84. Chione (Chione) cancellata (Linnaeus), F. Hodson, H. K. Hodson, and Harris, Bull. Amer. Paleont., vol. 13, No. 49, p. 61, pl. 35, fig. 5. Chione (Chione) cancellata (Linnaeus), Palmer, Palaeontographica Americana, vol. 1, No. 5, pp. 359-360 (1927), pl. 37, figs. 1-8, 11, 15 (1929). Chione (Omphaloclathrum) cancellata (Linnaeus), Trechmann, Geol. Mag., vol. 70, p. 35, pl. 4, fig. 7. Chione cancellata (Linnaeus), Johnson, Boston Soc. Nat. Hist., Proc., vol. 40, No. 1, p. 48. Chione cancellata (Linnaeus), Richards, Jour. Paleont., vol. 9, No. 3, p. 256. Venus (Chione) cancellata Linnaeus, Lermond, Check List of Florida Marine Shells, Gulfport, p. 24. Venus (Chione) cancellata Linnaeus, McLean, Soc. Cubana Hist. Nat. “Felipe Poey,” Mem., vol. 10, No. 1, p. 41. Venus (Chione) cancellata Linnaeus, Clench and McLean, Soc. Cubana Hist. Nat. “Felipe Poey,’”’ Mem., vol. 10, No. 3, p. 167. Chione cancellata (Linnaeus), Smith, East Coast Marine Shells, p. 53, IE, tes OS Al soy Se Chione cancellata (Linnaeus), Richards, Geol. Soc. Amer., Bull., vol. 49, pt. 2, p. 291. Venus cancellata Linnaeus, Lamy and Fischer-Piette, Mus. Nat. Hist. nat. Paris, Bull., 2d. ser., vol. 10, No. 4, pp. 401-402. Chione cancellata (Linnaeus), Mansfield, State of Florida Dept. Conserv., Geol. Bull. No. 18, pp. 13, 14, 17, 18, 19, 23, 26, 30, 35, 56, 57, 58. Chione cancellata (Linnaeus), Stenzel, Nautilus, vol. 54, No. 1, p. 21. Chione cancellata (Linnaeus), Stubbs, Jour. Paleont. vol. 14, No. 5, yoy Slike Chione cancellata (Linnaeus), Jaume and Pérez Farfante, Soc. Cubana Hist. Nat. “Felipe Poey,” Mem., vol. 16, No. 1, p. 39. Chione cancellata (Linnaeus), Hackney, Nautilus, vol. 37, No. 2, p. 58. Venus cancellata, Lamarck, van Bentham Jutting, Geolog.-Mijnbouk. Genootschap Nederland en Kolonien, Geol. ser., vol. 14, p. 77. Chione cancellata (Linnaeus), Jaume, Soc. Malac. “Carlos de La Torre,” Rev., vol. 4, No. 3, p. 101. Chione cancellata a, Lange de Morretes, Mus. Paranaense, Arqiavola7 mart. il epesi- Chione (Chione) pa ay (Linnaeus), McLean, New York Acad. Sci. Scientific Survey of Porto Rico and the Virgin Islands, Vol. 7Mipt: 15 p: 84, pl. 17, fig. 4. Chione cancellata (Linnaeus), Pulley, Texas Jour. Sci. vol. 4, No. 2, p. 182, pl. 10, figs. 16-17. Venus cancellata Linnaeus, Dodge, Amer. Mus. Nat. Hist., Bull., vol. 100, art. 1, pp. 93-94. Chione (Chione) cancellata (Linnaeus), Olsson and Harbison, Acad. Nat. Sci. Philadelphia, Mon. No. 8, pp. 111-112. Chione cancellata (Linnaeus), Abbott, American Seashells, p. 407, pl. 39h. Chione cancellata (Linnaeus), Perry and Schwengel, Marine Shells of the Western Coast of Florida, p. 73, pl. 14, fig. 86. Chione cancellata (Linnaeus), Parker, Amer. Assoc. Petrol. Geol., Bull. vol. 40, No. 2, pp. 309, 331, 370, pl. 4, figs. 17a, 17b. Chione cancellata (Linnaeus), Abbott, Acad. Nat. Sci. Philadelphia, Mon. Nori ps 129; VENEZUELAN CENOzoIC PELECYPODS: WEISBORD 309 1958. Chione cancellata (Linnaeus), Olsson and McGinty, Bull. Amer. Paleont., vol. 39) No; tai ep. 21. 1958. Chione (Chione) cancellata (Linnaeus), DuBar, Florida Geol. Sur., Geol. Bull. No. 40, pp. 173-174, pl. 7, fig. 1; pl. 8, fig. 2. 1959. Chione cancellata (Linnaeus), Parker, Amer. Assoc. Petrol. Geol., Bull., vol. 43, No. 9, pp. 2125, 2127, 2132, 2161, 2164, pl. 2, VI, figs. 14a, 14b. 1959. Chione cancellata (Linnaeus), Nowell-Usticke, A Check List of the Marine Shells of St. Croix, pp. 14-15. 1961. Chione cancellata (Linnaeus), Moore, Gulf Research Repts., vol. 1, No. 1, pp. 16, 43. 1961. Chione (Chione) cancellata (Linnaeus), van Regteren Altena, Koninkl. Nederl. Akad. Wetensch.-Amsterdam, Proc., ser. B, vol. 64, No. 2, p. 300. 1961. Chione (Chione) cancellata (Linnaeus), Warmke and Abbott, Caribbean Seashells, p. 185, pl. 4£; 38-0. Numerous fossil examples of this species were collected at La Salina and the Cabo Blanco area. The shell is moderately compressed to moderately inflated, subtrigonally ovate, slightly attenuated post- eriorly, the disk with a feeble radial depression or flattening behind the middle. Anterior end well rounded, ventral margin generally shallowly rounded, posterior end subangularly rounded at the curve of the ventral and posterodorsal margins, the posterodorsal margin long and straight except near the beak where it forms a slight hump. Beak appressed in the adult, sharply pointed, prosogyrate, situated in front of the middle. Lunule relatively large, broadly cordate, de- fined by a sharply incised groove, sculptured by low radial ridges which are crossed by concentric, often lamellose striae. Escutcheon lanceolate, flat, sloping inward, narrowly lipped adjacent to the liga- mental groove, marked by numerous fine longitudinal striae, de- limited by the sharp edge of the disk. Hinge plate strong, the middle cardinal of the left valve the stoutest, the base of the plate bowed down somewhat beneath the anterior cardinal. Right valve with a long narrow groove along the edge of the escutcheon, the correspond- ing groove of the left valve a little lower and more delicate. Anterior adductor scar high, rather deeply sunken, semi-elliptical, its inner margin straight and impressed, the outer margin a little thickened; posterior adductor scar relatively faint, broader and shorter than the anterior scar, and subsquarish or suboval. The pallial sinus is a very short and rather broadly triangular embayment with a blunt or rounded apex not rising above the median line of the posterior scar, and close to but not touching the margin of the scar. The ventral and anterodorsal margins are closely crenate, the crenulations of the ventral margin occurring in pairs or clusters and obsolescent at 310 BULLETIN 204 the rear, the denticles of the anterodorsal margin small and single, extending along the edge of the lunule and terminating above the central cardinal of the hinge. External sculpture consisting of slightly thickened elevated lamellar concentric ribs, with low strong radial cords in the interspaces, the cords themselves crossed by numerous concentric growth striae. The concentric ribs are generally widely spaced, are closely frilled on top, and prominently fluted or corru- gated on their under, or ventrad side. The radial cords are single on the umbo, but below the umbo intercalary cords develop, and attain with growth the same size as the primary ones; all of the cords continue weakly up the upper, or dorsad face of the concentric ribs. Generally a number of the radial cords behind the middle of the disk are a little broader and flatter than the ones in front or at the very rear. Such coloration that still remains on some of the fossil shells is seen as narrow brown stripes or flammules crossing the escutcheon, some of the stripes straight, others curved, all of them rather widely separated. Dimensions —Specimen C400a, right valve, length 21 mm.; height 18.1 mm.; thickness 5.6 mm. Specimen C400b, left valve, length 23 mm.; height 21.2 mm.; thickness 4.7 mm. Specimen T400a, right valve, length 23.2 mm.; height 19.4 mm.; thickness 4.6 mm. Specimen T400b, left valve, length 32.1 mm.; height 26 mm.; thick- ness 8 mm. Specimen 1400a, right valve, length 17 mm.; height 15.1 mm.; thickness 3.9 mm. Specimen 1400b, left valve, length 17.8 mm.; height 15.9 mm.; thickness 4 mm. Specimen J400a, right valve, length 18.2 mm.; height 15.4 mm.; thickness 3.7 mm. Specimen J400b, left valve, length 39.4 mm.; height 33 mm.; thickness 9.4 mm. Localities—La Salina, west of Puerto Cabello, State of Cara- bobo. Two hundred eighty-seven specimens including one hundred fifty-one right valves and one hundred thirty-seven left valves. Upper Mare formation, in stream 250 meters south-southwest of mouth of Quebrada Las Pailas. Eleven specimens including six right valves and five left valves. Upper Mare formation at W-14, on hill- side above west bank of Quebrada Mare Abajo. Nine specimens including five right valves and four left valves. Mare formation at W- 25, south flank of Punta Gorda anticline. One left valve. Lower Mare formation at W-13, on hillside above west bank of Quebrada Mare Abajo. Thirty-three specimens including seventeen right valves and VENEZUELAN CENOzOIC PELECYPODS: WEISBORD Sti sixteen left valves. Lower Mare formation, in small stream 100 meters west of Quebrada Mare Abajo. Twelve specimens including nine left valves and three right valves. Playa Grande formation (Maiquetia member) at W-23, north flank of Punta Gorda anticline. Three specimens including two left valves and one right valve. Recent, on beach southeast of Higuerote, State of Miranda. Two left valves, the identification doubtful. Remarks.—Although variable in shape and in details of sculp- ture, Chione cancellata (Linnaeus) is characterized by the usually widely spaced concentric ribs, and by a short, nearly erect pallial sinus. The species is locally exceedingly abundant, either living or fossil, throughout its chronologic and geographic range. The shells from La Salina are slightly thinner than those from the Cabo Blanco area, and none of them is as large as the largest of the latter. A number of specimens from both areas are more closely and regularly ribbed concentrically than the majority of examples, but the two variants seem to represent the same species. - Range and distribution—Miocene to Recent. The living C. cancellata ranges from Virginia, U. S. A., through the Gulf of México and the Caribbean Sea, to Brazil. In the Pleistocene, C. cancellata occurs in South Carolina, Florida, Louisiana (in well cuttings), Panama, St. Kitts, St. Eustatius, Barbados, Curacao, and Venezuela. In the Pliocene it is found in South Carolina, Florida, the Yucatan Peninsula of México, Venezuela (near Cumana), and Trinidad (at Matura). The species also occurs in the Miocene of Venezuela, and has been reported from deposits of that age in South Carolina and from the Galveston well (1550-2871 feet) in Texas. Chione (Chione) pailasana, new species, Pl. 44, figs. 9-11 Adult shell large, sturdy, rounded subtrigonal, inequilateral, nearly equivalve. Anterodorsal margin relatively short, anterior end and ventral margin rounded, posterior end acutely rounded, posterodorsal margin long and somewhat convex. Beak appressed, sharply pointed, prosogyrate, situated in front of the middle. Lunule large, cordate, slightly depressed, defined by a sharply incised groove, the half of the lunule on the right valve a little wider than on the left valve. The area of the lunule immediately under the beak is sculptured by low radial ridges crossed by a few concentric laminae, 312 BuLLeETIN 204 but the ventrad area of the lunule is sculptured by numerous coarse concentric lamellae on the upper face of which there may be weak radial riblets. Escutcheon large, lanceolate, sloping inward, a little broader on the left valve than on the right, and also narrowly lipped adjacent to the ligamental groove of the left valve, delimited by the sharp raised edge of the disk, and sculptured by numerous fine longitudinal striae. Hinge plate strong, the base of the plate bowed down a little under the anterior cardinal. Dentition normal, the middle cardinal of each valve the highest. Right valve with a long narrow groove along the edge of the escutcheon into which fits the cor- responding edge of the left valve. Anterior adductor scar high, rather deeply sunken, semi-elliptical, the inner margin of the scar straight, the outer margin somewhat thickened; posterior scar not so deeply impressed, broadly pyriform or subcylindrical. The pallial sinus is a short triangular embayment with a blunt apex not rising above the median line of the posterior adductor scar, and close to, but not touching the margin of the scar. The ventral and anterodorsal margins are closely crenate within, the crenulations of the ventral margin sometimes occurring in pairs or clusters, and obsolescent at the rear, the crenulations of the anterodorsal margin small and single, extending along the edge of the lunule and terminating above the central cardinal tooth of the hinge. Sculpture of the exterior consisting of up to 32 concentric ribs, the ribs of the upper two- fifths or so of the disk widely separated, the ones below subequal and closely spaced. The upper concentrics are raised and lamellar, closely frilled on top and corrugated or fluted on their ventrad side, these corrugations becoming obsolescent on the ribs toward the base of the valve. The concentrics on the lower three-fifths or so of the disk are thicker, flattened, and recurved toward the umbo, the inter- spaces much narrower than those on the umbonal area. However, the lower concentrics lose their flatness on the posterior fourth of the disk where they become more erect and decidedly lamellar. The interspaces of the lowest concentric ribs are lined with low sharp concentric striae or laminae, but radial markings are absent. How- ever, the radial sculpture is pronounced on the upper area of the disk. On the umbo the radial cords are single but below the umbo intercalary cords develop, and attain with growth, the same size as the primary ones; all of the radial cords continue weakly up the VENEZUELAN CENOzOIC PELECYPODS: WEISBORD 313 upper, or dorsad face of the concentric ribs. Generally, a number of radial cords behind the middle of the disk are a little broader and flatter than the ones in front or at the rear. Such coloration that still remains on some of the fossils is seen as narrow brown stripes or flammules crossing the escutcheon, some of the stripes straight, others curved, all of them widely spaced. Dimensions—Holotype (P40la), a doublet, length 47 mm.,; height 43 mm.; thickness of pair 27.5 mm. Paratype (R40la), left valve, length 43.8 mm.; height 39 mm.; thickness (not including elevation of ribs) 13.2 mm. Type locality —Playa Grande formation (Maiquetia member), north bank of Quebrada Las Pailas, about 35 meters south of Mare Abajo fault and 150 meters southwest of junction of Maiquetia anticline with the Mare Abajo fault. Three specimens including one doublet, one right valve, and one left valve. Other localities —Playa Grande formation (Maiquetia member) at W-26, in Quebrada Las Bruscas, approximately 125 meters up- stream from junction with Quebrada Las Pailas. One left valve. Comparisons—The nearest related species is the middle Mio- cene Chione atlanticana Anderson (1929, California Acad. Sci., Proc., ser. 4, vol. 18, p. 172, pl. 23, figs. 5-6) from northern Colombia, that species differing, however, in having a straighter posterodorsal margin than C. pailasana, n. sp., and in having a subtruncate pos- terior end instead of the acutely rounded one of the Venezuelan shell. The umbonal area of C. pailasana is similar to that of the Miocene to Recent C. cancellata (Linnaeus), but C. cancellata 1s less inflated, has a smaller lunule, and is always characterized by a posterior flattening of the disk not present on the new species. Also I have seen no Recent examples of C. cancellata with as many concentric ribs as the new species, and on none of the Recent ex- amples of C. cancellata do the closely spaced concentric ribs start as high up on the disk as they do on C. pailasana. The Recent C. pinchott Pilsbry and Olsson (Nautilus, vol. 64, No. 4, pp. 109-110, pl., g, figs. 7-8), from Limon Bay, Panama, is a smaller, more tri- gonal shell, with fewer concentric ribs, and a moderately deep pallial sinus. Chione (Chione ?) mamoensis, new species Plis33pfigs: aya: Pl. 44, figs. 12, 13; Pl. 45, figs. 1, 2 314 BuLueTIn 204 Shell small, moderately compressed to somewhat inflated, oval- subquadrate, slightly depressed posteriorly. Anterodorsal margin short and fairly straight, anterior end rounded, ventral margin shallowly arcuate, posterior end usually subtruncate, posterodorsal margin long and straight. Umbo moderately full, the beak proso- gyrate, situated a little anterior to the middle. Lunule cordate, not impressed, circumscribed by a thin sharp groove, ornamented with small radial riblets which are crossed and frilled by low concentric lamellae. Escutcheon lanceolate, flat to slightly depressed medially, marked by concentric growth laminae, defined by the subangular edge of the disk, colored by a few irregular transverse streaks of faded brown. Surface reticulated by fairly regular radial cords crossed by subequally spaced concentric lirae, the lirae elevated and recurved slightly toward the umbo, but becoming laminar near the posterior end where they lie nearly flat. The gently rounded radial cords, averaging 24 in number, are mostly single and separated by subequal interspaces, but in front of the middle and toward the base, the cords are double on some specimens. Occasionally there may be an interstitial thread between the primary radii. In addition to the numerous fine concentric growth striae traversing the disk there are an average of 24 primary concentric lirae, the lirae elevated and minutely scalloped at the top on most of the disk but flatter-lying and frilly on the posterior fourth of the valve. Right valve with a minor cardinal tooth adjacent to the nymph; in front of that is a taller erect triangular cardinal tooth separated from the posterior one by a narrow sulcus; the socket in front of the middle cardinal is subtrapezoidal, the anterior tooth bordering the socket the largest of the triad and more or less cuneate in appearance; the anterior and medial cardinals converge toward the beak but do not meet; ahead of the right anterior cardinal tooth there is an arcuate socket with a small laminar tooth above it. Along the posterodorsal margin of the right valve there is a long, rather prominent groove which receives the edge of the other valve. Hinge of left valve with a minor posterior cardinal, a stout cuneate central cardinal, and a smaller and narrow anterior cardinal tapering toward the beak. Anterior adductor scar high, ovate, impressed; posterior scar faint, suboval, and with a broad low radial hump running through it on the left valve, the hump not discernible on the right valve. Pallial VENEZUELAN CENOzoIC PELECYPODS: WEISBORD 315 sinus obscured. Ventral, anterior, and lunular margins crenulate within, the crenulations coarse and single or faintly bidenticulate along the middle of the ventral margin, then suddenly becoming finer, closer and arranged in series on the anterior end, and sub- sequently longer and somewhat oblique at the lunular margin, Dimensions—Holotype (S401la), right valve, length 13 mm.; height 11.2 mm.; thickness 4 mm. Paratype (S401b), left valve, length 11.2 mm.; height 9.7 mm.; thickness 3.3 mm. Paratype (D40la), right valve, length 10 mm.; height 9 mm.; thickness 3.7 mm. Type locahty.—Playa Grande formation (Maiquetia member) at W-23, north flank of Punta Gorda anticline. Eight specimens including five right valves and three left valves. Other localities —Abisinia formation at W-30, eastern edge of Play Grande village. One right valve. Comparisons.—This species closely resembles the Recent C. guatulcoensis Hertlein and Strong (1948, Zoologica, vol. 33, p. 182, pl. 1, figs. 2, 4, 6, 10; pl. 2, figs. 1, 8, 12, 13) which ranges from México and Panama in depths to seven fathoms, but C. guatulco- ensts 1s a little more pointed posteriorly and less regularly lirate than C. mamoensis, n. sp., and the radial sculpture of C. guatulco- ensis 1s obsolete in the medial anterior ventral area. Compared with the type of C. mazycku Dall (1902, U. S. Nat. Mus. Proc. vol. 26, No. 1312, pp. 373, 382-383, pl. 13, fig. 2), a Recent species of the Western Atlantic which is reported as ranging from North Carolina, U.S.A., to Brazil, C. mamoensis bears more concentric lirae. The subgeneric classification of C. mamoensis is uncertain as the pallial sinus cannot be made out on any of the Cabo Blanco specimens. Chione (Chione ?) laciniosa, new species Pl. 45, figs. 3-6 Shell suborbicular, somewhat inequilateral, moderately inflated, rather solid. Margin of disk in front of the beak concave, the an- terior and ventral margins forming part of a circle, the posterodorsal margin long and gently convex with an overall slope of about 40 degrees from the horizontal, the union of the posterodorsal and ventral margins obtusely angulate. Umbo full, the beak fairly high, prosogyrate, situated a little forward of the middle. Lunule large, slightly appressed, elongate-cordate, sharply defined by a narrow 316 BULLETIN 204 impressed groove, sculptured by coarse concentric lamellae bearing faint microscopic radial striations. Escutcheon narrow, hardly de- veloped. Surface sculpture consisting of subregular concentric lam- inae with low radial riblets on the dorsad face, the spaces between the laminae narrow and flat, and marked by single radial threads. The concentric laminae are sharp and foliaceous, particularly at the posterior submargin, in the early stages of growth, and somewhat thickened in the adult stage, the summit of the laminae minutely scalloped. The radial threads in the interspaces are rather strong, each one terminating at the groove between the riblets at the base of the dorsad face of the laminae, but continuing up the lower, or ventrad face of the laminae. Hinge of right valve with three sepa- rate cardinal teeth, the anterior one a lamina rising from the wall under the lunular margin, the middle one stout and cuneate, the posterior tooth large, high, slightly arcuate and weakly sulcate, the groove of the nymph behind it deep. Below the posterodorsal margin of the right valve there is a narrow groove which receives the edge of the opposite valve. Adductor scars faint, the anterior suboval, the posterior subpyriform. Pallial line rather remote from, and parallel with the basal margin. The configuration of the pallial sinus cannot be made out but there is the suggestion that it is small and close to the posterior adductor scar. Ventral and lunular margins crenulated within. Dimensions —Holotype (1401a), immature right valve, length 2.4 mm.; height 2.3 mm.; approx. thickness 0.7 mm. Paratype (1405a), hinge area of broken adult right valve, length of fragment 3.7 mm.; approx. thickness at umbo 1.1 mm. Type localty.—Lower Mare formation at W-13, on hillside above west bank of Quebrada Mare Abajo. Two right valves, one a whole adolescent, the other a broken adult. Comparisons——Among the numerous allied forms, the closest perhaps is C. morsitans Olsson and Harbison (1953, p. 112, pl. 13, fig. 3) from the upper Miocene and Pliocene of Florida, the Vene- zuelan shell differing from that in its more orbicular outline. Other analogous species from east and west America are the following: C. bainbridgensis Dall (1916, U. S. Nat. Mus., Proc., vol. 51, No. 2162, p. 499, pl. 84, figs. 5-6). Upper Oligocene and lower Miocene, southeastern United States. The union of the posterodorsal VENEZUELAN CENOzoIC PELECYPODS: WEISBORD 317 and ventral margins is more rounded than on C. laciniosa, n. sp. C. cortinaria (Rogers) (see Mansfield, 1932, Florida State Geol. Sur., Bull. No. 8, pp. 125-126, pl. 23, fig. 8). Upper Miocene in Virginia and Florida, U. S. A. The anterior and middle cardinals of the right valve are more closely approximate, and the outline of the valve more trigonal than on C. lacimosa. C. cribraria (Conrad) (see Palmer, 1927, Palaeontographica Americana, vol. 1, No. 5, p. 142, pl. 38, figs. 1, 8, 9; pl. 39, figs. 3, 24, 1929). Miocene and Pliocene from Virginia to South Caro- lina, U. S. A. The outline is subtrigonal, that of the Venezuelan shell suborbicular. C. guppyana Maury (1912, Acad. Nat. Sci. Philadelphia, Jour., 2 ser., vol. 15, p. 59, pl. 9, fig. 19). Miocene and Pliocene of Trinidad. The pallial sinus is deep and obtusely triangular. C. intapurpurea (Conrad) (see Abbott, 1954, American Sea- shells, p. 401, pl. 39g). Pleistocene of the Gulf states; Recent from North Carolina to the West Indies. The right anterior and middle cardinals are roughly parallel, subequal in size, and separated by a deep narrow cleft; also the lunule is shorter and more broadly cor- date than on C. laciniosa. C. pubera Valenciennes (see Palmer, 1927, p. 141, pl. 38, figs. 2, 5, 6, 12). Recent, Gulf of México and Caribbean Sea. This is more elongated than C. laciniosa. C. retugida Woodring (1925, Carnegie Inst. Washington Publ. No. 366, pp. 161-162, pl. 22, figs. 5-6). Middle Miocene of Jamaica. This is elongate-ovate whereas the Venezuelan shell is suborbicular. C. sawkinst Woodring (1925, pp. 159-160 pl. 21, figs. 12-14). Lower Miocene of the Dominican Republic; middle Miocene of Jamaica. The right anterior cardinal is much stouter and more rounded than on C. laciniosa. C. socia Pilsbry and Johnson (1917, Acad. Nat. Sci. Phila- delphia, Proc., vol. 69, p. 199; Pilsbry, 1921, zbid, vol. 73, p. 423, pl. 47, figs. 12, 13). Miocene of the Dominican Republic. This has fewer concentric laminae than C. laciniosa, and the crenulations at the middle of the ventral margin are paired. C. spencert Cooke (1919, Carnegie Inst. Washington, Publ. No. 291, p. 150, pl. 15, figs. la, b). Oligocene of Antigua. The concentric Lamainae “are stinath on the dorsal surface and on the upper part 318 BuLLeETIN 204 of the ventral surface, but with a row of beads, contiguous to the radial ribbing, at the base of the ventral surface.” C. walli (Guppy) (1866, Geol. Soc. London, Quart. Jour., vol. 22, p. 581, pl. 26, fig. 16). Miocene in Trinidad, Colombia, and Peru. This is more trigonal in outline than C. laciniosa. C. woodwardi (Guppy) (1866, p. 292, pl. 18, fig. 1). Lower Miocene of the Dominican Republic; middle Miocene of Jamaica. The right anterior cardinal is stouter and more rounded than on C. lacimosa. C. californiensis (Broderip) (1835, Zool. Soc. London Proc., p. 43; Sowerby, 1855, Thes. Conchyl., vol. 2, p. 711, pl. 154, figs. 40- 41). Upper Pliocene to Recent, the Recent shell ranging from Cali- fornia to Panama in depths to 38 fathoms. The concentric laminae are less frilly than on C. laciniosa. C. fluctifraga (Sowerby) (1855, Thes. Conchyl., vol. 2, p. 712, pl. 154, figs. 42-43). Upper Pliocene to Recent, the Recent shell ranging, mainly intertidally, from California to México. This species lacks the well-defined lunule of the Venezuelan shell. C. oulotricha Gardner (1936, State of Florida Dept. Conserv., Geol. Bull. No. 14, pp. 33-34, pl. 7, figs. 1-2). Middle Miocene in Ten Mile Creek, Calhoun County, Florida. More elongated than C. laciniosa. C. richthofem Hertlein and E. K. Jordan (1927, California Acad. Sci., Proc., ser. 4, vol. 16, No. 19, pp. 619-620, pl. 17, figs. 4, 7, 8). Lower Miocene of Baja California, México. The lunular area is more concave than on C. laciniosa. C. temblorensis Anderson (1905, California Acad. Sci., Proc., ser. 3, vol. 2, No. 2, p. 196, pl. 14, figs. 36-38). Lower Miocene, Cali- fornia. The escutcheon is much more pronounced than on the Vene- zuelan C. laciniosa, n. sp. C. undatella (Sowerby) (1835, Zool. Soc. London Proc., p. 22; 1885, Thes. Conchyl., vol. 2, p. 711, pl. 153, fig. 22). Pliocene to Re- cent, the Recent shell ranging from southern California to Peru in depths to 50 fathoms. The laminae are less frilly than on C. lacimiosa. Chione (Timoclea) tacaguana, new species Pl. 45, figs. 7, 8; Pl. 46, figs. 1, 2 Shell small, sturdy, moderately inflated, oval-suboblong, a little VENEZUELAN CENOZOIC PELECYPODS: WEISBORD 319 longer than high, slightly depressed posteriorly. Anterodorsal margin straight and slightly sloping, anterior end rounded, ventral margin arcuate, posterior end subtruncate, posterodorsal margin long and nearly straight. Beak moderately high, prosogyrate, situated well in front of the middle. Lunule fairly large, cordate, not impressed, circumscribed by a fine groove, sculptured by coarse concentric lamellae which overrun small radial riblets. Escutcheon elongate- elliptical, flat to hardly depressed, narrowly thickened adjacent to the ligamental groove, delimited by the angulate edge of the disk, marked by fine longitudinal striae. Surface reticulated by more or less evenly spaced radial cords crossed by numerous subequal con- centric lirae, the lirae slightly wider apart on the upper middle of the disk than on the umbo or base. The radial cords number 30 or more, and from about the middle of the valve toward the rear they are medially bifurcated. The concentric lirae, of which there may be 50 or so, are laminar, minutely ruffled on the middle of the disk, scalloped, slightly overlapping and crowded on the anterior end, and more open and frilled on the posterior end. Hinge with three discrete cardinal teeth on the left valve, the anterior one narrowly cuneate, the middle stout and subrectangular, the posterior laminar and arcuate. On the right valve the posterior cardinal is laminar, the middle one high and platy, the anterior large and cuneate; in front of the nght anterior cardinal there is an oblique socket bordered above by a small laminar tooth, and behind the right posterior cardinal the arcuate ligamental groove is deep and narrow. Along the posterodorsal margin of the right valve there is a strong, long, asymmetrical groove which receives the edge of the opposite valve. Anterior adductor scar impressed and ovate, the posterior scar larger but fainter, and subquadrate in outline. Pallial sinus small, subtriangular, with a rounded apex which is embayed to opposite the middle of the posterior adductor scar. Ventral and lunular mar- gins crenulate within, the posterior end of the valve smooth. The escutcheon of the holotype is traversed transversely by five widely separated stripes of faded brown. Dimensions —Holotype (S401c), left valve, length 13 mm.; height 11 mm., thickness 4.2 mm. Paratype (S401d), right valve, length 11.8 mm.; height 10.4 mm.; thickness 3.9 mm. Largest 320 BuLLeETIN 204 specimen, left valve, length 16.4 mm.; height 13.7 mm.; thickness 5 mm. Type locality—Playa Grande formation (Maiquetia member) at W-23, north flank of Punta Gorda anticline. Three specimens including two left valves and one right valve. Comparisons.—The new species at once recalls the Pleistocene to Recent C. pygmaea (Lamarck) (see Warmke and Abbott, 1961, Caribbean Seashells, p. 186, pl. 38)), but C. pygmaea is more elongat- ed and is well rounded at the posterior end rather than subtruncate as is C. tacaguana, n. sp. The new species is also similar to the Miocene to Recent C. grus (Holmes) (1860, Post-Pleiocene fossils of South Carolina, p. 37, pl. 7, fig. 5) but that is differentiated by its smaller size and by its much narrower and sunken escutcheon. Chione (Chionopsis) subrostrata (Lamarck) Pl. 45, figs. 9-14 1818. Venus subrostrata Lamarck, An. sans Vert., vol. 5, p. 588. 1835. Venus subrostrata Lamarck, Deshayes, An. sans Vert., vol. 6, p. 343. 1846. Venus portesiana d’Orbigny, Voyage dans |’Amérique Méridionale, p. 556, pl. 83, figs. 1-2. 1852. Venus Beaui Récluz, Jour Conchyl., vol. 3, p. 412, pl. 12, figs. 15 a, b. 1864. Venus Beauii Récluz, Krebs, The West Indian Marine Shells, p. 95. 1889. Venus Beaui Récluz, Dall, U. S. Nat. Mus., Bull. 37, p. 54. 1889. Venus beaui Récluz, Simpson, Davenport Acad. Nat. Sci., Proc., vol. 5, p. 64. 1902. Venus subrostrata Lamarck, Dall, U. S. Nat. Mus., Proc., vol. 26, No. 1312, pp. 373, 393 (part). 1903. Chione subrostrata (Lamarck), Dall, Wagner Free Inst. Sci., Trans., vol. 3, pt. 6, p. 1289. 1910. Chione subrostrata (Lamarck), Dall, U. S. Nat. Mus., Proc., vol. 37, No. 1704, p. 268 (part). 1925. Chione (Chione) subrostrata (Lamarck), Maury, Bull. Amer. Paleont., vol. 10, No. 42, p. 306. 1925. Chione (Chione) portesiana (d’Orbigny), Maury, Bull. Amer. Paelont., vol. 5, No. 42, p. 307, pl. 28, fig. 3; var. beaui Recluz, Maury, pp. 307- 308, pl. 28, fig. 3. 1927. Chione (Chione) subrostrata (Lamarck), Palmer, Palaeontographica Americana, vol. 1, No. 5, pp. 358-359, pl. 40, figs. 3, 4, 19, 20; pl. 44, fig. 20 (1929). 1934. Chione subrostrata Lamarck, Johnson, Boston Soc. Nat. Hist., Proc., vol. 40, No. 1, p. 48. 1936. Venus (Chione) subrostrata Lamarck, Lermond, Check List of Florida Marine Shells, Gulfport, p. 24. 19317 pseone subrostrata (Lamarck), Smith, East Coast Marine Shells, p. 54, pl. 20, fig. 7. 1938. Venus subrostrata Lamarck, Lamy and Fischer-Piette, Mus. Nat. Hist. nat. Paris, Bull., 2d ser., vol. 10, No. 4, p. 402. 1945. Venus subrostrata Lamarck, Van Bentham Jutting, Geolog.-Mijinbouwk. Genootschap Nederland en Kolonien, Geol. ser., vol. 14, p. 78. 1948. Chione subrostrata (Lamarck), Hertlein and Strong, Zoologica, vol. 33, pt. 4, No. 13, p. 184. VENEZUELAN CENOZzOIC PELECYPOoDS: WEISBORD 321 1949. Chione subrostrata (Lamarck), Lange de Morretes, Mus. Paranaense, Arq:, vol. 7,,art. 15 \p. 38: 1958. Chione subrostrata (Lamarck), Keen, Sea Shells of Tropical West America, p. 144. The Recent shell from Higuerote is moderately inflated, generally ovate-subtrigonal but occasionally suborbicular, the sub- trigonal form slightly produced posteriorly and subangularly rounded at the curve of the posterodorsal and ventral margins, the sub- orbicular form with a nearly semicircular ventral margin. Beak full, prosogyrate, a little anterior to the middle. Lunule cordate, de- fined by a finely incised groove, sculptured by seven to nine nodu- lose radial cords which are crossed by concentric laminae con- tinuing from the disk. Escutcheon elongate-elliptical, flattened, marked by numerous growth lines, the inner edge at the ligamental groove arcuate and narrowly thickened, the outer edge deliminated by the generally sharply angulate margin of the disk. Surface sculp- ture consisting of 20 to 40 low lamellar concentric ribs, with strong low radial cords in the interspaces, the cords crossed by numerous concentric growth striae. The concentric ribs extend from the beak to the base, are widely and subequally spaced on the umbo and central area of the disk but more closely spaced toward the ventral margin; the ribs are finely frilled along the top edge and corrugated on their ventrad face by strong short regular crenations. The radial cords are low, fairly broad, regularly spaced (although a little more crowded posteriorly), the interspaces a little narrower than the cords; on the umbonal area the radial cords appear to be single, but under the lens are seen to be compounded of one or two micro- scopic radii; below the umbo the cords become bipartite, and then tripartite toward the base, the divisions weak on some specimens, strong on others; on the posterior of the disk the radial cords are single. On the under, or ventrad face of the concentric ribs there are first two, and later three strong crenations of equal size, the crenations regularly disposed atop the radial cords. Hinge of left valve with a stout, somewhat sulcate middle cardinal, in front of which is an erect anterior tooth which fits into the deep narrow socket of the opposite valve. Hinge of right valve with a stout, slightly sulcate posterior cardinal, the receptor socket in front of it deep and subrectangular, the sides subparallel. Anterior adductor 322 BuL_etin 204 scar ovate, the posterior scar broadly subcylindrical. Pallial sinus oblique, obtusely triangular, rounded at the apex which is on a line with, but considerably removed from the upper margin of the pos- terior adductor scar. Ventral and lunular margins finely crenulate within. The coloration is variable. Some specimens are white through- out except for a tinge of purple on the inner face of the lunule and in the cavity to the rear of the escutcheon. On most of the specimens the lunule is brownish in whole or in part, and the escutcheon flecked, flammuled, or stained chestnut-brown. Several specimens are straw-colored on the exterior and bear interrupted rays of chestnut-brown. Three specimens are mostly black and gray on the outside, with bands and flushes of blue-black and gray in the in- terior, these specimens also having brown on the lunule and bands of chestnut-brown crossing the escutcheon. Dimensions.—Specimen B400a, right valve, light in color, length 21.3 mm.; height 19 mm.; thickness 5.1 mm. Specimen B400b, left valve, blackish, length 20 mm.; height 17 mm.; thickness 6 mm. Specimen A404a, right valve, worn, length 15 mm.; height 13 mm.; thickness 5 mm. Localities—Recent, on beach southeast of Higuerote, State of Miranda. Nine specimens including five left valves and four nght valves. Recent, on beach of Playa Grande Yachting Club, Distrito Federal. One worn right valve, the identification of which is some- what doubtful. Remarks.—The shells from Higuerote exhibit considerable vari- ation in color, shape, and number of concentric lirae. The more elongated forms are like d’Orbigny’s C. portesiana, and the sub- orbicular forms like C. beaui Récluz. Both of those, according to Palmer, are synonymous with C. subrostrata (Lamarck). Range and distribution—Recent, southern Florida to Brazil. Van Bentham Jutting (1945) reported Chione subrostrata as a fossil from the Quaternary at Punta Gorda, Venezuela, and although she gave no precise locality at Punta Gorda, I believe it must have been in the immedate vicinity of what I (Weisbord, 1957) have called the Punta Gorda anticline. On the south flank and near the axis of this faulted anticline a narrow fossiliferous wedge of the Mare formation (Fig. 5) is exposed. Unconformably atop this wedge are heterogeneous unfossiliferous cobble gravels. On the north flank VENEZUELAN CENOZzOIC PELECYPODS: WEISBORD 323 of the Punta Gorda anticline, and somewhat lower in elevation than the Mare wedge is the Maiquetia member of the Playa Grande formation with its included Lithothamnium bioherm (Figs. 6, 7) and associated mollusks. In one place or another at Punta Gorda the heterogeneous and unfossiliferous gravels unconformably overlie both the Mare and Playa Grande formations, and these gravels may well be Pleistocene in age. I did not find Chione subrostrata at Punta Gorda, but I would venture the opinion that the form identi- fied as this species was collected in either the Playa Grande or Mare formation, and as I continue the study of the fossils from these formations the evidence increasingly suggests that they are pre-Pleistocene in age. Chione (Lirophora) riomaturensis Maury Pl. 45, figs. ,15, 16; Pl. 47, figs. 1-6 1925. ?Chione (Lirophora) latilirata (Conrad), Maury, Bull. Amer. Paleont., vol. 10, No. 42, pp. 313-314, pl. 29, figs. 1, 2, 9. 1925. Chione (Lirophora) riomaturensis Maury, Bull. Amer. Paleont., vol. 10, No. 42, pp. 314-315, pl. 29, fig. 4. 1927. Chione (Lirophora) riomaturensis Maury, Palmer, Palaeontographica Americana, vol. 1, No. 5, p. 389, pl. 44, fig. 9 (1929). The Venezuelan shell referred to this Trinidad species is thick, moderately compressed, trigonal in outline, a little longer than high. Anterodorsal margin at the lunule subangularly concave, the anterior end acutely rounded, the ventral margin arcuate, the posterior end subangularly rounded, the posterodorsal margin long and straight except at the beak where it is slightly convex. Beak flattened on top, prosogyrate, situated a little forward. Lunule cordate, sunken in the middle, defined by a narrowly incised groove, the inner edge slightly elevated, marked by concentric striae which develop into low laminae with age. Escutcheon long, lanceolate, flattened to hardly concave, arcuately and weakly lipped adjacent to the ligamental groove, de- limited sharply by the angulate edge of the disk, marked by num- erous regular growth striae. Surface sculptured by five to fifteen concentric ribs, the number depending on the stage of development. The prodissoconch is small and smoothish, but on the umbo there are two or three widely spaced low laminar ribs, the later of these with a tendency to become recurved toward the beak. Below the umbo the ribs are broad, swollen, and billowy on adolescent speci- 324 BuLLETIN 204 mens but convex and shingle-like or older shells, the ribs on the latter rising slightly above the base of the preceding rb and sep- arated from it by a deep narrow channel. Generally, on the umbo, there is one rib which is larger than ones immediately above it as well as the first one or two below it. Anteriorly the principal ribs ter- minate just before the lunular groove, but posteriorly, more often than not, the swollen ribs suddenly thin out and are continued over the posterior area as narrow elevated ridges to the border of the escutcheon. Occasionally a rib or two does not pinch out into a lamina but ends a short distance away from the border of the escut- cheon. Rarely, a rib is outflung into a pointed tip at the posterior extremity. On larger specimens the face of the ribs is marked by delicate wavy concentric growth incrementals, and at the base of the ribs there are generally faint radial lineations. The interspaces themselves are smooth. Hinge strong and normal, each valve with three cardinals, the anterior one, especially that of the right valve, the smallest; on the right valve the posterior cardinal has a deep groove behind it whereas on the left valve the posterior cardinal is fused to the nymph. Nymph pitted on left valve, arrayed with small chevron-like denticles on the right valve. Along the edge of the escutcheon is a narrow groove, the groove longer and sharper on the right valve than the left. Anterior adductor scar ovate, impressed, thickened slightly at the outer margin; posterior adductor scar faint, suboval. Pallial sinus short and triangular, the apex subacute, pointed forward and upward, embayed to a point opposite the middle of the posterior adductor scar. Ventral and lunular margins closely crenate. Dimensions.—Specimen 1398a, left valve, length 36.6 mm.; height 32.1 mm.; thickness (excluding ribs) 10 mm. Specimen H398a, right valve, length 34.7 mm.; height 28.2 mm.; thickness (excluding ribs) 7 mm. Specimen J398a, right valve, length 14.6 mm.; height 12 mm.; thickness (excluding ribs) 3.1 mm. Specimen J398b, left valve, length 14.3 mm.; height 12.3 mm.; thickness (ex- cluding ribs) 4 mm. Localities —Lower Mare formation at W-13, on hillside above west bank of Quebrada Mare Abajo. Five specimens including three nght valves and two left valves. Lower Mare formation, in small stream 100 meters west of Quebrada Mare Abajo. Four specimens VENEZUELAN CENOZOIC PELECYPODS: WEISBORD 325 including two right valves and two left valves. Upper Mare forma- tion at W-14, on hillside above west bank of Quebrada Mare Abajo. Nine specimens including five left valves and four right valves. Mare formation at W-25, south flank of Punta Gorda anticline. Five nght valves. Comparisons.—Like many of the billowy-ribbed species of the subgenus Lirophora, the Cabo Blanco shell referred to C. (L.) ri0- maturensis Maury exhibits considerable variation in superficial sculpture, particularly at different stages of development. Young Cabo Blanco specimens of C. riomaturensis, for example, also closely resemble the small Trinidad shell identified by Maury as C. latilirata (Conrad), though it may well be that both of Maury’s forms represent the same species, one of them being the adolescent, the other the adult. However, I doubt that this species is the typical Miocene to Recent C. Jatilirata of Conrad as the ribs of C. latihrata s.s. (Conrad) are rather regular, and cease, without pinching out, before reaching the border of the escutcheon. The Trinidad and Venezuelan forms here referred to C. riomaturensis Maury are closer to the upper Miocene of Recent C. Jatilirata athleta (Conrad) (see Mansfield, 1932, Florida State Geol. Sur., Bull. No. 8, p. 130, pl. 25, figs. 8-9) although according to Conrad the ribs of C. 1. athleta are without posterior laminae whereas on C. riomaturensis the ribs are often, though not always, pinched into a lamina on the posterior area near the escutcheon. On the Pleistocene and Recent C. paphia (Linnaeus) (see McLean, 1951, p. 86, pl. 17, fig. 9; and Fischer, 1887, p. 1084, pl. 20, fig. 7) the concentric ribs are more regular and more numerous than on C. riomaturensis, and each of them pinches out posteriorly into a lamina rather far removed from the escutcheon. Other fossil analogues of C. riomaturensis Maury are the fol- lowing: C. chiriquensis Olsson (1922, p. 420, pl. 32, figs. 9-10). Middle Miocene, Costa Rica. In side view, with the short axis of the valve held vertically, the lunular margin is seen to be arcuate where- as on the Cabo Blanco C. riomaturensts the forward end of the lunular margin is nearly straight and horizontal. C. cartagenensis H. K. Hodson (1927, p. 63, pl. 31, fig. 4; pl. 35, fig. 6) from the Miocene at Cartagena, Colombia, and C. 326 BuLLeTIN 204 matarucana H. K. Hodson (1927, p. 64, pl. 35, fig. 4) from the Miocene in the State of Falcon, Venezuela, do not have so steep a posterodorsal margin as does C. riomaturensis, and the ribs are less billowy than on C. momaturensts. C. latilirata colombiana Weisbord (1929, pp. 254-255, pl. 4, figs. 8-10). Middle Miocene, Colombia. This has more regular ribs than the Cabo Blanco shell, and none of them pinches out into a lamina near the escutcheon. C. hendersoni Dall (see Woodring, 1925, Carnegie Inst. Washington, Publ. No. 366, pp. 163-164, pl. 22, figs. 7-10). Oligocene and lower Miocene of Puerto Rico; Lower and middle Miocene of the Dominican Republic, middle Miocene of Jamaica. The concen- tric ribs are more numerous and more regular than those of C. rio- maturensts. C. cymaina Gardner (1936, State of Florida Dept. Con- serv., Geol. Bull. No. 14, pp. 36-37, pl. 5, figs. 14-15). Middle Miocene, Florida. The ribs are broader, fewer, and even more irregu- lar than on the Cabo Blanco C. riomaturensts. Range and distribution.—Pliocene at Matura, Trinidad. The form listed by Guppy (1867, Sci. Assoc. Trinidad Proc., pt. 3, p. 189) as Venus paphia Linnaeus, from the Pliocene near Cumana, Venezuela, is probably the same species as the one referred to herein as C. riomaturensis. Chione (Lirophora) cultellata, new species Pl. 47, figs. 7-12 Shell small, compressed, trigonal, inequilateral. Anterodorsal margin long and hardly concave, anterior end acutely rounded to subangular, ventral margin arcuate, posterior end subangularly rounded, posterodorsal margin steeply inclined, somewhat humped at the umbo, straight and long below. Lunule scarcely depressed, ill-defined, long, narrow, subcordate to ellipical, marked by a few faint growth striae. Escutcheon long, flat, lanceolate, nearly smooth. Beak appressed, prosogyrate, subcentral. Surface sculptured, below the smooth prodissoconch, by remote, elevated, thin to laminar concentric ribs (five on the paratype) extending across the disk from the edge of the lunule to the border of the escutcheon. With growth the ribs on the main part of the disk become progressively higher, thicker at their base, and bent or recurved toward the VENEZUELAN CENOzOIC PELECYPODS: WEISBORD S27. umbo, but along the border of the escutcheon the ribs retain their lamellar character. The wide and flattish interspaces between the ribs are nearly smooth, though they are scored with microscopic concentric lineations through which the fine radii of the inner layer of the shell may be vaguely reflected if not already bared through corrosion of the surface layer. Ligamental groove narrow and arcuate. Hinge of right valve with a small laminar anterior, a mod- erately stout and deltoid medial, and an elongated posterior cardi- nal. Cardinal teeth of left valve diverging from beneath the beak, the anterior tooth larger than that of the opposite valve, and the posterior cardinal smaller than that of the opposite valve. Along the escutcheon of the right valve there is a long narrow groove to re- ceive the edge of the left valve. Anterior adductor scar ovate and slightly sunken, the posterior scar faint, and more or less oval. Pallial sinus U-shaped, moderately short and broad, nearly erect, the apex well rounded and embayed to a point near and a little below the top of the posterior adductor scar. The ventral margin of the valves is finely crenate within, but because of imperfect preser- vation, it cannot be determined whether the narrow lunular margin is also crenate. Dimensions—Holotype (G409a), right valve (broken along ventral margin), length 4.3 mm. Paratype (G408a), left valve, length 4.7 mm.; height 3.9 mm. Paratype (1406a), left valve, length 4 mm.; height 3.7 mm.; thickness (excluding ribs) approximately 1 mm. Type locality—Upper Mare formation at W-14, on hillside above west bank of Quebrada Mare Abajo. Two valves, one right and one left. Other localities —Lower Mare formation at W-13, on hillside above west bank of Quebrada Mare Abajo; one left valve. Comparisons.—The nearest related species is C. quirosensis H. K. Hodson (1927, Bull. Amer. Paleont., vol. 13, No. 49, p. 62, pl. 35, fig. 9) from the upper Oligocene or lower Miocene in the State of Falcon, Venezuela, but the Cabo Blanco shell is more inequilateral and has a steeper posterodorsal slope than the Falcon form. PETRICOLIDAE Petricola (Naranio) lapicida (Gmelin) Pl. 47, figs. 13, 14 328 1791. 1791. 1801. 1825. 1843. 1853. 1853. 1853. 1864. 1878. 1886. 1889. 1889. 1895. 1900. 1900. 1901. 1910. 1922. 1933: 1934. 1936. 1936. 1937. 1940. 1945. 1951. 1952. 1953. 1954. BuLteTIN 204 Venus lapicida Gmelin, Syst. Nat., vol. 6, p. 3269. Chemnitz, 1788, Syst. Conchylien-Cabinet, vol. 10, p. 356, pl. 172, figs. 1664-1665. Venus divergens Gmelin, Syst. Nat., vol. 6, p. 3629. Chemnitz, 1788, Syst. Conchylien-Cabinet, vol. 10, p. 357, pl. 172, figs. 1666-1667. Petricola costata Lamarck, Syst. An. sans Vert., p. 121. Venus lapicida Gmelin, Wood, Index Testaceologicus, pl. 8, fig. 72. Petricola costata Lamarck, Hanley, An Illustrated and Descriptive Cata- logue of Recent Bivalve Shells, p. 53. Naranio costata (Lamarck), Gray, An. Mag. Nat. Hist., vol. 11, p. 38. Naranio lapicida (Gmelin), Deshayes, Catalogue of the Conchifera or Bivalve Shells in the British Museum, p. 216. Petricola divaricata d’Orbigny, [in] La Sagra, Hist. phys., polit. et nat. l’Ile de Cuba, vol. 2, p. 265. Petricula divaricata (Chemnitz) and P. lapicida (Chemnitz), Krebs, The West Indian Marine Shells, p. 108. Petricola lapicida (Chemnitz), Mérch, Catalogue of West-India Shells, p. 15: Petricola divaricata (Chemnitz), Dall, Mus. Comp. Zool., Bull., vol. 12, No. 6, p. 276. Petricola divaricata (Chemnitz), Simpson, Davenport Acad. Nat. Sci., Proc., vol. 5, p. 63. Petricola (Naranio) lapicida (Gmelin), Dall, U. S. Nat. Mus., Bull. 37, p. 58. Choristodon lapicidum (Chemnitz), Gregory, Geol. Soc. London, Quart. Jour., vol. 51, p. 292. Petricola (Naranaio) lapicida (Gmelin), Verrill, and Bush, Connecticut Acad. Arts and Sci., Trans., vol. 10, art. 12, p. 519, pl. 63, figs. 14-15. Petricola lapicida (Gmelin), Dall, Wagner Free Inst. Sci., Trans., vol. Spt 55) Pp.) 1059. : Petricola lapicida (Gmelin), Dall and Simpson, U. S. Fish Com., Bull., vol. 20 for 1900, pt. 1, p. 483. Petricola lapicida (Chemnitz), Jukes-Browne, Malac. Soc. London, Proc., vol. 9, pt. 3, p. 218. Petricola (Naranio) lapicida (Chemnitz), Lamy, Jour. Conchyl., vol. 67, No. 4, pp. 317, 318, 337-340. Petricola lapicidum (Chemnitz), Trechmann, Geol. Mag., vol. 70, No. 823, Dp:36; ; Petricola lapicida (Gmelin), Johnson, Boston Soc. Nat. Hist., Proc., vol. 40, No. 1, p. 50. Petricola lapicida (Gmelin), McLean, Nautilus, vol. 49, No. 4, p. 119. Petricola lapicida (Gmelin), Lermond, Check List of Florida Marine Shells, Gulfport, p. 18. Petricola lapicida (Gmelin), Smith, East Coast Marine Shells, p. 56, plo; fe Eh. Petricola lapicida (Gmelin), Bales, Nautilus, vol. 54, No. 2, p. 40. Petricola lapicida (Gmelin), van Bentham Jutting, Geolog.-Mijnbouwk. Genootschap Nederland en Kolonien, Geol. ser., vol. 14, p. 78. Naranio lapicida (Gmelin), McLean, New York Acad Sci. Scientific Survey of Porto Rico and the Virgin Islands, vol. 17, No. 1, p. 88, pl. 18, figs. 3-4. Rupellaria lapicida (Gmelin), Pulley, Texas Jour. Sci., vol. 4, No. 2, p. 183. Petricola (Petricola) lapicida (Gmelin), Olsson and Harbison, Acad. Nat. Sci. Philadelphia, Mon. No. 8, p. 121. Petricola (Naranio) lapicida (Gmelin), Abbott, American Seashells, pp. 419-420. VENEZUELAN CENOzOIC PELECYPODS: WEISBORD 329 1955. Petricola lapicida (Gmelin), Perry and Schwengel, Marine Shells of the Western Coast of Florida, p. 75, pl. 15, fig. 93. 1958. Petricola lapicida (Gmelin), Olsson and McGinty, Bull. Amer. Paleont., vol. 39, No. 177, p. 21. 1959. Petricola (Naranio) lapicida (Gmelin), Nowell-Usticke, A Check List of the Marine Shells of St. Croix, p. 16. 1961. Petricola lapicida (Gmelin), Warmke and Abbott, Caribbean Seashells, p. 191, pl. 44e. Shell subquadrate, slightly oblique, inflated, inequilateral, the ventral margin and posterior end more or less subtruncate. Beak moderately high, somewhat flattended on top, situated a little for- ward of the middle, prosogyrate. Lunule and escutcheon wanting. Teeth relatively short, consisting, on the left valve, of a laminar anterior, a broad stout bifid medial, and a platy posterior cardinal, the latter nearly parallel with and shorter than the ridge at the nymph from which it seems to be splayed off. Anterior adductor scar elliptically ovate, the posterior scar rudely orbicular. Pallial sinus wide, U-shaped, shallowly rounded at the apex, extending somewhat obliquely to slightly beyond the middle of the valve. Surface sculptured by numerous distinct radial divaricating and chevron-like threads, the disk also crossed by fine concentric growth lamellae and several narrow sulci at intervals of growth stoppage. Inner margins plain. Dimensions —Specimen $549a, left valve, length 12 mm.; height 11.2 mm.; thickness 3.9 mm. Locahty.—Playa Grande formation (Maiquetia member) at W-23, north flank of Punta Gorda anticline. Three left valves. Also reported from Quaternary at Punta Gorda by van Bentham Jut- ting (1945, p. 78). Range and distribution—Recent from South Carolina to Brazil at depths of 68 fathoms. Smith (1885, Voyage of H.M.S. Challenger, Zoology, pp. 4, 17, 113) reported the occurrence of a few juveniles in 7 and 8 fathoms off the north coast of Australia, and the species has been recorded in the Pacific and Indian Oceans as well as in the Red Sea. As a fossil P. Japicida (Gmelin) is found in the Pleisto- cene of Barbados and the Pliocene of Florida. Petricola (Rupellaria) typica (Jonas) Pl. 47, fig. 15; Pl. 48, figs. 1-6 1844. Choristodon typicum Jonas, Zeitschr. f. Malakozool., yr. 1, p. 185. 1844. Choristodon typicum Jonas, Molluskologische Beitrage, p. 1, pl. 7, fig. 3. 330 1853. 1864. 1878. 1880. 1887. 1889. 1889. 1907. 1900. 1910. 1920. 1922. 1934. 1935. 1937. 1939. 1940. 1942. 1944. 1945. 1946. 1949. 1951. 1952. 1954. 1955. 1958. 1961. BuLLeTINn 204 Petricola typica (Jonas), Deshayes, Catalogue of the Conchifera or Bi- valve shells in the British Museum, p. 210. Petricula (Choristodon) typica (Jonas), Krebs, The West Indian Marine Shells, p. 108. Petricola (Choristodon) typica (Jonas), Moérch, Catalogue of West India Shells, p. 15. Petricola lithophaga Arango y Molina, Contribucién a la Fauna Mala- colégica Cubana, p. 248. Not of Retzius and Lamarck. Petricola (Choristodon) typicus (Jonas), Fischer, Manuel de Conchylio- logie et de Paléontologie Conchyliologique, p. 1089. Choristodon robusta Dall, U. S. Nat. Mus., Bull. 37, p. 58. Not of Sowerby. SL pid ees typicum Jonas, Simpson, Davenport Acad. Nat. Sci., Proc., vol. 5, p. 63. Petricola typica (Jonas), von Ihering, Mus. Nac. Buenos Aires, An., vol. 14, p. 531. Petricola (Rupellaria) typica (Jonas), Dall, Wagner Free Inst. Sci., Trans., vol. 3, pt. 5, p. 1059. Petricola typica (Chemnitz), Jukes-Browne, Malac. Soc. London, Proc., VoliO pt: 93; 7p.218: Petricola (Rupellaria) typica (Jonas), Maury, Bull. Amer. Paleont., vol. 8, No. 34, p. 110. Petricola typica (Jonas), Lamy, Jour. Conchyl., vol. 67, No. 4, pp. 322-333. Rupellaria typicum (Jonas), Johnson, Boston Soc. Nat. Hist., Proc., vol. 40, No. 1, p. 50. Petricola typica (Jonas), Richards, Jour. Paleont., vol. 9, No. 3, p. 257. Rupellaria typica (Jonas), Smith, East Coast Marine Shells, p. 56, pl. 25 etigs. 7a 7D: Petricola (Rupellaria) typica (Jonas), Weisbord, Nautilus, vol. 39, No. 3, p. 84. Rupellaria typica (Jonas), Bales, Nautilus, vol. 54, No. 2, Rupelaria typicum (Jonas), Jaume and Pérez Farfante, oe ‘Cubana Hist. Nat. “Felipe Poey,” Mem., vol. 16, No. 1, p. 39. Rupellaria typica (Jonas), Hackney, Nautilus, ‘vol. 58, No. 2, p. 58. Petricola typica (Jonas), van Bentham Jutting, Geolog. * Mijaboune. Genootschap Nederland en Kolonien, Geol. ser., vol. 14, p. 78. Rupellaria typica (Jonas), Jaume, Soc. Malac. “Carlos de La Torre,” Rev., vol. 4, No. 3, p. 101. Petricola (Petricola) typica (Jonas), Mus. Paranaense, Arq., vol. 7, art. 1, p. 39. Petricola typica (Jonas), McLean, New York Acad. Sci. Scientific Survey of Porto Rico and the Virgin Islands, vol. 17, pt. 1, p. 88, pl. 18, fig. 2. Rupellaria typicum (Jonas), Pulley, Texas Jour. Sci. vol. 4, No. 2, p. 183, pl. 11, figs. 8-9. Rupellaria typica (Jonas), Abbott, American Seashells, p. 420, pl. 30e. Rupellaria typica (Jonas), Perry and Schwengel, Marine Shells of the Western Coast of Florida, p. 76, pl. 15, fig. 94. Rupellaria typica (Jonas), Olsson and McGinty, Bull. Amer. Paleont., VO 39s NOW 77 pe Zi. Rupellaria typica (Jonas), Warmke and Abbott, Caribbean Seashells, p. 191, pl. 44b. Shell rude, inflated, somewhat distorted, inequilateral, vary- ing in shape from subtrapezoidal to ovate (the posterior end of the former shallowly rounded to subtruncate, the latter moderate- ly attenuated posteriorly), the ventral margin generally obliquely VENEZUELAN CENOZOIC PELECYPODS: WEISBORD 331 subtruncate and embayed slightly behind the middle, the embay- ment coinciding with a broad radial depression on the disk which forms below the umbonal region and continues to the base. Umbo rounded, the beak low, flattened on top, directed anteriorly, situated in front of the middle, the distance from the middle greater on the ovate forms than on the boxy ones. Below, and a little ahead of the beak there is a short pronounced linear sulcus. Surface sculp- tured by fairly sharp subequally spaced vermicular radiating ribs (of which there are as many as 46 on one of the specimens), the ribs strongest on the posterior fourth of the disk, fainter and more crowded on the anterior submargin. Crossing the ribs are fine close- ly spaced concentric growth lamellae, these forming small triangular vaulted arches on the basal area of the posterior submargin on adults. Hinge of right valve with two cardinals, a spikelike anterior and a platy posterior, separated by a broad open socket. Hinge of left valve with a rudimentary anterior cardinal, a stout bifid medial cardinal, and a platy posterior cardinal which is lower than and subparallel with the medial tooth. Anterior adductor scar rather long and sub- elliptical, the posterior scar a little smaller and more or less orbicular. Pallial sinus wide, slightly ascending, broadly and shallowly rounded at the apex, projecting forward to not quite the middle line of the valve. Ventral margin delicately crenate within. The shell color is straw without, whitish within but often stained there a pale brown in the sinus area and along the ventral margin. Dimensions.—Specimen A506a, valves attached, length 11 mm.; height 9 mm.; thickness of pair 8.3 mm. Specimen A 506b, left valve, length 13.8 mm.; height 13 mm.; thickness 5.1 mm. Specimen A506c, right valve, length 16 mm.; height 13.5 mm.; thickness 4.6 mm. Fossil specimen D506a, incomplete right valve, length 13.3 mm.; height 11 mm., thickness 5 mm. Largest specimen (Recent), length 18.8 mm.; height 15.1 mm.; thickness 6.2 mm. Localities —Recent, on beach at Playa Grande Yachting Club, Distrito Federal. Seventeen specimens including nine left valves, six right valves, and two doublets. Abisinia formation at W-30, eastern edge of Playa Grande village. Two poorly preserved left valves. Also reported from Quaternary at Punta Gorda by van Bentham Jutting (1945, p. 78), but the fossiliferous strata at Punta Gorda are probably pre-Pleistocene in age. $32 BuLtetin 204 Remarks.—The west American analogue is the Pleistocene and Recent P. robusta Sowerby (see Keen, 1958, p. 152, fig. 349), that differing slightly from P. typica by its shorter pallial sinus. Range and distribution—The Recent P. typica ranges from North Carolina, U. S. A., to Brazil and Argentina. The species also occurs in the Pleistocene of Cuba, and, according to Dall, in the Pliocene of Florida. Pleiorytis venezuelensis, new species Pl. 48, figs. 7-12 Shell small, thin, moderately inflated, subquadrate, inequilateral, the ventral margin of the left valve (1507b) warped and turned in (probably fortuitously) anteriorly, Anterior end of right valve (15- 07a, the holotype) well rounded, posterior end subtruncate, ventral margin shallowly arcuate and with a mere suggestion of a gape behind the middle where the disk below the umbonal region is slightly depressed; posterodorsal margin long, fairly straight, and moderately sloping, the anterodorsal area in front of the beak slightly concave. Umbonal region full, the beak moderately high, appressed on top, directed forward, situated near the anterior fourth of the valve. Lunule and escutcheon not developed. Exter- nally the valve is concentrically wrinkled by uneven undulations and small subregular threads, the surface also crossed by numerous fine, wavy radial striae which are minutely granular. Hinge of right valve with a shallow ligamental sulcus bordered by a pinched and moderately elevated nymph resembling a posterior cardinal; in front of the nymph, and separated from it by a narrow slit, is a small fairly high bifid medial cardinal, and anterior to that, but below and diverging from it, is a laminar anterior cardinal. Hinge of left valve with a thin triangular posterior cardinal, a short wide triangular and seemingly bifid medial cardinal, and a short laminar spurlike anterior cardinal projecting from beneath the edge of the lunular area. Adductor scars distinct, the anterior large and arcu- ately ovate, the posterior scar a little smaller and subrounded, the base of both scars lying below the midline of the interior. Pallial sinus large and deep, projecting obliquely to well above the center of the valve, the apex subacute. Pallial line faint, roughly parallel with the ventral margin. Inner margins thin but built up incre- mentally, VENEZUELAN CENOzoIC PELECYPoDS: WEISBORD 335 Dimensions——Holotype (1507a), right valve, length 4 mm.; height 3 mm.; thickness 1:5 mm. Paratype (1507b), left valve, length 3.7 mm.; height 3.3 mm.; thickness 1.4 mm. Paratype (T507a), right valve, length of broken specimen 4.5 mm. Type locality—Lower Mare formation at W-13, on hillside above west bank of Quebrada Mare Abajo. Two specimens including one right valve and one left valve. Other localities—Upper Mare formation, in stream 250 meters south-southwest of mouth of Quebrada Las Pailas. One right valve. Lower Mare formation, in small stream 100 meters west of Quebrada Mare Abajo. One small broken right valve. Remarks.—The distinguishing characters of this shell are the deep oblique pallial sinus, the relatively low adductor scars, and the long, moderately sloping posterodorsal margin. The form is close to P. caromiana (Maury) (1925, pp. 274-275, pl. 20, fig. 16) from the upper Miocene of Trinidad and to P. delicata (Weisbord) (1929, p. 257, pl. 5, fig. 4, as Asaphis) from the middle Miocene of Venezuela, the latter considered by Vokes (1938, Amer. Mus. No- vitates No. 988, p. 15, fig. 11) to be the same as P. caromana, and also reported from the upper Miocene of Trinidad. It is difficult to compare the Cabo Blanco shell with P. caroniana and P. delicata because of the paucity of specimens, the considerable differences in size, and the inaccessibility of the interior of the types of P. caromana and P. delicata. Superficially, however, the young P. venezuelensis, n. sp. seems to be distinguishable from the adolescent holotype of P. caromiana and the adult topotype of P. caroniana by its longer, straighter, and more sloping posterodorsal margin. The superficial resemblance between P. venezuwelensis and P. del- tcata (Weisbord) is rather close but as the interior of the type P. delicata is not known and the valve much larger than that from Cabo Blanco, the latter is provisionally considered distinct. Other species with a surface sculpture similar to that of P. venezuelensis are the following: Petricola multistriata Brown and Pilsbry (1912, Acad. Nat. Sci. Philadelphia Proc., vol. 64, pp. 516-517, pl. 26, fig. 2). Middle Miocene, Panama Canal Zone. This lacks the long, straight, and sloping posterodorsal margin of Pleiorytis venezuelensis, n. sp. Petricola caimitica Maury (1917, Bull. Amer. Paleont., vol. 5, 334 BULLETIN 204 No. 29, pp. 383-384, pl. 37, fig. 11). Middle Miocene, Dominican Republic, This is more orbicular than the Cabo Blanco P. venezue- lensts. Pleiorytis centenaria Conrad (see Gardner, 1936, State of Flor- ida Dept. Conserv., Geol. Bull. No. 14, p. 39, pl. 6, figs. 3-4). Upper Miocene of Virginia, North Carolina, South Carolina, and Florida. Much larger, much more prominently threaded radially, and with higher adductor scars than P. venezuelensts. Petricola harrisi Dall (1900, Wagner Free Inst. Sci., Trans., vol. 3, pt. 5, p. 1060, pl. 43, fig. 1). Later Miocene, Maryland. This has an angulate pallial sinus and a high posterior adductor scar. Mansfield (1932, Florida State Geol. Sur. Bull. No. 8, p. 149) suggested that this might be a deformed specimen of Pletorytis centenaria Conrad. Pleiorytis boweni Gardner (1936, State of Florida Dept. Con- serv., Geol. Bull. No. 14, pp. 40-41, pl. 6, figs. 5, 8, 9). Middle Mio- cene of Florida. The pallial sinus is only slightly ascending and is truncated at the apex. Petricola calvertensis Dall (1900, p. 1060, pl. 44, fig. 14). Later Miocene of Maryland. This has a broader, more rounded, and less oblique pallial sinus than Pletorytis venezuelensis, n. sp. Petricola tellymyalis (Carpenter) (see Pilsbry and Lowe, 1932, p. 97, pl. 13, figs. 12-13). Recent from southern California. This has a shorter and more broadly rounded pallial than Pletorytis venezuelensis. (Palmer, 1958, p. 100, pl. 12, figs 1-5 holotype.) Petricola botula Olsson (1961, Panamic-Pacific Pelecypoda, p. 317, pl. 55, figs. 7, 7a, 8). Recent from the Pacific coast of Panama. This has a large rounded pallial sinus. Petricola charapota Olsson (1961, p. 317, pl. 54, fig. 7). Recent, along the coast of Ecuador. The posterior adductor scar is higher than on the Cabo Blanco fossil from Venezuela. Petricola peruviana Olsson (1961, p. 315, pl. 55, fig. 9). Recent from Ecuador to northern Peru. The large rounded pallial sinus extends nearly to the middle of the shell cavity whereas the sinus of Pleiorytis venezuelensis is more linguiform and extends to well above the center of the interior. VENEZUELAN CENOZOIC PELECYPODS: WEISBORD 335 TELLINIDAE Tellina (Tellina ?) species indeterminate Pl. 48, fig. 13 Figured for the sake of completeness is the mold of a right valve on which the shell material of the umbo is adherent. The valve is thin and elongate-oval, with the merest suggestion of a posterior twist. The shell surface is smooth but marked by faint concentric undulations and lineations. The beak is appressed, fairly acute, situated a little behind the middle. The dorsal region after the beak is flattish. The nymph is prominent, coarsely scored, and lanceolate, bordered by a deep ligamental groove. Just visible through the fine sandstone matrix is a narrow but deeply bifid posterior cardinal tooth and a simple but moderately stout anter- ior tooth. Dimenstons—Specimen Q446a, right valve, length 43 mm.; height 26 mm. Locality.—Playa Grande formation (Maiquetia member) at W-4, Quebrada Las Pailas. One imperfect right valve. Remarks.—Reminiscent of the Recent Western Atlantic 7. radiata Linnaeus (1758, Syst. Nat., ed. 10, p. 675, no. 42) but not so narrow as that. Tellina (Eurytellina) punicea Born Pl. 48, figs. 14, 15; Pl. 49, figs. 1, 2 1780. Tellina punicea Born, Testacea Musei Caesarei Vindobonensis, p. 33, pla2. fies8: 1791. Tellina punicea Born, Gmelin, Syst. Nat., 13th ed., pt. 6, p. 32339, No. 59. 1817. Tellina punicea Born, Dillwyn, A Descriptive Catalogue of Recent Shells, pp. 90-91, No. 44. 1818. Yellina punicea Born, Lamarck, An. sans Vert., vol. 5, p. 525, No. 21 (part). 1846. Tellina punicea Born, Sowerby, Thes. Conchyl., p. 239, No. 33, pl. 58, fig. 89; pl. 60, fig. 154. 1846. Tellina punicea Born, d’Orbigny, Voyage l’Amérique Méridionale, vol. 5, pt. 3, Mollusques, pp. 535-536. i 1853. Tellina punicea Born, d’Orbigny, [In] La Sagra, Hist. phys., polit., et nat. Ile de Cuba, vol. 2, pp. 243-244. 1864. Tellina punicea Born, Krebs, The West Indian Marine Shells, pp. 103- 104. 1866. Tellina punicea Born, Reeve, Conch. Icon., vol. 17, pl. 12, sp. 53. 1869. Tellina (Peronacoderma) punicea Born, Tryon, Amer. Jour. Conch., vol. 4, pt. 5, Appendix, No. 15, p. 87. 1871. Tellina punicea Born, Romer, Syst. Conchylien-Cabinet, vol. 10, pt. 4, pp. 97-99, pl. 25, figs. 1-3. 336 BuLtetTin 204 1873. Tellina (Peronaeoderma) punicea Born, Gabb, Amer. Philos. Soc., Trans., new ser., vol. 15, p. 248 (part). 1878. Tellina punicea Born, Bertin, Mus. Hist. Nat., Nouv. Arch., sér. 2, vol. 1, pp. 211, 258. 1878. Tellina punicea Born, Mérch, Catalogue of West-India Shells, p. 14. 1878. Tellina punicea Born, Arango y Molina, Contribucién a la Fauna Mala- cologica Cubana, p. 244. 1884. Tellina (Peronaeoderma) punicea Born, Tryon, Structural and Syste- matic Conchology, vol. 3, p. 168, pl. 111, fig. 57. 1887. Tellina (Eurytellina) punicea Born, Fischer, Manuel de Conchyliologie et de Paléontologie Conchyliologique, p. 1147. 1889. Tellina punicea Born, Simpson, Davenport Acad. Nat. Sci., Proc., vol. 5, p. 63. 1900. Tellina (Eurytellina) punicea Born, Dall, U. S. Nat. Mus., Proc., vol. 23, No. 1210, pp. 290, 294. 1900. Tellina (Eurytellina) punicea Born, Dall, Wagner Free Inst. Sci., Trans., vol. 3, pt. 5, pp. 1004, 1013. 1921. Tellina punicea Born, Pilsbry, Acad. Nat. Sci. Philadelphia, Proc., vol. 73, p. 424 (part). 1940. Tellina punicea Born, Smith, World-wide Sea Shells, p. 115, fig. 1506. 1953. Tellina (Eurytellina) punicea Born, Olsson and Harbison, Acad. Nat. Sci. Philadelphia, Mon. No. 8, p. 123. 1954. Tellina (Eurytellina) punicea Born, Abbott, American Seashells, p. 428. 1961. Tellina (Eurytellina) punicea Born, Olsson, Panamic-Pacific Pelecypoda, p. 428. 1961. Tellina (Eurytellina) punicea Born, Warmke and Abbott, Caribbean Seashells, p. 195, pl. 4g. 40d. Shell fairly large, rather solid, shiny, elongate-subtrigonal in outline, somewhat compressed, subequilateral, subequivalve, gently tapering behind. Submargins slightly depressed, the anterior sub- margin narrow and feebly sulcate, the posterior a little wider; posterior submargin of the right valve vaguely bipartite, defined from the disk by a narrow, shallowly incised groove, the posterior submargin of the left valve bounded by a subtle rise or midge. Anterodorsal margin hardly convex, anterior end well rounded, ventral margin subtruncate at the middle and subangulate at the rear, posterior end rather narrow and obliquely truncate, posterodor- sal margin long and nearly straight, sloping at an angle of 27 to 31 degrees from the beak. Escutcheonal area flat and narrow, that of the left valve a trifle the wider; lunular area of the left valve narrow and flattish, that of the right valve linear and inflected. Beak low, pointed, situated a little anterior to the middle. Surface sculptured by flat subregular concentric fillets with faint radial lineations, the fillets of the right valve more persistent than those of the left valve; on the posterior submargin, the fillets become lamellar, and at the edge of the posterodorsal margin they cul- VENEZUELAN CENOzOIC PELECYPODS: WEISBORD 337 minate in slightly projecting elevations before thinning out into striae on the escutcheonal area itself. Right valve with two car- dinals, the posterior bilobed, the anterior rather strong and rugose but simple, the resilifer deep and narrowly triangular. Immediately in front of the right anterior cardinal there is a short embayment in the hinge plate terminating into a stubby, erect, lateral tooth; the right posterior lateral is far removed from the beak, lying near the superior end of the posterior adductor scar, and is well developed. On the left valve the anterior cardinal is bifid, the posterior one rudi- mentary and lamellar; in front of the left anterior cardinal the hinge plate is also shortly embayed, but both laterals are obsolete and rep- resented by but a slight thickening. Nymph narrowly elliptical, roughened by vertical rugae, and bounded by a fairly deep groove. Interior glossy. Anterior adductor scar deep and lenticular, margined behind by a stout radial ridge, the scar marked by a line or crease running lengthwise through it and joining the pallial line proper of which it is an extension; posterior adductor scar broadly pyriform. The upper line of the pallial sinus is arcuate, rising from the inner side of the base of the posterior adductor scar, touching the inner edge of the adductor scar at its base, thence turning abruptly to join the pallial line. Pallial line simple, not far removed from the basal margin, terminating well below the posterior adductor scar. A small curved wedge is formed immediately below the base of the anterior adductor scar by the merging of the pallial lines. Dimensions.—Specimen 1448a, right valve, height 28 mm. length 44 mm.; thickness 4.6 mm. Specimen T448a, left valve, height 22.5 mm.; length 39 mm.; thickness 3 mm. Specimen T448b, left valve, height 18.8 mm.; length 34 mm.; thickness 3.1 mm. Specimen T448c, right valve, height 18.6 mm.; length 31 mm.; thickness 3 mm. Specimen J448a, young right valve, height 7 mm.; length 11 mm.; thickness 1.1 mm. Localities —Lower Mare formation at W-13, on hillside above west bank of Quebrada Mare Abajo: Five specimens including three right valves and two left valves. Lower Mare formation, in small stream 100 meters west of Quebrada Mare Abajo. One adult right valve, one young right valve (J448a), and one young left valve. Up- per Mare formation, in stream 250 meters south-southwest of mouth of Quebrada Las Pailas. Seven specimens including four left valves 338 BuLuetTin 204 and three right valves. Playa Grande formation (Maiquetia mem- ber) at W-23, north flank of Punta Gorda anticline. One right valve. Remarks.—The Cabo Blanco fossil has much the same outline as T. alternata Say and T. angulosa Gmelin, but in shape as well as in other characters it is identical with, or closely related to T. punicea Born. On the Pliocene to Recent JT. alternata from east America, and on the Recent Western Atlantic T. angulosa, the pallial sinus does not touch the anterior muscle scar, whereas on the Recent Western Atlantic T. pwnicea and on the Cabo Blanco fossil the pallial sinus does touch the anterior scar. Other tellinids which the Cabo Blanco fossil resembles are the following: T. georgiana Dall (1900, U. S. Nat. Mus., Proc., vol. 23, No. 1210, pp. 310-311, pl. 2, fig. 3). Recent in the Western Atlantic from the Gulf of Mexico and the West Indies. The posterodorsal margin immediately after the beak is somewhat concave whereas on the Cabo Blanco shell that margin is straight. T. georgiana is probably the same as 7. nitens C. B. Adams. T. mtens C. B. Adams (see Clench and Turner, 1950, Occas. Papers on Mollusks, vol. 1, No. 15, p. 317, pl. 44, figs. 3-4). Recent, Jamaica. This is smaller than 7. punicea, and the posterodorsal margin is concave rather than straight as on T. punicea. T. mantaensis Pilsbry and Olsson (1943, Nautilus, vol. 56, No. 3, pl. 8, figs. 1-4). Recent in the Eastern Pacific from Panama to Ecuador. The pallial sinus does not quite reach the anterior muscle scar, and the outline of 7. mantaensis is slightly less angular than that of the Cabo Blanco fossil. T. cf. punicea Born, Toula (1911, K.-K. Geol. Reichs., Jahrb., vol. 61, pl. 31, figs. 6a, 6b). Gatun formation, Panama Canal Zone. The posterior end is subrounded rather than subtruncate ob- liquely as on the typical T. punicea. T. roburina Dall (1900, Wagner Free Inst. Sci., Trans., vol. 3, pt. 5, p. 1024, pl. 47, fig. 9). Middle Miocene, Florida. The distal angle of the pallial sinus does not quite touch the anterior muscle scar. T. riocanensis Maury (1917, Bull. Amer. Paleont., vol. 5, No. 29, pp. 384-385, pl. 38, fig. 3). Middle Miocene, Dominican Republic. On both valves there is a distinct anterior and posterior sulcus. VENEZUELAN CENOzoIC PELECYPODS: WEISBORD 339 T. costaricana Olsson (1922, Bull. Amer. Paleont., vol. 9, No. 39, pp. 423-424, pl. 26, figs. 6, 9). Middle Miocene, Costa Rica. The concentric fillets are more uniform than on the Cabo Blanco shell. Range and distribution.—The living Tellina (Eurytellina) pum- cea Born is said to range from Florida to Brazil. This is the first report of its occurrence as a fossil in northern South America, al- though the species, from near Cumana, Venezuela, is contained in Collection No. 18408 of the U. S. National Museum. This collection was obtained by P. Henry and J. A. Tong in September 1931 from about 2.5 kilometers east of Cumana, State of Sucre, Venezuela, at a point N80°E from Cumana castle and $30°W from the village of Caiguire Abajo, in a yellowish brown sandy marl about 30 feet thick dipping steeply northward. The formation near Cumana, to judge from the fossils, is equivalent to part of the Mare—Playa Grande sequence in the Cabo Blanco area, and is believed to be Pliocene in age. Tellina (Eurytellina) nitens C. B. Adams Pl. 49, figs. 3-10 1845. Tellina nitens C. B. Adams, Boston Soc. Nat. Hist., Proc., vol. 2, p. 10. 1854. Noe nitens C. B. Adams, Deshayes, Zool. Soc. London, Proc., p. 358, o. 187. 1864. eet nitens C. B. Adams, Krebs, The West Indian Marine Shells, p. 02. 1869. Tellina (Angulus) nitens C. B. Adams, Tryon, Amer. Jour. Conch., vol. 4, pt. 5, Appendix, No. 15, p. 94. 1878. Tellina nitens C. B. Adams, Bertin, Mus. Hist. Nat., Nouv. Arch., sér. 2, vol. 1, pp. 211, 297. 1889. Tellina nitida Lamarck var. carolinensis Dall, U. S. Nat. Mus., Bull. 37, p. 60. Not T. carolinensis Conrad, 1875. 1900. Tellina (Eurytellina ?) georgiana Dall, U. S. Nat. Mus., Proc., vol. 23, No. 210, pp. 294, 310, pl. 2, fig. 3. 1901. Tellina (Eurytellina) georgiana Dall, Dall and Simpson, U. S. Fish Com., Bull., vol. 20 for 1900, pt. 1, p. 479. 1920. Tellina (Eurytellina) georgiana Dall, Maury, Bull. Amer. Paleont., vol. 8, No. 34, p. 113. 1934. Tellina (Eurytellina) georgiana Dall, Johnson, Boston Soc. Nat. Hist., Proc., vol. 40, No. 1, p. 51. 1936. Tellina georgiana Dall, Lermond, Check List of Florida Marine Shells, Gulfport, p. 22. 1936. Tellina (Eurytellina) georgiana Dall, McLean, Soc. Cubana Hist. Nat. “Felipe Poey,’ Mem., vol. 10, No. 1, p. 42. 1945. Tellina georgiana Dall, Smith, Nautilus, vol. 59, No. 1, pp. 35-36. 1950. Tellina nitens C. B. Adams, Clench and Turner, Occas. Papers on Mol- lusks, vol. 1, No. 15, p. 317, pl. 44, figs. 3-4. 1956. Tellina georgiana Dall, Parker, Amer. Assoc. Petrol. Geol., Bull., vol. 40, No. 2, pp. 309, 317, pl. 7, figs. 18a, 18b. 340 BuL.etTin 204 1961. Tellina (Eurytellina) georgiana Dall, Warmke and Abbott, Caribbean Seashells, p. 195, pl. 40a. The Cabo Blanco fossil is of medium size, thin, chalky white within, a little inflated, elongate-suboval, inequilateral, subequivalve, with a moderately pronounced posterior rostration. Anterodorsal margin long and nearly straight, anterior end produced and well rounded, ventral margin straightish to shallowly rounded, posterior end obliquely subtruncate, posterodorsal margin concave. Beak small, pointed, situated behind the middle. Surface shiny when fresh, sculptured by low subregular concentric fillets separated by fine incisions, the fillets or bands more distinct near the base and sides of the valve; on the posterior rostration, and especially on the right valve, the fillets develop into slightly raised coarse lamellae with fine concentric striae between them. Faintly decussating the con- centric bands are microscopic radial lineations which are vertically disposed on the disk, curve outward on the anterior end, are obsolete on the rostration of the right valve and are oblique on the rostra- tion of the left valve. The hinge is fine, and the components sharply defined. On the right valve, the posterior cardinal tooth is bilobed, the anterior tooth single and relatively strong, the resilifer deep and triangular; in front of the anterior cardinal tooth the hinge plate is embayed into a hamate arc, with an erect lateral tooth at the distal end of the arc; the right posterior lateral is farther from the beak than the anterior, and is a pointed lamina with a narrow elliptical socket behind it. On the left valve the anterior cardinal tooth is narrowly cuneate and bifid, the posterior tooth laminar and curved a little distally, the resilifer somewhat shallower than on the opposite valve; the lateral teeth of the left valve are obsolete and are represented by a slight thickening. Anterior adductor scar len- ticular, marked by a thin line running through it and joining the pallial line, bordered behind by a low radial ridge broadening up- ward, the posterior adductor scar broadly pyriform. Upper line of pallial sinus arcuate, rising from the inner side and base of the posterior adductor scar, descending toward and not touching the anterior adductor scar on the left valve, but touching the scar on the right valve, and then curving sharply to join the pallial line with which it is confluent thereafter. The pallial line is simple, ter- VENEZUELAN CENOzOIC PELECYPODS: WEISBORD 341 minating below the posterior adductor scar. In the interior of the left valve there is a fairly pronounced sulcus running through the posterior adductor scar and terminating at the posterior corner of the valve. Most specimens are minutely denticulate at the ventral and lateral margins within, but a few are smooth. Dimensions.—Specimen G448a, right valve, height 12 mm.; length 21.8 mm.; thickness 2.2 mm. Specimen G448b, immature right valve, broken at posterior end, height 4.8 mm.; length 8.1 mm.; thickness 0.9 mm. Specimen G448c, left valve, height 16 mm.; length 29 mm.; thickness 2.3 mm. Specimen G448d, immature left valve, height 5.6 mm.; length 10.2 mm.; thickness about 1 mm. Localities —Upper Mare formation at W-14, on hillside above west bank of Quebrada Mare Abajo. Twenty-four specimens in- cluding thirteen left valves and eleven right valves. Playa Grande formation (Maiquetia member) at W-23, north flank of Punta Gorda anticline. One small right valve. Playa Grande formation (Maiquetia member), in Quebrada Las Bruscas approximately 125 meters upstream from junction with Quebrada Las Pailas. One small left valve. Remarks.—The Cabo Blanco fossils are a trifle more elongated than the Recent 7. mtens from Jamaica but are otherwise identical. I have compared the types of T. mitens C. B. Adams and T. georgi- ana Dall, and they too are identical. According to Dall, the pallial sinus of 7. georgiana is “similar in both valves, touching the anterior adductor scar, wholly confluent below,” but in my examination of the types of T. georgiana (No. 93777, U. S. National Museum) I found that the pallial sinus touches the anterior scar on the right valve but does not reach the anterior scar on the left valve. The same delineation occurs on the type of T. nitens C. B. Adams, and as the two are alike in all other characters, the name 7. mitens has priority. 7. mitens C. B. Adams and T. georgiana Dall are much like T. puntcea Born except that the posterodorsal margin is more con- cave than on T. punicea, and the concentric markings are not so pronounced as on T. punicea. Range and distribution—T. mtens C. B. Adams ranges from the southern and southeastern U. S. A. to the Caribbean. It has not hitherto been recorded as a fossil. 342 BuLetin 204 Tellina (Eurytellina) alternata ? Say Pl. 49, figs. 11, 12 1822. Tellina alternata Say, Acad. Nat. Sci. Philadelphia, Jour., ser. 1, vol. 2, Pp: 275. 1830. Tellina alternata Say, Conrad, American Marine Conchology, pl. 65, fig. 1. 1857. Tellina alternata Say, Toumey and Holmes, Pleiocene Fossils of South Carolina, p. 89, pl. 22, fig. 4. 1860. Tellina alternata Say, Holmes, Post-Pleiocene Fossils of South Carolina, p. 45, pl. 8, fig. 1. 1866. Tellina alternata Say, Reeve, Conch. Icon., vol. 17, pl. 12, sp. 52. 1869. Tellina (Peronaeoderma) alternata Say, Tryon, Amer. Jour. Conch., vol. 4, pt. 5, Appendix, No. 15, p. 86. 1871. Tellina alternata Say, Romer, Syst. Conchylien-Cabinet, vol. 10, pt. 4, pp. 102-103, pl. 25, figs. 10-12. 1871. Tellina alternata Say, Coues, Acad. Nat. Sci. Philadelphia, Proc. vol. 2555p.) 138. 1878. Tellina alternata Say, Bertin, Mus. Hist. Nat., Nouv. Arch. sér. 2, vol. 1, pp. 211, 260. 1881. Tellina (Peronaeoderma) alternata Say, Gabb, Acad. Nat. Sci. Phila- delphia, Jour., ser. 2, vol. 8, p. 371. 1889. Tellina alternata Say. Dall, U. S. Nat. Mus., Bull. 37, p. 60. 1889. Tellina alternata Say, Simpson, Davenport Acad. Nat. Sci., Proc., vol. 5, p. 63. 1892. Tellina alternata Say, Singley, Geol. Sur. Texas, Fourth An. Rept. p. 328. 1900. Tellina (Eurytellina) alternata Say, Dall, U. S. Nat. Mus., Proc., vol. 23, No. 1210, p. 294. 1900. Tellina (Eurytellina) alternata Say, Dall, Wagner Free Inst. Sci., Trans., vol. 3, pt. 5, pp. 1029-1030. 1901. Tellina (Eurytellina) alternata Say, Dall and Simpson, U. S. Fish Com., Bull., vol. 20 for 1900, pt. 1, p. 479. 1903. Tellina alternata Say, Vanatta, Acad. Nat. Sci. Philadelphia, Proc., vol. 55, pv 57< 1913. Tellina (Eurytellina) alternata Say, Brown and Pilsbry, Acad. Nat. Sci. Philadelphia, Proc., vol. 65, p. 497. 1920. Tellina (Eurytellina) alternata Say, Maury, Bull. Amer. Paleont., vol. 8, No. 34, pp. 112-113. 1921. Tellina alternata Say, Pilsbry, Acad. Nat. Sci. Philadelphia, Proc., vol. 73, p. 424. 1925. Tellina alternata Say, Clench, Nautilus, vol. 38, No. 3, p. 94. 1929. Tellina alternata Say, Clench, Nautilus, vol. 43, No. 1, p. 35. 1932. Tellina (Eurytellina) alternata Say, Mansfield, Florida State Geol. Sur., Bull. No. 8, p. 136, pl. 30, fig. 1. 1934. Tellina (Eurytellina) alternata Say, Salisbury, Malac. Soc. London, Proc., vol. 21, pt. 2, p. 89. 1934. Tellina (Eurytellina) alternata Say, Johnson, Boston Soc. Nat. Hist., Proc., vol. 40, No. 1, p. 51. 1936. Tellina alternata Say, Lermond, Check List of Florida Marine Shells, Gulfport, p. 20. 1937. Tellina (Eurytellina) Say, Smith, East Coast Marine Shells, p. 57, pl. 22, fig. 4. 1938. Tellina alternata Say, Richards, Geol. Soc. Amer., Bull., vol. 49, pt. 2, p. 1292. 1938. Tellina alternata Say, Smith, Nautilus, vol. 51, No. 3, p. 91. 1940. Tellina alternata Say, Stubbs, Jour. Paleont., vol. 14, No. 5, p. 511. VENEZUELAN CENOZOIC PELECYPODS: WEISBORD 343 1942. Tellina alternata Say, Jaume and Pérez Farfante, Soc. Cubana Hist. Nat. “Felipe Poey,’’ Mem., vol. 16, No. 1, p. 39. 1944. Tellina alternata Say, Hackney, Nautilus, vol. 58, No. 2, p. 59. 1949. Eurytellina alternata (Say), Lange de Morretes, Arq. Mus. Paranaense, Vole 7.parntele pad 5. 1951. Tellina (Arcopagia) alternata Say, McLean, New York Acad. Sci. Scien- tific Survey of Porto Rico and the Virgin Islands, vol. 17, pt. 1, p. 93, pl. 19, fig. 1: 1952. Tellina alternata Say, Pulley, Texas Jour. Sci. vol. 4, No. 2, p. 184, pl. 13, figs. 10-11. 1953. Tellina (Eurytellina) alternata Say, Olsson and Harbison, Acad. Nat. Sci. Philadelphia, Mon. No. 8, pp. 123-124, pl. 14, figs. 2-3. 1954. Tellina (Eurytellina) alternata Say, Abbott, American Seashells, pp. 427-428, pl. 40n. 1955. Tellina (Arcopagia) alternata Say, Perry and Schwengel, Marine Shells of the Western Coast of Florida, pp. 77-78, pl. 15, fig. 99. 1956. Tellina alternata Say, Parker, Amer. Assoc. Petrol. Geol., Bull., vol. 40, No. 2, pp. 309, 315, 326, 371, pl. 3, fig. 11; pl. 6, fig. 9. 1958. Tellina (Eurytellina) alternata Say, DuBar, Florida Geol. Sur., Geol. Bull. No. 40, pp. 176, 211. 1959. Tellina alternata Say, Olsson and McGinty, Bull. Amer. Paleont., vol. 39° Nos 1775 ps 21. 1959. Tellina alternata Say, Nowell-Usticke, A Check List of the Marine Shells of St. Croix, p. 17. 1959. Tellina alternata Say, Parker, Amer. Assoc. Petrol. Geol., Bull., vol. 43, No. 9, pp. 2132, 2162, pl. 4, VIII, figs. 16a, 16b. 1961. Tellina alternata Say, Moore, Gulf Research Repts., vol. 1, No. 1, pp. 16, 45. 1961. Tellina (Eurytellina) alternata Say, Warmke and Abbott, Caribbean Seashells, p. 195, pl. 40h. The fragment illustrated is of a thin fossil shell that compares closely with Recent specimens of 7. alternata Say from Florida. Dimensions—Specimen R447a, left valve, length of fragment 34 mm.; height 21 mm. Locality.—Playa Grande formation (Maiquetia member), in Quebrada Las Bruscas about 125 meters upstream from junction with Quebrada Las Pailas. A single left valve, broken. Range and distribution—Upper Miocene to Recent. The living shell ranges from North Carolina and the Gulf of Mexico to Brazil. In the Pleistocene, it is reported from South Carolina, Florida, Loui- siana (in wells), Cuba, and the Isthmus of Panama. In the Pliocene it is recorded from South Carolina, Florida, and Costa Rica. And, in the upper Miocene, T. alternata was identified in Washington and Leon Counties, Florida, by Mansfield. Tellina (Merisca) cristallina Spengler Pl. 49, figs. 13, 14; Pl.+50) figs: 122 1795. Tellina crystallina Chemnitz, Syst. Conchylien-Cabinet, vol. 11, p. 210, pl. 199, figs. 1947-1948. 344 1798. 1815. 1825. 1846. 1853. 1864. 1864. 1872. 1873. 1878. 1878. 1900. 1900. 1910. 1917. 1917. 1921. 1922. 1924. 1928. 1932. 1934. 1936. 1937. 1941. 1944. 1949. 1955. 1958. 1961. 1961. BULLETIN 204 Tellina cristallina Spengler, Skr. Nat. Selsk. Copenhagen, vol. 4, No. 2, p. 113. Tellina crystallina Wood, General Conchology, or a description of shells, p. 149. Tellina crystallina Wood, Index Testaceologicus, pl. 3, fig. 10. Tellina crystallina Chemnitz, Hanley, [in] Sowerby, Thesaurus Conchy- liorum, vol. 1, p. 270, pl. 57, fig. 43. Tellina schrammi Récluz, Jour. Conchyl., vol. 4, p. 152, pl. 6, figs. 7-8. Tellina crystallina Chemnitz, Krebs, The West Indian Marine Shells, p. 101. Tellina crystallina Chemnitz, Reeve, Conch. Icon., vol. 17, pl. 22, sp. 112. Tellina crystallina Chemnitz, Rémer, Syst. Conchylien-Cabinet, vol. 10 pt. 4, pp. 196-197, pl. 3, figs. 3-4; pl. 38, figs. 1-2. ? Tellina crystallina Chemnitz, Gabb, Amer. Philos. Soc., Trans., new ser., vol. 15, p. 249. Tellina crystallina Chemnitz, Bertin, Mus. Hist. Nat., Nouv. Arch., sér 2, vol. 1, pp. 220, 241. Tellina crystallina Chemnitz, Mérch, Catalogue of West-India Shells, p. 14. Tellina (Merisca) crystallina Wood, Dall, U. S. Nat. Mus., Proc., vol. 23, No. 1210, pp. 290, 302, 311-312, pl. 2, fig. 10. Tellina (Merisca) ‘crystallina Wood, Dall, Wagner Free Inst. Sci., Trans., vol. 3, pt. 5, pp. 1012, 1216. Tellina crystallina Wood, Dall, U. S. Nat. Mus., Proc., vol. 37, No. 1704, p. 270. ? Tellina (Merisca) crystallina Chemnitz, Maury, Bull. Amer. Paleont., vol. 5, No. 29, pp. 387-388, pl. 38, fig. 4. Tellina (Merisca) errati ? Pilsbry and Johnson, Acad. Nat. Sci. Phila- delphia, Proc., vol. 69, p. 201. Tellina (Merisca) errati ? Pilsbry and Johnson, Pilsbry, Acad. Nat. Sci. Philadelphia, Proc., vol. 73, p. 425, pl. 41, fig. 7. ? Tellina (Merisca) crystallina Wood, Olsson, Bull. Amer. Paleont., vol. 9, No. 39, pp. 191, 194, 249-250, pl. 26, fig. 10. Tellina crystallina Wood, Olsson, Nautilus, vol. 37, No. 4, p. 139. Tellina (Merisca) crystallina (Chemnitz), Wood, Gardner, U. S. Geol. Sur., Prof. Paper 142-E, pp. 191-192. Tellina crystallina Wood, Pilsbry and Lowe, Acad. Nat. Sci. Philadelphia, Proc., vol. 84, p. 132. Tellina (Merisca) crystallina Wood, Johnson, Boston Soc. Nat. Hist., Proc., vol. 40, No. 1, p. 51. Tellina crystallina Wood, Lermond, Check List of Florida Marine Shells, Gulfport, p. 22. Tellina (Merisca) crystallina Wood, Smith, East Coast Marine Shells, p. 57, pl. 19, fig. 8. Tellina (Merisca) crystallina ee Pilsbry and Olsson, Acad. Nat. Sci. Philadelphia, Proc., vol. 93, p. 68. Tellina (Merisca) crystallina Wood, Smith, Panamic Marine Shells, p 64, fig. 834. Tellina (Merisca) crystallina Spengler, Hertlein and Strong, Zoologica, vol. 34, pp. 82-83. Tellina (Merisca) crystallina Spengler, Hertlein and Strong, Amer. Mus. Nat. Hist., Bull., vol. 107, art. 2, pp. 198-199. Tellina (Merisca) cristallina Spengler, Keen, Sea Shells of Tropical West America, p. 168, fig. 387. Tellina (Merisca) cristallina Wood, Warmke and Abbott, Caribbean Seashells, p. 196, pl. 40b. Merisca crystallina (Spengler), Olsson, Panamic-Pacific Pelecypoda, p 382, pl. 70, figs. 2, 2a. VENEZUELAN CENOzoIC PELECYPoDS: WEISBORD 345 The Cabo Blanco shell is rounded-subtrigonal, inequilateral, thin, compressed, the right valve a little more flattened than the left, somewhat attenuated behind, narrowly rostrated along the posterodorsal margin, and with a shallow radial sulcus before the rostration. Anterodorsal margin hardly convex, anterior end and ventral margin rounded, the posterior end narrow and obliquely truncate, the posterodorsal margin hardly concave. Beak subcentral, erect, pointed. Prodissoconch sculptured by fine, evenly and closely spaced concentric laminae, the disk sculptured by sharp, rather distant concentric lamellae which, on the radial sulcus in front of the posterior rostration are slightly convex upward, and on the rostration itself are V-shaped. At the posterodorsal margin of the single, well-preserved right valve, the termini project slightly as in Tellidora. In the broad flat interspaces there are faint concentric striae and numerous scarcely visible radial lineations. The right posterior cardinal tooth is strong, cuneate, and asymmetrically bifid, the right anterior cardinal lamellar, the socket between them deep and narrowly triangular; the cardinals of the left valve are sub- equal, the anterior one a little the larger, both of them rendered bifid by a narrow groove, the socket between the left cardinals deep and somewhat more widely triangular than on the might valve. There are two grooved laterals on the right valve, the posterior lateral larger and somewhat farther removed from the center of the hinge than the anterior; on the single left valve the laterals are simple and obsolete. The anterior adductor scar is long and lenticular, narrowing upward, the posterior scar smaller and round- ed-subquadrate. The upper line of the pallial sinus is discrepant on the valves: on the right valve it rises from the inner margin of the posterior scar as a high inverted “U,” and then descends rather regularly to the lower line of the sinus without touching the base of the anterior adductor scar; on the left valve, the upper line of the pallial sinus is more irregular. Starting at the inner margin of the right posterior adductor scar there is a narrow ridgelet extending upward with some diminution in strength to the hinge plate a short distance behind the right posterior cardinal; on the left valve this ridgelet is obsolete. Dimensions.—Specimen T454a, right valve, height 20.3 mm.; width 27 mm.; thickness 2.4 mm. Specimen J455a, upper half of a 346 BuLLETIN 204 left valve, height of fragment 13.1 mm.; width 17.4 mm.; thickness 3.2 mm, Localities ——Upper Mare formation, in stream 250 meters south- southwest of mouth of Quebrada Las Pailas. One right valve entire. Lower Mare formation, in small stream 100 meters west of Quebrada Mare Abajo. One broken left valve. Remarks.—The Cabo Blanco fossil agrees so well with Dall’s figure of the Recent 7. crystallina from South Carolina and with Smith’s figure of the Recent 7. crystallina from Barcelona, Vene- zuela, that it must be considered the same species. A number of authors also agree with Dall (1900, p. 302) that the Recent Western Atlantic and Eastern Pacific forms referred to this species are like- wise identical. Gabb and Maury reported 7. crystallina from the lower-middle Miocene of the Dominican Republic, and Olsson de- scribed it from the middle Miocene of Costa Rica. It should be pointed out that the anterodorsal margin of the Dominican fossil is truncate to slightly concave, whereas on the Recent Western Atlantic shell the anterodorsal margin is slightly convex, and it may have been for this slight difference in outline that Pilsbry and John- son gave the Dominican fossil the name of T. errati. The Costa Rican fossil, on the other hand, does have a slightly convex antero- dorsal margin but a rather strongly concave posterodorsal margin and a prominent embayment of the ventral margin at the posterior sulcus. Whether the small differences between the fossil and living forms referred to T. cristallina Spengler are due to individual varia- tion rather than to specific differentiation is difficult to assess be- cause of the scarcity of specimens, though there is no doubt, as pointed out by Hertlein and Strong (1949) in their excellent dis- cussion, that they are indeed all similar. Range and distribution —Living in the Western Atlantic from South Carolina to northern South America, and in the Eastern Pacific from Baja California, Mexico, to Ecuador where it occurs in the intertidal zone to depths of 13 fathoms. Pleistocene at Magda- lena Bay, Baja California. Pliocene in Ecuador, and near Cumana, Venezuela (Collection No. 18408, U. S. National Museum). Middle Miocene of the Dominican Republic ? and Costa Rica ? Strigilla pisiformis (Linnaeus) Pl. 50, figs. 3-8 1758. 1767. 1803. 1846. 1853. 1864. 1864. 1367. 1867. 1869. 1872. 1873. 1878. 1878. 1878. 1889. 1900. 1900. 1901. 1917. 1921. 1922. 1925. 1925. 1934. 1936. 1936. 1937. 1949. 1951. VENEZUELAN CENOzOIC PELECYPODS: WEISBORD 347 Tellina pisiformis Linnaeus, Syst. Nat., ed. 10, p. 677, No. 54. Tellina pisiformis Linnaeus, Syst. Nat., ed. 12, p. 1120, No. 69. Cardium discors Montagu, Testacea, or Natural History of British Shells, p. 84. Tellina pisiformis Linnaeus, Hanley, [in] Sowerby, Thesaurus Conchy- liorum, p. 261, pl. 56, fig. 30. Tellina pisiformis Linnaeus, d’ Pts [in] La Sagra, Hist. phys., polit. et nat. Ile de Cuba, vol. 2, p. 249 Tellina pisiformis Linnaeus, Krebs, The West Indian Marine Shells, p. 103. Strigilla carnaria (Linnaeus), Guppy, Sci. Assoc. Trinidad, Trans., p. 36. Not S. carnaria (Linnaeus) Strigilla carnaria (Linnaeus), Guppy, Sci. Assoc. Trinidad, Proc., pt. 3, p. 162. Not S. carnaria (Linnaeus). Matura, Trinidad. Tellina pisiformis Linnaeus, Reeve, Conch. ‘Icon., Tellina, vol. 17, pl. 42, sp. 250. Strigilla pisiformis (Linnaeus), Tryon, Amer. Jour. Conch., vol. 4, pt. 5, Appendix, No. 15, p. 99. Tellina pisiformis Linnaeus, Rémer, Syst. Conchylien-Cabinet, vol. 10, pt. 4, pp. 188-189, pl. 37, figs. 1-3. Strigilla pisiformis (Linnaeus), Gabb, Amer. Philos. Soc. Trans., new ser., vol. 15, p. 249. Strigilla pisiformis (Linnaeus), Bertin, Mus. Hist. Nat., Nouv. Arch., Sere2, Vole L app.2i1,, 315: Strigilla pisiformis (Linnaeus), Morch, Catalogue of West-India Shells, p. 14. Tellina pisiformis Linnaeus, Arango y Molina, Contribucién a la Fauna Malacolégica Cubana, p. 244. Strigilla pisiformis (Linnaeus), Dall, U. S. Nat. Mus., Bull. 37, p. 62. Strigilla pisiformis (Linnaeus), Dall, Usass Nat Mus., Proc.) vol. 25, No. 1210, p. 298. Strigilla ’ pisiformis (Linnaeus), Dall, Wagner Free Inst. Sci., Trans., vol. 3, pt. 5, pp. 1038-1039. Strigilla pisiformis (Linnaeus), Dall and Simpson, U. S. Fish Com., Bull., vol. 20 for 1900, pt. 1, p. 482. Strigilla pisiformis (Linnaeus), Maury, Bull. Amer. Paleont., vol. 5, No. 29, p. 389, pl. 39, fig. 6. Strigilla pisiformis (Linnaeus), Pilsbry, Acad. Nat. Sci. Philadelphia, Proc., vol. 73, p. 426. Strigilla pistformis (Linnaeus), Olsson, Bull. Amer. Paleont., vol. 9, No. 39, pp. 426-427. Strigilla (Strigilla) pisiformis (Linnaeus), Woodring, Carnegie Inst. Washington, Publ. No. 366, pp. 175-176, pl. 24, figs. 17-18. Strigilla pisiformis (Linnaeus), Maury, Bull. Amer. Paleont., vol. 10, No. 42, pp. 272-273, pl. 20, fig. 13. Strigilla pisiformis (Linnaeus), Johnson, Boston Soc. Nat. Hist., Proc., vol. 40, No. 1, p. 53. Strigilla pisiformis (Linnaeus), McLean, Soc. Cubana Hist. Nat. “Felipe Poey,” Mem., vol. 10, No. 1, p. 42. Strigilla pisiformis (Linnaeus), Lermond, Check List of Florida Marine Shells, Gulfport, p. 20. Strigilla pisiformis (Linnaeus), Smith, East Coast Marine Shells, p. 60, pl. 19, figs. 9a, 9b. Strigilla pisiformis (Linnaeus), Lange de Morretes, Arq. Mus. Para- naense, vol. 7, art. 1, p. 44. Strigilla pisiformis (Linnaeus), McLean, New York Acad. Sci. Scientific Survey of Porto Rico and the Virgin Islands, vol. 17, pt. 1, p. 98, pl. 20, fig. 7. 348 BuLLeTIN 204 1952. Tellina pisiformis Linnaeus, Dodge, Amer. Mus. Nat. Hist., Bull., vol. 100, art. 1, p. 52. 1954. Strigilla pisiformis (Linnaeus), Abbott, American Seashells, p. 429. 1958. Strigilla pisiformis (Linnaeus), Olsson and McGinty, Bull. Amer. Paleont., vol. 39, No. 177, p. 21. 1961. Strigilla pisiformis (Linnaeus), Warmke and Abbott, Caribbean Sea- shells, p. 197, pl. 41e. The Recent Higuerote shells referred to this species are small, rather solid, inflated, inequilateral, subtrigonal-ovate, with a low rounded radial ridge on the posterior, and a slightly undulatory submargin on the anterior. The umbo is full, the beak appressed, situated a little anterior to the middle. Lunule small, impressed, sub- lanceolate. The surface of the disk is finely engraved by regular, oblique, gently curved grooves extending from the umbo to the base, meeting the ventral margin at an angle of about 45 degrees, and terminating on the posterior ridge; on that part of the posterior submargin immediately behind the posterior ridge there is another set of closely spaced grooves divaricating sharply upward in chevron- like fashion from the termini of the disk grooves, the closely spaced grooves terminating midway between the radial ridge and posterior margin; on the hindmost area adjacent to the margin there is yet another series of markings, these in the form of slightly arcuate lirae, the lirae farther apart than, and divaricating from the terminae of the closely spaced grooves. On the anterior submargin, the grooves from the disk are bent a little downward and then continue flexu- ously to the anterior margin. Crossing the valve are numerous microscopic concentric striae. In well-preserved specimens the in- terior is shiny. The right posterior cardinal tooth is sharply bifid and caret-like, the anterior cardinal platy, the cardinal socket deep and triangular. The lateral teeth are well developed, the anterior closer to the cardinal process than the posterior. The anterior ad- ductor scar is relatively long and rudely lenticular with a ragged or unevenly scalloped inner margin, whereas the posterior scar is more or less subquadrate. The upper line of the pallial sinus is asym- metrically and subangularly curved, joining the posterior adductor scar at the middle, but running below the base of the anterior adduc- tor scar. The shell is whitish within and without, but there is a fairly large area of pink in the umbonal cavity. Dimensions—Recent specimen (B466a) from Higuerote, right valve, height 7.5 mm.; width 7.8 mm.; thickness 2.6 mm. Recent VENEZUELAN CENOZOIC PELECYPODS: WEISBORD 349 specimen (B468a), left valve, height 8 mm.; width 7.9 mm.; thick- ness 2.3 mm. Fossil specimen (D467a) from the Abisinia formation, right valve, height 4.6 mm.; width 5.1 mm., approx. thickness 1.2 mm. Localities —Recent, on beach southeast of Higuerote, State of Miranda. Four right valves, one left valve. Abisinia formation at W-30, eastern edge of Playa Grande village. One right valve, weath- ered. Range and distribution.—S. pisiformis (Linnaeus) has been reported from the Cercado formation (lower-middle Miocene) of the Dominican Republic; from the middle Miocene of Jamaica and Costa Rica; from the Pliocene at Matura, Trinidad; from “the Ple- istocene of the Antillean region generally” (Dall, 1900, p. 1039); and living from the Florida Keys to Brazil. Strigilla carnaria (Linnaeus) Pl. 50, figs. 9-12; Pl. 51, figs. 1-6 1758. Tellina carnaria Linnaeus, Syst. Nat., ed. 10, p. 676, No. 51. 1767. Tellina carnaria Linnaeus, Syst. Nat., ed. 12, p. 1119, No. 66. 1818. Lucina carnaria (Linnaeus), Lamarck, An. sans Vert. vol. 5, p. 541, No. 8. 1822. Strigilla carnaria (Linnaeus), Turton, Conchylia dithra insularum Bri- tanicarum, p. 117, pl. 7, fig. 15. 1847. Strigilla areolata Menke, Zeitschr. f. Malakozool., yr. 4, p. 188. 1853. Tellina carnaria Linnaeus, d’Orbigny, [in] La Sagra, Hist. phys., polit. et nat. l’Ile de Cuba, vol. 3, p. 244. 1864. Tellina carnaria Linnaeus, Krebs, The West Indian Marine Shells, p. 100. 1866. Tellina carnaria Linnaeus, Reeve, Conch. Icon., vol. 17, pt. 9, sp. 37a, 37b. 1867. Strigilla carnaria (Linnaeus), Guppy, Sci. Assoc. Trinidad, Proc., pt. By Ds 162) (part). 1869. Strigilla carnaria (Linnaeus), Tryon, Amer. Jour. Conch., vol. 4, pt. 5, appendix, No. 15, p. 98. 1872. Tellina carnaria Linnaeus, Romer, Syst. Conchylien-Cabinet, vol. 10, pt. 4, pp. 183-186, pl. 36, figs. 7-9. 1878. Strigilla carnaria (Linnaeus), Mérch, Catalogue of West-India Shells, p. 14. 1878. Strigilla carnaria (Linnaeus), Bertin, Mus. Hist. Nat., Nouv. Arch., sér. 2, vol. 1, pp. 211, 3 1878. Tellina carnaria Linnaeus, Arango y Molina, Contribucién a la Fauna Malacolégica Cubana, p. 242. 1884. Strigilla carnaria (Linnaeus), Tryon, Structural and Systematic Conch- ology, vol. 3, p. 170, pl. 112, figs. 71-73. 1887. Strigilla carnaria (Linnaeus), Fischer, Manuel Conchyliologique et de Paléontologie Conchyliologique, p. 1149, pl. 21, fig. 6. 1889. Strigilla carnaria (Linnaeus), Dall, U. S. Nat. Mus., Bull. 37, p. 62. 1900. Strigilla carnaria (Linnaeus), Dall, Wagner Free Inst. Sci., Trans., vol. 3, pt. 5, pp. 1038, 1039. 350 BULLETIN 204 1900. Strigilla carnaria (Linnaeus), Dall, U. S. Nat. Mus., Proc., vol. 23, No. 1210, p. 297. 1901. Strigilla carnaria (Linnaeus), Dall and Simpson, U. S. Fish Com., Bull. vol. 20 for 1900, pt. 1, p. 482. 1916. Strigilla carnaria (Linnaeus), Dall, [in] Matson, U. S. Geol. Sur., Prof. Paper 98-L, p. 177. 1920. Strigilla carnaria (Linnaeus), Maury, Bull. Amer. Paleont., vol. 8, No. 34, p. 117. 1928. Strigilla carnaria (Linnaeus), Gardner, U. S. Geol. Sur., Prof. Paper 142-E, p. 198. 1934. Strigilla carnaria (Linnaeus), Johnson, Boston Soc. Nat. Hist., Proc., vol. 40, No. 1, p. 52. 1936. Strigilla carnaria (Linnaeus), Lermond, Check List of Florida Marine Shells, Gulfport, p. 20. 1937. Strigilla carnaria (Linnaeus), Smith, East Coast Marine Shells, p. 60, pl. 19, fig. 4. 1940. Strigilla carnaria (Linnaeus), Smith, World-wide Sea Shells, p. 115, fig. 1513. 1949. Strigilla carnaria (Linnaeus), Lange de Morretes, Arq. Mus. Paranaense, vol. 7, art. 1, p. 44. 1951. Strigilla carnaria (Linnaeus), McLean, New York Acad. Sci. Scientific Survey of Porto Rico and the Virgin Islands, vol. 17, pt. 1, p. 98, pl. 20, fig. 4. 1953. Strigilla (Strigilla) carnaria (Linnaeus), Haas, Fieldiana-Zoology, vol. 34, No. 20, p. 203. 1953. Tellina carnaria Linnaeus, Dodge, Amer. Mus. Nat. Hist., Bull., vol. 100 Nant, [epsol. 1955. Strigilla carnaria (Linnaeus), Perry and Schwengel, Marine Shells of the Western Coast of Florida, p. 83, pl. 43, fig. 306. 1958. Strigilla carnaria (Linnaeus), Olsson and McGinty, Bull. Amer. Paleont., VOl39. No: l77-spps 2151484 pl: 5: firs 5: 1961. Strigilla carnaria (Linnaeus), Warmke and Abbott, Caribbean Seashells, p. 197, pl. 29f, 41d. The Recent shells from Venezuela are subtrigonally oval, mod- erately compressed in the adult, thin but strong, with a fairly long truncated posterodorsal margin sloping at an angle of about 36 degrees from the horizontal. The ventral margin is rounded, the anterior end subtruncate, anterodorsal margin hardly concave, and, in front of the posterior submargin, there is a faint radial sulcus. The umbo is triangular in outline on mature specimens but fuller and more rounded on juveniles, the beak low and situated anterior to the middle. The posterior submargin is narrow and compressed, the anterior submargin broader, and gently undulatory. Outer sur- face of disk finely engraved by regular, slightly oblique grooves; on the posterior sulcus the grooves diverge abruptly upward in a narrow chevron-like pattern, and then curve gently to the posterior margin; on the anterior submargin the radial grooves from the disk become flexuous and continue thus to the anterior margin. The VENEZUELAN CENOZOIC PELECYPODS: WEISBORD 55H interior of the shell is glossy, and generally there are two or three low narrow radial ridges near the rear, the ridges coinciding with the external radial sulcus, and usually more evident in the right valve than in the left. The anterior muscle scar is relatively long and lenticular, with a ragged inner margin and smooth outer margin; the posterior scar is broadly funnel-shaped with a short irregular spout at the base. The upper line of the pallial sinus is discrepant in the two valves but on both of them it rises from the inner side of the posterior scar and dips to join the base of the anterior scar at the inner margin. The lower border of the pallial sinus emerges from the base of the anterior adductor scar and continues regularly to its termination short of the posterior scar. There are two lateral teeth in each valve, the anterior one closer to the cardinal process than the posterior. The right posterior cardinal tooth is bifid and caret-shaped, the right anterior cardinal platy; on the left valve, the anterior cardinal is narrowly and shallowly bifid, the posterior one long and laminar; the socket between the cardinals is deep and tri- angular. The surface is colored in concentric bands of light purplish pink and pinkish white, the beaks a deep rose; the interior is a bright watermelon red with whitish margins. The fossil specimens herein referred to S. carnaria are all young, small, and somewhat variable in shape and plumpness, but except for size they seem to be identical with the Recent shell. Dimensions.—Specimen A464al-2, a doublet, height 14.7 mm.; width 15.8 mm.; thickness of pair 7 mm. Specimen D464a, right valve, height 6 mm.; width 6.8 mm.; thickness 1.2 mm. Specimen 1465a, right valve, height 4.2 mm.; width 4.8 mm.; thickness 1.4 mm. Specimen I465b, left valve, height 4.05 mm.; width 4.9 mm.; thickness 1.2 mm. Localities—Recent, on beach of Playa Grande Yachting Club, Distrito Federal. Fourteen specimens including five right valves, four left valves, and four doublets. Recent, on beach southeast of Higuerote, State of Miranda. Nine specimens including five left valves and four right valves. Abisinia formation at W-30, eastern edge of Playa Grande village. One mght valve and one juvenile left valve. Upper Mare formation, in stream 250 meters south-south- west of mouth of Quebrada Las Pailas. Three immature specimens including two left valves and one night valve. Lower Mare formation, 352 BuLLeETIN 204 in small stream 100 meters west of Quebrada Mare Abajo. One small left valve. Lower Mare formation at W-13, on hillside above west bank of Quebrada Mare Abajo. Eight specimens including five right valves and three left valves, all of them small. Range and distribution—The Recent S. carnaria ranges from North Carolina, U.S.A., to Brazil. As a fossil, the species has been recorded in the Pleistocene by Maury from a well at Ft. Morgan, Alabama, at depths of 100-112 feet and 169-175 feet. Although its occurrence in the Eastern Pacific has been gener- ally denied, Olsson (1961, Panamic-Pacific Pelecypoda, pp. 387- 388, pl. 73, figs. 4, 4a) recorded S. carnaria from Panama to north- ern Peru and stated that numerous specimens of a Strigilla from the coasts of northern Peru and Ecuador appear identical with typical Caribbean examples of S. carnaria or differ merely in size and minor details of sculpture. Macoma (Psammacoma) hybrida, new species Pl. 46, figs. 3, 4 This species is described from a single right valve. Shell of medium size, thin, a little inflated, elongate-oval, in- equilateral, tapering slightly toward the rear, rostrate behind, the rostration gently concave and bordered by a low umbonal ridge widening progressively to the basal margin; in front of the umbonal ridge is a slightly depressed radial platform, and on the forward side of that there is a fairly broad, very gentle sulcus. Anterodorsal margin long, hardly convex, and slightly inclined from the horizontal, the anterior end of the valve rather acutely rounded, the ventral margin nearly straight; at the base of the umbonal ridge the margin is shallowly embayed, and the posterior end above it subtruncate; the posterodorsal margin is straight except where it curves upward to the beak. Beak low, situated well behind the middle. Surface marked by delicate concentric bands which, on the posterior rostra- tion, are slightly raised and sublamellar, and which, on the disk, are traversed by numerous radial lineations visible through a lens. Interior marked by numerous fine radial corrugations visible in certain light without the aid of a lens. Lateral teeth absent. Right posterior cardinal tooth strong and linearly bilobed, the anterior tooth strong, simple and somewhat arcuate, the teeth not joined at the apex, the resilifer between them deep. In front of the right VENEZUELAN CENOzOIC PELECYPODS: WEISBORD 353 anterior cardinal there is a shallow wedge-shaped depression. The nymph behind the posterior tooth is comma-shaped, depressed, the tail attenuated posteriorly and bordered on the inner side by the slightly raised liplike edge of the hinge plate; the ligamental groove bounding the back of the nymph is fairly wide, straight, and shallow. Right anterior adductor scar long, compound-lenticular, the pos- terior scar broad and semicylindrical, bordered along the inner edge by a feeble radial ridge. Pallial sinus asymmetrically arcuate as it rises from the inner and upper side of the posterior adductor scar, obtusely subangular at the forward end, joining the faint pallial line about half way between the extremities of the valve. Running through the arc of the pallial sinus and extending to the ventral margin there is a narrow gentle upward crease in the interior, the crease reflecting the boundary line between the platform and sulcus on the outer surface of the valve. Dimensions.—Holotype (1665a), right valve, height 21 mm.; length 36.2 mm.; thickness 4.1 mm. Type locality—Lower Mare formation at W-13, on hillside above west bank of Quebrada Mare Abajo. One right valve, the holotype. Comparisons.—Macoma hybrida, n. sp. is similar to M. tagel- formis Dall (1900, Wagner Free Inst. Sci., Trans., vol. 3, pt. 5, p. 1055; 1901, U. S. Fish Com., Bull., vol. 20 for 1900, pt. 1, p. 482, pl. 55, figs. 10, 11, 15), but the Pleistocene to Recent M. tageliformis lacks the inner rib bordering the edge of the posterior adductor scar. Also, the pallial sinus of M. tageliformis is higher and slightly shorter. Another allied species is the east American, Pliocene to Recent M. brevifrons Say (see Dall and Simpson, 1901, U. S. Fish Com., Bull., vol. 20 for 1900, pt. 1, pp. 481-482, pl. 55, figs. 3, 12, 13), that, however, differing from M. hybrida in lacking the flat- tened area in front of the umbonal ridge. M. elytrwm Keen (1958, Bull. Amer. Paleont., vol. 38, No. 172, p. 244, pl. 30, fig. 14), an Eastern Pacific form ranging from Baja California to Ecuador, is more prominently sulcate behind the middle, and is also wanting in the platform between the sulcus and the umbonal ridge. SEMELIDAE Semele purpurascens (Gmelin) Pl. 51, figs. 7, 8 354 1791. 1815. 1818. 1821. 1845. 1853. 1853. 1862. 1862. 1864. 1867. 1869. 1874. 1874. 1878. 1878. 1881. 1884. 1885. 1886. 1889. 1889. 1891. 1900. 1901. 1913. 1920. 1925. 1926. 1932. 1934. 1936. BuLLETIN 204 Venus purpurascens Gmelin, Syst. Nat., ed. 13, pt. 6, p. 3288, No. 91. Tellina obliqua Wood, General Conchology, pl. 61, figs. 1-2. Amphidesma variegata Lamarck, An. sans Vert., vol. 5, p. 490. Amphidesma variegata Lamarck, Sowerby, The Genera of Recent and Fossil Shells, pt. 9, fig. 1. Amphidesma variegata Lamarck, d’Orbigny, [in] La Sagra, Hist. Fis., Polit., y Nat. Isla de Cuba, pt. 2, vol. 5, Moluscos, p. 296. Semele purpurascens (Gmelin), Mérch, Catalogus Conchyliorum, pt. 2, p. 16. Amphidesma obliqua (Wood), Reeve, Conch. Icon., vol. 8, Amphidesma, Pil) sp. Saso5b: Davila variegata (Lamarck), Chenu, Manuel de Conchyliologie et de Paléontologie Conchyliologique, vol. 2, p. 80, fig. 346. Semele ornata Gould, Otia Conchologica, p. 239. Semele purpurascens (Gmelin), Krebs, The West Indian Marine Shells, p. 106. Semele variegata (Lamarck), Guppy, Sci. Assoc. Trinidad, Proc., pt. 3, p. 162. Semele variegata (Lamarck), Tryon, Amer. Jour. Conch., vol. 4, pt. 5, Appendix, No. 15, p. 122. Semele ornata Gould, Tryon, Amer. Marine Conch., p. 155. Semele variegata (Lamarck), Guppy, Geol. Mag., decade 2, vol. 1, p. 441. Semele purpurascens (Gmelin), Mérch, Catalogue of West-India Shells, p. 14. Semele purpurascens (Gmelin), Arango y Molina, Contribucién a la Fauna Malacologica Cubana, p. 246. Semele variegatum (Lamarck), Gabb, Acad. Nat. Sci. Philadelphia, Jour., ser. 2, vol. 8, p. 372. Semele variegata (Lamarck), Tryon, Structural and Systematic Conch- ology, vol. 3, p. 163, pl. 110, fig. 34. Semele obliqua (Wood), Smith, Voyage H.M.S. Challenger, Zoology, vol. 13, p. 84. Semele obliqua (Wood), Dall, Mus. Comp. Zool., Bull., vol. 12, No. 6, p. 279: Semele obliqua (Wood), Dall, U. S. Nat. Mus., Bull. 37, p. 62. Semele obliqua (Wood), Simpson, Davenport Acad. Nat. Sci., Proc., vol. 5, p. 72. Semele variegata (Lamarck), Baker, Acad. Nat. Sci. Philadelphia, Proc., vol. 43, p. 48. Semele purpurascens (Gmelin), Dall, Wagner Free Inst. Sci. Trans., vol. 3, pt. 5, p. 993. Semele purpurascens (Gmelin), Dall and Simpson, U. S. Fish Com., Bull., vol. 20 for 1900, pt. 1, p. 477. Semele purpurascens (Gmelin), Lamy, Jour. Conchyl., vol. 61, pp. 350-35. Semele purpurascens (Gmelin), Maury, Bull. Amer. Paleont., vol. 8, No. 34, p. 122. Semele purpurascens (Gmelin), Maury, Bull. Amer. Paleont., vol. 10, No. 42, pp. 269-270, pl. 20, fig. 17. Semele purpurascens (Gmelin), Weisbord, Nautilus, vol. 39, No. 3, p. 84. Semele purpurascens (Gmelin), Mansfield, Florida State Geol. Sur., Bull. No. 8, pp. 145-146, pl. 30, fig. 11. Semele purpurascens (Gmelin), Johnson, Boston Soc. Nat. Hist., Proc., vol. 40, No. 1, p. 53. Semele purpurascens (Gmelin), Lermond, Check List of Florida Marine Shells, Gulfport, p. 20. VENEZUELAN CENOZzOIC PELECYPOoDS: WEISBORD 355 1936.. Semele purpurascens (Gmelin), Clench and McLean, Soc. Cubana Hist. Nat. “Felipe Poey,’”’ Mem., vol. 10, No. 3, p. 168. 1937. Semele purpurascens (Gmelin), Smith, East Coast Marine Shells, p. 61, pl. 23, fig. 12. 1940. pase variegata (Lamarck), Smith, World-wide Sea Shells, p. 113, ig. 1479. 1946. Semele purpurascens (Gmelin), Jaume, Soc. Malac. “Carlos de La Torre,” Rev., vol. 4, No. 3, p. 101. 1949. Semele (Semele) purpurascens (Gmelin), Lange de Morretes, Arq. Mus. Paranaense, vol. 7, art. 1, p. 43. 1949. Semele purpurascens (Gmelin), Hertlein and Strong, Zoologica, vol. 34, pt. 4, No. 19, p. 248. 1951. Semele purpurascens (Gmelin), McLean, New York Acad. Sci. Scientific Survey of Porto Rico and the Virgin Islands, vol. 17, pt. 1, p. 106, pl. 22, fig. 1. 1952. Semele purpurascens (Gmelin), Pulley, Texas Jour. Sci., vol. 4, No. 2, p. 184, pl. 13, fig. 3. 1953. Semele purpurascens (Gmelin), Olsson and Harbison, Acad. Nat. Sci. Philadelphia, Mon. No. 8, p. 133. 1954. Semele purpurascens (Gmelin), Abbott, American Seashells, p. 435, pl. 40b. 1955. Semele purpurascens (Gmelin), Perry and Schwengel, Marine Shells of the Western Coast of Florida, p. 84, pl. 16, fig. 104. 1956. Semele purpurascens (Gmelin), Parker, Amer. Assoc. Petrol. Geol., Bull., vol. 40, No. 2, pp. 309, 371. 1959. Semele purpurascens (Gmelin), Parker, Amer. Assoc. Petrol. Geol., Bull., vol. 43, No. 9, pp. 2136, 2164, pl. 6, fig. 11. 1961. Semele purpurascens (Gmelin), Olsson, Panamic-Pacific Pelecypoda, p. 363. The Recent Venezuelan shell is thin and obliquely oval, with a produced and rounded anterior end. The surface is marked by delicate concentric lineations and numerous microscopic radii, crossed, on the anterior two-thirds of the valve, by fine, slightly raised, straightish threads running obliquely across the concentric markings. The pallial sinus is broadly semi-oval, extending forward about seven-tenths the length of the shell. Externally, the upper half of the valve is suffused a pale lavender; the lower half is cream- colored with purplish brown linear mottlings. The interior is glossy and whitish, with two large blotches of chocolate, one dark, the other light, and numerous purplish brown mottlings on the sides and base. Dimensions—Specimen A456a, left valve, height 13 mm.; length 16.7 mm., thickness 3 mm. Locality.—Recent, on beach of Playa Grande Yachting Club, Distrito Federal. One left valve. Remarks.—The Eastern Pacific analogue is S. sparsilineata Dall (1915, Acad. Nat. Sci. Philadelphia, Proc., vol. 67, p. 26) which ranges from Nicaragua to Ecuador to depths of 40 fathoms. Ac- 356 BuLLETIN 204 cording to Dall, the oblique threads are sparser on S. sparsiineata than on S. purpurascens. Range and distribution —Semele purpurascens (Gmelin) ranges from late Miocene to Recent. The Recent form extends from North Carolina, U.S.A., to Brazil. In the Pliocene, S. purpurascens has been recorded from Florida, Costa Rica, and Trinidad, and in the upper Miocene it was reported from the Choctawhatchee formation of Florida by Mansfield. Semele proficua (Pulteney) Pl. 51, figs. 9-14 1767. ? Tellina reticulata Linnaeus, Syst. Nat., ed. 12, p. 1119. 1799. Tellina proficua Pulteney, Hutch. Dorset., p. 29, pl. 5, fig. 4. 1803. Tellina proficua Pulteney, Montagu, Testacea, or Natural History of British Shells, p. 66. NS1SS 27; ae reticulata Linnaeus, Pulteney, Catalogue Dorset., 2nd ed., p. 30, pl. 5, fig. 4. 1815. Tellina decussata Wood, General Conchology, p. 190, pl. 43, figs. 2-3. 1822. Amphidesma orbiculata Say, Acad. Nat. Sci. Philadelphia, Jour., ser. 1, vol. 2, p. 307. 1826. Amphidesma radiata Say, Acad. Nat. Sci. Philadelphia, Jour., ser. 1, vol. 5, p. 230. 1845. Amphidesma jayanum C. B. Adams, Boston Soc. Nat. Hist., Proc., vol. 2, p. 10. 1845. Amphidesma reticulata (Chemnitz), d’Orbigny, [in] La Sagra, Hist. Fis., Polit., y Nat. Isla de Cuba, pt. 2, vol. 5, Moluscos, pp. 296-297. 1853. Amphidesma reticulata (Chemnitz), Reeve, Conch. Icon., vol. 8, Amphi- desma, pl. 5, sp. 29. 1853. Amphidesma decussata (Wood), Reeve, Conch. Icon., vol. 8, Amphi- desma, pl. 4, sp. 23. 1856. Amphidesma radiata Reeve, Hanley, An Illustrated and Descriptive Catalogue of Bivalve Shells, p. 342, pl. 12, fig. 8. Not of Reeve 1853. 1857. Amphidesma orbiculata Say, Tuomey and Holmes, Pleiocene Fossils of South Carolina, p. 94, pl. 23, fig. 4. 1860. Semele orbiculata (Say), Holmes, Post-Pleiocene Fossils of South Caro- lina, p. 51, pl. 8, fig. 9. 1860. pees radiata (Say), Holmes, Post-Pleiocene Fossils of South Carolina, pl. 8, fig. 11. 1864. Semele decussata (Wood), Krebs, The West Indian Marine Shells, p. 106. 1867. Semele carolinensis Conrad, Amer. Jour. Conch., vol. 3, pt. 1, No. 5, p. 14. 1869. Semele decussata (Wood), Tryon, Amer. Jour. Conch., vol. 3, pt. 1, No. 5, p. 14. 1871. Semele orbiculata (Say), Coues, Acad. Nat. Sci. Philadelphia, Proc., vol. 23, p. 138. 1878. Semele reticulata (Linnaeus) ?, Mérch, Catalogue of West-India Shells, p. 14. 1878. Semele reticulata (Linnaeus), Arango y Molina, Contribucién a la Fauna Malacolégica Cubana, p. 247. 1884. Semele reticulata (Chemnitz), Tryon, Structural and Systematic Conch- ology, vol. 3, p. 163, pl. 110, fig. 35. 1887. Semele reticulata (Spengler), Fischer, Manuel de Conchyliologie et de Paléontologie Conchyliologique, p. 1153, pl. 21, fig. 11. 1889. Semele reticulata (Gmelin), Dall, U. S. Nat. Mus., Bull. 37, p. 62. 1889. 1889. 13890. 1891. 1900. 1900. 1901. 1913. 1916. 1920. 1924. 1925. 1926. 1934. 1935. 1936. 1936. 1936. 1937. 1938. 1940. 1942. 1944. 1945. 1946. 1949. 1950. 1951. 1952. 1952. 1954. VENEZUELAN CENOZOIC PELECYPOoDS: WEISBORD 357 Seacle reticulata (Lamarck), Simpson, Davenport Acad. Nat. Sci., Proc., Wol. Sip. 72- Semele reticulata (Gmelin), Dall, U. S. Nat. Mus., Proc., vol. 12, No. 773, p. 274. Semele cordifornis (Chemnitz), Smith, Linnean Soc, London, Jour., Zoology, vol. 20, p. 498. Semele reticulata (Gmelin), Baker, Acad. Nat. Sci. Philadelphia, Proc., vol. 43, p. 48. Semele proficua (Pulteney), Dall, Wagner Free Inst. Sci. Trans., vol. 3, pt. 5, pp. 991-992. Semele orbiculata var. radiata (Say), Verrill and Bush, Connecticut Acad. Arts and Sci., Trans., vol. 10, art. 12, p. 521. Semele proficua (Pulteney), Dall and Simpson, U. S. Fish Com., Bull. vol. 20 for 1900, pt. 1, p. 477. Semele proficua (Pulteney), Lamy, Jour. Conchyl., vol. 61, pp. 314, 316, 331-333, 334. Semele proficua (Pultney), Thiele, Zool. Jahr., Suppl. 11, p. 131. Semele proficua (Pulteney), Maury, Bull. Amer. Paleont., vol. 8, No. 34, pp. 121-122. Semele proficua (Pulteney), Mansfield, Florida State Geol. Sur., Fifteenth An. Rept., pp. 37, 39, 40. Semele proficua (Pulteney), Maury, Bull. Amer. Paleont., vol. 10, No. 42, p. 269, pl. 21. fig. 5. Semele proficua (Pulteney), Weisbord, Nautilus, vol. 39, No. 3, p. 84. Semele proficua (Pulteney), Johnson, Boston Soc. Nat. Hist., Proc., vol. 40, No. 1, p. 53. Semele orbiculata (Say), Richards, Jour. Paleont., vol. 9, No. 3, p. 257. Semele proficua (Pulteney), Lermond, Check List of Florida Marine Shells, Gulfport, p. 20. Semele proficua (Pulteney), McLean, Soc. Cubana Hist. Nat. “Felipe Poey,’”’ Mem., vol. 10, No. 1, p. 42. Semele proficua (Pulteney), Clench and McLean, Soc. Cubana Hist. Nat. “Felipe Poey,” Mem., vol. 10, No. 3, p. 168. Semele proficua (Pulteney), Smith, East Coast Marine Shells, p. 61, pl. 23, fig. 11. Semele proficua (Pulteney), Richards, Geol. Soc. Amer., Bull., vol. 49, pt. 2, ps 1292. Semele proficua (Pulteney), Stenzel, Nautilus, vol. 54, No. 1, p. 21. Semele proficua (Pulteney), Jaume and Pérez Farfante, Soc. Cubana Hist. Nat. “Felipe Poey,’’ Mem., vol. 16, No. 1, p. 39. Semele proficua (Pulteney), Hackney, Nautilus, vol. 58, No. 2, p. 59. Semele decussata (Wood), van Bentham Jutting, Geolog.-Mijnbouk. Genootschap Nederland en Kolonien, Geol. Ser., vol. 14, p. 78. Semele proficua (Pulteney), Jaume, Soc. Malac. “Carlos de La Torre,” Rev., vol. 4, No. 3, p. 101. Semele (Semele) proficua (Pulteney), Lange de Morretes, Arq. Mus. Paranaense, vol. 7, art. 1, p. 43. Amphidesma jayanum C. B. Adams, Clench and Turner, Occas. Papers on Mollusks, vol. 1, No. 15, p. 298, pl. 43, figs. 3-4. Semele proficua (Pulteney), McLean, New York Acad. Sci. Scientific Stee), of Porto Rico and the Virgin Islands, vol. 17, pt. 1, p. 106, pl. 21, fig. 9. Semele proficua (Pulteney), Pulley, Texas Jour. Sci., vol. 4, No. 2, p. 184, pl. 13, figs. 4-5. Semele proficua (Pulteney), Dodge, Amer. Mus. Nat. Hist., Bull., vol. 100, art. 1, p. 50. Semele proficua (Pulteney), Abbott, American Seashells, p. 434, pl. 40g. 358 BULLETIN 204 1955. Semele proficua (Pulteney), Perry and Schwengel, Marine Shells of the Western Coast of Florida, p. 84, pl. 16, fig. 103. 1956. Semele proficua (Pulteney), Parker, Amer. Assoc. Petrol. Geol., Bull., vol. 40, No. 2, pp. 309, 315, 326, 353, 371, pl. 3, figs. 9a, 9b. 1958. Semele proficua (Pulteney), Olsson and McGinty, Bull. Amer. Paleont., VOl. 39) NOs 177, ps 22- 1959. Semele proficua (Pulteney), Nowell-Usticke, A Check List of the Marine Shells of St. Croix, p. 19. 1959. Semele proficua (Pulteney), Parker, Amer. Assoc. Petrol. Geol., Bull., vol. 43, No. 9, pp. 2125, 2161, pl. 2, VI, figs. 18a, 18b. 1961. Semele proficua (Pultney), Moore, Gulf Research Repts., vol. 1, No. 1, pp. 16, 46. 1961. Semele proficua (Pulteney), Olsson, Panamic-Pacific Pelecypoda, p. 370. 1961. Semele aff. proficua (Pulteney), van Regteren Altena, Konikl, Nederl. Akad. Wetens.-Amsterdam, Proc., ser. B, vol. 64, No. 2, p. 300. Shell suborbicular, nearly equilateral, a little longer in front, subinflated. Beak low, slightly behind the middle, a narrow sunken lunule in front of it. Posterior gently flexed, sometimes with a faint narrow radial ridge or two on the broad submargin. Sculpture consisting of fine raised narrow concentric riblets and closely spaced wrinkle-like radial threads in the interspaces. Interior glossy. Hinge plate relatively short, the lateral teeth close to the cardinals. Right valve with two slightly divergent cardinals and two laterals, the posterior lateral slightly the stouter. Left valve with two cardinals, the anterior the stronger, and two subequal laterals. Ligamental area prominent, elliptical, depressed. Pallial sinus regular, “U’-shaped, extending upward and forward slightly past the middle line of the valves. Color straw without, whitish within, the interior flecked with lavendar at the umbo. Dimensions.—Specimen A424a, right valve, height 21.6 mm.; length 23.1 mm.; thickness 4.2 mm. Specimen A 424b, left valve, height 14 mm.; length 16 mm.; thickness 2.2 mm. Specimen J425a, height 17.3 mm.; length 19.7 mm.; thickness 3.5 mm. (left valve). Locality—Recent, on beach of Playa Grande Yachting Club, Distrito Federal. Five specimens including three right valves and two left valves. Lower Mare formation, in small stream 100 meters west of Quebrada Mare Abajo, One left valve, weathered. Lower Mare formation at W-13, on hillside above west bank of Quebrada Mare Abajo. One right valve. Range and distribution —Pliocene to Recent. Living in shallow water from North Carolina to Brazil; Pleistocene in South Caroli- VENEZUELAN CENOZOIC PELECYPODS: WEISBORD 359 na, Florida, St. Kitts?, Cuba, and Venezuela. Pliocene in South Carolina and Florida. Remarks.—Olsson (1961) observed that the type of S. medi- americana Pilsbry and Lowe (1932, p. 92, pl. 12, figs. la, 1b, 2), purportedly from the Pacific coast of Nicaragua, evidently was collected from the Caribbean coast of that country and is the same as S. proficua (Pulteney). Semelina nuculoides (Conrad) PE i52, fisss 1,02 1841. Amphidesma nuculoides Conrad, Amer. Jour. Sci., 1st ser., vol. 41, p. 347. 1845. Amphidesma nuculoides Conrad, Fossils of the Medial Tertiary of the United States, p. 73, pl. 41, fig. 6. 1863. Abra nuculoides (Conrad), Acad. Nat. Sci. Philadelphia, Proc., vol. 14, p-. 574. 1864. Abra nuculoides (Conrad), Meek, Smithsonian Misc. Collections, vol. 7, No. 183, p. 11. 1889. Semele nuculoides (Conrad), Dall, U. S. Nat. Mus., Bull. 37, p. 62. 1889. Semele nuculoides (Conrad), Dall, U. S. Nat. Mus., Proc., vol. 12, No. 773, pp. 274-275, pl. 14, fig. 5. 1900. Semele nuculoidea (Conrad), Dall, Wagner Free Inst. Sci., Trans., vol. 3, pt. 5, pp. 986, 994. 1901. Semele (Semelina) nuculoides (Conrad), Dall and Simpson, U. S. Fish Com., Bull., vol. 20 for 1900, pt. 1, p. 477. 1913. Semele nuculoides (Conrad), Lamy, Jour. Conchyl., vol. 61, p. 316. 1919. Semele nuculoides (Conrad), Gardner and Aldrich, Acad. Nat. Sci. Philadelphia, Proc., vol. 71, p. 19. 1920. Semele (Semelina) nuculoides (Conrad), Maury, Bull. Amer. Paleont., vol. 8, No. 34, p. 123. 1932. Semele (Semelina) nuculoides (Conrad), Mansfield, Florida State Geol. Sur., Bull. No. 8, p. 146, pl. 30, fig. 9. 1934. Semele nuculoides (Conrad), Johnson, Boston Soc. Nat. Hist., Proc., vol. 40, No. 1, p. 53. 1936. Semele nuculoides (Conrad), Lermond, Check List of Florida Marine Shells, p. 20. 1937. Semele nuculoides (Conrad), Smith, East Coast Marine Shells, p. 61, pl. 10, fig. 7. 1942. Semele (Semelina) nuculoides (Conrad), Gardner, U. S. Geol. Sur., Prof. Paper 199-A, pp. 102-103, pl. 17, figs. 18-21. 1949. Semele (Semelina) nuculoides (Conrad), Lange de Morretes, Mus. Par- anaense, Arq., vol. 7, art. 1, p. 43. 1951. Semele nuculoides (Conrad), McLean, New York Acad. Sci. Scientific ae of Porto Rico and the Virgin Islands, vol. 17, pt. 1, p. 107, pl. 22, ig. 3. 1953. Semelina nuculoides (Conrad), Olsson and Harbison, Acad. Nat. Sci. Philadelphia, Mon. No. 8, p. 134. 1955. Semele nuculoides (Conrad), Perry and Schwengel, Marine Shells of the Western Coast of Florida, pp. 84-85, pl. 16, fig. 105. 1958. Semele nuculoides (Conrad), Olsson and McGinty, Bull. Amer. Paleont., vol. 39, No. 177, p. 22. 1959. Semele nuculoides (Conrad), Nowell-Usticke, A Check List of the Marine Shells of St. Croix, p. 19. ; 360 BuLtetin 204 1961. Semele nuculoides (Conrad), Moore, Gulf Research Repts., vol. 1, No. 1, pp. 16, 46. 1961. Semelina nuculoides (Conrad), Olsson, Panamic-Pacific Pelecypoda, p. 375. Shell small, moderately inflated, elongate-nuculoid in outline, longest and a little oblique anteriorly. Beak low, near the posterior end. Surface sculptured by closely spaced subregular concentric lirae (some of them not reaching the margins), separated by interspaces which are a little wider than the lirae at the umbo but narrower than the lirae below; in the interspaces on the lower half of the anterior end, as well as elsewhere, there are obsolescent microscopic radial striae. Hinge of left valve with a sharp, elevated, cuneate and bifid anterior cardinal tooth; behind that there is a deep triangular socket, and after the socket a shallower subrhomboidal chondrophore, the chondrophore bordered by the posterior cardinal. The left posterior cardinal tooth is a thickened lamina situated above the posterior adductor scar; the left lateral tooth is represented by a slight thickening far down the anterodorsal edge above the anterior ad- ductor scar. Anterior adductor scar moderately elongate and more or less elliptical, the posterior scar impressed and subquadrate. The pallial sinus is large, arising at the inner margin of the posterior adductor scar, embayed to about 0.3 mm. from the anterior ad- ductor scar, the lower limb of the sinus a narrowish finger-like projection extending toward the rear about two-thirds the length of the valve, the posterior end of the limb bluntly rounded; the lower line of the limb parallels the ventral margin of the valve and continues to join the lower end of the anterior adductor scar. Inner margin smooth, Lunular area narrow, elongate, elliptical, sunk- en slightly below the border of the disk. Escutcheonal area rel- atively short, sublinear, slightly depressed. Dimensions.—Specimen §458a, height 2.9 mm.; length 4.3 mm.; approx. thickness 1.1 mm. Locality.—Playa Grande formation (Maiquetia member) at W-23, north flank of Punta Gorda anticline. One left valve. Remarks.—According to Dall (1900, p. 994), certain variants of S. nuculoides, chiefly among Recent specimens, are marked by faint radial striations, and such occur on the Venezuelan fossil. Range and distribution —Semelina nuculoides (Conrad) ranges VENEZUELAN CENOZOIC PELECYPODS: WEISBORD 361 from upper Miocene to Recent. The living form is found from Cape Hatteras, North Carolina, to Brazil, occurring off the west coast of Florida in six to seven fathoms. In the Pleistocene, Maury reported it from New Orleans, Louisiana, in the Gymnasium Club well at 1200 feet. In the Pliocene, S. nuculotdes occurs in North Carolina, and Florida, and in the upper Miocene, in Virginia, North Carolina, and Florida. DONACIDAE Donax denticulatus Linnaeus Pl. 52, figs. 3-8 1758. Donax denticulata Linnaeus, Syst. Nat., ed. 10, p. 683, No. 86. 1767. Donax denticulatus Linnaeus, Syst. Nat., ed. 12, p. 1127, No. 107. 1782. 1825. 1854. 1864. 1866. 1869. 1869. 1878. 1878. 1879. 1884. 1886. 1889. 1889. 1891. 1892. 1900. 1901. 1914. 1920. 1934. 1936. Donax denticulata Linnaeus, Chemnitz, Syst. Conchylien-Cabinet, vol. 6, pp. 262-264, pl. 26, figs. 256-257. Donax denticulata Linnaeus, Wood, Index Testaceologicus, pl. 6, fig. 8. Donax denticulata Linnaeus, Reeve, Conch. Icon., vol. 8, Donax, pl. 7, sp. 48a-c. Donax denticulata Linnaeus, Krebs, The West Indian Marine Shells, p: 99: Donax denticulata Linnaeus, Sowerby, Thes. Conchyl., vol. 3, p. 281, figs. 32-36. Donax denticulatus Linnaeus, Tryon, Amer. Jour. Conch., vol. 4, pt. 5, Appendix, No. 15, p. 108. Donax denticulatus Linnaeus, Romer, Syst. Conchylien-Cabinet, vol. 10, pt. 3, pp. 21-24, pl. 2, figs. 4-5., pl. 5, figs 1-7. Donax denticulata Linnaeus, Morch, Catalogue of West-India Shells, Dp: 15: Donax denticulatus Linnaeus, Arango y Molina, Contribucién a la Fauna Malacolégica Cubana, p. 247. Donax (Chion) denticulatus Linnaeus, Bertin, Mus. Hist. Nat. Nouv. Arch., sér. 2, pp. 81-82. Donax denticulatus Linnaeus, Tyron, Structural and Systematic Con- chology, vol. 3, p. 172, pl. 112, figs. 80-81. Donax denticulatus Linnaeus, Fischer, Manuel de Conchyliologie et de Paléontologie Conchyliologique, p. 1102, pl. 21, fig. 19. Donax denticulatus Linnaeus, Dall, U. S. Nat. Mus., Bull. 37, p. 58. Donax denticulatus Linnaeus, Simpson, Davenport Acad. Nat. Sci., Broce vil.) 54D. 165. Donax denticulatus Linnaeus, Baker, Acad. Nat. Sci. Philadelphia, Proc., vol. 43, p. 48. Donax denticulata Linnaeus, Dall, Nautilus, vol. 5, No. 11. p. 125. Donax denticulata Linnaeus, Dall, Wagner Free Inst. Sci., Trans., vol. 3, pt. 5, pp. 963,965. Donax denticulata Linnaeus, Dall and Simpson, U. S. Fish Com., Bull., vol. 20 for 1900, pt. 1, p. 476. Donax denticulata Linnaeus, Lamy, Mus. Nat. Hist. nat. Paris, Bull., vol. 20, No. 6, p. 340. Donax denticulata Linnaeus, Maury, Bull. Amer. Paleont., vol. 8, No. 34, p. 128. Donax denticulata Linnaeus, Johnson, Boston Soc. Nat. Hist., Proc., vol. 40, No. 1, p. 54. Donax denticulata Linnaeus, McLean, Soc. Cubana Hist. Nat. “Felipe Poey”, Mem., vol. 10, No. 1, p. 40. 362 BULLETIN 204 1937. Donax denticulata Linnaeus, Smith, East Coast Marine Shells, p. 62, pla zotigy 3. 1940. Donax denticulatus Linnaeus, Smith, World-wide Sea Shells, p. 113, fig. 1481. 1940. Donax denticulata Linnaeus, Richards, Soc. Venezolana Cienc. Nat. Bol., vol. 6, No. 46, p. 306. 1943. Donax denticulata Linnaeus, Richards, Jour. Paleont. vol. 17, No. 1, peiet, 1945. Donax denticulatus Linnaeus, van Bentham Jutting, Geolog.-Mijnbouwk, Genootschap Nederland en Kolonien, Geol. Ser., vol. 14, p. 78. 1949. Donax denticulatus Linnaeus, Lange de Morretes, Arg. Mus. Parana- ense, vol. 7, art. 1, p. 41. 1951. Donax denticulata Linnaeus, McLean, New York Acad. Sci. Scientific Survey of Porto Rico and the Virgin Islands, vol. 17, pt. 1, p. 105, plz. figs 7. 1952. Donax denticulatus Linnaeus, Dodge, Amer. Mus. Nat. Hist., Bull. vol. 100, art. 1, p. 83. 1952. Donax denticulata Linnaeus, Pulley, Texas Jour. Sci., vol. 4, No. 2, p. 183. 1954. Donax denticulata Linnaeus, Abbott, American Seashells, p. 438, pl. 30p. 1958. Donax denticulata Linnaeus, Olsson and McGinty, Bull. Amer. Paleont., vol. 39° No: 17:7, p: 22. 1959. Donax denticulata Linnaeus, Nowell-Usticke, A Check List of the Marine Shells of St. Croix, p. 19. 1961. Donax denticulatus Linnaeus, Warmke and Abbott, Caribbean Sea- shells, p. 201, pl. 4L; 42d. The Recent shell from Higuerote occurs in two forms, one with a relatively high trigonal outline, the other narrower and more elongated. On the former, the embayment of the ventral margin is short and slight, and sometimes not present; on the latter it is longer and generally somewhat more pronounced. Except for the average smaller size of the elongated variant, the two forms are otherwise identical, and there seems no doubt that they are con- specific. The species is characterized by a low narrow arcuate an- gulation on the posterior truncation, the angulation dividing the truncation into two unequal and sharply defined areas. The area adjacent to the posterior ridge is sculptured by five to seven neat radial riblets with numerous regularly spaced threads in the inter- spaces; the marginal area is somewhat wider and is sculptured by rather strong vermicular concentric cords between which are nar- rower subregular radial lirae. Both valves are marked by a faint radial depression in front of the posterior ridge, the depression broader and gentler on the elongated form. Inner margins crenulated, the denticles extending from near the posterior lateral tooth around the base to the anterior end where they become obsolescent and cease at the curve of the anterior end and the anterodorsal margin VENEZUELAN CENOZzOIC PELECYPODS: WEISBORD 363 which is smooth. The base is finely serrated, the pallial sinus large and subangulately rounded. The anterior lateral of the hinge is longer than the posterior. The coloration is highly variable. Some specimens are a plain white, straw, salmon, or flesh on the surface, others are broadly or narrowly rayed in brown, gray, lavender or purple. The shiny interior is usually suffused wholly or in part with deep purple, and there is an occasional specimen with bright orange in the body cavity. Dimensions.—Specimen B469a, left valve, length 29.3 mm.; height 20.5 mm.; thickness at posterior ridge 6.9 mm. Specimen B469b, right valve, length 20.8 mm.; height 15 mm.; thickness at posterior ridge 5 mm. Specimen B469c, left valve, length 25.4 mm.; height 18.7 mm.; thickness at posterior ridge 6 mm. Specimen B469d, right valve, length 27.3 mm.; height 20.3 mm.; thickness at posterior ridge 6.8 mm. Average elongated form, length 22 mm.; height 13 mm.; thickness at posterior ridge 5 mm. Locality.—On beach, southeast of Higuerote, State of Miranda. One hundred fifty specimens including ninety-seven left valves and fifty-three right valves. Range and distribution.—The living Donax denticulatus Lin- naeus is a near-shore species ranging from Brazil through the West Indies to perhaps as far north as the Florida Keys. As a fossil it has been found in the Pleistocene of Colombia and Venezuela. Donax striatus Linnaeus Pl. 52, figs. 9-17 1767. Donax striata Linnaeus, Syst. Nat., ed. 12, p. 1127, No. 106. 1772. Donax striata Linnaeus, Knorr, Vergnugen der Angen und des Gemuths 1G 1 hye 7A sates 7 1782. Donax striata Linnaeus, Chemnitz, Syst. Conchylien-Cabinet, vol. 6, pp. 261-262, pl. 26, fig. 255. 1818. Donax caianensis Lamarck, An. sans Vert., vol. 5, p. 550. 1841. Donax caianensis Lamarck, Delessert, Recueil de coquilles décrites par Lamarck dans son Histoire Naturelle des Animaux sans Vertébres et non encore figurées, pl. 6, figs. 13a, 13b. 1845. Donax cayanensis Lamarck, d’ Orbigny, [in] La Sagra, Hist. Fis., Polit., y Nat. Isla de Cuba, pt. 2, ‘vol. 5, Moluscos, p. 308. 1853. Donax flexuosus Gould, Boston Jour. Nat. Hist., vol. 6, p. 395, pl. 15 fig. 8. Not of Cooper 1888. 1854. Donax lamarckii Deshayes, [in] Reeve, Conch. Icon, vol. 8, Donax, pl. SSD are. 1855. Donax striata Linnaeus, Hanley, An Illustrated and Descriptive Cata- logue of Recent Bivalve Shells, p. 82, pl. 14, fig. 32. 1864. ?Donax cayennensis Lamarck, Krebs, The West Indian Marine Shells, p. 99; 364 BuLuetin 204 1864. Donax striata Linnaeus, Guppy, Sci. Assoc. Trinidad, Trans., pp. 164, 167. 1866. Donax striata Linnaeus, Sowerby, Thes. Conchyl., vol. 3, p. 309, pl. 281, fig. 52. 1867. Donax striata Linnaeus, Guppy, Sci. Assoc. Trinidad, Proc., pt. 3, p. 162. 1869. Donax (Serrula) striatus Linnaeus, Tryon, Amer. Jour. Conch., vol. 4, pt. 5, Appendix, No. 15, p. 113. 1869. Donax striatus Linnaeus, Romer, Syst. Conchylien-Cabinet, vol. 10, pt. 3, pp. 12-13, pl. 5, figs. 8-10. 1878. Donax striata Linnaeus, Mérch, Catalogue of West-India Shells, p. 15. 1879. Donax striatus Linnaeus, Bertin, Mus. Hist. Nat. sér. 2, Nouv. Arch., p. 94. 1892. Donax striata Linnaeus, Dall, Nautilus, vol. 5, No. 11. p. 125. 1900. Donax striata Linnaeus, Dall, Wagner Free Inst. Sci., Trans., vol. 3, pt. 5, p. 968. 1914. Donax striata Linnaeus, Lamy, Mus. Nat. Hist. nat. Paris, Bull., vol. 20, No. 6, p. 338. 1924. Donax striata Linnaeus, Strong, Nautilus, vol. 37, No. 3, p. 83. 1925. Donax striata Linnaeus, Maury, Bull. Amer. Paleont., vol. 10, No. 42, p. 268. 1934. Donax striata Linnaeus, Maury, Amer. Mus. Nat. Hist., Bull., vol. 67, art. 4, pp. 165-166, pl. 19, fig. 5. 1945. Donax striatus Linnaeus, van Bentham Jutting, Geolog.-Mijnbouwk. Genootschap Nederland en Kolonien, Geol. ser., vol. 14, p. 78. 1952. Donax striatus Linnaeus, Dodge, Amer. Mus. Nat. Hist., Bull., vol. 100, pt. 1, pp. 81-82. 1954. Donax striata Linnaeus, Abbott, American Seashells, p. 438. 1958. Donax striatus Linnaeus, Olsson and McGinty, Bull. Amer. Paleont., vol. 39, No. 177, p. 22. 1961. Donax striatus Linnaeus, Warmke and Abbott, Caribbean Seashells, p 202, pl. 42h. 1961. Donax striatus Linnaeus, Olsson, Panamic-Pacific Pelecypoda, pp. 340, 343. The Recent Higuerote shell referred to this species is wedge- shaped, moderately solid, trigonal in outline, produced anteriorly, characterized by a sharply carinated posterior ridge and a flat to slightly concave posterior truncation with a nearly vertical slope. The posterodorsal margin descends more steeply than the anterodor- sal margin. Anterior end narrowed and well rounded, ventral margin subangularly arcuate with a downsag near the middle, the margin behind the sag truncate to hardly embayed. The corner at the ventral and posterodorsal margins is acute, and the posterior end is short and truncated. In front of the posterior ridge there is a slight radial depression, and often another barely discernible one before the anterior end. Beak sharp, fairly high, flattened on top, opisthogyrate, situated at the posterior third. On the hinge there is an oval ligamental fosset immediately under the beak, the hinge plate turned up at the distal end of it. The laterals are prominent, VENEZUELAN CENOzOIC PELECYPODS: WEISBORD 365 the groove between them on the right valve deeper on the posterior set than on the anterior. Cardinals of left valve subequal, divergent, united above, the socket separating them triangular; on the right valve the central cardinal is stout, the anterior one minor. Inner margins regularly crenulated, the denticles extending around the edge from the posterior lateral to where the anterior end merges with the anterodorsal margin, which itself is smooth. Rim of basal margin serrated by the termini of the external ribs. Adductor im- pressions distinct, the anterior one narrowly pyriform, the posterior transversely oval. Pallial sinus U-shaped, projected horizontally to near the middle line of the interior, the apex rounded. Pallial line fairly close to the margin posteriorly, more remote anteriorly, the line bowed up where it meets the end of the sinus, the upper line of the sinus and hinder end of the pallial line subparallel. Exterior of disk sculptured by low flat narrow radial riblets which are more distinct in front of the posterior ridge than they are anteriorly. The posterior truncation is sculptured by 19 to 23 equal to subequal neat radial cords which are sometimes faintly crenate, the interspaces crowded with microscopic concentric striae. The rib forming the carina of the posterior ridge is strong and usually doubled toward the base. The color is plain white, gray, light yellow, salmon or pale lavender on the surface, and usually deep purple and white in the interior, although occasional specimens are pinkish or ashy within. Dimensions—Specimen B470a, valves attached, length 26.3 mm.; height 16.4 mm., max. thickness of pair 11.5 mm. Specimen B470b, a young doublet, length 12.3 mm.; height 7.9 mm.; max. thickness of pair 5.2 mm. Specimen B470c, left valve, length 25.9 mm.; height 17 mm.; thickness at posterior ridge 5 mm. Specimen B470d, right valve, length 23.3 mm.; height 14.1 mm., thickness at posterior ridge 4.6 mm. Specimen B470el-2, paired valves, length 28.1 mm.; height 18.2 mm.; max. thickness of pair 12.2 mm. Localhity.—Recent, on beach southeast of Higuerote, State of Miranda. Twenty-seven specimens including thirteen left valves, ten right valves, and four doublets. Remarks.—D. striatus is at once differentiated from D. denticu- latus by its flat, rather than angulated posterior slope, and the slope is uniformly sculptured longitudinally. 366 BuLLeETIN 204 Range and distribution —The Recent D. striatus ranges from Brazil to the southern Caribbean. As a fossil it has been reported from the Pleistocene in Colombia and on the coast of Rio Grande do Norte in Brazil, and by Guppy from the Pliocene at Matura, Trini- dad. As pointed out by Hanley, the figure of D. catanensis Lamarck portrayed by Delessert and based on the original Lamarckian speci- mens, agrees so well with D. striatus Linnaeus, that they may be the same. Donax higuerotensis, new species Pl. 53, figs. 1-9 Shell relatively narrow, inequilateral, oblong subtrigonal in outline, about twice as long as high, produced anteriorly. Antero- dorsal margin gently sloping, nearly parallel with the anterior half of the ventral margin; posterodorsal margin moderately steep, slight- ly humped above the posterior lateral tooth, hardly concave distally; corner of posterodorsal and ventral margins rounded to subtruncate; posterior half of ventral margin shallowly embayed, the anterior half gently arcuate; anterior end a little narrowed and well rounded. Posterior ridge subrounded to subangulate, the posterior slope slight- ly convex adjacent to the ridge, flattened to hardly concave toward the margin. Between the posterior ridge and middle of the disk there is a broad shallow radial depression. Beak low, appressed on top, situated aft of the middle. Laterals of left valve prominent, the anterior lateral tooth longer than the posterior. Between the beak and the posterior lateral the hinge plate is upswept on both valves. Central cardinal of right valve stout, joined above to the smaller anterior cardinal which diverges nearly horizontally. Cardinals of left valve subequal, joined above, diverging equally from the apex. Interior shiny. Inner margins crenulated, the denticles extending around the edge from the posterior lateral to where the anterior end and anterodorsal margin meet, the anterodorsal margin itself smooth. Anterior adductor scar pyriform, the posterior transversely suboval, lying athwart the posterior angle. Pallial sinus U-shaped, extending forward horizontally to a little before the mid-line of the valve, the apex broadly rounded. Pallial line fairly close to the margin near the posterior corner, becoming more remote from the margin on its course to the base of the anterior adductor scar, the line bowed up where it meets the pallial sinus, the after end of the VENEZUELAN CENOZOIC PELECYPODS: WEISBORD 367 pallial line nearly parallel with the upper line of the sinus. Entire surface sculptured by radial riblets, those on the disk faint, flat, and narrow, the ones (22 to 24) on the posterior truncation thinner and much more distinct. On the left valve the radial riblets on the truncation are more or less equal, but on the right valve there are five or six adjacent to the posterior ridge that are slightly broader than the others. Crowded microscopic concentric striae traverse the surface, the striae much more distinct in the intercostal spaces of the posterior slope than elsewhere. The basal rim of the valves is finely serrated by the projecting termini of the external rblets. On the exterior the ground color is generally dull white but sometimes buff, with concentric bands and stripes of gray, or lavender, or pale purple, or rarely, light yellow. Excepting those which are monotone in color, all specimens exhibit a broad, usually single but occasionally double ray of ground color diverging sharply from the beak, the ray confined to the radial depression of the valve and broadening to the base. In the interior of the valve this ray shows up in white, generally with purple on either side. Dimensions—Holotype (B471a), paired valves, length 25 mm.; height 12.2 mm.; max. thickness of pair 7.5 mm. Paratype (B471b), left valve, length 23 mm.; height 10.7 mm.; thickness at posterior ridge 4 mm. Paratype (B47Ic), right valve, length 22 mm.; height 10.9 mm.; thickness at posterior ridge 4 mm. Type locahty.—Recent, on beach southeast of Higuerote, State of Miranda. Fifty-four specimens including thirty right valves, twenty-three left valves, and one doublet. Other localities—Unnamed (as of November 1961) Recent specimens of this species are contained in the collections of the U. S. National Museum from Cienaga, near Santa Marta, Colombia (U. S. N. M. No. 444095), and from Chaguaramas Bay, Trinidad (U.S. N. M. No. 518549). Higuerote, in Venezuela, lies on the coast between those localities but nearer Trinidad. Comparisons.—Donax higuerotensis, n. sp. is found on the beach at Higuerote together with D. striatus Linnaeus, but is differentiated from D. striatus by its consistently more elongated outline, by its longer and more prominent embayment of the ventral margin behind the middle, and by its more pronounced radial depression of the disk above the embayed margin. The type (No. 51589, Academy of 368 BuLtetin 204 Natural Sciences of Philadelphia) of D. protractus Conrad (1849, Acad. Nat. Sci. Philadelphia, Jour., ser. 2, vol. 1, p. 208) from Flon- da is smaller, thinner, and not as definitely rayed from umbo to base as is D. higuerotensis. D. mediamericana Pilsbry (1919, Acad. Nat. Sci. Philadelphia, Proc., vol. 71, pp. 222-223, pl. 11, fig. 10) from Livingston, Guatemala, is, as later acknowledged by Pilsbry (1920, Acad. Nat. Sci. Philadelphia, Proc., vol. 72, p. 195), a vari- ant of D. stratus Linnaeus, with the altitude three-fifths of the length compared to an altitude of slightly less than half the length on D. higuerotensis. The nearest Eastern Pacific analogue is D. culter Hanley (see Keen, 1958, Sea Shells of Tropical West America, p. 185, fig. 448), but that is less robust and more flexuous than D. higuerotensts. Range and distribution.—Donax higuerotensis, n. sp., is present- ly known from northern South America. Donax vagus, new species Pl. 53, figs. 10, 11 Shell small, fairly solid, moderately inflated, obtusely trigonal in outline, inequilateral, somewhat produced and attenuated an- teriorly. Anterodorsal margin long and straight, with a slope of about 35 degrees from the horizontal, the anterior end well rounded, the ventral margin shallowly arcuate but with a slight downsag near the middle, the posterodorsal margin slightly convex. Posterior ridge low and rounded, merging evenly with the relatively narrow posterior area which itself is a little convex basally but with a nearly vertical slope above. Beak low and appressed, situated about two-fifths of the length of the shell from the posterior end. Although the surface sculpture is nearly obliterated it is seen to consist, on the disk, of low faint narrow radial riblets typical of the genus, with vestiges of riblets also appearing on the posterior slope. Hinge of left valve consisting of a short elevated posterior lateral tooth close to the beak and a long slender anterior lateral more distant from the beak. The central cardinals of the left valve are subequal, united above, diverging equally from the apex, the subumbonal socket between them triangular. Anterior adductor scar gently im- pressed, fairly low, narrowly subpyriform, rather sharply attenuated above, the posterior scar scarcely visible, oval, also fairly low, lying astride the posterior angle of the interior. Pallial sinus not visible. VENEZUELAN CENOZOIC PELECYPODS: WEISBORD 369 Inner margins denticulate, the crenulations extending from near the posterior lateral around the rim of the valve to where the anterior end meets the anterodorsal margin. Dimensions.—Holotype (1542a), left valve, length 5.1 mm.; height 3.6 mm.; max. thickness 1.4 mm. Type Localtty—Lower Mare formation at W-13, on hillside above west bank of Quebrada Mare Abajo. One left valve, the holotype. Comparisons.—The want of a sharply carinated posterior ridge immediately distinguishes the new species from D. denticulatus Lin- naeus and D. striatus Linnaeus. Among other Recent species, D. vagus, N. sp. is reminiscent of D. texasianus Philippi (1847, Zeitschr. f. Malakozool., yr. 4, p. 77) and D. roemert Philippi (1848, Zeitschr. f. Malakozool., yr. 5, p. 147), but those are slightly narrower forms with a subangular rather than rounded posterior ridge. Among fossil species, D. vagus resembles D. chuckatuckensis Gardner (1943, U.S. Geol. Survey Prof. Paper 199-A, p. 106, pl. 23, figs. 6-7) from the up- per Miocene Yorktown formation of Virginia. D. chuckatuckensis, however, has a somewhat more posterior beak than D. vagus and is a slightly narrower and flatter shell. The Pliocene D. moenensts Gabb (1881, Acad. Nat. Sci. Philadelphia, Jour., ser. 1, vol. 8, pp. 371-372, pl. 47, fig. 72) from Costa Rica is also similar, but D. moenensis is a more delicate shell, has a slightly concave anterodorsal margin whereas that of D. vagus is straight, and the anterior end of the Costa Rican species is more attenuated than on the Venezuelan shell. Donax marensis, new species Pie da) figs, 125413 Shell small, thin, slightly inflated, inequilateral, somewhat pro- duced and moderately attenuated anteriorly. Anterodorsal margin long and straight, with a slope of near 30 degrees from the horizon- tal; anterior end bluntly rounded, ventral margin feebly arcuate; posterior end subtruncate, posterodorsal margin hardly convex. Pro- dissoconch subtranslucent. Beak low, opisthogyrate, situated a little posterior to the mid-line of the valve. Posterior ridge low and obtuse, the posterior slope not compressed. Exterior polished, sculptured by narrow, regular, microscopic, subsurficial radial riblets, the riblets on the posterior slope finer than those on the disk. Lateral teeth of right valve well developed, the posterior set shorter and nearer the 370 Buttetin 204 beak than the anterior set. Central cardinal tooth small, stout, and subcuneate, the higher anterior cardinal much thinner and with a slope subparallel with the margin; behind the central cardinal is a sublinear socket against which the hinge plate is upturned in the manner characteristic of the genus. Base of hinge plate between the laterals nearly horizontal. Adductor scars indistinct, the anterior seemingly suboval, the posterior broadly diamond-shaped and lying astride the posterior angle. Pallial sinus and pallial line not visible. Basal margin finely serrate. Dimensions.—Holotype (T472a), right valve, length 2.7 mm.; height 2 mm. Type locality—Upper Mare formation, in stream 250 meters south-southwest of mouth of Quebrada Mare Abajo. One juvenile right valve, the holotype. Comparisons. —D. marensis, n. sp. is more fragile, less inflated, and with a gentler posterior slope than D. vagus, n. sp. described on the preceding page. D. marensis resembles the young of the upper Miocene to Recent D. fossor Say (see Gardner, 1943, U. S. Geol. Survey Prof. Paper 199-A, pp. 106-107, pl. 23, figs. 2, 11) but is a thinner shell than that, and the posterior end proper is subtruncate rather than subrounded as on D. fossor. SANGUINOLARIIDAE Sanguinolaria (Psammoftella) operculata (Gmelin) Pl. 53, figs. 14-17 1782. Tellina rufescens Chemnitz, Syst. Conchylien-Cabinet, vol. 6, p. 105, pl. 11, fig. 97. 1791. Tellina operculata Gmelin, Syst. Nat., ed. 13, vol. 1, p. 3235. 1791. Tellina rufescens Gmelin, Syst. Nat., ed. 13, vol. 1, p. 3238. 1815. q clline operculata Gmelin, Wood, General Conchology, p. 165, pl. 42, ig. 1. 1878. Tellina rufescens Chemnitz, Mérch, Catalogue of West-India Shells, p. 14. 1887. Tellina (Psammotella) operculata (Gmelin), Fischer, Manuel de Con- chyliologie et de Paléontologie Paleontologique, p. 1147. 1898. Sanguinolaria (Psammotella) operculata (Gmelin), Dall, Acad. Nat. Sci. Philadelphia, Proc., vol. 50, pp. 58, 62. 1900. Sanguinolaria (Psammotella) operculata (Gmelin), Dall, Wagner Free Inst. Sci., Trans., vol. 3, pt. 5, pp. 973, 978. 1917. Sanguinolaria (Psammotella) rufescens (Gmelin), Maury, Bull. Amer. Paleont., vol. 5, No. 29, p. 393. 1920. Sanguinolaria (Psammotella) operculata (Gmelin), Maury, Bull. Amer. Paleont., vol. 8, No. 34, pp. 125-126. 1922. Sanguinolaria (Psammotella) operculata (Gmelin), Olsson, Bull. Amer. Paleont., vol. 9, No. 39, p. 433. VENEZUELAN CENOZOIC PELECYPODS: WEISBORD Si/4h 1934. Sanguinolaria (Psammotella) operculata (Gmelin), Johnson, Boston Soc. Nat. Hist., vol. 40, No. 1, p. 54. 1943. Sanguinolaria operculata (Gmelin), Stewart, Nautilus, vol. 60, p. 19. 1949. Sanguinolaria (Psammotella) operculata (Gmelin), Lange de Morretes, Arq. Mus. Paranaense, vol. 7, art. 1, p. 43. 1950. Sanguinolaria (Psammotella) operculata (Gmelin), Hertlein and Strong, Zoologica, vol. 35, pt. 4, No. 19, p. 221. 1952. Sanguinolaria operculata (Gmelin), Pulley, Texas Jour. Sci. vol. 4, No. 2, p. 183. Shell elongate, ovate, the height about half the length, in- equilateral, subequivalve, the right valve inflated and a little twisted, the left valve flattish and somewhat more tapering. Behind, the valves are gently rostrated by a low subrounded radial ridge, the posterior submargin adjacent to the ridge slightly con- cave, the area in front of the ridge a little depressed, the depression widening rapidly toward the base. Anterodorsal margin straight, nearly horizontal, short to moderately long, the anterior end well rounded, the basal margin subtruncate at the middle but embayed at the posterior depression, the posterior end narrowed and ob- liquely truncate, the posterodorsal margin subtruncate away from the hinge, straight to hardly concave at the hinge. Beak low, pointed, situated a little behind the middle. Surface marked by numerous fine concentric lineations which are obsolescent on the umbo and faint on the disk, but crowded, low, and sublamellar on the pos- terior submargin. Traversing the lower half of the disk but absent on the posterior submargin are feeble, rather closely spaced sub- regular shallow radial grooves. Ligament external, the nymph plat- form lanceolate and roughened by numerous vertical rugae. Right cardinal teeth forming a caret, the posterior tooth cuneate, strongly bifid, curving a little outward, and larger than the anterior, the anterior tooth also roughly cuneate but simple. The hinge plate on the right valve forms a slightly thickened upswept lip at the rear of the nymph. On the left valve the anterior cardinal is also bifid, and fits into the triangular socket of the right valve; the left posterior cardinal is more or less lamellar, and fits into the groove of the posterior tooth of the right valve. Anterior muscle scar lenticular, posterior scar broadly subcylindrical. Pallial sinus ample, the upper line rising slightly from the inner edge of the posterior muscle scar, then descending and later turning in to join the pallial line at about the middle of its length on the right valve. On fresh 372 BuL.etin 204 shells the interior is glossy, and the ventral margin finely crinkled. Extending from a little above the posterior adductor scar, and pass- ing along the inner edge of the scar to a little above the ventral margin, there is a feeble radial ridge at the termination of which there is a whitish node. Within, the color of the valves is generally a uniform pink but sometimes peach, with the margins a deeper tone of the same hue. The surface is colored in bands of lighter and darker pink, the umbo suffused a darker rose. Dimensions—Specimen B445a, right valve, height 34 mm.; length 65.5 mm.; approx. thickness 10.2 mm. Specimen B445b, a broken doublet, the larger fragment (right valve) 34 mm. in length. The umbonal area of a large broken left valve is 4 mm. in thickness. Largest specimen, a right valve, height 36 mm.; length 70.5 mm.; approx. thickness 10 mm. Locality.—On beach, southeast of Higuerote, State of Miranda. Twenty-two specimens including seventeen right valves, four doub- lets all with the attached valves broken, and one left valve with the sides and base broken away. Remarks.—Sanguinolaria operculata (Gmelin) is narrower and more elongate than the Recent Western Atlantic S. sanguinolenta (Gmelin) but is close to the Recent Eastern Pacific S. bertini Pilsbry and Lowe (1932, p. 91, pl. 10, figs. 7-8), differing perhaps in the somewhat greater angle that the upper line of the pallial sinus on S. operculata joins the pallial line, and perhaps, as suggested by Hertlein and Strong, in the greater distance of confluence of the lines on S. operculata. A fossil species that is closely related to both S. operculata and S. bertini is S. smithwoodwardi Maury (1917, Bull. Amer. Paleont., vol. 5, No. 29, pp. 393-394, pl. 38, figs. 1-2) from the middle Miocene of the Dominican Republic. There is a slight dif- ference in shape between the right valve of S. smithwoodwardi and the Recent Higuerote specimens of S. operculata, and, according to Maury, the left valve of S. smithwoodwardi (of which she had 10 examples) is marked only by delicate concentric striae instead of both the delicate concentric and radial lineations that are discernible on the Higuerote left valve. The middle Miocene S. alowatta Olsson (1922, Bull. Amer. Paleont., vol. 9, No. 39, pp. 432-433, pl. 29, figs. 5-6) is another fossil relative of S. operculata, but that too differs in outline, with the anterdorsal margin of the right valve and the VENEZUELAN CENOZzOIC PELECYPODS: WEISBORD 373 posterodorsal margin of the left valve being more concave than on the respective valves of S. operculata. Range and distribution—Recent in the Western Atlantic from the Gulf of Mexico ? to Brazil. Tagelus plebeius (Solander) Pl. 54, figs. 1-4 1685. Chama angustior, etc., Lister, Historiae sive synopsis methodicae conchy- liorum et tabularum anatomicarum, pl. 421, fig. 265. 1786. Solen plebejus Solander, A Catalogue of the Portland Museum, pp. 42, 101, 156. 1794. Solen gibbus Spengler, Skrivt. Nat. Selsk. Copenhagen, vol. 3, p. 104. 1795. Solen guineensis Chemnitz, Syst. Conchylien-Cabinet, vol. 11, p. 202, pl. 198, fig. 1937. 1817. Siliguaria notata Schumacher, Essai d’un nouveau systéme des habita- tions des vers testacés, Copenhagen, p. 129, pl. 7, figs. 2-3. 1817. Solen guineensis Chemnitz, Dillwyn, A Descriptive Catalogue of Recent Shells, p. 62. 1818. Solen caribaeus Lamarck, An. sans Vert., vol. 5, p. 454. 1819. Solen declivis Turton, A Conchological Dictionary of the British Is- lands, p. 164, fig. 80. 1822. Psammobia declivis (Turton), Conchylia Dithyra Insularum Brtitanni- carum, p. 91. 1823. Solen plebeius Solander, Dillwyn, Index Conch., ed. 3, p. 22. 1827. Solecurtus caribaeus (Lamarck), Blainville, Dictionnaire des sciences naturelles, vol. 49, p. 420. 1831. Solecurtus caribaeus Blainville, Conrad, American Marine Conchology, p. 22, pl. 4, fig. 3. 1835. Solen guineensis Chemnitz, Wood, General Conchology, p. 129. 1841. Solecurtus caribaeus (Lamarck), Gould, A Report on the Invertebrates of Massachusetts, p. 30. 1843. Solecurtus caribaeus (Lamarck), Mighels, Boston Jour. Nat. Hist., vol. 4, p. 312. 1843. Solen caribaeus Lamarck, De Kay, Zoology of New York, pt. 5, p. 243, fig. 302. 1846. Cultellus caribaeus (Lamarck), Conrad, Amer. Jour. Sci., ser. 2, vol. 1, p. 404. 1856. Siliquaria gibba (Spengler), H. & A. Adams, The Genera of Recent Mollusca, vol. 2, p. 347, Not pl. 93, figs. 5, 5a. 1858. P [anopea] caribaeus Emmons, Report on the North Carolina Geological Survey, p. 299, fig. 228a. 1860. Siliquaria caribaea (Blainville), Holmes, Post-Pleiocene Fossils of South Carolina, p. 54, pl. 8, fig. 14. 1862. Siliguaria carolinensis Conrad, Acad. Nat. Sci. Philadelphia, Proc., vol. 14, p. 571 (part). 1864. Solen gibbus Spengler, Krebs, The West Indian Marine Shells, p. 112. 1868. Siliquaria gibba (Spengler), Conrad, Amer. Jour. Conch., vol. 3, pt. 3, Appendix, No. 9, p. 23. 1870. Tagelus gibbus (Spengler), Dall, Boston Soc. Nat. Hist., Proc., vol. 13, p. 251. 1871. Siliquaria gibba (Spengler), Coues, Acad. Nat. Sci. Philadelphia, Proc., vol. 23, pp. 138-139. 1874. Solecurtus caribaeus (Lamarck), Sowerby, [in] Reeve, Conch. Icon., pl. 4, sp. 21a, 21b. 1878. Solen gibbus Spengler, Mérch, Catalogue of West-India Shells, p. 14. 374 1887. 1889. 1889. 1891. 1892. 1898. 1900. 1901. 1906. 1906. 1914. 1919. 1920. 1924. 1927. 1929. 1929. 1934. 1935. 1936. 1936. 1937. 1938. 1940. 1940. 1942. 1943. 1944. 1946. 1949. 1951. 1952. BuLLeTINn 204 Tagelus caribaeus (Lamarck), Fischer, Manuel de Conchyliologie et de Paléontologie Conchyliologique, p. 1107, pl. 22, fig. 9. Tagelus gibbus (Spengler), Dall, U. S. Nat. Mus., Bull. 37, p. 58, pl. 55, fig. 3; pl. 56, fig. 3. Solecurtus gibbosus (Spengler), Simpson, Davenport Acad. Nat. Sci., Proc., vol. 5, p. 71. Tagelus gibbus (Spengler), Baker, Acad. Nat. Sci. Philadelphia, Proc., vol. 43, p. 48. Tagelus gibbus (Spengler), Singley, Geol. Sur. Texas, Fourth An. Rept, p. 328. Tagelus gibbus (Spengler), Dall, Acad. Nat. Sci. Philadelphia, Proc., vol. 50, pp. 59, 60, 61. Tagelus gibbus (Spengler), Dall, Wagner Free Inst. Sci., Trans., vol. 3, pt. 5, p. 983. Tagelus gibbus (Spengler), Dall and Simpson, U. S. Fish Com., Bull. vol. 20 for 1900, pt. 1, p. 475. Tagelus gibbus (Spengler), Clark, Maryland Geol. Sur., Pliocene and Pleistocene, p. 200, pl. 57, figs. 1-4. Solecurtus (Tagelus) gibbus (Spengler), Bose, Inst. Geol. México, Bol. No: 22) p: 83) pl 12° fig: 2: Tagelus gibbus (Spengler), Henderson and Bartsch, U. S. Nat. Mus., Proc., vol. 47, No. 2055, p. 413. Tagelus gibbus (Spengler), Gardner and Aldrich, Acad. Nat. Sci. Philadelphia, Proc., vol. 71, p. 19. Tagelus gibbus (Spengler), Maury, Bull. Amer. Paleont., vol. 8, No. 34, pp. 126-127. Tagelus gibbus (Spengler), Mansfield, Florida State Geol. Sur., Fifteenth An. Rept., list following p. 28. Tagelus gibbus (Spengler), Wood, Nautilus, vol. 41, No. 1, p. 15. Tagelus gibbus (Spengler), Johnson, Nautilus, vol. 42, No. 3, p. 84. Tagelus gibbus (Spengler), Richards, Nautilus, vol. 43, No. 2, p. 64. Tagelus gibbus (Spengler), Johnson, Boston Soc. Nat. Hist., Proc., vol. 40, No. 1, p. 54. Tagelus gibbus (Spengler), Richards, Jour. Paleont., vol. 9, No. 3, p. 257. Tagelus gibbus (Spengler), Lermond, Check List of Florida Marine Shells, Gulfport, p. 20. Tagelus gibbus (Spengler), McLean, Soc. Cubana Hist. Nat. “Felipe Poey,’ Mem., vol. 10, No. 1, p. 42. Tagelus gibbus (Spengler), Smith, East Coast Marine Shells, p. 64, pl. 25, fig. 4. Tagelus gibbus (Spengler), Richards, Geol. Soc. Amer. Bull. vol. 49, p. 1292. Tagelus gibbus (Spengler), Smith, World-wide Sea Shells, p. 116, fig. 1518. Tagelus gibbus (Spengler), Stenzel, Nautilus, vol. 54, No. 1, p. 21. Tagellus gibbus (Spengler), Jaume and Pérez Farfante, Soc. Cubana Hist. Nat. “Felipe Poey,” Mem., vol. 16, No. 1, p. 40. Tagelus gibbus (Spengler), Jacobson, Nautilus, vol. 56, No. 4, p. 142. Tagelus gibbus (Spengler), Hackney, Nautilus, vol. 58, No. 2, p. 59. Tagelus gibbus (Spengler), Stewart, Nautilus, vol. 60, No. 1, p. 19. Tagelus (Tagelus) gibbus (Spengler), Lange de Morretes, Mus. Para- naense, Arq., vol. 7, art. 1, p. 43. Tagelus gibbus (Spengler), McLean, New York Acad. Sci. Scientific Survey of Porto Rico and the Virgin Islands, vol. 17, pt. 1, pp. 103-104, pl. 21, fig. 6. Tagelus gibbus (Spengler), Pulley, Texas Jour. Sci., vol. 4, No. 2, p. 184, pl: 12; fig. 9: VENEZUELAN CENOZOIC PELECYPODS: WEISBORD 375 1953. Tagelus (Tagelus) gibbus (Spengler), Haas, Fieldiana-Zoology, vol. 34, No. 20, p. 203. 1954. Tagelus plebeius (Solander), Abbott, American Seashells, p. 440, pl. 30d. 1955. Tagelus plebeius (Solander), Perry and Schwengel, Marine Shells of the Western Coast of Florida, p. 87, pl. 17, fig. 110. 1956. Tagelus plebeius (Solander), Parker, Amer. Assoc. Petrol. Geol., Bull., vol. 40, No. 2, pp. 309, 318 (as. T. gibbus), 319, 326, 371, pl. 3, figs. 7a, 7b. 1958. Tagelus caribaeus (Lamarck), Keen, Sea Shells of Tropical West Ameri- ca, p. 192. 1958. Tagelus plebeius (Solander), Olsson and McGinty, Bull. Amer. Paleont., vol. 39, No. 177, p. 22. 1959. Tagelus plebeius (Solander), Parker, Amer. Assoc. Petrol. Geol., Bull., vol. 43, No. 9, pp. 2119, 2161, 2166, pl. 1, II, figs. 8a, 8b. 1961. Tagelus plebeius (Solander), Moore, Gulf Research Repts., vol. 1, No. 1, pp. 16, 47. 1961. Tagelus plebeius (Solander), Warmke and Abbott, Caribbean Seashells, p. 203, pl. 42n. The Recent Higuerote shell referred to this species is moder- ately large, thin, oblong, and subequilateral. Postumbonal portion of shell a little narrower than the preumbonal by reason of a slight downwarp of the posterodorsal margin behind the beak. Posterior end subangularly rounded, anterior end shallowly rounded; basal margin truncate, sometimes hardly embayed behind the middle, the embayment coinciding with the broad feeble radial depression on the lower half of the valve; anterodorsal margin with a slight slope. Beak low, nearly central. Posterior area delimited by a low ob- scure radial ridge extending from the umbo to the ventral margin; there is also a faint radial swelling delimiting the anterior submargin from the disk. Hinge with two slender projecting cardinals in each valve. Anterior adductor impression elongated, subtrigonal, and tapering upward, the posterior impression broadly pyriform, both impressions high. Pallial line remote from the ventral margin. Pal- lial sinus large, extending horizontally a little beyond the median line of the valve, the apex of the sinus rounded. Surface sculptured by irregular concentric growth lines. Periostracum dull brown, puckered by fine irregular concentric wrinkles and rather widely spaced thin irregular radial wrinkles at the base. Color white on the exterior and interior. Dimensions——Specimen B492a, right valve, length 51.5 mm.; height 18.7 mm.; thickness 5.2 mm. Specimen B492b, left valve (broken away posteriorly and basally) length 37.7 mm.; thickness 4 mm. 376 BuLLeTIn 204 Locality.—On beach, southeast of Higuerote, State of Miranda. Six specimens including five right valves and one left valve. Remarks.—The Higuerote shell has much the same configura- tion as the late Miocene to Recent east American T. (Mesopleura) divisus (Spengler), but there is no indication whatsoever of the characteristic internal radial rib of that species. The west American analogue of T. plebeius is the Pleistocene to Recent T. affims (C. B. Adams) (see Turner, 1956, Occas. Papers on Mollusks, vol. 2, No. 20, p. 29, pl. 19, figs. 17-18), but according to the original descrip- tion given by Adams there is one tooth in the left valve and two in the right, whereas on T. plebeius there are two teeth in each valve. Range and distribution—tThe chronologic range of T. plebews is late Miocene to Recent. The living shell ranges from Cape Cod, Massachusetts, to Brazil. In the Pleistocene it is recorded from Massachusetts, Maryland, South Carolina, Florida, and Louisiana. In the Pliocene it is reported from North Carolina, South Carolina, Florida, and México. In the upper Miocene it occurs in Virginia. SOLENIDAE Solen (Solena) obliquus Spengler Pl. 54, figs. 5, 6 1794. Solen obliquus Spengler, Skrivt. Nat. Selsk. Copenhagen, vol. 3, p. 92. 1818. Solen ambiguus Lamarck, An. sans Vert., vol. 5, p. 452. 1828. oe obliquus Spengler, Wood, Index Testaceologicus, Supplement, pl. De fre 72 1864. Solen obliquus Spengler, Krebs, The West Indian Marine Shells, p. 112. 1868. Solena obliquus (Spengler), Conrad, Amer. Jour. Conch., vol. 3, pt. 3, Appendix, No. 9, p. 27. 1874. Solen ambiguus Lamarck, Sowerby, [in] Reeve, Conch. Icon., vol. 19, pl. 5, sp. 21b, c. 1878. Solena obliqua Spengler, Arango y Molina, Contribucién a la Fauna Malacolégica Cubana, p. 239. 1878. Solen obliquus Spengler, Mérch, Catalogue of the West-India Shells, p. 14. 1884. Solena obliqua (Spengler), Tryon, Structural and Systematic Conchology, vol. 3, p. 130, pl. 106, fig. 7. 1887. Solen (Hypogella) ambiguus Lamarck, Fischer, Manuel de Conchyliologie et de Paléontologie Conchyliologique, p. 1110. 1899. Solen (Solena) obliquus Spengler, Dall, U. S. Nat. Mus., Proc., vol. 22, No. 1185, p. 107. 1900. Solen (Solena) obliquus, Spengler, Dall, Wagner Free Inst. Sci. Trans., vol. 3, pt. 5, pp. 949, 954. . 1901. Solen (Solena) obliquus Spengler, Dall and Simpson, U. S. Fish Com., Bull., vol. 20 for 1900, pt. 1, p. 475. 1917. Solen (Solena) obliquus Spengler, Maury, Bull. Amer. Paleont., vol. 5, No. 29, p. 394. 1925. Solen (Solena) obliquus Spengler, Maury, Bull. Amer. Paleont., vol. 10, No. 42, p. 267, pl. 18, fig. 12. VENEZUELAN CENOzOIC PELECYPODS: WEISBORD 377 1930. Solen obliquus Spengler, Stewart, Acad. Nat. Sci. Philadelphia, Spec. Publ. No. 3, p. 290. 1932. Solen ambiquus Lamarck, Lamy, Mus. Nat. Hist. nat. Paris, Bull., vol. 4, No. 4, p. 431. 1951. Solen obliquus Spengler, McLean, New York Acad. Sci. Scientific Survey of Porto Rico and the Virgin Islands, vol. 17, pt. 1, p. 109, pl. 22, fig. 9. 1958. Solen (Solena) obliquus Spengler, Keen, Sea Shells of Tropical West America, p. 206. 1960. Solen (Solena) obliquus Spengler, Olsson, Panamic-Pacific Pelecypoda, p. 420. 1961. Solen obliquus Spengler, Warmke and Abbott, Caribbean Seashells, p. 203, pl. 433. Shell solid, elongate-rectangular, the long posterodorsal margin parallel with the ventral margin, the short posterodorsal margin somewhat sloping; anterior end obliquely subtruncate, longer below, rounded at the corner with the base, angulated at the corner with the anterodorsal margin, the posterior end squarely truncated. Beak low, situated one-sixth the length of the shell from the anterior end. Left valve with one cuneate cardinal tooth which is bordered be- hind by a deep narrow furrow. Anterior muscle scar horizontally disposed, elongate-reniform, placed under the beak, the posterior scar suboval, lying about three-eighths the length of the shell from the posterior end. Pallial line long, subparallel with the ventral mar- gin but slightly descending, joined to the base of the anterior muscle scar by a short vertical line, and joined to the apex of the short pallial sinus which lies below, and does not project beyond the posterior muscle scar. Anterior half of valve sculptured by rude hori- zontal growth lines which are squared off and continue vertically at the anterior end; extending from the umbo obliquely toward the posterior of the valve are a series of faint tan rays, the lowest of which divides the valve obliquely in two; the horizontal growth lines on the anterior half of the shell abut against the lowest ray, veering therefrom abruptly, nearly vertically, and slightly arcuately to the dorsal margin. Periostracum brown, and wrinkled to conform with the growth lines on the surface of the shell. The color of the two Higuerote specimens is off-white both within and without. Dimensions.—Specimen B489a, left valve, length 90 mm.; height 23 mm.; thickness 5 mm. Locahty.—Recent on beach southeast of Higuerote, State of Miranda. Two left valves. Remarks.—The Eastern Pacific analogue of S. obliquus is the 378 BuLLeTin 204 Recent S. rudis C. B. Adams (see Turner, 1956, p. 83, pl. 19, figs. 1-2) which ranges from Costa Rica to Peru. However, the ratio of height to length is 1 to 4-1/2 on S. rudis, 1 to 4 on S. obliquus; fur- thermore, the beak is one-seventh of the length of the valve from the anterior extremity on S. rudis, one-sixth on S. obliquus. Range and distribution.—Solen obliquus Spengler is recorded from Miocene to Recent. The living shell is Caribbean in habitat, extending from Cuba and Puerto Rico to northern South America. Internal molds of a form assumed to be this species were collected by me in 1925 from a limestone of Pleistocene or Pliocene age west of Tunkas, in the State of Yucatan, México. In the Pliocene, S. obliquus has been found at Matura, Trinidad, and in the Miocene, a fragment of a shell closely resembling the Recent S. obliquus, was collected by Maury in the Rio Cana at Caimito, Dominican Re- public. Solen species Pl. 54, figs. 7-10 The following description is reconstructed from a number of fragments. Shell moderately thin but strong, subcylindrical, narrow and much elongated, the length estimated at 4-1/2 to 5 times the height, the valves tapering slightly toward the posterior end. Dorsal margin long and straight, ventral margin shallowly arcuate, posterior end hardly rounded to subtruncate, anterior end not seen. On none of the fragments is the hinge conserved, but it is inferred to be terminal. Posterior muscle scar broadly trigonal, the anterior scar narrow, elongated, slightly arcuate, and more or less parallel with the dorsal margin. Pallial line distant from the base, long, subparallel with the ventral margin but ascending a little from the front to the apex of the pallial sinus which it joins. Pallial sinus short, projecting hori- zontally, the upper limb of the sinus joined to the posterior muscle scar, the apex not extending beyond the midline of the scar. An- other line, representing the dorsal edge of the body of the animal, runs irregularly parallel with the dorsal margin; this line joins the upper anterior angle of the posterior scar, but runs above the an- terior muscle scar, possibly joining the latter at its anterior tip. Surface sculptured by fine growth lines, the lines on the anterior half of the valve conforming with the outline of the valve; dividing the VENEZUELAN CENOzOIC PELECYPODS: WEISBORD 379 valve obliquely there is a hardly discernible division, descending from front to rear, along which the lines of growth veer abruptly, the upper lines vertically arcuate to the dorsal margin, the lower lines divaricating horizontally. Dimensions.—Specimen 1490a, posterior portion of left valve, length 55 mm.; height 13 mm.; thickness 5.4 mm. Specimen T490a, posterior portion of right valve, length 42 mm.; height 14.3 mm.,; thickness 6 mm. Localities —Lower Mare formation at W-13, on hillside above west bank of Quebrada Mare Abajo. Four fragments. Lower Mare formation, in small stream 100 meters west of Quebrada Mare Abajo. Two fragments. Upper Mare formation, in stream 250 meters south- southwest of the mouth of Quebrada Las Pailas. Four fragments. Remarks.—The Cabo Blanco specimens are too fragmentary to be definitively compared. The Pliocene to Recent S. viridis Say, among other slight differences, is smaller and thinner. The Recent S. tehuelcus d’Orbigny from Brazil and Argentina is also similar, but it too is a more fragile shell, as is the Miocene to Recent S. rosaceus Carpenter from west America. Solecurtus cumingianus (Dunker) Pl. 54, figs. 11, 12 1861. Macha cumingiana Dunker, Zool. Soc. London, Proc. for 1861, p. 425. 1868. Macha Cumingiana Dunker, Conrad, Amer. Jour. Conch., vol. 3, pt. 3, Appendix, No. 9, p. 24. 1881. ? Tagelus lineatus Gabb, Acad. Nat. Sci. Philadelphia, Jour., ser. 2, vol. 8, p. 370, pl. 47, fig. 71. 1889. Solecurtus (Macha) Cumingiana (Dunker), Dall, U. S. Nat. Mus., Bull. 37;0p2170! 1898. Mactra multilineata Dall, Wagner Free Inst. Sci., Trans., vol. 3, pt. 4, p. 923. pl. 28, fig. 15. (Mactra by typographical error). 1900. Psammosolen Cumingianus (Dunker), Dall, Wagner Free Inst. Sci., Trans., vol. 3, pt. 5, p. 961; pt. 4, pl. 28, fig. 15 (1898). 1920. Psammosolen (Azor) cumingianus (Dunker), Maury, Bull. Amer. Paleont., vol. 8, No. 34, pp. 127-128. 1934. Psammosolen cumingianus (Dunker), Johnson, Boston Soc. Nat. Hist., Proc., vol. 40, No. 1, p. 55. 1936. Psammosolen (Macha) cumingianus (Dunker), Lermond, Check List of Florida Marine Shells, Gulfport, p. 20. 1949. Solecurtus cumingianus (Dunker), Lange de Morretes, Mus. Paranaense, Arq,., vol. 7, art. 1, p. 43. 1950. Solecurtus cumingianus (Dunker), Hertlein and Strong, Zoologica, vol. 35, pt. 4, No. 19, p. 229. 1952. Psammosolen cumingianus (Dunker), Pulley, Texas Jour. Sci. vol. 4, No. 2, p. 184. 1953. Solecurtus cumingianus (Dunker), Olsson and Harbison, Acad. Nat. Sci. Philadelphia, Mon. No. 8, p. 137. 1954. Solecurtus cumingianus (Dunker), Abbott, American Seashells, pp. 444- 445. 380 BuLtetin 204 1956. Solecurtus cumingianus (Dunker), Parker, Amer. Assoc. Petrol. Geol. Bull., vol. 40, No. 2, pp. 309, 371. 1958. Solecurtus cumingianus (Dunker), Olsson and McGinty, Bull. Amer. Paleont., vol. 39, No. 177, p. 22. 1961. Solecurtus cumingianus (Dunker), Warmke and Abbott, Caribbean Sea- shells, p. 203, pl. 43h. The following description pertains to the right valve. Shell moderately thin and convex, narrowly oblong, the length about 2-1/2 times the height. Dorsal and ventral margins perfectly parallel, the ends of the valve shallowly rounded. Anterior submargin delimited by a broad radial swelling or ridge, the middle of the disk with a broad but feeble depression near the base. Beak low, situated at the anterior third, slightly opisthogyrate. Hinge of right valve with two cardinals seemingly united above, the anterior cardinal nearly vertical, the posterior one oblique, the socket between them deep and obliquely subelliptical. Anterior adductor impression pear- shaped, the posterior subangularly cylindrical. Pallial line remote from ventral margin, joining the base of the anterior adductor im- pression. Pallial sinus long, linguiform, extending horizontally for- ward for about two-thirds the length of the valve from the posterior end, the lower line of the sinus confluent with the pallial line a little behind the middle of the valve, the upper line joining the inner angle of the posterior adductor impression. Surface sculptured predominantly by fine and coarse irregular concentric striae or wrinkles, the striae crossing several disjointed thin radial riblets or wrinkles on the posterior submargin, the riblets descending from below the umbonal region to near the posterior end; similar but obsolescent radial threads are present on the lower half of the anterior submargin; diverging from their apex at the beak are two faint linear impressions which extend to the ventral margin. The posterior half of the right valve is scored by widely spaced, sharp, zigzag to vermicular grooves slanting down from the dorsal side toward the front; under a lens shorter, closer, but less continuous grooves are seen on the anterior half of the valve, slanting down toward the rear. Apparently the pattern of these grooves is variable as on the anterior half of another Cabo Blanco specimen the grooves form a connected series of small chevron-like triangles. Dimensions——Specimen 149la, right valve, length 61 mm.; height 24.7 mm.; thickness 8.1 mm. VENEZUELAN CENOZzOIC PELECYPODS: WEISBORD 381 Localities —Lower Mare formation at W-13, on hillside above west bank of Quebrada Mare Abajo. One right valve, Upper Mare formation at W-14, on hillside above west bank of Quebrada Mare Abajo. One specimen, the posterior half of a mght valve. Playa Grande formation (Maiquetia member) at W-26, in Quebrada Las Bruscas approximately 125 meters upstream from its junction with Quebrada Las Pailas. One specimen, the anterior half of a right valve. Remarks.—Dall listed S. lineatus (Gabb) as synonymous with S. cumingtanus (Dunker), and although the two are alike, the type of S. imeatus is a thinner shell than S. cumingianus, and there is a more pronounced radial depression across the middle of the valve than on S. cumingianus. Range and distribution —Solecurtus cumingianus (Dunker) is reported as ranging from Pliocene to Recent. The living shell ex- tends from North Carolina, U.S.A., to Brazil. The fossil is recorded from the Pliocene of Florida and Costa Rica. MACTRIDAE Mactra (Mactrellona ?) iheringi (Dall) Plis55>:figs..15,2 1897. Mactrella iheringi Dall, Nautilus, vol. 10, No. 11, pp. 121-123. 1902. Macnee theringi Dall, U. S. Nat. Mus., Proc., vol. 24, No. 1264, p. 510, pl. 32, fig. 8. 1915. Mactrella iheringi Dall, Nautilus, vol. 29, p. 62. 1917. Mactra (Mactrella) iheringi Dall, Lamy, Jour. Conchyl., vol. 63, p. 265. 1949. Mactrella iheringi Dall, Lange de Morrestes, Mus. Paranaense, Arq., vol. 7, art. 1, p. 41. A single worn and broken left valve is referred to this species. The shell is thin, convex, large, broadly oval, bluntly pointed pos- teriorly, and with a slight gape in the ventral margin near the pos- terior end. The pallial sinus is long and sublinguiform, extending horizontally to a little beyond the median line of the valve, the apex of the sinus rounded. The exterior is straw-colored with a band of faded gray around the margin, the gray reflected through to the interior, Dimensions.—Specimen B554a, left valve, length 52 mm.; thick- ness 21 mm. Locality.—Recent, on beach southeast of Higuerote, State of Miranda. One left valve, broken away at the umbo. 382 BuLvetin 204 Remarks.—Dall’s original description is as follows: Shell thin, white, inflated, with small and prominent beaks, externally with fine concentric, and a few irregular, radial lines, and a silky-yellowish epidermis, the beaks median, smooth, with an obsolete posterior keel, the lunular region widely and deeply impressed; hinge of the subgenus, the pallial sinus angular, reaching to the vertical of the beaks. Lon. 65.0; alt. 52.0; diam. 32.0 mm. Range and distribution—Recent, northern coast of South America to Brazil. Mulinia cleryana (d’Orbigny) Pl. 55, figs. 3-6 1846. Mae Cleryana d’Orbigny, Voyage l’Amérique Méridionale, vol. 5, pt. 3, p. 510. 1852. Mactra guadelupensis Récluz, Jour. Conchyl., ser. 2, vol. 3, p. 249, pl. 10, figs. 4-4’. 1853. Mactra guadelupensis Récluz, Petit, Jour. Conchyl., ser. 2, vol. 4, p. 414. 1856. Mulinea portoricensis Shuttleworth, Jour. Conchyl., ser. 2, ‘vol. 5, pp. 174- 75: 1856. Mulinea portoricensis Shuttleworth, H. & A. Adams, The Genera of Recent Mollusca, vol. 2, p. 380. 1858. Mactra guadelupensis Récluz, Beau, Ext. Rev. Coloniale, p. 26. 1864. Mactra donacaeformis Krebs (non Gray), and M. juadclapente Récluz, Krebs, The West Indian Marine Shells, p. 105. 1864. Mactra guadeloupensis Récluz, Krebs, The West Indian Marine Shells, p. 105. 1868. Mulinea portoricensis Shuttleworth, Conrad, Amer. Jour. Conch., vol. 3, pt. 3, Appendix, No. 10, p. 31. 1868. Mactra guadelupensis Récluz, Conrad. Amer. Jour. Conch., vol. 3, pt. 3, Appendix, No. 10, p. 32. 1868. Trigonella Guadelupensis (Récluz), Conrad, Amer. Jour. Conch., vol. 3, pt. 3, Appendix, No. 10, p. 37. 1873. Gnathodon guadelupensis (Récluz), Sowerby, [in] Reeve, Conch. Icon., vol. 19, pl. 1, sp. 2. 1873. Gnathodon Cantrainei Récluz (MSS), Sowerby, [in] Reeve, Conch. Icon., vol. 19, pl. 1, sp. 3. 1883. Gnathodon Cantrainei Récluz, Gundlach, Soc. Espafiola Hist. Nat. An., vol. 12, pp. 280, 322. 1884. Mactra portoricensis (Shuttleworth), Weinkauff, Syst. Conchylien- Cabinet, p. 30, pl. 10, figs. 3-4. 1884. Mactra guadelupensis Récluz, Weinkauff, Syst. Conchylien-Cabinet, p. 33, pl. 11, figs. 1-3. 1894. Mulinia guadelupensis (Récluz), Dall, U. S. Nat. Mus., Proc. vol. 17, No. 988, pp. 104-105. 1894. Mulinia guadelupensis (Récluz), Dall, Nautilus, vol. 8, No. 3, p. 27. 1917. Mulinia guadelupensis (Récluz), Lamy, Jour. Conchyl., ser. 4, vol. 17 (63), pp. 341-342. 1946. Mulinia guadeloupensis (Récluz), Stewart, Nautilus, vol. 60, No. 1, yary Ie 1949. Mulinia guadeloupensis (Récluz), Lange de Morretes, Mus. Paranaense, Arq., vol. 7, art. 1, p. 40. 1961. Mulinia portoricensis Shuttleworth, Warmke and Abbott, Caribbean Sea- shells, p. 204, pl. 43d. VENEZUELAN CENOZOIC PELECYPODS: WEISBORD 383 Shell of medium size and thickness, inflated, subequilaterally triangular in outline, with a narrow but fairly sharp posterior car- ination bounding the rather wide posterior area, and with a faint anterior angulation bounding the wide lunular area. Dorsal margins sloping about equally, anterior end subangularly rounded, ventral margin shallowly subarcuate to subsinuous except at the rear where it is obliquely subtruncate to hardly embayed, posterior corner slightly attenuated, posterior end short and obtusely angulated. Disk with a faint radial sulcus or depression in front of the posterior carination. Posterior submargin with one or two feeble ridgelets diverging from the umbo, the after ridgelet bounding the large sub- elliptical escutcheonal area which is twice as wide as the submargin proper. Lunule not defined, the greater lunular area or submargin elliptical, bounded by the faint angulation descending from the umbo. Umbo full, rather sharply divergent. Beaks high, subcentral, acutely downcurved, directed slightly forward at the tip, the dorsal margins projecting beyond them to form a ledge which keeps the beaks well apart when the valves are closed; on the ledge there is a somewhat asymmetrical caret-like area, the tip of the beak bisecting the apex of the caret, the sides of the caret defined by a faint groove on the right valve, the posterior side of the caret on the left valve depressed and bordered by a small elevated ridge. External surface shiny, sculptured by concentric striae and fine wrinkles, exhibiting here and there stronger grooves representing periods of arrested growth, the striae finer, closer, and more regular on the escutcheonal and lunular areas. In addition, the disk is seen under a lens to be marked by numerous short irregular vermicular and divaricating radii which impart a shagreen effect to the surface. Hinge equipped with strong lateral teeth, the grooves of the right valve receiving the elevated teeth of the left. Anterior and posterior cardinal teeth of the right valve laminar, not coalescent above, diverging at a little less than 90 degrees, the anterior cardinal oblique to the dorsal margin, the posterior vertical. Resilium of right valve deeply sunken, pear-shaped, overhung by the dorsal margin. Cardinals of left valve fused into a tentlike process, the posterior arm of the process nearly vertical, the anterior divergent, the process with a small triangular pit below it; there is a thin accessory lamina proxi- mate to, and parallel with the posterior arm, and after that is the 384 Buttetin 204 sunken resilium. Interior glossy. Adductor impressions somewhat de- pressed, the anterior semi-elliptical, the posterior suboval. Pallial line parallel with the margin, the pallial sinus low (about a fourth of the altitude of the valve in from the margin), linguiform, join- ing the pallial line in an acutely rounded end, the upper line of the sinus horizontal and somewhat sinuous, the apex of the sinus nar- rowly rounded and projecting to about two-fifths the width of the valve in from the posterior end. Most of the shells are cream and gray-black on the surface, the gray-black occurring as concentric bands on the lower half of the valve and on the sides of the umbonal area; the interior is white, with the darker tone of the exterior re- flected through. Dimensions——Specimen B545a, right valve, length 23 mm.; height 18.3 mm.; thickness 5.2 mm. Specimen B545b, left valve, length 24.2 mm.; height 21 mm.; thickness 6.9 mm. Largest speci- men, a left valve, length 32.1 mm.; height 26.9 mm.; thickness 10.1 mm. Locahty.—Recent, on beach southeast of Higuerote, State of Miranda. Forty-one specimens including twenty-four left valves and seventeen right valves. Remarks.—The Venezuelan shell is identical to the species labeled, in one collection or another as M. cleryana (d’Orbigny), M. guadelupensis (Récluz), or M. portoricensis Shuttleworth. The synonymy presented in this work follows that of Dall and Lamy who combine M. guadelupensis, M. portoricensis, M. cantrainei (Récluz), and M. donacaeformis Krebs (not Gray). Warmke and Abbott apply the name M™. portoricensis to the Puerto Rican form, and this does seem to be a little different than the original illustration of M. guwadelupensis from Guadeloupe Island in the Antilles. Nevertheless, the species is a variable one, and if all the forms mentioned are indeed synonymous, M. cleryana has priority, though it was not figured by D’Orbigny. The original description of M. cleryana is as follows: N.° Mactre de Cléry, Mactra Cleryana, d’Orb., 1846 M. testa triangulari, compressa, tenui, concentricé, substriata, alba, epidermide fuscescente; latere buccali brevi, angulato; latere anali externé, subcarinato. Dimensions: Longueur, 28 mill. Par rapport 4 la longueur: largeur 79/100; épaisseur 53/100; longueur de la région anale, 58/100; angle apical, 98 degrés. Coquille triangulaire, assez comprimée, mince, pourvese de quelques stries fines d’accroissement, et d’un épiderme trés-mince, lui-méme strié, presque équi- VENEZUELAN CENOzOIC PELECYPODS: WEISBORD 385 latérale; le céte anal est plus long, anguleux et pourvu en dehors d’une caréne assez prononcée. Le cote buccal est arrondi et étroit. Elle est propre aux environs de Rio de Janeiro (Brésil), ot elle a été recueille par M. Cléry, et nous a été communiquée par M. Petit de la Saussaye. Range and distribution.—Living, West Indies to Brazil. Labiosa (Raeta) aff. plicatella (Lamarck) PIRSDaIeSte tao 1818. Lutraria plicatella Lamarck, An. sans Vert., vol. 5, p. 470. 1822. Lutraria canaliculata Say, Acad. Nat. Sci. Philadelphia, Jour., ser. 1, vol. 2, p. 310. 1828. Mactra campechensis Gray, [in] Wood, Supplement to the Index Testa- ceologicus, fig. 3. 1831. mse: canaliculata Say, Conrad, American Marine Conchology, p. 46, pl. 10, fig. 1. 1835. Lutraria plicatella Lamarck, Deshayes, An. sans Vert., vol. 6, p. 93. 1837. Lutraria campechensis Gray, Loudon’s Mag. Nat. Hist., new ser., vol. 1, Das 5e 1842. Lutraria plicatella Lamarck and L. canaliculata Say, Hanley, An Illus- trated and Descriptive Catalogue of Bivalve Shells, p. 27. 1843. Lutraria canaliculata Say, De Kay, Nat. Hist. New York Zool., Mollusca, p. 232, pl. 31, fig. 298. 1846. Lavignon papyracea d’Orbigny, Voyage l’Amérique Meéridionale, p. 527. Not of Chemnitz, fide Lamy, 1917. 1853. Raéta campechensis Gray, An. Mag. Nat. Hist., ser. 2, vol. 11, p. 43. 1854. Mactra canaliculata (Say), Reeve, Conch. Icon., vol. 8, Mactra, sp. 122. 1856. ads canaliculata (Say), Chenu, Manuel de Conchyliologie, vol. 2, p. 62, ig. 251. 1860. Labiosa canaliculata (Say), Holmes, Post-Pleiocene Fossils of South Caro- lina, p. 43, pl. 7, fig. 13. 1867. Raeta canaliculata (Say), Conrad, Amer. Jour. Conch., vol. 3, pt. 3, No. 10, Supplement, p. 41. 1871. Raeta canaliculata (Say), Coues, Acad. Nat. Sci. Philadelphia, Proc., vol. 23, p. 137. 1884. Labiosa (Raeta) canaliculata (Say), Tryon, Structural and Systematic Conchology, vol. 3, p. 161, pl. 110, fig. 25. 1889. Labiosa canaliculata (Say), Dall, U. S. Nat. Mus., Bull. 37, p. 64. 1889. Labiosa canaliculata (Say), Simpson, Davenport Acad. Nat. Sci., Proc., vol. 5, p. 72. 1892. Labiosa canaliculata (Say), Singley, Geol. Sur. Texas, Fourth An. Rept., p-4530: 1894. Labiosa canaliculata (Say), Dall, Nautilus, vol. 8, No. 3, p. 28. 1894. Labiosa (Raeta) canaliculata (Say), Dall, Malac. Soc. London, Proc., vol. 1, p. 212. 1895. Labiosa canaliculata (Say), Harris, Bull. Amer. Paleont., vol. 1, No. 3, p. 94. 1898. Labiosa (Raéta) canaliculata (Say), Dall, Wagner Free Inst. Sci., Trans., vol. 3, pt. 4, pp. 882, 907. 1903. Labiosa canaliculata (Say), Vanatta, Acad. Nat. Sci. Philadelphia, Proc., vol. 55, p. 757. 1913. Lutraria plicatella Lamarck, Lamy, Mus. Nat. Hist. nat. Paris, Bull., vol. 19, p. 347. 1914. Labiosa (Raeta) canaliculata (Say), Henderson and Bartsch, U. S. Nat. Mus., Proc., vol. 47, No. 2055, p. 413. 386 BuLLETIN 204 1917. Labiosa (Raeta) plicatella (Lamarck, Lamy, Jour. Conchyl., vol. 63, pp. 353-354, 363, pl. 7, fig. 6. 1920. Labiosa (Raeta) canaliculata (Say), Maury, Bull. Amer. Paleont., vol. 8, No. 34, pp. 137-138. 1923. Raeta canaliculata (Say), Clench, Nautilus, vol. 37, No. 2, p. 54. 1924. Labiosa canaliculata (Say), Mansfield, Florida State Geol. Sur., Fif- teenth An. Rept., list following p. 28. 1926. Labiosa (Raeta) canaliculata (Say), Weisbord, Nautilus, vol. 39, No. 3, pp. 82, 84. 1931. Anatina (Raéta) plicatella (Lamarck), Grant and Gale, San Diego Soc. Nat. Hist., Mem., vol. 1, pp. 407-408. 1934. Labiosa (Raeta) canaliculata (Say), Johnson, Boston Soc. Nat. Hist., Proc., vol. 40, No. 1, p. 56. 1936. Labiosa (Raeta) canaliculata (Say), Smith, Nautilus, vol. 49, No. 4, p. 135. 1936. Anatina (Raeta) canaliculata (Say), Lermond, Check List of Florida Marine Shells, Gulfport, p. 6. 1937. Anatina canaliculata (Say), Smith, East Coast Marine Shells, p. 65, pl. 26, fig. 3. 1938. Labiosa canaliculata (Say), Richards, Geol. Soc. Amer., Bull., vol. 49, p. 1292. 1940. Labiosa (Raeta) canaliculata (Say), Stenzel, Nautilus, vol. 54, No. 1, p. 21. 1946. Anatina (Raeta) canaliculata (Say), Jaume, Soc. Malac. “Carlos de La Torre,” Rev., vol. 4, No. 3, p. 102. 1949. Labiosa (Raeta) plicatella (Lamarck), Lange de Morretes, Mus. Paran- aense, Arq., vol. 7, art. 1, p. 41. 1950. Anatina (Raéta) canaliculata (Say), Hertlein and Strong, Zoologica, vol. 35, pt. 4, No. 19, p. 236. 1951. Labiosa (Raeta) plicatella (Lamarck), Rogers, The Shell Book, pp. 333 (as L. canaliculata Say), 499. 1953. Raeta canaliculata (Say), Olsson and Harbison, Acad. Nat. Sci. Phila- delphia, Mon. No. 8, p. 143. 1954. Labiosa plicatella (Lamarck), Abbott, American Seashells, p. 449, pl. 32q. 1955. Anatina (Raeta) plicatella (Lamarck), Perry and Schwengel, Marine Shells of the Western Coast of Florida, p. 90, pl. 18, fig. 117. 1961. Labiosa plicatella (Lamarck), Moore, Gulf Research Repts., vol. 1, No. 1, pp. 16, 47. 1961. Raeta plicatella (Lamarck), Olsson, Panamic-Pacific Pelecypoda, p. 332. The single specimen, consisting of an attached pair of valves, is broken and worn. The thin valves are plump anteriorly, com- pressed posterior to the middle. The surface is sculptured by smooth subregular concentric lirae, and the lirae and interspaces are covered by numerous fine vermicular radial threads. Dimensions.—Specimen Q463a, a broken doublet, height 26 mm.; thickness 18 mm. Localhtty—Playa Grande formation (Maiquetia member) at W-4, Quebrada Las Pailas. One imperfect doublet. Remarks.—The species cannot be identified with certainty but VENEZUELAN CENOzOIC PELECYPODS: WEISBORD 387 it is close to L. plicatella (Lamarck) as well as to the Miocene to Recent L. undulata (Gould) (see Hertlein and Strong, 1950, Zoo- logica, vol. 35, pt. 4, No. 19, pp. 235-236; and Olsson, 1961, Panamic- Pacific Pelecypoda, p. 332, pl. 56, figs. 6a, 6b). L. plicatella is dis- tinguished from L. undulata in having the beak somewhat nearer the posterior end. The Cabo Blanco fossil also superficially resembles the middle Miocene L. gardnerae Spieker (1922, Johns Hopkins Univ. Studies in Geol., No. 3, pp. 168-169, pl. 10, fig. 10) from Peru and Colombia, and the form referred to by Maury (1925, Bull. Amer. Paleont., vol. 10, No. 42, p. 331, pl. 31, fig. 9) as Thracia (Cyatho- donta) meridionalis (Guppy). According to Rutsch (1943, Natur- forschenden Gesellschaft Verhandl., vol. 54, p. 126, pl. 6, fig. 4) Maury’s Thracia meridionalis from the Springvale Miocene of Trini- dad is not the same as Raeta meridionalis Guppy (Agric. Soc. Trini- dad and Tobago, Soc. Paper No. 454, vol. 11, pl. 2, fig. 1) also from the Springvale Miocene of Trinidad but is, rather, the same as Thracia tristant Olsson (Bull. Amer. Paleont., vol. 9, No. 39, p. 383, pl. 20, fig. 3) from the middle Miocene of Costa Rica. In the same publication mentioned above, Rutsch (pp. 121-122, pl. 4, fig. 3) refers Raeta meridionalis Guppy to Anatina (Raeta) cf. undulata (Gould). Range and distribution—tThe living L. plicatella ranges from New Jersey, U.S.A., to Brazil. In the Pleistocene the species has been recorded from Texas, Louisiana, Florida, and South Carolina; in the Pliocene it occurs in Florida; and in the upper Miocene it has been reported from Texas (in the Galveston well) and Florida. MESODESMATIDAE Ervilia nitens venezuelana, new subspecies Pl. 55, figs. 9-14; Pl. 56, figs. 1-8 Shell small, longer than high, inequilateral, triangularly oval, compressed to scarcely inflated, the posterior end produced and slightly narrowed. Ventral margin gently rounded, anterior and posterior ends well rounded, the dorsal margins straightish, the anterodorsal margin a little shorter and descending at a slightly greater angle. Immature specimens are thin and translucent, adults relatively thin. Beak in front of the middle, full and projecting 388 BuLuetin 204 above the hinge on young specimens, subacute and appressed on mature specimens. Surface marked by delicate concentric linea- tions or fine subregular concentric fillets, crossed, on a number of examples, by numerous microscopic radii. On the holotype and several other specimens, the radial striae are more pronounced on the hinder part of the valve and ephemeral on the rest of the valve; on some specimens the radii are ephemeral throughout, and on others they cannot be seen at all. Interior glossy. On the right valve, the broad triangular chondrophore is bordered anteriorly by a strong protruberant cuneate cardinal tooth and posteriorly by a lower and smaller tooth; the lateral grooves of the right valve are delicate, the posterior the longer. The lunule of the right valve is rudimentary and linear, the escutcheon short and vestigial, the dorsal margin immediately aft of the escutcheon thin and slightly convex upward. On the left valve, the lunule is slightly depressed and wider than on the right valve; the escutcheon is flattish and hardly developed; the chondrophore is triangular with the base slightly convex upward; in front of the chondrophore there is a deeper, narrowly triangular socket which receives the right an- terior cardinal tooth of the right valve, the posterior edge of the socket developed as a sharp laminar ridge. The laterals of the left valve are absent or vestigial, the inner edge of the dorsal margins fitting into the grooves of the right valve. Muscle scars faint, the anterior irregularly pear-shaped, the posterior semicylindrical. Pal- lial sinus “U”-shaped, bluntly rounded in front, embayed more or less parallel with the long axis of the valve and extending forward to near the median vertical of the interior; the margin of the sinus obliquely truncates the pallial line posterior to the middle, the sinus margin continuing some distance below the cut-off of the pallial line. Dimensions.—Holotype (J449a), right valve, height 5.3 mm.; length 7.3 mm.; thickness 1.3 mm. Paratype (J449b), left valve, height 5.6 mm.; length 9 mm.; thickness 1.3 mm. Paratype (G449a), right valve, height 5.3 mm.; length 7.8 mm.; approx. thickness 1.2 mm, Paratype (G449b), young left valve, height 2.8 mm.; length 4.1 mm.; thickness 0.9 mm. Paratype (1449a), right valve, height 4.4 mm.; length 6.7 mm.; thickness 1 mm. Paratype (T449a), juvenile right valve, height 2.5 mm.; length 3.8 mm.; VENEZUELAN CENOzOIC PELECYPODS: WEISBORD 389 thickness 0.9 mm. Paratype (T453a), juvenile left valve, height 2.2 mm.; length 3.3 mm.; thickness 0.8 mm. Type locality—Lower Mare formation, in small stream 100 meters west of Quebrada Mare Abajo. Fifteen specimens including six right valves and nine left valves. Other localities —Lower Mare formation at W-13, on hillside above west bank of Quebrada Mare Abajo. Twenty-one specimens including fourteen right valves and seven left valves. Upper Mare formation at W-14, on hillside above west bank of Quebrada Mare Abajo. Four specimens including three right valves and one left valve. Upper Mare formation, in stream 250 meters south-southeast of mouth of Quebrada Las Pailas. Eighteen specimens including ten right valves and eight left valves. Playa Grande formation (Mai- quetia member) at W-23, north flank of Punta Gorda anticline. Twenty-nine specimens including fifteen left valves and fourteen right valves. Comparisons.—The new subspecies differs from EF. mtens nitens (Montagu) (See Maxwell Smith, 1937, East Coast Marine Shells, p. 66, pl. 26, figs. 10a, 10b) in being more compressed and a little more elongate. It differs from E. subcancellata E. A. Smith (1885, Voyage of H.M.S. Challenger, Zoology, vol. 13, pp. 80-81, pl. 6, figs. 2-2b) in lacking the thickening, which, rising beneath the umbo, descends to the inner side of the anterior muscle scar. Both E. nitens s. 5s. and EF. subcancellata are Recent Western Atlantic species. Ervilia antilleana, new species Pl. 56, figs. 9-12 Shell small, solid, compressed, suboval, inequilateral, the pos- terior end produced and slightly narrowed. Ventral margin shallowly rounded, the anterior and posterior ends well rounded, the antero- dorsal margin straight, the posterodorsal margin hardly convex on young specimens, straight to hardly concave on adults. Beak in front of the middle, the apex full and projecting a little above the hinge. Surface marked by fine concentric lineations or fillets, crossed on a few examples by closely spaced microscopic radial striae on the pos- terior part of the valve. Interior typically with three low broad di- verging ridges originating beneath the hinge, one of the ridges de- scending to the inner side of the anterior muscles scar, another to 390 BULLETIN 204 the inner side of the posterior muscle scar, and the third descending obliquely rearward to near the top of the pallial sinus. On a number of specimens, however, the interior ridges are absolescent. Right valve with a triangular chondrophore, the anterior cardinal tooth strong, cuneate, and protruberant, the posterior cardinal lower and smaller. Lateral grooves of the right valve rather well developed, the hinder a little stronger and longer. On the left valve, the chondro- phore is triangular, with a deeper and narrower triangular socket in front of it, and the lateral grooves are rudimentary. The muscle scars are somewhat depressed, the anterior pear-shaped, the pos- terior semicylindrical. The pallial sinus is “U’-shaped, well rounded in front, embayed more or less parallel with the long axis of the valve, and extending forward to not quite the median vertical; the margin of the sinus obliquely truncates the pallial line aft of the middle, the margin continuing some distance below the cut-off of the pallial line. Dimensions.—Holotype (G450a), right valve, height 2.3 mm.; length 3.4 mm.; approx. thickness 0.8 mm. Paratype (G450b), left valve, height 1.5 mm.; length 2.2 mm.; approx. thickness 0.7 mm. Type locality—Upper Mare formation at W-14, on hillside above west bank of Quebrada Mare Abajo. Fight specimens includ- ing seven right valves and one left valve. Other localities——Upper Mare formation, in stream 250 meters south-southwest of mouth of Quebrada Las Pailas. Eight specimens including seven right valves and one left valve. Lower Mare forma- tion at W-13, on hillside above west bank of Quebrada Mare Abajo. Four specimens including two right valves and two left valves. Lower Mare formation, in small stream 100 meters west of Quebrada Mare Abajo. Four right valves. Playa Grande formation (Maiquetia member) at W-23, north flank of Punta Gorda anticline. One right valve. Comparisons.—This species occurs with the preceding E. nitens venezuelana, and there are occasional specimens which are difficult to distinguish from that. Generally, however, E. antilleana, n. sp. may be discriminated from E. n. venezuelana by its flatter, sturdier, and whiter shell, by the somewhat stronger development of the lateral grooves, and by the broad radial internal ridges arising be- neath the hinge. The new species is also close to the Recent E. sub- cancellata E. A. Smith (1885, Voyage of H.M.S. Challenger, Zoology, VENEZUELAN CENOZOIC PELECYPODS: WEISBORD 391 vol. 13, 80-81, pl. 6, figs. 2-2b), but the valves are more compressed. The Pliocene to Recent E. concentrica (Gould) (see McLean, 1951, p. 112, pl. 23, fig. 3) is more inflated, has a more concave postero- dorsal margin, and is more trigonal in outline than £. antilleana, n. sp. E. valhosierr Gardner (1928, U.S. Geol. Surv., Prof Paper 142-F, pp. 225-226, pl. 34, figs. 6-9) from the middle Miocene Chipola formation of Florida is a more triangular shell with a lower and more appressed beak. Ervilia caribbeana, new species Pl. 56, figs. 13, 14 Shell small, subequilateral, moderately inflated, trigonal in out- line, the anterodorsal margin hardly convex, the posterodorsal mar- gin straight and a little longer, the slope of the dorsal margins about equal, the ends of the valve well rounded, the basal margin gently arcuate. Beak small, smooth, full, opisthogyrate, situated slightly forward of the middle. Below the prodissoconch the surface is sculp- tured by fine raised subregular concentric lirae separated by wider interspaces, the interspaces, especially those on the posterior end and toward the base, but to some extent those on the forward end as well, marked by numerous microscopic threads. Left valve with a broadly triangular rather shallow chondrophore; in front of the chondrophore is a deep narrowly triangular socket, the tooth be- tween the chondrophore and socket rather thin, sharp, and elevated. Nymph more or less triangular, somewhat pointed at the middle of the inner edge, bounded by a moderately pronounced groove. The lateral grooves of the left valve are scarcely perceptible and virtu- ally obsolete. Neither the pallial sinus nor the muscle scars are dis- cernible but there is a low ridge descending from beneath the hinge along the inner margin of the anterior muscle scar; in certain light a faint thickening is also observed descending from beneath the middle of hinge, and there is yet another feebler swelling near the inner margin of the left posterior scar. Dimensions.—Holotype (S459), young left valve, height 1.8 mm.; length 2.6 mm.; approx. thickness 0.8 mm. Type locality—Playa Grande formation (Maiquetia member) at W-23, north flank of Punta Gorda anticline. One left valve, the holotype. 392 BULLETIN 204 Comparisons.—This form is close to the Recent Western At- lantic E. swbcancellata Smith (1885, Voyage of H.M.S. Challenger, Zoology, vol. 13, pp. 80-81, pl. 6, figs. 2-2b) and to the middle Mio- cene £. gabbi Woodring (1925, Carnegie Inst. Washington, Publ. No. 366, p. 185, pl. 25, figs. 17-18) from Jamaica. It is more trigonal, and the ends more acutely rounded than on S. subcancellata, and is less inflated and slightly less attenuate posteriorly than EF. gabbi. From E. nitens venezuelana, n. subsp. and E. antilleana, n. sp. the present form is distinguished by its sharper concentric lirae. Ervilia mareana, new species Pl. 56, figs. 15, 16; Pl: Si figs. 2 Shell small, subequilateral, suboval, broadly and gently rostrate behind, moderately inflated. Anterodorsal margin straightish to hardly convex, anterior end blunt above, basal margin evenly arcu- ate, posterior end obliquely subtruncate, posterodorsal margin straight. Prodissoconch plump and smooth, the beak subcentral, projecting slightly above the hinge. Sculpture consisting of flattish subregular concentric ribs separated by slightly narrower inter- spaces, and of radial striae which are scarcely visible on the pos- terior end and obscure elsewhere. Hinge of right valve rather strong, the anterior cardinal tooth obliquely bifid, and well developed, the inner prong the stouter; chondrophore triangular, the tooth along the posterior margin smaller than the prong along the anterior mar- gin. Nymph small, more or less diamond shaped. Lateral grooves of right valve delicate, the posterior slightly the larger. Interior glossy. Right anterior muscle scar narrowly pear-shaped, bordered along the inner margin by a faint narrow ridge extending to the under side of the hinge. Right posterior muscle scar and pallial sinus not visible. Dimensions—Holotype (1452a), right valve, length 2.85 mm.; height 2.1 mm.; approx. thickness 1.1 mm. Paratype (J452a), right valve, length 3.8 mm.; height 2.7 mm.; approx. thickness 1.1 mm. Type locality—lLower Mare formation at W-13, on hillside above west bank of Quebrada Mare Abajo. Three right valves. Other localties—Lower Mare formation, in small stream 100 meters west of Quebrada Mare Abajo. Two night valves including the paratype which is damaged at margin behind the beak. VENEZUELAN CENOZOIC PELECYPODS: WEISBORD 393 Comparisons.—E. mareana, n. sp. is fuller at the umbo than £. nitens (Montagu), and is more equilateral than the Pliocene to Recent EF. concentrica Gould. E. mareana, n. sp. is suboval in outline whereas E. rostratula Rehder and E. subcancellata FE. A. Smith are subtrigonal. Compared with the other species of Ervilia described from the Cabo Blanco area, EF. mareana is more equilateral than E. mtens venezuelana, n. subsp., is more inflated and thinner than E. antilleana, n. sp., and is more broadly ribbed than £. cartbbeana, n. sp. £. mareana is less attenuate posteriorly than the middle Mio- cene £. gabbi Woodring, and the dorsal margins are less steeply descending than on the Jamaican form. CORBULIDAE Corbula (Juliacorbula) aequivalvis Philippi Pl. 57, figs. 3-6 1836. Corbula aequivalvis Philippi, Archiv f. Naturgeschichte, vol. 2, p. 227, pl. 7, fig. 4. 1842. Corbula cubaniana d’Orbigny, [in] La Sagra, Hist., phys., polit., et nat. VIle de Cuba, Atlas, pl. 26, figs. 51-54; text, vol. 5, p. 322, 1845; vol. 2, p. 283, 1853. 1852. Corbula Knoxiana C. B. Adams, Contrib. to Conchology, No. 12, pp. 238-239. 1864. Corbula cubaniana d’Orbigny, Krebs, The West Indian Marine Shells, p. 109. 1864. Corbula Knoxiana C. B. Adams, Krebs, The West Indian Marine Shells, p. 110. 1867. Corbula cubaniana d’Orbigny, Guppy, Sci. Assoc. Trinidad, Proc., pt. 3, p. 161. 1869. Corbula equivalvis Philippi, Tryon, Amer. Jour. Conch., vol. 4, pt. 5, Appendix, No. 13, p. 64. 1869. Corbula Knoxiana C. B. Adams, Tryon, Amer. Jour. Conch., vol. 4, pt. 5, Appendix, No. 13, p. 65. 1878. Corbula cubaneana d’Orbigny, Mérch, Catalogue of West-India Shells, Dsy5 1878. Corbula aequivalvis Philippi, Arango y Molina, Contribucién a la Fauna Malacologica Cubana, p. 252. 1886. Corbula cubaniana d’Orbigny, Dall, Mus. Comp. Zool., Bull., vol. 12, No. 6, p. 313, pl. 1, figs. 3-3c. 1889. Corbula cubaniana Orbigny, Dall, U. S. Nat. Mus., Bull. 37, p. 70, pl. 1, figs. 3-3c. 1901. Corbula aequivalvis Philippi, Dall and Simpson, U. S. Fish Com., Bull., vol. 20 for 1900, pt. 1, p. 473. 1913. Corbula aequivalvis Philippi, Brown and Pilsbry, Acad. Nat. Sci. Phila- delphia, Proc., vol. 65, p. 497. 1921. Corbula knoxiana C. B. Adams, Pilsbry, Acad. Nat. Sci. Philadelphia, Proc., vol. 73, p. 427. 394 BULLETIN 204 1925. Corbula cubaniana d’Orbigny, Maury, Bull. Amer. Paleont., vol. 10, No. 42, pp. 255-256, pl. 20, figs. 2-4. 1932. Corbula (Tenuicorbula) aequivalvis Philippi, Olsson, Bull. Amer. Pale- ont., vol. 19, No. 68, p. 142. 1934. Corbula cubaniana Orbigny, Johnson, Boston Soc. Nat. Hist., Proc., vol. 40, No. 1, p. 57. 1938. Corbula cubaniana d’Orbigny, Perry, Schwengel, and Dranga, Nautilus, vol. 52, No. 1, p. 28. 1941. Corbula aequivalvis Philippi, Lamy, Jour. Conchyl., vol. 84, No. 2, p. 129. 1943. Corbula cubaniana d’Orbigny, Gardner, U. S. Geol. Sur., Prof. Paper 199-A, p. 141. 1943. Corbula (Tenuicorbula) aequivalvis Philippi, Rutsch, Naturforschenden Gesell. Basel, Verhandl., vol. 54, p. 125. 1949. Aloidis (Caryocorbula) cubaniana (Orbigny), Lange de Morretes, Mus. Paranaense, Arq., vol. 7, art. 1, p. 47. 1950. Corbula Knoxiana C. B. Adams, Clench and Turner Occas. Papers on Mollusks, pp. 299-300, pl. 47, figs. 11-12. 1951. Corbula aequivalvis Philippi, McLean, New York Acad. Sci. Scientific Survey of Porto Rico and the Virgin Islands, pp. 114-115, pl. 23, fig. 7. 1953. Corbula (Caryocorbula) cubaniana Orbigny, Haas, Fieldiana-Zoology, vol. 34, No. 20, p. 203. 1953. Juliacorbula cubaniana (d’Orbigny), Olsson and Harbison, Acad. Nat. Sci. Philadelphia, Mon. No. 8, pp. 148, 149. 1955. Corbula cubaniana d’Orbigny, Perry and Schwengel, Marine Shells of the Western Coast of Florida, p. 91, pl. 44, fig. 310. 1958. Corbula aequivalvis Philippi and Juliacorbula knoxiana C. B. Adams, Olsson and McGinty, Bull. Amer. Paleont., vol. 39, No. 177, p. 22. 1961. Corbula aequivalvis Philippi, Warmke and Abbott, Caribbean Seashells, p. 207, text fig. 31g. The fossils referred to this species are small, subtrapezoidal, inequilateral, inflated, subequivalve. Although there are no paired valves in the collection, it is inferred that the right valve is slightly overlapping as there is a groove developed parallel with, and proximate to the margins except on the posterior end where it is absent. This groove engages the rim of the left valve. Antero- dorsal margin nearly straight, anterior end well rounded, ventral margin hardly arcuate to subtruncate, posterior end nearly ver- tical truncated, posterodorsal margin slightly convex. Rostral keel acute, extending from the beak to the base. Area behind rostrum somewhat concave, set at an angle of 90 degrees or more from the disk. Posterior area with a gentle, arcuate upfold or angu- lation diverging from the keel at the beak, extending to and broaden- ing toward the base where it is placed about a third of the width of the posterior slope in from the keel. On the posterior area bordering the escutcheon there is a narrow crenated ridglet. A gentle radial VENEZUELAN CENOzOIC PELECYPODS: WEISBORD 395 depression is present on the disk from the umbo to the middle of the basal margin. Beak low, flattened on top, prosogyrate, sub- central. Lunule suggested but not defined by the obsolescence of the ribs continuing thereon from the disk. Escutcheon sublanceolate, perhaps a little larger on the left valve, defined by a narrow ridglet, marked by faint continuations of the ribs from the posterior area. External sculpture consisting of 38 or so strong, more or less equal concentric ribs continuing from near the anterior margin over the disk and posterior area to the edge of the escutcheon. The ribs are prominent but smaller, subregular, and more closely spaced on the posterior area; on the upper half of the valve the ribs are flexuous where they cross the rostral keel, but on the lower half the ribs run straight across the keel. On the disk there are a few faint microscopic secondaries between the main ribs, and on the best preserved speci- mens there are numerous surficial microscopic radial striae on the posterior area, such striae appearing also on the disk where the sur- face is worn to expose the under layer of shell. Hinge tooth of nght valve strong, cuneate, flattened in front, upturned and curved in toward the beak at the apex, the apex elevated a little above the beak. Behind that tooth the resilial pit is large and deep. Hinge of left valve with an upcurved laminar tooth, in front of which, and directly below the beak, is an obtusely triangular socket. Adductor impressions distinct, the anterior one arcuate and narrowly lenticular, the posterior one subpyriform, lying on the posterior slope a short distance in from the interior groove, the groove representing the internal correlative of the rostral keel. Pallial line regular, joining the base of both adductors at the inner side, the line occasionally bowed up slightly at the middle. Dimensions.—Specimen C535a, right valve, length 12.3 mm.; height 8 mm.; thickness 3.6 mm. Specimen C535b, left valve, length 10.2 mm.; height 7 mm.; thickness 2.8 mm. Locality—La Salina, west of Puerto Cabello, State of Cara- bobo. Twenty-eight specimens including sixteen right valves and twelve left valves. Remarks.—The fossils from La Salina are identical to the Recent C. knoxiana C. B. Adams from Jamaica, and that, as well as C. cubamana d’Orbigny, is considered the same as the earlier-named C. aequivaluis Philippi. 396 BuLtetin 204 Range and distribution—Recent, from Florida to Brazil. Pleis- tocene in the Panama Canal Zone. Pliocene, at Matura, Trinidad. Antecedents are C. aequivalvis stainforthi Rutsch (1943, pp. 124 125, pl. 3, figs. 8-9) from the upper Miocene of Trinidad, and C. knoxtana fossilis Pilsbry (1921, p. 427, pl. 46, fig. 14) from the middle Miocene of the Dominican Republic. Corbula (Caryocorbula) cf. lavalleana d’Orbigny Pl. 57, figs. 7-14 1842. Corbula Lavaleana d’Orbigny [in] La Sagra, Hist. phys., polit. et nat. V'Ile de Cuba, Atlas, pl. 27, figs. 9-12. 1845. Corbula Lavalleana d’Orbigny, [in] La Sagra, Hist. Fis., Polit. y Nat. Isla de Cuba, vol. 5, Moluscos, p. 323. 1853. Corbula Lavalleana d’Orbigny, [in] La Sagra, Hist. phys., polit. et nat. VIle de Cuba, vol. 2, p. 284. 1864. Corbula Lavalleana d’Orbigny, Krebs, The West Indian Marine Shells, p. 110. 1867. Corbula Lavalleana d’Orbigny, Schramm, Cat. Coq. Guadeloupe, p. 18. 1873. ?Corbula Lavaleana d’Orbigny, Gabb, Amer. Philos. Soc., Trans., new ser., vol. 15, p. 253. 1881. Corbula Lavaleana d’Orbigny, Gabb, Acad. Nat. Sci. Philadelphia, Jour., ser. 2, vol. 8, pp. 343, 371. 1898. Corbula Lavalleana Orbigny, Dall, Wagner Free Inst. Sci., Trans., vol. 3, pt. 4, p. 849. 1917. Corbula Lavaleana d’Orbigny, Maury, Bull. Amer. Paleont., vol. 5, No. 29; p. 396. 1941. Corbula (Cuneocorbula) Lavalleana d’Orbigny, Lamy, Jour. Conchyl., vol. 84, p. 231. 1951. 2?Corbula lavalleana d’Orbigny, McLean, New York Acad. Sci. Scientific Survey of Porto Rico and the Virgin Islands, vol. 17, pt. 1, p. 115. Shell small, fairly solid, inflated, ovate-subtrigonal in outline, rostrate behind, inequilateral, subequivalve. The base of the right valve is somewhat incurved, and this, together with the gutter near the margin of the right valve, suggests that it incloses or over- laps the left valve at its rim. Anterodorsal margin straight, anterior end symmetrically rounded, ventral margin subtruncate to shal- lowly arcuate (the arcuate form embayed slightly in front of the posterior ridge), posterior end produced and obtusely pointed, pos- terodorsal margin hardly sinuous. Central area of disk evenly in- flated, but before the posterior ridge there may be a slight radial depression. Posterior ridge angulate to subangulate, the posterior area a little concave, sloping more steeply near the beak than at the base. Beak moderately low, appressed on top, subcentral, pro- sogyrate. Lunule not defined. Escutcheon on right valve narrow and VENEZUELAN CENOZOIC PELECYPODS: WEISBORD 397 bordered by a faint ridge. Sculpture consisting of irregular obso- lescent concentric folds on the umbonal area, these developing into stronger subregular and subsinuous lirae or riblets below, a few of the lirae on the disk discontinuous, the continuous ones extending from the anterior margin to the faint ridge bordering the escut- cheon; on the posterior area the lirae are a little sharper and closer together. On a number of specimens and especially where the sur- face is worn, there are fine subequally and rather widely spaced radial filaments on the disk, the filaments crowded on the posterior slope. Hinge of right valve with a strong cuneate upturned tooth, rounded in front, incurved at the apex which rises a little above the beak; behind the tooth there is a large deep subtrigonal pit. Hinge of left valve with an upturned platy cardinal, in front of which is a triangular socket. Body cavity deep, its posterior margin, par- ticularly on the right valve, warped and thickened. Adductor scars distinct, situated on the marginal platforms of the interior, the an- terior scar reniform, the posterior suboval. Pallial line distinct, running closer to the margin posteriorly than anteriorly, joining the base of the adductor scars at their inner side, the line forming an abrupt angle of more than 90 degrees where it turns before joining the posterior scar. The gutter along which the valves are closed is nearer and parallel with the margin anteriorly, a little farther from the margin and subparallel with it behind the middle. Dimensions.—Specimen C536a, right valve, length 9.8 mm.; height 7 mm.; thickness 4 mm. Specimen C536b, left valve, length 10.2 mm.; height 6.1 mm.; thickness 3.9 mm. A few young shells, tentatively referred to this species, were collected in the Cabo Blanco area, and the measurements of the ones illustrated are as follows: Specimen T536a, right valve, length 5.5 mm.; height 3.8 mm.; thickness 1.7 mm. Specimen J536a, left valve, length 5.8 mm.; height 3.8 mm.; thickness 1.7 mm. Specimen 1537a, left valve, length 5.9 mm.; height 3.8 mm.; thickness 1.9 mm. Locahties—La Salina, west of Puerto Cabello, State of Cara- bobo. Seventeen specimens including fourteen right valves and three left valves. The Cabo Blanco localities of the young specimens referred to above are as follows: upper Mare formation, in stream 250 meters west-southwest of the mouth of Quebrada Las Pailas. Two right 398 BuLteTIn 204 valves. Lower Mare formation, in small stream 100 meters west of Quebrada Mare Abajo. One left valve. Lower Mare formation at W-13, on hillside above west bank of Quebrada Mare Abajo. One left valve. Remarks.—Except perhaps for the somewhat more widely spaced radial filaments than are shown on D’Orbigny’s illustra- tion of C. lavalleana, the La Salina fossils from Venezuela seem to be identical with D’Orbigny’s Recent shell from Cuba. Also, the La Salina fossils cannot be distinguished from the Recent shells labeled C. davalleana in the Museum of Comparative Zoology, No. 183924, from Haiti. D’Orbigny stated that his C. lavalleana could be differentiated from his C. caribaea by the occurrence on the for- mer of radial striae, but as such striae are seen on some examples and not on others of the same species, it may be, as suggested by McLean, that C. lavalleana is a radially striate variation of the prior-named C. caribaea. McLean suggested that C. swiftiana C. B. Adams may also be a synonym of C. caribaea, and I would add that C. kjoeriana C. B. Adams (see Dall, 1886, Mus. Comp. Zool., Bull., vol. 12, No. 6, p. 316, pl. 1, figs. 6-6b; and Clench and Turner, 1950, Occas. Papers on Mollusks, vol. 1, No. 15, pp. 298-299, pl. 47, figs. 1-2) is likewise hardly distinguishable from the C. cartbaea-laval- leana complex. C. daphnis Maury (1925, Bull. Amer. Paleont., vol. 10, No. 42, p. 256, pl. 20, fig. 10) from the Matura Pliocene of Trinidad is yet another closely allied species, though according to Maury the radial sculpture of C. daphnis is absent. Corbula cf. lavalleana from La Salina also resembles the follow- ing species: C. contracta Say (1822, Acad. Nat. Sci. Philadelphia, Jour., ser. 1, vol. 2, p. 312). Pliocene to Recent. Typically, the basal margin of C. contracta is contracted near the middle; this contraction is not present on C. cf. lavalleana. C. cala Gardner (1936, State of Florida Dept. Conserv., Geol. Bull. No. 14, pp. 46-47, pl. 8, figs. 8-12). Middle Miocene Shoal River formation, Florida. This is differentiated from the Venezuelan ex- amples of C. cf. lavalleana by the acute angle of the pallial line where it turns to join the posterior muscle scar. C. domimcensis Gabb (see Pilsbry, 1921, Acad. Nat. Sci. Phila- delphia, Proc., vol. 73, p. 427, pl. 46, figs. 12-13). Middle Miocene VENEZUELAN CENOZOIC PELECYPODS: WEISBORD 399 of the Dominican Republic. According to Gabb, C. dominicensis is a thin shell whereas the adults of C. cf. lavalleana from La Salina are robust. According to Pilsbry the number of ribs on the posterior half of the disk is nearly doubled by splitting. This does not occur on the Venezuelan specimens. C. urumacoensis F. Hodson (1931, Bull. Amer. Paleont., vol. 16, No. 59, pp. 25-26, pl. 12, figs. 1-7). Upper-middle Miocene, State of Falcon, Venezuela. The concentric sculpture is much finer than on the La Salina fossils. C. democraciana F. Hodson (1931, Bull. Amer. Paleont., vol. 16, No. 59, pp. 26-27, pl. 11, figs. 1-6). Upper-middle Miocene, State of Falcon, Venezuela. On the posterior slope of the left valve there is a small keel bordering a rather well-defined and moderately large escutcheon. The escutcheon of the adult La Salina shell is ill defined, and the concentric ribs on the disk are smaller than on C. democra- clana. Range and distribution—Corbula lavalleana dOrbigny is a Recent Caribbean species. The Recent C. caribaea d’Orbigny is reported from Florida to Brazil. The fossil C. caribaea is known from the Pliocene of Trinidad and from the Pliocene near Cumana, Venezuela (U. S. National Museum Collection No. 18408). Corbula (Notocorbula) bruscasensis, new species Pl. 46, figs. 5, 6 The following description pertains to the left valve. Shell small, the valves unequal, the left valve inferred to be inclosed by, and snugged into the larger and more tumid right valve. Left valve fairly thin, moderately inflated, subtrigonal in outline, subequilateral, with a vague subrounded posterior ridge. Dorsal margins sloping nearly equally, the anterodorsal margin hardly convex, the posterodorsal margin straight; anterior end rounded, posterior end somewhat obliquely subtruncate, the ventral margin horizontally truncated behind the middle, arcuate as it meets the anterior end. Beak low, subcentral, prosogyrate. Lunule and escut- cheon not defined. Surface sculptured by narrow subregular concen- tric lirae and a few microscopic concentric striae in the interspaces, the lirae strongest at the middle of the valve. Under certain light the surface also seems to be traversed by occasional obsolescent radial 400 BuL.etTin 204 filaments which do not reach the umbo, but the disposition of the radials cannot be determined. Hinge with an upturned laminar chon- drophore, in front of which, directly under the beak, is a subtriangu- lar socket. Adductor scars faint, the anterior one obtusely subquad- rate, the posterior obtusely subtriangular. Pallial line remote from the margin, running from the inner angle at the base of the anterior adductor scar, subparallel with the ventral margin to below the pos- terior adductor scar where, on its shallowly sigmoidal course to join the inner angle of the scar, it is embayed to form a short subrounded sinus. Dimensions—Holotype (R667a), left valve, length 3 mm.; height 2.5 mm. Type localty.—Playa Grande formation (Maiquetia member) at W-26, Quebrada Las Bruscas approximately 125 meters upstream from its junction with Quebrada Las Pailas. One young left valve, the holotype. Comparisons.—This species is close to the following: C. krebsiana C. B. Adams (see Dall, 1886, Mus. Comp. Zool. Bull., vol. 12, No. 6, pp. 314-315, pl. 1, figs. 4-4b). Recent, Florida to the Caribbean at depths of 3 to 85 fathoms. The concentric mark- ings are less prominent and more numerous than the lirae on C. bruscasensis, n. sp. C. disparilis d’Orbigny (1842, [in] La Sagra, Hist. phys., polit., et nat. l’Ile de Cuba, Atlas, pl. 27, figs. 1-4; text, vol. 2, p. 283, 1853. Spanish ed., vol. 5, Moluscos, p. 322, 1845). Authors consider C. operculata Philippi (1848, Zeitschr. f. Malakozool., yr. 5, p. 13) and C. phlippu Smith (1885, Voyage of H.M.S. Challenger, Zoology, vol. 13, pp. 33-34, pl. 7, figs. 4-4b) to be synonymous. Pliocene to Recent, the Recent shell occurring at depths of 5 to 805 fathoms from North Carolina to northern South America. This is a sturdier and more strongly sculptured shell than C. bruscasensis, with a more sharply truncated posterior end on the left valve, and with a less sigmoidal pallial sinus than on the Venezuelan fossil. C. caloosae Dall (1898, Wagner Free Inst. Sci., Trans., vol. 3, pt. 4, p. 853, pl. 36, fig. 16). Pliocene, Florida. The left valve is smoother, or with finer concentric growth lines than on C. bruscasen- sis, and the posterior ridge is sharper than on C. bruscasensts. C. zuliana F. Hodson (1931, Bull. Amer. Paleont., vol. 16, No. VENEZUELAN CENozoIc PELECYPoDS: WEISBORD 401 59, pp. 22-23, pl. 10, figs. 1-3, 5). Upper Oligocene-lower Miocene, District of Miranda, State of Zulia, Venezuela. The posterior end of the left valve is more definitely truncated than on C. bruscasensis, but otherwise the left valves of both species are much alike. Corbula (Notocorbula) puntagordensis, new species Pl. 57, figs. 15, 16 The following description is based on a single specimen which is a young left valve. Left valve small, well inflated, solid, subequilateral, subquad- rate in outline. Anterior submargin compressed, posterior slope mod- erately steep and slightly concave, the umbonal or posterior ridge broad and rounded. Anterodorsal margin with a slope of about 20 degrees, the posterodorsal margin with a slope of about 40 degrees, the latter somewhat the longer. Anterior end rounded, ventral margin shallowly arcuate, posterior end nearly vertically truncate. Umbo full and broad, the beak moderately high, a little forward of the middle, prosogyrate. The surface is sculptured by microscopic concentric growth wrinkles, the disk also marked by eight or nine irregularly spaced threadlike radial riblets, the riblets a little closer on the anterior half than on the posterior, all of them originating below the beak and extending to the basal margin. Hinge with a thick, somewhat projecting, and slightly upturned chondrophore which seems to be vaguely sulcate on top, and in front of the chon- drophore is a triangular socket immediately under the beak. Ad- ductor scars faint, the anterior subovate and slightly arcuate, the posterior seeming to be broadly and angulately oval. Pallial line regular, a little removed from, and parallel with the ventral margin, developing into a small sinus with a rounded apex before joining the posterior adductor scar. It is inferred that the left valve is inclosed by, and snugged into the right valve, of which there are no examples in the collection. Dimensions —Holotype (H55la), left valve, length 2.9 mm.; height 2.6 mm.; thickness 1.3 mm. Type locality—Mare formation at W-25, south flank of Punta Gorda anticline. One young left valve, the holotype. Comparisons—This species is similar to the form known vari- ously as C. disparilis d’Orbigny, C. operculata Philippi, and C. 402 BuLLeETIN 204 philippu Smith, but comparing the Punta Gorda fossil with Recent specimens of C. disparilis from Cuba and from off the east coast of Florida, it is seen that the left valve of C. disparilis is slightly less obese and somewhat more elongate, that it has a wider and shallower pallial sinus, that its anterodorsal margin is a little concave, and that often there are as many as 11 radial riblets (although the type of C. philippu from off Bermuda has 8). Left valves of C. vieta Guppy, described by Guppy (1886, Geol. Soc. London Quart. Jour., vol. 22, pp. 582-583, pl. 26, fig. 6) as Erycina tensa, from the lower Miocene Manzanilla formation of Trinidad are more compressed than C. puntagordensis, n. sp., bear a few more radiating mblets, and have a more pointed umbo. The left valve of C. heterogena Dall (see Woodring, 1925, Carnegie Inst. Washington, Publ. No. 366, pp. 187-188, pl. 26, figs. 3-4) from the middle Miocene of Jamaica and the Panama Canal Zone has a more laminar and more recurved chondrophore than C. puntagordensis, and the radial riblets are more numerous. The left valve of C. isla-trinitatis Maury (1925, Bull. Amer. Paleont., vol. 10, No. 42, pp. 253-254, pl. 19, figs. 10) from the upper Miocene Springvale formation of Trinidad has a sharper umbonal ridge, fewer radial riblets, and a narrower um- bonal area than C. puntagordensis. The present form differs from C. bruscasensis, n. sp. in having a thicker shell, stronger hinge, simpler pallial sinus, less pronounced concentric lirae, and a subob- long rather than subtrigonal outline. Remarks—Authors differ in the identification, priority, and synonymy of the Recent Western Atlantic species known variously as Corbula (Varicorbula) disparilis d’Orbigny, C. operculata Philippi, and C. philippi Smith. C. disparilis was first named and illustrated by D’Orbigny in 1842 in the Atlas of La Sagra’s “Histoire physique, politique et naturelle de I’Ile de Cuba” on plate 27, figures 1-4. It was later described in the Spanish edition of the text on page 322, 1845, and in the French edition of the text in volume 2, p. 283, 1853. As pointed out by Olsson and Harbison (1953, p. 148), “Recent Florida shells commonly identified as C. disparilis d’Orbigny, do not agree well with the original description and figures of that species, which indicate a form with nearly equal valves and high prominent umbones and beaks,” and it is true that the original figures do not indicate the highly discrepant valves of a notocorbulid. In 1848, VENEZUELAN CENOZzOIC PELECYPODS: WEISBORD 403 Philippi (Zeitschr. f. Malakozool., yr. 5, p. 13) described, but did not illustrate his C. operculata. In 1885, E. A. Smith (Voyage H.M.S. Challenger, Zoology, vol. 13, pp. 33-34, pl. 7, figs. 4-4b) described and figured admirably his C. philtppu, and remarked that “In the inequality of the valves it resembles Corbula operculata Philippi, from St. Thomas Island, but differs from that species in size, form, the absence of the double keel in the right valve, and in the differ- ent sculpture of the left.” In 1886, Dall (Mus. Comp. Zool., Bull., vol. 12, No. 6, pp. 314-315, pl. 1, figs. 4-4b) synonymized both C. operculata Philippi and C. philippu Smith, stating his reasons thusly: “Those who consult d’Orbigny’s figures will observe that they differ from the shell figured by my friend Smith in repre- senting the valves as nearly equal, and also in the absence of epidermal radiations on the smaller valves and the carina on the larger one. But I infer from d’Orbigny’s remarks, that he had only separated valves, and probably those which had lost their epidermis; and it is probable that the artist represented two valves together which did not belong together. The carina is a variable feature in this species, as in C. nucleus. At all events, the specimens I have are certainly the same as C. philippi Smith, and I believe them to be the species described by d’Orbigny. The species extends northward to Cape Hatteras, and the smaller valve is frequently of a pink color or pinkish brown. It reaches a length of 8.0 mm. and is variable in its pro- portions and sculpture. I have no doubt that it is the operculata of Philippi, but the C. Krebsiana of C. B. Adams is a different and more delicate species.” Despite Dall’s atypical illustrations, no less an authority than Lamy (1941, Jour. Conchyl., vol. 84, No. 3, pp. 218-219) subscribed to Dall’s opinion, although later conchologists, among them Abbott (1954, pp. 456-457), would refer to the species in question as [Noto- corbula| operculata (Philippi). PHOLADIDAE Martesia striata (Linnaeus) Pl. 58, figs. 1-3 1758. Pholas striatus Linnaeus, Syst. Nat., ed. 10, p. 669, No. 12. BuLLetTin 204 . Pholas pusillus Linnaeus, Syst. Nat., ed. 10, p. 670, No. 14. . Pholas conoides Parsons, Philos. Trans., vol. 55, p. 1, pl. 1. . Pholas striatus Linnaeus, Syst. Nat., ed. 12, p. 1111, No. 22. . Pholas striatus Linnaeus, Chemnitz, Syst. Conchylien-Cabinet, vol. 8, p. 364, pl. 102, figs. 864-866. . Pholas nanus ‘Solander’ Pulteney, Catalogue of the Birds, Shells, ... Plants of Dorsetshire, p. 27. . Pholas nanus ‘Solander’ Pulteney, Catalogue of the Birds, Shells, ... Plants of Dorsetshire, 2d ed., p. 27, pl. 1, fig. 7. . Pholas falcata Wood, General Conchology, p. 84, pl. 16, figs. 5-7. . Pholas clavata Lamarck, An. sans Vert., vol. 5, p. 446. . Pholas tenuistriata Blainville, Dictionnaire des Sciences Naturelles, vol. 39, p. 531. Based on Encycl. Méth., 1792, Atlas, vol. 2, pl. 170, figs. 4-8. . Pholas decussata ‘Valenciennes’ Bory de Saint-Vincent, Tableau Encycl. Méth., Atlas, vol. 1, p. 145, pl. 170, figs. 1-3. . Pholas atomus ‘Valenciennes’ Bory de Saint-Vincent, Tableau Encycl. Méth., Atlas, vol. 1, p. 145, pl. 170, figs. 4-8. . Pholas striata Linnaeus, Brown, Illustrations of the Recent Conchology of Great Britain and Ireland, pl. 8, figs. 5, 8. . Pholas ovum Wood, Supplement to Index Testaceologicus, p. 2, pl. 1, fig. 4. . Pholas striata Linnaeus, Reeve, Conchologica Systematica, vol. 1, p. 44, pl. 24, fig. 2. . Pholas Hornbeckii d’Orbigny, [in] La Sagra, Hist. phys., polit. et nat., l’Ile de Cuba, Atlas, pl. 25, figs. 23-25; text, vol. 2, p. 217 (1853). . Penitella xylophaga Valenciennes, Voyage Autour du Monde, Atlas Zool., Mollusques, pl. 24, fig. 2. Not Pholas xylophaga Deshayes 1835. . Pholas striata Linnaeus, Sowerby, Thes. Conchyl., vol. 2, pt. 10, p. 494, pl. 104, figs. 40-42; pl. 105, figs. 43-44. . Pholas teredinaeformis Sowerby, Thes. Conchyl., vol. 2, pt. 10, p. 490, pl. 108, figs. 97-98. . Pholas corticaria ‘Gray’ Sowerby, Thes. Conchyl., vol. 2, pt. 10, p. 495, pl. 108, figs. 94-96. . Pholas rosea C. B. Adams, Contrib. Conch., No. 5, pp. 75-76. . Pholas Beauiana Récluz, Jour. Conchyl., vol. 4, p. 49, pl. 2, figs. 1-3. . Martesia striata (Linnaeus), H. and A. Adams, The Genera of Recent Mollusca, vol. 2, p. 330, pl. 90, figs. 5-5a. . Martesia striata (Linnaeus), Tryon, Acad. Nat. Sci. Philadelphia, Proc., vol. 14, pp. 92, 220. . Pholas striata Linnaeus, Krebs, The West Indian Marine Shells, p. 114. . Martesia striata (Linnaeus), Guppy, Sci. Assoc. Trinidad, Proc., pt. 3, p. 161. . Martesia striata (Linnaeus), Tryon, Amer. Jour. Conch., vol. 3, pt. 3, Appendix, No. 8, p. 10. . Pholas striata (Linnaeus), Sowerby, [in] Reeve, Conch. Icon., pl. 8, sp. 32a-c. . Pholas striata Linnaeus, Moérch, Catalogue of West-India Shells, p. 14. . Martesia striata (Linnaeus), Arango y Molina, Contribucién a la Fauna Malacolégica Cubana, p. 236. . Martesia striata (Linnaeus), Gabb, Acad. Nat. Sci. Philadelphia, Jour., ser. 2, vol. 8, p. 370. . Martesia striata (Linnaeus), Fischer, Manuel de Conchyliologie et de Paléontologie Conchyliologique, p. 1136, pl. 23, fig. 21. 1889. 1889. 1889. 1893. 1898. 1898. 1901. 1905. 1906. 1909. 1920. 1924. 1924. 1925. 1927. 1930. 1932. 1934. 1936. 1936. 1937. 1938. 1940. 1945. 1945. 1945. 1945. 1945. 1949. VENEZUELAN CENOZOIC PELECYPODS: WEISBORD 405 Martesia striata (Linnaeus), Dall, U.S. Nat. Mus., Bull. 37, p. 72. Martesia striata (Linnaeus), Morlet, Jour. Conchyl., vol. 37, p. 173. csi striata (Linnaeus), Crosse and Fischer, Jour. Conchyl., vol. 37, p. 294. Martesia striata (Linnaeus), Clessin, Syst. Conchylien-Cabinet, vol. 11, pt. 4a, p. 45, pl. 10, figs. 2-3. Martesia striata (Linnaeus), Dall, Wagner Free Inst. Sci., Trans., vol. 3, pt. 4, p. 820. Martesia striata (Linnaeus), Melvill and Standen, Jour. Conch., vol. 9, p. 84. Martesia striata (Linnaeus), Hedley, Australian Assoc. Advancement Sci., vol. 8, p. 249, pl. 10, figs. 10-11. Martesia striata (Linnaeus), Johnson, Nautilus, vol. 18, p. 100, fig. 1. Martesia striata (Linnaeus), Melvill and Standen, Zool. Soc. London, Proc., p. 845. Martesia curta Sowerby, Dall, U.S. Nat. Mus., Proc., vol. 37, No. 1704, p. 161. Not of Sowerby 1834. Martesia striata (Linnaeus), Maury, Bull. Amer. Paleont., vol. 8, No. 34, pp. 144-145. Martesia striata (Linnaeus), Miller, Univ. California Publ. Zool., vol. 26, p. 146, pl. 8, figs. 1-5. Pholas cupula Yokoyama, Imperial Univ. Tokyo, Jour. College Sci., vol. AO Fas bh fos 675 Wh VE sates 21D Martesia striata (Linnaeus), Lamy, Jour. Conchyl., vol. 69, pp. 194-205. Martesia striata tokyoensis Yokoyama, Imperial Univ. Tokyo, Jour. Faculty Sci., sect. 2, vol. 1, pt. 10, p. 428, pl. 48, figs. 2-3. Pholas striatus Linnaeus, Stewart, Acad. Nat. Sci. Philadelphia, Spec. Publ. No. 3, p. 295. Martesia pulchella Yokoyama, Imperial Univ. Tokyo, Jour. Faculty Sci., sect. 2, vol. 3, pt. 6, p. 238, pl. 2, fig. 5. Martesia striata (Linnaeus), Johnson, Boston Soc. Nat. Hist., Proc., vol. 40, No. 1, p. 58. Hiata infelix Zetek and McLean, Nautilus, vol. 49, p. 110. Martesia striata (Linnaeus), Lermond, A Check List of Florida Marine Shells, Gulfport, p. 14. Martesia striata (Linnaeus), Smith, East Coast Marine Shells, p. 69, fig. 37. Martesia hawaiiensis Dall, Bartsch and Rehder, Bernice P. Bishop Mus., Bull., No. 153, p. 205, pl. 52, figs. 1-7. Martesia striata (Linnaeus), Smith, World-wide Sea Shells, p. 124, figs. 1591la-c. Martesia (Martesia) striata (Linnaeus), Bartsch and Rehder, Smith- sonian Misc. Collections, vol. 104, No. 11, pp. 4-5, pl. 1, figs. 1-2; pl. 3, figs. 19-20. Martesia (Diploplax) americana Bartsch and Rehder, Smithsonian Misc. Collections, vol. 104, No. 11, p. 13, pl. 2, figs. 1-2; pl. 3, figs. 3-4. Martesia (Diploplax) funisicola Bartsch and Rehder, Smithsonian Misc. Collections, vol. 104, No. 11, p. 14, pl. 3, figs. 1-2, 13-14. Mesopholas intusgranosa Taki and Habe, Venus, vol. 14, p. 110. Mesopholas nucicola Taki and Habe, Venus, vol. 14, p. 110. Martesia striata (Linnaeus), Lange de Morretes, Mus. Paranaense, Arq,, vol. 7, art. 1, p. 49. 406 BULLETIN 204 1950. Martesia intercalata Carpenter, Hertlein and Strong, Zoologica, vol. 35, No. 19, p. 250. Not of Carpenter 1857. 1951. Martesia striata (Linnaeus), McLean, New York Acad. Sci. Scientific ee of Porto Rico and the Virgin Islands, vol. 17, pt. 1, p. 19, pl. 24, ig. 5. 1952. Martesia striata (Linnaeus), Pulley, Texas Jour. Sci., vol. 4, No. 2, p. 185. 1952. Pholas striata Linnaeus, Dodge, Amer. Mus. Nat. Hist., Bull., vol. 100, art. 1, p:. 26. 1954, M erste striata (Linnaeus), Abbott, American Seashells, pp. 464-465, pl. 32w. 1955. Martesia striata (Linnaeus), Perry and Schwengel, Marine Shells of the Western Coast of Florida, p. 95, pl. 19, figs. 127a,b. 1955. Martesia (Martesia) striata (Linnaeus), Turner, Johnsonia, vol. 3, No. 34, pp. 103-111, pls. 35, 61-64. 1958. Martesia striata (Linnaeus), Olsson and McGinty, Bull. Amer. Paleont., vol. 39, No. 39, No. 177, p. 22. 1958. Martesia striata (Linnaeus), Keen, Sea Shells of Tropical West America, pp. 216-218, fig. 550. 1961. Martesia striata (Linnaeus), Olsson, Panamic-Pacific Pelecypoda, p. 446, pl. 79, figs. 6-7a. 1961. Martesia striata (Linnaeus), Warmke and Abbott, Caribbean Seashells, p. 209, pl. 44). The callum and mesoplax are broken away on the single Vene- zuelan specimen from Higuerote, but all other characters are the same as in Martesia striata (Linnaeus). The color is white. Dimensions.—Specimen B505a, length 24 mm.; height 11.6 mm.; thickness 6 mm. Locality.—Recent, on beach southeast of Higuerote, State of Miranda. One left valve. Remarks.—The references to and synonymy of this ubiquitous species as given in this work are by no means complete. Full in- formation on this and other pholads are to be found in the classic by Turner (1954-1955) in Johnsonia, volume 3. Voluminous refer- ences to Martesia striata and to other species considered as syno- nyms of Martesia striata by Turner, are given by Lamy (1925) in the Journal de Conchyliologie. Range and distribution—The Recent Martesia striata (Lin- naeus), a wood borer, is a subtemperate to tropical species inhabit- ing the Atlantic, Pacific, and Indian Oceans. Among late Cenozoic occurrences, the fossil is reported from Japan, and from the Pliocene of Costa Rica and Trinidad in the Americas. VENEZUELAN CENOzOIC PELECYPODS: WEISBORD 407 PERIPLOMATIDAE Periploma margaritacea (Lamarck) Pl. 58, figs. 4-9; Pl. 59, figs. 1-2 1797. Corbula sp. Bruguiére, Encycl. Méth., pl. 230, figs. 6a-b. 1801. Corbula margaritacea Lamarck, Syst. An. sans Vert., p. 137. 1817. Periploma inaequivalvis Schumacher, Essais d’un nouveau systéme des habitations des vers testacés, p. 116, pl. 5, figs. la-b. 1818. Anatina trapezoides Lamarck, An. sans Vert., vol. 5, p. 464. 1825. Osteodesma trapezoidalis Blainville)s Man. Malac. et Conchyl., p. 660, pk 75, fiz. 8. 1832. Periploma trapezoides (Lamarck), Deshayes, Encycl. Méth., vol. 3, p. 733. 1835. Anatina trapezoides Lamarck, Deshayes, An. sans Vert., 2d ed., vol. 6, p. 79. 1835. Periploma trapezoides (Lamarck), Deshayes, An. sans Vert., 2d ed., vol. 6, p. 80. 1839. Periploma trapezoides (Lamarck), Couthouy, Boston Jour. Nat. Hist., vol. 2, p. 160. 1842. Thracia inequalis C. B. Adams, Amer. Jour. Sci., vol. 43, p. 143. 1843. Periploma trapezoides Deshayes, C. B. Adams, Amer. Jour. Sci., vol. 44, p. 420. 1843. Periploma inaequavalvis Schumacher, Deshayes, Tr. élém. conch., vol. 1, pt. 2, p. 219, pl. 8, figs. 15-19. 1843. Anatina trapezoides Lamarck, Hanley, An Illustrated and Descriptive Catalogue of Recent Bivalve Shells, p. 20. 1846. Periploma inaequivalvis Schumacher, d’Orbigny, Voyage Amérique Méri- dionale, vol. 5, p. 513. 1852. Periploma margaritacea (Lamarck), Mérch, Catalogus Conchyliorum Comes de Yoldi, pt. 2, p. 31. 1853. Periploma trapezoides (Lamarck), Petit de la Saussaye, Jour. Conchyl., vol. 4, p. 414. 1856. Periploma trapezoides (Lamarck), Hanley, An Illustrated and Descrip- tive Catalogue of Recent Bivalve Shells, p. 329, pl. 10, fig. 32. 1856. Periploma inaequivalvis Schumacher, H. and A. Adams, The Genera of Recent Mollusca, vol. 2, p. 361, pl. 96, figs. 2a-2b. 1862. Periploma trapezoides (Lamarck), Chenu, Man. Conchyl. et Paléont. Conchyliologique, vol. 2, p. 38, figs. 167-169. ; 1864. Periploma inaequivalvis Schumacher, Krebs, The West Indian Marine Shells, p. 108. 1867. Periploma trapezoides Deshayes, Schramm, Cat. Coq. Guadeloupe, p. 19. 1869. Anatina trapezoides Lamarck, Conrad, Amer. Jour. Conch., vol. 4, pt. 5, Appendix, No. 12, p. 51. 1869. Periploma inaequivalvis Schumacher, Conrad, Amer. Jour. Conch., vol. 4, pt. 5, Appendix, No. 12, p. 51. 1879. Periploma inaequivalvis Schumacher, Guppy, Quart. Jour. Conch., vol. 2, p. 162. - 1884. Periploma inaequivalvis Schumacher, Tryon, Structural and Systematic Conch., vol. 3, p. 145, pl. 108, figs. 57-59. 1886. Periploma inaequivalvis Schumacher, Dall, Mus. Comp. Zool., Bull., vol. 12, No. 6, p. 305. Fret 1887. Periploma inaequivalvis Schumacher, Fischer, Manuel de Conchyliologie et de Paléontologie Conchyliologique, p. 1170. 1889. Periploma inaequivalvis Schumacher, Dall, U.S. Nat. Mus., Bull. 37, p. 64. 408 BULLETIN 204 1903. Periploma inaequivalvis Schumacher, Dall, Wagner Free Inst. Sci. Trans., vol. 3, pt. 6, p. 1528. 1920. Periploma inaequivalvis Schumacher, Maury, Bull. Amer. Paleont., vol. 8, No. 34. 1925. Anatina trapezoides Lamarck, Lamy, Mus. Nat. Hist. nat. Paris, Bull., Vole31 op. 375: 1926. Periploma inaequivalvis Schumacher, Gardner, U.S. Geol. Sur., Prof. Paper 142-A, p. 61. 1931. Periploma margaritacea (Lamarck), Lamy, Jour. Conchyl., vol. 75, pt. 4, pp. 304-306. 1934. Periploma inaequivalvis Schumacher, Johnson, Boston Soc. Nat. Hist. Proc., vol. 40, No. 1, p. 30. 1940. 7 ha trapezoides (Lamarck), Smith, World-wide Sea Shells, p. 101, ig. 1364. 1943. Periploma inaequivalvis Schumacher, Gardner, U.S. Geol. Sur., Prof. Paper 199-A, p. 42. 1949. Periploma itaequivalve Schumacher, Lange de Morretes, Mus. Paranaense, Arg: vol. 7, art.15 p..50: 1952. Periploma inaeqguivalvis Schumacher, Pulley, Texas Jour. Sci., vol. 4, No. 2, p. 185. 1954. Periploma inaequivalvis Schumacher, Abbott, American Seashells, p. 473. 1958. Periploma inaequivalvis Schumacher, Olsson and McGinty, Bull. Amer. Paleont., vol. 39, No. 177, p. 22. 1960. Periploma inaequivalvis Schumacher, Olsson, Panamic-Pacific Pelecypoda, p. 460. Shell thin, moderately inflated, somewhat distorted, trans- versely suboval to subquadrate in outline, inequilateral, slightly inequivalve ( the right valve a little shorter but a little higher than the left), the valves when closed with a gape at the posterior end. On the suboval form the anterodorsal margin is short, the anterior end is obliquely subtruncate, the ventral margin of the right valve is shallowly arcuate but on the left valve obliquely truncated in front, the posterior end is subangularly rounded, and the postero- dorsal margin is long, gently sloping, and hardly concave. The beak on the suboval form is situated well toward the anterior end. On the subquadrate form the anterodorsal margin is flared upward a little, the anterior end is ragged and subtruncate, the ventral margin is rounded in front and obliquely truncated behind, the posterior end is nearly vertically truncated, and the posterodorsal margin is hardly concave. The beak on the subquadrate form is low, and situated somewhat in advance of the middle. Posterior area fairly broad, slightly sulcate, defined from the disk by a low ridge descending from the umbo to the posterior corner of the ventral margin, the dorsal edge of the posterior area faintly ridged against the ill-defined, slightly depressed, narrow escutcheonal area. Interior nacreous. VENEZUELAN CENOzoIC PELECYPoDS: WEISBORD 409 Hinge with a small but greatly thickened oval chondrophore, the face of which is more or less concave. An internal ridge diverges from under the hinge a short distance toward the posterior end. Ad- ductor scars shiny, the anterior elongated and narrowly lenticular, the posterior broader and subpyriform. Pallial line moderately re- mote from the margin. Pallial sinus broad, asymmetrically embayed to a distance of about one-third the length of the valve from the posterior end, the lower limb of the sinus swinging back to join the pallial line with which it forms a narrow, recumbent, U-shaped in- dentation with a more or less rounded apex. Body cavity with faint concentric undulations reflected through from the exterior, and studded with small scattered nodules. The external sculpture con- sists of low irregular concentric undulations, and over the whole of the surface there are crowded minute granulations. The color of the Recent shell is white within and dull white on the exterior. The periostracum is brown. Dimensions.—Specimen A558a 1-2, paired; right valve of pair (A558a-1), length 13.3 mm.; height 8.4 mm.; left valve of pair (A558a-2), length 13.9 mm.; height 8.1 mm.; thickness of pair 5.5 mm. Specimen A534a (subquadrate form), length 14.3 mm.; height 15.1 mm.; thickness 2.5 mm. Fossil specimen (1509a), fragment of right valve, heighth of fragment 9 mm. Localities —Recent, on beach at Playa Grande Yachting Club, Distrito Federal. Two specimens, one collected as an attached pair, the other a laterally foreshortened right valve. Lower Mare forma- tion at W-13, on hillside above west bank of Quebrada Mare Abajo. One fragment of a right valve. Range and distribution—tThe living P. inaequvalvis (= P. margaritacca) ranges from the Antilles to Brazil. If there is a pre- vious record of its occurrence as a fossil, it has escaped my notice. THRACIIDAE Cyathodonfa cf. tristani Olsson Pl. 59, figs. 3-6 1922. Thracia (Cyathodonta) Tristani Olsson, Bull. Amer. Paleont., vol. 9, No. 39, p. 383, pl. 20, fig. 3. 1925. Thracia (Cyathodonta) meridionalis (Guppy), Maury, Bull. Amer. Paleont., vol. 10, No. 42, p. 331, pl. 31, fig. 9. Not Raeta meridionalis Guppy, 1910, Agr. Soc. Trinidad and Tobago Soc. Paper No. 454, p. 8, pl. 2, fig. 1 (fide Rutsch, 1943). 410 BuLLETIN 204 1943. Thracia (Cyathodonta) tristani Olsson, Rutsch, Naturf. Gesell. Basel, Verhandl., vol. 54, p. 126, pl. 6, fig. 4. The Cabo Blanco form referred to this species is described from three imperfect molds of paired valves. Shell thin, large, suboval, inequilateral, inequivalve, the right valve larger and more convex than the left, the beak of the right valve rising above and curved over the beak of the left valve. The left valve of our largest speci- men (M462a) is broadly and shallowly depressed medially but this is probably due to crushing as the other two specimens, though not so complete, do not display this character. Anterodorsal margin long, nearly straight, and gently sloping, anterior end broadly rounded, ventral margin shallowly arcuate, posterior end obliquely truncate, posterodorsal margin somewhat concave. Posterior sub- margin depressed, the submargin broader on the left valve than on the right, the depression, or rostration bounded by the umbonal ridge of the disk. On the right valve there is a narrow sulcus in front of the umbonal ridge, but this is not present on the left valve. Beaks low and flattened, situated slightly behind the middle. Sculp- ture consisting of moderately large subregular concentric lirae or undulations which are about as wide as their intervals, the lirae on the two smaller specimens forming a slight angulation along a line at about the anterior third of the disk; the lirae extend over the whole of the disk from the beak to the ventral margin but cease at the umbonal ridge of both valves and are obsolescent in the sulcus fronting the umbonal ridge on the right valve. It is surmised that on the surface of the shell proper the undulations are somewhat tangential to the concentric growth lines, and that there are also minute lineolate granules, but as the concentric undulations on the molds are impressed from the inner surface of the valves the ex- ternal ornamentation cannot be seen on the specimens at hand. The hinge characters are not known. Dimensions —Specimen M462a, an internal mold of an at- tached pair with the beaks and posterior end broken away, length 62 mm.; height 50 mm.; thickness of pair 24 mm. Specimen L460a, an internal mold of an attached pair with the base missing, length 34 mm.; thickness of pair 10 mm. Localities —Playa Grande formation (Catia member) at W-15, VENEZUELAN CENOzOIC PELECYPoDS: WEISBORD 411 south side of Playa Grande road 40 meters southeast of its inter- section with the Playa Grande Yachting Club road. Two incomplete doublets. Playa Grande formation (Catia member), south side of Playa Grande road about 220 meters west of W-15. One incomplete doublet. Remarks.—Considering normal variability, the poor preserva- tion, and the distortion of all specimens (including the type), the Cabo Blanco shell seems to agree with C. tristant except perhaps in not being quite as long relative to height. Rutsch has shown that Maury’s C. meridionalis from the upper Miocene of Trinidad is the same as C. tristani from Costa Rica and has further suggested that Olsson’s C. tristani may eventually prove, with better material for comparison, to be identical with C. gatwnensis (Toula) (1909, K.-k. Geol. Reichsanst. Jahrb., vol. 58, p. 757, text fig. 15) from the middle Miocene of the Panama Canal Zone. The Recent west American analogue of C. tristani is C. undulata Conrad (see Keen, 1958, Sea Shells of Tropical West America, p. 232, fig. 595), but that has a nearly vertically truncated posterior end compared with the oblique truncation of the Cabo Blanco shell. Range and distribution.—C. tristani Olsson occurs in the middle Miocene of Costa Rica and of Venezuela (Paraguana Peninsula), and in the upper Miocene Springvale formation of Trinidad. PHOLADOMY IDAE Pholadomya cf. candida Sowerby Pl. 59, figs. 7, 8 1823. Pholadomya candida Sowerby, The Genera of Recent and Fossil Shells, No. 19, fig. 184. 1847. Pholadomya candida Sowerby, Gray, Zool. Soc. London, Proc., p. 194. 1858. Pholadomya candida Sowerby, H. and A. Adams, The Genera of Recent Mollusca, vol. 3, pl. 97, fig. 1. 1864. Pholadomya candida Sowerby, Krebs, The West Indian Marine Shells, p. 111. 1868. Pholadomya candida Sowerby, Conrad, Amer. Jour. Conch., vol. 4, pt. 5, Appendix, No. 12, p. 56. 1872. Pholadomya candida Sowerby, [in] Reeve, Conch. Icon., vol. 18, pl. 1, sp. la-c. 1878. Pholadomya candida Sowerby, Moérch, Catalogue of West-India Shells, p. 14. 1884. Pholadomya candida Sowerby, Tryon, Structural and Systematic Conch- ology, vol. 3, p. 151, pl. 108, figs. 76-77. 1887. Pholadomya candida Sowerby, Fischer, Manuel de Conchyliologie et de Paléontologie Conchyliologique, p. 1179, pl. 22, fig. 15. 412 BuLLeETIN 204 1889. Pholadomya candida Sowerby, Lorié, Samml. Geol. Reichs-Mus. Leiden, ser. 2, vol. 1, pp. 128-129, 141, pl. 2, figs. 34a, b. 1903. Pholadomya candida Sowerby, Dall, Wagner Free Inst. Sci.. Trans., vol. 3, pt. 6, p. 1532. 1909. Pholadomya candida Sowerby, Dall, Nautilus, vol. 22, p. 116. 1925. Pholadomya candida Sowerby, Maury, Bull. Amer. Paleont., vol. 10, No. 42, p. 333. 1930. Pholadomya candida Sowerby, Stewart, Acad. Nat. Sci. Philadelphia, Special Publ. No. 3, p. 300. 1940. Pholadomya candida Sowerby, Smith, World-wide Sea Shells, pp. 100- 101, figs. 1353a-c. Shell large, thin, subnacreous, elongated and somewhat ob- liquely suboval, moderately inflated. Anterior end short, hardly rounded, the valves seemingly with a narrowly lanceolate gape in front of the beak; ventral margin shallowly arcuate; posterior end a little broader than the anterior, somewhat alated, and gaping; posterodorsal margin long and moderately concave. Umbonal area full, the beaks situated just behind the anterior end, and appressed on top. The sculpture consists of a dozen or so radial ribs crossed by more numerous and fairly regular low concentric lirae which produce crenations at the intersections with the radials. The radial ribs are subequal to unequal on the lower half of the valve (where they enlarge gradually toward the base) but are regular and equal in size on the umbonal area. The radial ribs are absent on the an- terior fifth of the valve, are strongest on the middle of the disk, and become obsolescent on the posterior slope. The concentric lirae are pronounced on the umbo, where, together with the radial riblets they form a decussated pattern but are fainter toward the base. The interior is inaccessible. Dimensions.—Specimen M357a, paired valves, length 104 mm.; height (beak to base along anteriormost radial) 72 mm.; thickness of pair 61 mm. Locahty.—Playa Grande formation (Catia member) at W-15, south side of Playa Grande road, 45 meters southeast of its inter- section with the Playa Grande Yachting Club road. Two specimens, both of them doublets with a filling of calcareous sandstone. Remarks.—So far as can be determined with the imperfectly preserved specimens, the Cabo Blanco fossil seems to be the same as the Recent Caribbean P. candida Sowerby. There are only a few specimens of any of the late Cenozoic species of Pholadomya from VENEZUELAN CENOZOIC PELECYPODS: WEISBORD 413 tropical America, and none of them is perfect. Furthermore, the illustrations of P. candida by authors suggest that there is consider- able variation in details of sculpture, so that all of the known fossil species are similar to one variant or another of the Recent P. can- dida. Therefore, the Cabo Blanco fossil also resembles the following later Tertiary species of Pholadomya of the southern Caribbean area: P. walli Maury (1925, Bull. Amer. Paleont., vol. 10, No. 42, pp. 332-333, pl. 31, figs. 8, 11). Earlier Miocene (Machapoorie) of Trinidad. P. sawkinst Maury (1925, pp. 333-334, pl. 31, fig. 10). Earlier Miocene (Machapoorie) of Trinidad. P. falconensis F. and H. Hodson (1927, Bull. Amer. Paleont., vol. 13, No. 49, p. 44, pl. 26, fig. 6; pl. 27, figs. 1-2). Miocene, State of Falcon, Venezuela. P. walli Maury is an exceedingly ventricose shell, but otherwise, to judge from the incomplete specimen, it is much like P. candida Sowerby. P. sawkinst Maury is a smaller shell, but as noted by Maury herself, is close to the typical P. candida, and if not the same species as that, may be a precursor. P. falconensis F. and H. Hodson is relatively broader than P. candida and bears more numerous radial riblets than the typical P. candida. Vokes (1938, Amer. Mus. Novi- tates, No. 988, pp. 17-18) reported Pholadomya species from the upper Miocene Springvale formation of Trinidad which has the general outline of P. sawkinst Maury but sculptural details that closely approximate those of P. falconensis F. and H. Hodson. Range and distribution—tThe Recent P. candida Sowerby is a Caribbean species. As a fossil it occurs in the Pleistocene of Aruba. 414 BuLLeTiIn 204 BIBLIOGRAPHY Abbott, R. Tucker 1950. The Molluscan fauna of the Cocos-Keeling Islands, Indian Ocean. Raffles Mus., Bull. No. 22, pp. 68-98. 1955. The Titean R. Peale collection. Nautilus, vol. 68, No. 4, pp. 123- 126, pl. 4. 1959. The family Vasidae in the Indo-Pacific. Indo-Pacific Mollusca, vol. 1, No. 1, pp. 15-32, pls. 1-10. 1960. The genus Strombus in the Indo-Pacific. Indo-Pacific Mollusca, vol. 1, No. 2, pp. 33-146, pls. 11-117. 1961. The genus Lambis in the Indo-Pacific. Indo-Pacific Mollusca, vol. 1, No. 3, pp. 147-174, pls. 118-134. Adam, W., and Leloup, E. 1938-39. Resultats scientifiques du voyage aux Indes Orientales Néerlan- daises de LL. AA. RR. le Prince et la Princesse Léopold de Bel- gique. Mus. Roy. Hist. nat. Belgique, Mém., hors sér., vol. 2, No. 19, Prosobranchia et Opisthobranchia, pp. 1-209, pls. 1-8 (1938) ; No. 20, Gastropoda-Pulmonata, Scaphopoda et Bivalvia, pp. 1- 126, 5 figs., pls. 1-7, 1 map (1939). Adams, Arthur 1850c. Description of new species of the genus Cumingia, with some additional characters. Zool. Soc. London, Proc., pt. 18, pp. 24-25. 1850d. Monographs of Cyclostrema, Marryat, and Separatista, Gray, two genera of gasteropodous mollusks. Zool. Soc. London, Proc., pt. 18, pp. 41-45. 1850e. Monograph of Phos, a genus of gasteropodous Mollusca. Zool. Soc. London, Proc., pt. 18, pp. 152-155. 1850f. A monograph of Modulus, a genus of gasteropodous Mollusca, of the family Littorinidae. Zool. Soc. London, Proc., pt. 18, pp. 203- 204. 1863. On the genera and species of Fossaridae found in Japan. Zool. Soc. London, Proc. for 1863, pp. 110-113. 1864. On some new genera and species of Mollusca from the seas of China and Japan. Ann. Mag. Nat. Hist., ser. 3, vol. 15, pp. 307- 310. 1865. On some new genera of Mollusca from the seas of Japan. Ann. Mag. Nat. Hist., ser. 3, vol. 15, pp. 322-324. Adams, A. C., and Kendall, W. C. 1891. Report upon an investigation of the fishing grounds off the west coast of Florida. U.S. Fish Com., Bull. vol. 9 for 1890, pp. 289- 312. Adams, Arthur, and Reeve, Lovell 1848-50. Mollusca. [In] A. Adams, The zoology of the voyage of H.M.S. Samarang; under the command of Captain Sir Edward Belcher. London, pt. 1, i-x + 24 pp., pls. 1-9 (1848); pt. 2, pp. 25-44, pls. 10-17 (1850); pt. 3, pp. 45-87, pls. 18-24 (1850). Adams, Charles Baker 1842. Description of a new species of Thracia. Assoc. Amer. Geol. and Natural., art. 3, p. 145, figs. Adams, Henry 1861a. Descriptions of some new genera and species of shells from the collection of Hugh Cuming, Esq. Geol. Soc. London, Proc. for 1861, pp. 383-385. 1861b. Description of a new genus of shell from the collection of Hugh Cuming, Esq. Zool. Soc. London, Proc. for 1861, p. 272. VENEZUELAN CENOzoIC PELECYPops: WEISBORD 415 BIBLIOGRAPHY Adams, George Irving 1908. An outline review of the geology of Peru. Smithsonian Inst., Ann. Rept. for 1908, pp. 385-430, 5 maps, text figs. Adanson, M. 1757. Histoire naturelle du Sénégal. Coquillages. Paris, viii + 275 pp., 19 pls., 1 map Agassiz, Louis 1848,1854. Bibliographia Zoologiae et Geologiae. A general catalogue of all books, tracts, and memoires on zoology and geology. Roy Soc., London, vol. 1, 506 pp. (1848) ; vol. 2, 604 pp. (1854); vol. 3, 657 pp. (1854) ; vol. 4, 604 pp. (1854). Aguilera, José G., and Ordonez, Ezequiel 1893. Datos para la Geologia de Mexico. Tacubaya, 87 pp. Ameghino, Florentino 1903. L’dge des formations sédimentaires de Patagonia. Soc. Cientif. Ar- gentina, An., vols. 50, 54, 231 pp. 1911. L’age des formations sédimentaires Tertiaires de VArgentine en relation avec l’antiquité de Phomme. Note supplémentaire. Mus. Nac. Buenos Aires, An., ser. 3, vol. 15 (22), pp. 169-179. American Malacological Union 1940. Scientific contributions made from 1882 to 1939 by Henry A. Pilsbry, Sc.D. Amer. Malac. Union, 63 pp. Anderson, Frank Marion, and Martin, Bruce 1914. Neocene record in the Temblor Basin, California, and Neocene deposits of the San Juan District, San Luis Obispo County. Califor- nia Acad. Sci., Proc., ser. 4, vol. 4, pp. 15-112, pls. 1-10. Andre, Marc 1943. Liste des publications scientifiques de Edouard Lamy. Abbeville, 21 pp. 1877. Descriptions of one genus [Mysilla] and twenty-five species of marine shells from New South Wales. Zool. Soc. London, Proc. for 1877, pp. 171-177, pl. 26. Anthony, J. W. 1955. Geological stratigraphy. Geochronology. Univ. Arizona Phys. Sci. Bull., No. 2, pp. 82-86. Apgar, A. 1891. Mollusks of the Atlantic Coast of the United States to Cape Hat- teras. New Jersey Nat. Hist. Soc., Jour., vol. 2, No. 2, pp. 75-162, 3 pls. Aradas, Andrea, and Benoit, Luigi 1870. Conchigliologica vivente marina della Sicilia. Catania, 321 pp., 5 pls. d‘Argenville, Antoine Joseph Dezallier 1742, 1757, 1780. L’histoire naturelle ... de la Société Royale des Sciences de Montpelier. Paris. Second edition, Paris, 1757. Third edition [by MM. de Favanne de Montcervelle, pére et fils], Paris, 3 vols., 1780. Arango y Molina, Rafael 1862. Description d’espéces nouvelles de’ VIle de Cuba. Jour. Conchyl., vol. 10, pp. 408-410. Arnold, Ralph, and Anderson, Robert 1910. Geology and oil resources of the Coalinga District, California. U.S. Geol. Sur., Bull. 398, 354 pp., 52 pls. Bahamonde N., Nibaldo 1950. Moluscos marinos colectados en Tarapacd. Investig. Zool. Chilenos, No. 2, pp. 9-11. 416 BULLETIN 204 Baker, Frank Collins 1895. Preliminary outline of a new classification of the family Muricidae. Chicago Acad. Sci., Bull., vol. 2, No. 2, pp. 169-189. 1897. Critical notes on the Muricidae. Acad. Sci. St. Louis, Trans., vol. 7, No. 16, pp. 371-391. 1903. Note on Murex marcoensis Sowerby. Nautilus, vol. 17, pp. 88-89. Baker, Fred 1925. A new species of mollusk (Dentalium hannai) from Lower Cali- fornia, with notes on other forms. California Acad. Sci. Proc., 4th ser., vol. 14, No. 4, pp. 83-87, pl. 10. Balch, Francis Noyes 1899. List of marine Mollusca of Coldspring Harbor, Long Island, with descriptions of one new genus and two new species of nudibranchs. Boston Soc. Nat. Hist., Proc., vol. 29, No. 7, pp. 133-162, pl. 1. Bales, Blenn Rife 1942. Albinos of Muricidea ostrearum Conrad. Nautilus, vol. 56, No. 1, pp. 35-36. Bandy, O. L. 1958. Dominant molluscan faunas of the San Pedro Basin, California. Jour. Paleont., vol. 32, pp. 703-714, figs. Barker, R. W. 1933. Notes on the Tablazo faunas of S. W. Ecuador. Geol. Mag., vol. 70, pp. 84-90, 1 fig. Barnard, K. H. 1958. Contributions to the knowledge of South African marine Mollusca. Pt. 1. Gastropoda: Prosobranchiata; Toxoglossa. South African Mus., Ann., vol. 44, pt. 4, pp. 73-163, figs. 1-30, pl. 2. Barnes, D. H. 1824. Notice of several species of shells. Lyc. Nat. Hist. New York, Ann., vol. 1, pp. 131-140, pl. 9. Bartrum, J. A. 1919. New fossil Mollusca. New Zealand Inst., Trans., vol. 51, pp. 96- 100, pl. 7. Bartsch, Paul 1908. A new shipworm from the United States. Biol. Soc. Washington, Proc., vol. 21, pp. 211-212. 1909. More notes on the family Pyramidellidae. Nautilus, vol. 23, pp. 54-59. 1918. A new marine mollusk of the genus Cerithiopsis from Florida. Biol. Soc. Washington, Proc., vol. 31, pp. 135-136. 1920c. A new shipworm. Biol. Soc. Washington, Proc., vol. 33, pp. 69-70. 1923. Additions to our knowledge of shipworms. Biol. Soc. Washington, Proc., vol. 36, pp. 95-101. 1945. The west Pacific species of the molluscan genus Aforia. Washing- ton Acad. Sci., Jour., vol. 35, No. 12, pp. 388-393. 1947a. A monograph of the west Atlantic mollusks of the family Aclididae. Smithsonian Misc. Collections, vol. 106, No. 20, publ. 3868, 29 pp., 6 pls. 1947b. The little hearts (Corculum) of the Pacific and Indian oceans. Pacific Sci., vol. 1, No. 4, pp. 221-226, pls. 1-2. Bartsch, Paul, and Rehder, Harald A. 1945. The west Atlantic boring mollusks of the genus Martesia. Smith- sonian Misc. Collections, vol. 104, No. 11, publ. 3804, 16 pp., 3 pls. Bartsch, Paul, Rehder, Harald Alfred, and Shields, Beulah E. 1946. A bibliography and short biographical sketch of William Healy Dall. Smithsonian Misc. Collections, vol. 104, No. 15, 96 pp., 1 pl. VENEZUELAN CENOZOIC PELECYPops: WEISBORD 417 Baughman, J. L. 1948. An annotated bibliography of oysters with pertinent material on mussels and other shellfish and an appendix on pollution. Texas A. & M. Research Found., 794 pp. Bavay, Arthur 1905. Sur quelques espéces nouvelles, mal connues ou faisant double emploi dans le genre Pecten. Jour. Conchyl., vol. 53, pp. 18-30, pl. 2. 1911. Une marginellidée nouvelle de Cuba. Mus. Nat. Hist. nat. Paris, Bull., vol. 17, No. 4, pp. 240-243, fig. 1. 1936. [In] Lamy, Edouard, Catalogue des Pectenidae vivants du Muséum National d’Histoire Naturelles de Paris déterminés par feu A Bavay. Jour. Conchyl., vol. 79, pp. 306-321 Bayle, E. 1879. Liste recticative de quelques noms de genre. Jour. Conchyl., vol. 27, pp. 34-35. 1880. Liste recticative de quelques noms de genres et d’espéces. Jour. Conchyl., vol. 27, pp. 240-251. Beal, C. 1948. Reconnaissance of the geology and oil possibilities of tae Cali- fornia, México. Geol. Soc. Amer., Mem., vol. 31, pp. i-x + 138, pls. 1-11. de la Beche, H. T. 1829. Remarks on the geology of Jamaica. Geol. Soc. London, Trans., ser. 2, vol. 2, pp. 142-194, pls. 18-22. Beets, C. 1941. Eine jungmiocdne Mollusken-Fauna von der Halbinsel Mangkali- hat, Ost-Borneo (nebst Bemerkungen iiber andere Faunen von Ost- Borneo; die Leitfossilien-Frage). Geol.-Mijnbouwk. Genootschap Nederland en Kolonién Verhandl., Geol. ser., vol. 13, pt. 1, pp. 1- 218, pls. 1-9. 1950. Précis des espéces fossiles du genre Cryptomya Conrad. Basteria, vol. 14, Nos. 1-2, pp. 16-20, fig. 1. Behre, E. H. 1950. Annotated list of the fauna of the Grand Isle region (1928-1946). Occas. Papers Marine Lab., No. 6, pp. 1-66. Bellardi, Luigi 1875. Monografia delle Nuculidi trovate finora vei terreni Terziari del Piemonte e della Liguria. Torino, 32 pp., 1 pl. 1876. Descrizione di un nuovo genere [Sabatia] della famiglia delle Bullidae fossile del terreno Pliocenico inferiore del Piemonte e della Liguria. Soc. Malac. Italiana, Bull., vol. 2, pp. 207-210. Belletante, Henri 1954. Catalogue des Cymatiidae du Muséum National d’Histoire Natu- relle de Paris. Jour. Conchyl., vol. 94, Nos. 2-3, pp. 70-96. van Bentham Jutting, Tera 1927. Marine molluscs of the Island of Curacao. Bijdr. Dierk. Kon. Zool. Gen., Natura Artis Magistra Amsterdam, vol. 25, pp. 1-36, figs. 1-5. Bentson, Herdis 1940. A systematic study of the fossil gastropod Exilia. Univ. California Publ., Bull. Dept. Geol. Sci. vol. 25, No. 5, pp. 199-238, pls. 1-3, 1 table. Bernard, Félix 1896b. Etudes comparatives sur la coquille des lamellibranches Condylo- cardia type nouveau de lamellibranches. Jour. Conchyl., vol. 44, pp. 189-206, pl. 6. 418 BuLLETIN 204 Berry, Edward W. 1918c. Paleogeographic significance of the Cenozoic floras of equatorial America. Geol. Soc. Amer., Bull., vol. 29, pp. 631-636. 1921a. Tertiary fossil plants from Costa Rica. U.S. Nat. Mus., Proc., vol. 59, pp. 169-185, pls. 22-26. 1928. A palm fruit from the Miocene of western Panama. Washington Acad. Sci., Jour., vol. 18, pp. 455-457, 1 fig. 1945. Fossil floras from southern Ecuador. Johns Hopkins Univ. Studies Geol., No. 14, pp. 1-150, pls. 6-10. Berry, Samuel Stillman 1944. A second California Dimya. Malac. Soc. London, Proc., vol. 26, pt. 1, pp. 25-26, figs. 1-4. 1957. Notices of new Eastern Pacific Mollusca. I. Leaflets in Malacology, vol. 1, No. 14, pp. 75-78. Bertin, Victor 1878. Revision des Tellinidés du Muséum d’Histoire Naturelle, Paris. Mus. Hist. Nat., Nouv. Arch., sér. 2, vol. 1, pp. 201-361, pls. 8-9. 1880. Revision des Garidées du Muséum d’Histoire Naturelle, Paris. Mus. Hist. Nat., Nouv. Arch., sér. 2, vol. 3, pp. 57-129, pls. 4-5. 1881. Revision des Donacidées du Muséum d’Histoire Naturelle, Paris. Mus. Hist. Nat., Nouv. Arch., sér. 2, vol. 4, pp. 57-129, pls. 3-4. Bigelow, H. B. 1926. Plankton of the offshore waters of the Gulf of Mexico. U. S. Bur. Fish., Bull., vol. 40, pt. 2, pp. 1-509, figs. 1-134. Binney, W. G. 1863-64. Bibliography of North American conchology previous to the year 1860. Smithsonian Misc. Collections, vol. 5, vii + 650 pp.; vol. 9, v + 306 pp. Biondi, Salvatore 1859. Descrizione di alcune specie malacologiche nuove che vivono ne nostro littorale. Accad. Gioenia Sci. Nat. Catania, Atti, ser. 2, vol. 14, pp. 115-122, 1 pl. Bizet, Edouard 1892. Catalogue des mollusques ... dans le Département de la Somme. Soc. Linnéenne du Nord de France, Mém., vol. 8, pp. 262-405. Blaney, Dwight 1904. List of shell-bearing Mollusca of Frenchman’s Bay, Maine. Boston Soc. Nat. Hist., Proc., vol. 32, No. 2, pp. 23-41, pl. 1. Bois-Reymond Marcus, Eveline de 1956. On some Prosobranchia from the coast of Sado Paulo. Bol. Inst. Oceanografico, vol. 7, Nos. 1-2, pp. 3-28, pls. 1-4. Boissevain, Maria 1906. The Scaphopoda of the Siboga Expedition treated together with the known Indo-Pacific Scaphopoda. Mollusca II. Siboga Expeditie, vol. 28, 76 pp., 6 pls., 39 text figs. Bolten, J. F. 1798. Museum Boltenianum ... pars secunda continens Conchylia sive Testacea univalvia, bivalvia & multivalvia. Hamburg, viii + 199 pp. Boone, Lee 1928. Scientific results of the First Oceanographic Expedition of the “Pawnee” 1925. Mollusca from tropical East American seas. Bingham Oceanogr. Coll., Bull., vol. 1, art. 3, pp. 1-20, figs. 1-5. Borchert, Aloys 1901. Die pea ntrenionna und das Alter der Parand-Stufe. Stuttgart, 78 pp., 5 pls. VENEZUELAN CENOzoIC PELECYpops: WEISBORD 419 Bosc, L. A. G. 1901. Histoire naturelle des coquilles. Paris, vol. 3. Bose, Emilio 1905. Resetia acerca de la geologia de Chiapas y Tabasco. Inst. Geol. Mexico, Bol., vol. 20, 116 pp., 9 pls. 1907. Sobre algunos fésiles Pleistocénicos en la Baja California recogi- dos por el Sr. Dr. E. Angermann. Inst. Geol. Mexico, Parergones, vol. 2, No. 2, pp. 41-45. de Boury, Eugéne 1911. Sur les Scalaria du Chili. Rev. Chilena Hist. Nat., afio 15, No. 1, pp. 33-37. 1912-13. Description de Scalidae nouveaux ou peu connus. Jour. Conchyl., vol. 60, pp. 169-196 (1912); pp. 270-322 (1913), pls. 7-10. 1913. Observations sur quelques espéces ou sous-genres de Scalidae. Jour. Conchyl., vol. 61, pp. 65-112. Bowles, Edgar 1939. Eocene and Paleocene Turritellidae of the Atlantic and Gulf Coast Plain of North America. Jour. Paleont., vol. 13, No. 3, pp. 267-336, pls. 31-34. Bousfield, E. L. 1958. Littoral marine arthropods and mollusks collected in western Nova Scotia, 1956. Nova Scotian Inst. Sci., Proc., vol. 24, pt. 3, pp. 303- 325, fig. 1. 1960. Canadian Atlantic Sea Shells. Nat. Mus. Canada, 72 pp., 133 figs. Bousfield, E. L., and Leim, A. H. 1958. The fauna of Minas Basin and Minas Channel. Nat. Mus. Canada, Bull. No. 166, Contrib. to Zool., pp. 1-29, figs. 1-3. Bradley, W. H., and Cooke, Peter 1959. Living and ancient populations of the clam Gemma gemma in a Maine coast tidal flat. Fish and Wildlife Serv., Fishery Bull. 137, pp. 305-334, figs. 1-18. Branner, John Casper 1919. Outlines of the geology of Brazil to accompany the Geologic Map of Brazil. Geol. Soc. Amer., Bull., vol. 30, pp. 189-338, pls. 7 (colored map), 8-10. Brown, C. Barrington 1879. On the Tertiary deposits on the Solimoes and Javary Rivers in Brazil. Geol. Soc. London, Quart. Jour., vol. 35, pp. 77-82. Brocchi, G. B. 1814. Conchiologia fossile Subapennina con osservazioni geologiche sugli Apennini e sul suolo adiacente. Milano, 2 vols., 712 pp., 16 pls. Bronn, H. G. 1832. Ergebnisse meiner naturhistorisch-dkonomischen Reisen. Zweyter Theil: Skizzen und Ausarbeitungen iiber Italien nach einem zweiten Besuche in Jahre 1827. Heidelburg, Leipzig, xviii + 686 pp., 3 pls. Brooks, Stanley T. 1933. Natica sancti-vicentii, sp. nov. Carnegie Mus., Ann., vol. 21, No. 4, p. 413, fig. 1. Brown, [Captain] Thomas 1835. Description of a new British shell—The clouded scallop—Pecten nebulosus. Edinburgh Jour. Nat. Hist., vol. 1, p. 9, text fig. Bruff, Stephen C. 1946. The paleontology of the Pleistocene molluscan fauna of the Newport Bay area, California. Univ. California Publ., Bull. Dept. Geol. Sci., vol. 27, pp. 213-240, 12 figs. 420 BULLETIN 204 Brugnone, G. A. 1862. Memoria sopra alcuni pleurotomi fossili dei dintorni di Palermo. Palermo, 41 pp., 2 pls. 1877. Osservazione critiche sul catalogo delle conchiglie fossili di Monte Pellegrino e Ficarazzi del March. di Monterosato. Soc. Malac. Italiana, Bull., vol. 3, pp. 17-46. Bucknill, C. E. R. 1924. On Turbonilla powelli, nov. spec. Malac. Soc. London, Proc., vol. 16; pt. 3; p. 1225 fig: 1927. Description of two new species of marine gasteropod. New Zea- land Inst., Trans., vol. 58, pp. 312, pl. 35. Burkenroad, M. D. 1933. Pteropoda from Louisiana. Nautilus, vol. 47, pp. 54-57. Burn, Robert 1960a. A bivalve gastropod. Nature, vol. 186, No. 4719, p. 179. 1960b. Australian bivalve gastropods. Nature, vol. 187, No. 4731, pp. 44-46, 14 text figs. Bush, Katherine J. 1883. Catalogue of Mollusca and Echinodermata dredged on the coast of Labrador by the expedition under the direction of Mr. W. A. Stearns in 1882. U. S. Nat. Mus., Proc., vol. 6, pp. 236-247, pl. 9. 1893. Report on the Mollusca dredged by the “Blake” in 1880, including descriptions of several new species. Mus. Comp. Zool., Bull., vol. 23, pp. 199-244, pls. 1-2. 1909a. Notes on the family Pyramidellidae. Amer. Jour. Sci., ser. 4, vol. 27, pp. 475-484, figs. 1-12. 1909b. A new Bela from Frenchman’s Bay, Maine. Nautilus, vol. 23, pp. 61-62, 1 fig. Button, Fred L. 1902. West American Cypraeidae. Jour. Conch., vol. 10, No. 8, pp. 254- 258. Butterlin, Jacques 1960. Géologie générale et régionale de la Republique d’Haiti. Inst. Htes. Amérique Latine, Trav. et Mém., No. 6, 194 pp., 17 figs., 18 pls., 15 tables, 1 geol. map. Cameron, Roderick 1961. Shells. [In] Pleasures and Treasures. New York, G. P. Putman’s Sons, 128 pp., 32 pls., 95 figs. Campbell, G. Bruce 1961. Colubrariidae (Gastropoda) of tropical west America, with a new species. Nautilus, vol. 74, No. 4, pp. 136-142. Carcelles, Alberto R. 1938. Moluscos del contenido estomocal de “Astropecten cingulatus” Sladen. Physis, vol. 12, pp. 251-266, pls. 1-2. 1939. “Pectunculus longior” y “Mesodesma mactroides” de la Argentina y Uruguay. Physis, vol. 17, pp. 735-743, figs. 1-3. 1941a. “Pododesmus” de la Argentina y Uruguay. Physis, vol. 19, pp. 5-10, pls. 1-2. 1941b. “Erodona mactroides” en el Rio de La Plata. Physis, vol. 19, pp. 11-21, 1 pl. 1942. Nota sobre el mejillon “Aulacomya magellanica” (Chemnitz). Physis, vol. 19, pp. 180-190, pls. 1-2. 1943a. Sobre las variaciones de Pitaria rostrata (Koch). Mus. Hist. Nat. Montevideo, Comunic. Zoolégicas, vol. 1, No. 7, pp. 1-10, pls. 1-3. VENEZUELAN CENOZOIC PELECYPOoDS: WEISBORD 421 1943b. Observaciones sobre Trophon varians (d’Orbigny). Inst. Mus. Univ. Nac. La Plata, Notas Mus. La Plata, Zoologia, vol. 8, No. 72, pp. 431-437, pls. 1-3. 1944a. Las especies del género Capulus Montfort 1810, en aguas Argen- tinas. Mus. Hist. Nat. Montevideo, Comunic. Zoolégicas, vol. 1, No. 9, pp. 1-5, figs. 1-2. 1944b. Nota sobre algunos moluscos Magallanicos obtenidos frente al Rio de La Plata. Mus. Hist. Nat. Montevideo, Comunic. Zoo- légicas, vol. 1, No. 19, pp. 1-11, pl. 1. 1944c. Nuevos datos sobre el contenido estomocal de “Astropecten cingu- latus” Sladen. Physis, vol. 19, pp. 461-472. 1944d. Catalogo de los moluscos marinos de Puerto Quequén (Repub- lica Argentina). Inst. Univ. Nac. La Plata, Rev. Mus. La Plata, nueva serie, seccién Zoologia, vol. 3, pp. 233-309, pls. 1-15. 1945a. Las especies actuales de “Tegula” en la Republica Argentina. Physis, vol. 20, pp. 31-40, figs. 1-19. 1945b. Nota sobre los moluscos citados Darwin, Ameghino y Bravard para la formacién pampeana de Puerto Belgrano, Republica Ar- gentina. Physis, vol. 20, pp. 41-49. 1946a. Notas sobre dos especies Argentinas de Marginellidae. Inst. Mus. Univ. Nac. La Plata, Notas Mus. La Plata, Zoologia, vol. 11, No. 92, pp. 51-57. 1946b. Observaciones sobre algunas especies actuales y fésiles de Trophon. Mus. Univ. Nac. La Plata, Notes Mus. La Plata, vol. 11, Zoologia, No. 93, pp. 59-89, figs. 1-13. 1947a. Notas sobre algunos gastrépodos marinos del Uruguay y la Argen- tina. Mus. Hist. Nat. Montevideo, Comunic. Zoolégicas, vol. 2, No. 40, pp. 1-27, pls. 1-7. 1947b. Notas sobre algunos bivalvos Argentinos. I. Notas sobre Plicatula mesembrina Dall. Mus. Hist. Nat. Montevideo, Comunic. Zoo- légicas, vol. 2, No. 41, pp. 1-10, figs. 1-3, pl. 1. 1950. Catdlogo de los moluscos marinos de la Patagonia. Mus. Nahuel Huapi Perito Dr. Francisco P. Moreno, An., pp. 41-100, pls. 1-6, map. 1953. Nuevas especies de gastrépodos marinos de las repiublicas oriental del Uruguay y Argentina. Mus. Hist. Nat. Montevideo, Comunic. Zoolégicas, vol. 4, No. 70, pp. 1-16, pls. 1-5. 1954a. Especies sudamericanas de Argobuccinum Burguiére 1792. Inst. Nac. Investig. Cienc. Nat. y Mus. Argentino Cienc. Nat. “Bern- ardino Rivadavia’, Rev., Cienc. Zoolégicas, vol. 2, No. 15, pp. 243-254, 1 pl. 1954b. Observaciones sobre los géneros Nucella, Chorus, y Concholepas. Inst. Nac. Investig. Cienc. Nat. y Mus. Argentino Cienc. Nat. “Bernardinao Rivedavia”, Rev., Cienc. Zoolégicas, vol. 2, No. 16, pp. 254-275, pls. 1-5. Carcelles, Alberto, and Parodiz, Juan José 1939. “Dorsaninae’ Argentinas y Uruguayas. Physis, vol. 17, pp. 745- 769, figs. 1-6, 1 pl. Carcelles, A. R., and Williamson, S. 1. 1951. Catdlogo de los moluscos marinos de la Provincia Magallanica. Inst. Nac. Investig. Cienc. Nat. y Mus. Argentino Cienc. Nat. “Bernardino Rivadavia”, Rev., Cienc. Zoolégicas, vol. 2, pp. 225- 383. Carlson, C. E. 1925. Geological notes on a part of southern Trinidad, B.W.I. Econ. Geol., vol. 20, pp. 152-167. 422 BuLLETIN 204 Carpenter, Horace F. 1889. A catalogue of the shell-bearing Mollusca of Rhode Island. Prov- idence, 2d ed., 7 pp. 1901-02. The shell-bearing Mollusca of Rhode Island. Nautilus, vol. 15, pp. 92-96, 104-107, 113-115, 130-132. Carpenter, Philip Pearsall 1863. Review of Prof. C. B. Adams’s Catalogue of the shells of Panama from the type specimens. Zool. Soc. London, Proc. pp. 1-31, 339-369. Carson, Carlton M. 1925. Some new species from the Pliocene of southern California with a few changes in nomenclature. Southern California Acad. Sci., Bull., vol. 24, pt. 2, pp. 31-35, pl. 1. Cary, L. R. 1906. A contribution to the fauna of the coast of Louisiana. Gulf Biol. Sta. Louisiana, Bull., vol. 6, pp. 50-59. Casey, Thomas L. 1904. Notes on the Pleurotomidae with descriptions of some new genera and species. Acad. Sci. St. Louis, Trans., vol. 14, No. 5, pp. 123- 170. Chapman, F., and Singleton, F. A. 1925. A revision of the Cainozoic species of Glycymeris in southern Australia. Roy. Soc. Victoria, Proc., vol. 37, new ser., pt. 1, art. 2, pp. 18-60, pls. 1-4. Chace, E. P. 1958. A new mollusk from San Felipe, Baja California. San Diego Soc. Nat. Hist., Trans., vol. 12, No. 19, pp. 233-234, fig. 1. 1958b. The marine molluscan fauna of Guadalupe Island, Mexico. San Diego Soc. Nat. Hist., Trans., vol. 12, No. 19, pp. 319-332, fig. 1. Chase, Philip W. 1933. The geology along the Perene and Tambo Rivers of eastern Peru. Jour. Geol., vol. 41, pp. 513-526. Chaster, G. W., Knight, G. A. F., Melvill, J. C., and Hoyle, W. E. 1901. List of British marine Mollusca and Brachiopoda. Jour. Conch., vol. 10, pp. 9-27. Chavan, André 1940. Sur deux nouveaux groupes de Carditidae. Jour. Conchyl., vol. 84, pp. 97-102, figs. 1-2. 1946. Nouvelles notes sur les Jagonia (Lamellibranches). Mus. Nat. Hist. nat. Paris, Bull., vol. 18, No. 4, pp. 345-347. Chenu, James Charles 1842-53. Illustrations conchyliologiques ou description et figures de tout les coquilles connues vivants et fossiles, classées suivant le systeme de Lamarck modifié d’apres les progrés de la science, et comprenant les genres nouveaux et les espéces récement dé- couvertes. Paris, 4 vols., 215 pp., 481 pls. 1845. Bibliothégue Conchyliologique. Le Conchyliologiste Universel ou figures des coquilles jusqu’a présent inconnues recueillies en divers voyages a la mer du sud depuis l’année 1764 par Thomas Martin. Ouvrage revu par J. C. Chenu. Ser. 1, vol. 2, pp. vi+32, pls. 1-56. Clapp, W. F. 1923. A new species of Teredo from Florida. Boston Soc. Nat. Hist., Proc., vol. 37, pp. 31-38, 1 fig., pls. 3-4. Clarke, Arthur H. 1954. Shell bearing marine mollusks of Cape Ann, Massachusetts. Nautilus, vol. 67, No. 4, pp. 112-120, pl. 9, right fig. VENEZUELAN CENOozoIC PELECYpops: WEISBORD 423 1959. New abyssal mollusks from off Bermuda collected by Lamont Geological Observatory research vessels. Malac. Soc. London, Proc., vol. 33, pt. 5, pp. 231-238, 1 text fig., pl. 13. Clench, William J. 1928. Venus mercenaria var. notata Say. Nautilus, vol. 14, pp. 120-124. 1951. Busycon coarcticum Sowerby. Occas. Papers on Mollusks, vol. 1, No. 16, pp. 405-412, pl. 50. 1955. 4 new Murex from Matanzas, Cuba. Breviora, No. 44, 2 pp. figs. 1-3. Clench, William J., and Aguayo, Carlos Guillermo 1939. A new Orthaulax from western Cuba. Soc. Cubana Hist. Nat. “Felipe Poey”, Mem., vol. 13, No. 5, pp. 357-358, pls. 47-48. Clench, William J., and Smith, Lillian Cassat 1944. The family Cardiidae in the Western Atlantic. Johnsonia, vol. iveNowl3) 32appss 13) pls: Clessin, Stephan 1887-89. Die Familie der Chamiden. Chama. [In] Martini and Chem- nitz, Syst. Conchylien-Cabinet, pts. 360, 362, 366, vol. 8, No. 5, pp. 1-16, pls. 3-10. Mytilacea. [In] Martini and Chemnitz, Syst. Conchylien-Cabinet, pt. 361, vol. 8, No. 3, pp. 125-132, pls. 33-34. Cardita. [In] Martini and Chemnitz, Syst. Conchylien-Cabinet, pts. 356, 360, vol. 10, No. 1, pp. 17-60, pls. 6-13. Solenacea. [In] Martini and Chemnitz, Syst. Conchylien-Cabinet, pts. 361, 362, 364, 366, vol. 11, Ni. 3, pp. 17-96, pls. 8-25. 1890-91. Die Familie Malleacea. [In] Martini and Chemnitz, Syst. Conchylien-Cabinet, vol. 8, No. 1, 108 pp., 50 pls. 1893-95. Die Familie Gastrochaenidae. [In] Martini and Chemnitz, Syst. Conchylien-Cabinet, vol. 11, No. 4a, 57 pp., 21 pls. 1904, Die Familie Vermetidae. [In] Martini and Chemnitz, Syst. Con- chylien-Cabinet, vol. 6, No. 6, 124 pp., 15 pls. Cleve, P. T. 1871. On the geology of the North-Eastern West India islands. Kongl. Svenska Vetenskabs-Akad. Handligar, vol. 9, No. 12, 48 pp., 2 pls. 1881. Outline of the geology of the NE. West Indian islands. New York Acad. Sci., Trans., vol. 1, pp. 21-24. 1882. Outline of the geology of the Northeastern West India islands. New York Acad. Sci., Ann., vol. 2, pp. 185-192, pl. 17. Cockerell, Theodore D. A. 1894. A list of the Brachiopoda, Pelecypoda, Pteropoda and Nudibran- chiata of Jamaica, living and extinct. Nautilus, vol. 7, pp. 103- 107, 113-118. Coe, W. R. 1953. Resurgent populations of littoral marine invertebrates and their dependence on ocean currents and tidal currents. Ecology, vol. 34, No. 1, pp. 225-229, fig. 1. 1955. Ecology of the bean clam Donax gouldi on the coast of southern California. Ecology, vol. 36, No. 3, pp. 512-514, figs. Coen, S. G. 1940. Sul genere “Astarte’ J. Sowerby 1811. Pontifica Academia Sci- entarum, Acta, vol. 4, No. 24, pp. 199-202, pls. 1-2. Colman, John 1932. A statistical test of the species concept in Littorina. Biol. Bull. vol. 62, No. 3, pp. 223-243, 11 figs., 8 tables. 424 BuLietin 204 Comfort, A. 1957. The duration of life in mollusks. Malac. Soc. London, Proc., vol. 32, pt. 6, pp. 219-241, 2 figs., 1 table. Conchological Club of Southern California 1944. Distribution list of the West American marine mollusks from San Diego to the Polar Sea. Conch. Club Southern California, Los Angeles, Minutes, No. 35, pp. 3-14a, 21 text figs. Conklin, Edwin G. 1898. Environmental and sexual dimorphism in Crepidula. Acad. Nat. Sci. Philadelphia, Proc., vol. 50, pp. 435-444, pls. 21-23. Conrad, Timothy A. 1831. American Marine Conchology; or descriptions and coloured fig- ures of the shells of the Atlantic coast of North America. Philadel- phia, 40 pp., 8 pls. 1834c. Description of a new species of Hinnita. Acad. Nat. Sci. Phila- delphia, Jour., 1st ser., vol. 7, pp. 182-183, pl. 14. 1838. Fossils of the Medial Tertiary of the United States. Philadelphia, 89 pp., 49 pls. 1848c. Observations on the Eocene formation, and descriptions of one hundred and five new fossils of that period, from the vicinity of Vicksburg, Mississippi; with an appendix. Acad. Nat. Sci. Philadelphia, Jour., ser. 2, vol. 1, pp. 111-134, pls. 11-14. 1849. Descriptions of new fossil and Recent shells of the United States. Acad. Nat. Sci. Philadelphia Jour., ser. 2, vol. 1, pp. 207-209. 1850. Description of one new Cretaceous and seven new Eocene fossils. Acad. Nat. Sci. Philadelphia, Jour., ser. 2, vol. 2, pp. 39-41, 1 pl. 1956. Descriptions of eighteen new Cretaceous and Tertiary fossils. Acad. Nat. Sci. Philadelphia, Proc., vol. 7, pp. 265-268. 1857e. Descriptions of three new genera; twenty-three new species of middle Tertiary fossils from California, and one from Texas. Acad. Nat. Sci. Philadelphia, Proc., vol. 8, pp. 312-316. 1862. Description of new genera, subgenera, and species of Tertiary and Recent shells. Acad. Nat. Sci. Philadelphia, Proc., vol. 14, pp. 284-291. 1866e. Descriptions of new marine bivalve Mollusca. Amer. Jour. Conch., vol. 2, pt. 3, No. 6, pp. 280-281, pl. 15. 1867. Paleontological miscellanies. Amer. Jour. Conch., vol. 3, pt. 1, No. 4, pp. 5-7. Cooke, C. Wythe 1928. New Vicksburg (Oligocene) mollusks from Mexico. U. S. Nat. Mus., Proc., vol. 73, No. 2731, art. 10, pp. 1-11, pls. 1-2. 1961. Cenozoic and Cretaceous echinoids from Trinidad and Venezuela. Smithsonian Misc. Collections, vol. 142, No. 4, Publ. No. 4459, 35 pp., 14 pls. Cooper, J. E., and Preston, H. B. 1910. Diagnoses of new species of marine and freshwater shells from the Falkland Islands, including descriptions of two new genera of marine Pelecypoda. Ann. Mag. Nat. Hist., ser. 8, vol. 5, pp. 110-114, pl. 4. Cossmann, Alexandre Edouard Maurice 1886. Catalogue des coquilles fossiles de l’éocéne des environs de Paris. Soc. Roy. Malac. de Belgique, Ann., vol. 21, pp. 17-186, pls. 1-8. 1899. Description de quelques coquilles de la formation Santacruzienne en Patagonie. Jour. Conchyl., vol. 47, pp. 223-242. Cotton, Bernard C. 1932. Notes on Australian Mollusca, with descriptions of new genera and new species. South Australia Mus., Rec., vol. 4, No. 4, pp. 537-547, figs. 1-9. VENEZUELAN CENOZOIC PELECYPODS: WEISBORD 425 Cotton, Bernard C., and Godfrey, Frank K. 1933. South Australian shells, Pt. 8, Scaphopoda. The South Australian Naturalist, pp. 135-150. 1934. South Australian Shells. Pt. 10, Fissurellidae. The South Australian Naturalist, pp. 41-56, pl. 1. 1945. A catalogue of the cone shells (Conidae) in the South Australian Museum. South Australian Mus., Rec., vol. 8, pp. 229-280. Cotton, Bernard C., and Wood, Nelly Hooper 1935. The correlation of Recent and fossil Turritellidae of southern Australia. South Australian Mus., Rec., vol. 5, No. 3, pp. 369-387, figs. 1-7. Coues, Elliott, and Yarrow, H. C. 1878. Notes on the natural history of Fort Macon, N. C., and vicinity (No. 5). Acad. Nat. Sci. Philadelphia, Proc., vol. 30, pp. 120-148. Cox, Leslie Reginald 1929a. Notes on the Mesozoic family Tancrediidae, with descriptions of several British upper Jurassic species, and of a new genus Eodonax. Ann. Mag. Nat. Hist., ser. 10, vol. 3, pp. 569-594, pls. 13-14. 1929b. Notes on the post-Miocene Ostreidae and Pectinidae of the Red Sea region. Malac. Soc. London, Proc., vol. 18, pp. 165-209. 1930. Miocene Mollusca. Pliocene Mollusca. Post-Pliocene Mollusca. [In] Reports on geological collections from the coastlands of Kenya Colony made by Miss M. McKinnon Wood. Geol. Dept. Hunterian Mus. Glasgow Univ., Mon., pp. 103-164, pls. 12-15. 1948. Neogene Mollusca from the Dent Peninsula, British North Borneo. Schweizerische Palaeont. Gesell., Abhandl., vol. 66, No. 2, pp. 1-70, 3 figs., pls. 1-6. 1960a. Thoughts on the classification of the Gastropoda. Malac. Soc. London, Proc., vol. 33, pt. 6, pp. 239-261. 1960b. Thoughts on the classification of the Bivalvia. Malac. Soc. Lon- don, Proc., vol. 34, pt. 2, pp. 60-88, 2 figs. Cox, L. R., and Rees, W. J. 1960. A bivalve gastropod. Nature, vol. 185, No. 4715, pp. 749-751. Crosse, H. 1865c. Description d’espéces nouvelles. Jour. Conchyl., vol. 13, pp. 27-32. 1867a. Descriptions d’espéces nouvelles. Jour. Conchyl., vol. 15, pp. 64-68. 1867b. Description d’un genre nouveau de la famille des Fissurellidae: Semperia. Jour. Conchyl., vol. 15, pp. 74°78, pl. 2, fig. 20. 1869. Diagnoses molluscorum novorum. Jour. Conchyl., vol. 17, pp. 183-188. 1872. Note sur quelques formes remarquables de Marginella provenant de la cote Atlantique du Sahara. Jour. Conchyl., vol. 20, pp. 215-217. 1875. Description du nouveau genre, Berthelinia. Jour. Conchyl., vol. 23yppy 79-84) pli 2 tig 3: Crosse, H., and Fischer, P. 1890. Mission scientifique au Mexique et Amérique Centrale. Zoologie, pt. 7, Mollusques, vol. 2, pp. 497-505, pl. 62. Cundall, Frank 1902. Bibliographia ... Jamaicensis. Kingston, 84 pp. Supplement, 1907, 38 pp. 1909. Bibliography of the West Indies (exclusive Jamaica). The Inst. of Jamaica, 179 pp. Dakin, William John 1928. The anatomy and phylogeny of Spondylus. Roy. Soc. London, Proc., ser B., vol. 103, pp. 337-354, figs 1-7. 426 BuL.eTiIn 204 Dall, William Healy 1870d. Revision of the Mollusca of Massachusetts. Boston Soc. Nat. Hist., Proc., vol. 13, pp. 240-257. 1880. Reports on the results of dredging, under the supervision of Alexander Agassiz, in the Gulf of Mexico and in the Caribbean Sea, 1877-79, by the U. S. Coast Survey Steamer Blake, Lieuten- ant-Commander Sigsbee, U.S.N., and Commander J. R. Bart- lett, U.S.N., commanding. V. General conclusions from a prelim- inary examination of the Mollusca. Mus. Comp. Zool., Bull., vol. 6, pp. 85-93. 1886c. Report on the mollusks collected by L. M. Turner at Ungava Bay, North Labrador, and from the adjacent Arctic seas. U. S. Nat. Mus., Proc., vol. 9, pp. 202-208, figs. 1-3. 1887. [Shells found in the Antilles]. Conch. Exchange, vol. 2, pp. 9-10. 1889e. Notes on the anatomy of Pholas (Barnea) costata Linné and Zirphaea crispata Linné. Acad. Nat. Sci. Philadelphia, Proc., vol. 41, pp. 274-276. 1891a.On a new subgenus of Meretrix with descriptions of two new species from Brazil. Nautilus, vol. 5, No. 3, pp. 26-29, 2 figs. 1891b. On some marine mollusks from the southern coast of Brazil. Nautilus, vol. 5, pp. 42-44; vol. 6, pp. 109-111. 1892a. On the species of Donax of eastern North America. Nautilus, vol. 5, pp. 125-127. 1892b. On an undescribed Cytherea from the Gulf of Mexico. Nautilus, vol. 5, No. 12, pp. 134-135. 1894h. Cruise of the steam yacht “Wild Duck” in the Bahamas, January to April, 1893, in charge of Alexander A’gassiz. II. Notes on the shells collected. Mus. Comp. Zool., Bull., vol. 25, No. 9, pp.113- 124, 1 pl. 18941. Report on the Mollusca and Brachiopoda dredged in deep water, chiefly near the Hawaiian Islands, with illustrations of hitherto unfigured species from northwest America. U. S. Nat. Mus., Proc., vol. 17, pp. 675-733, 2 figs., pls. 23-32. 1895. Three new species of Macoma from the Gulf of Mexico. Nautilus, vol. 9, pp. 32-34. 1896e. The mollusks and brachiopods of the Bahama Expedition of the State University of Towa. State Univ. Iowa, Nat. Hist. Bull. vol. 4, No. 1, pp. 12-127, 1 pl. 1896f. Report on the mollusks collected by the International Boundary Commission of the United States and Mexico, 1892-1894. U. S. Nat. Mus., Proc., vol. 19, No. 1111, pp. 333-379, pls. 31-33. 1896g. On some new species of Scala. Nautilus, vol. 9, pp. 111-112. 1896h. On the American species of Ervilia. Nautilus, ‘vol. 10, pp. 25-27. 1896i. On the American species of Cyrenoidea. Nautilus, vol. 10, pp. 51-52. 1897d. On a new form of Polygira from New Mexico. Nautilus, vol. 11, No. 1, pp. 2-3. 1897e. Synopsis of the Pinnidae of the United States and the West Indies. Nautilus, vol. 11, No. 1, pp. 25-26. 1898e. On the genus Halia of "Risso. Acad. Nat. Sci. Philadelphia, Proc., vol. 50, pp. 190-192. 1898f. A new species of Terebra from Texas. Nautilus, vol. 12, pp. 44-45. 1901d. Synopsis of the family Tellinidae and of the North American species. U. S. Nat. Mus., Proc., vol. 23, No. 1210, pp. 285-326, pls. 2-4. 1902d. Note on the names Elachista and Pleurotomaria. Nautilus, vol. 15, p. 127. VENEZUELAN CENOZzOoIC PELECYPOoDS: WEISBORD 427 1902e. 1903f. 1905d. 1907a. 1907b. 1907c. 1907d. 1907e. 1908d. 1909d. 1910d. On the genus Gemma, Deshayes. Jour. Conch., vol. 10, No. 8, pp. 238-243. Review of the classification of the Cyrenacea. Biol. Soc. Washing- ton, Proc., vol. 25, pp. 335-346. Fossils of the Bahama Islands, with a list of non-marine mollusks. Geogr. Soc. Baltimore, 47 pp., pls. 11-13. A review of the American Volutidae. Smithsonian Misc. Collec- tions, vol. 48, No. 1663, pt. 3, pp. 341-373. Three new species of Scala from California. Nautilus, vol. 20, No. 11, pp. 127-128. on new Cerithium from the Florida Keys. Nautilus, vol. 21, No. 1, 22-23. On the synonomic history of the genus Clava Martyn and Cerith- ium Bruguiére. Acad. Nat. Sci. Philadelphia, Proc., vol. 59, pp. 363-369. Description of new species of shells, chiefly Buccinidae, from the dredgings of the USS. “Albatross” during 1906, in the North- western Pacific, Bering, Okhotsk, and Japanese seas. Smithsonian Misc. Collections, vol. 50, pp. 139-173. A new West Indian Nitidella. Nautilus, vol. 22, pp. 31-32. Paradione n. n. vice Chionella. Malac. Soc. London, Proc., vol. Sips 197; List of shells collected by Dr. John I. Northrop in the Bahamas, identified by Professor William Healy Dall, Smithsonian Institu- tion, pp. 99-102. [In] J. I. Northrop, A Naturalist in the Bahamas. New York, Columbia University Press, xv + 281 pp., illustr. 1912c. Note on the genus Panope, Ménard. Malac. Soc. London, Proc., 1913c. 1914e. 1915h. 1918e. 1919c. 1920. 1921c. 1921d. 1921d. 1922f. 1923e. 1925e. 1926a. vol. 10, pt. 1, pp. 34-35. Note on the generic name Pectunculus. Malac. Soc. London, Proc., vol. 10, pp. 255-256. Mollusca from South Georgia [In] A report on the South Georgia Expedition. Mus. Brooklyn Inst. Arts and Sci., Sci. Bull., vol. 2, No. 4, pp. 69-70. An index to the Museum Boltenianum. Smithsonian Inst., Publ. 2360, 64 pp. Pleistocene fossils of Magdalena Bay, Lower California, collected by Charles Russell Orcutt. Nautilus, vol. 32, pp. 23-26. The Mollusca of the Arctic coast of America collected by the Canadian Arctic Expedition west from Bathurst Inlet, with an appended report on a collection of Pleistocene fossil Mollusca. Canadian Arctic Expedition Rept., Ottawa, vol. 8, pt. A, 29 pp., 3 pls. Pliocene and Pleistocene fossils from the Arctic coast of Alaska and the auriferous beaches of Nome, Norton Sound, Alaska. U. S. Geol. Sur., Prof. Paper 125-C, pp. 23-37, pls. 5-6. Nomenclatural notes. Nautilus, vol. 35, pp. 49-50. New shells from the Pliocene or early Pleistocene of San Quentin. West American Scientist, vol. 19, No. 3, pp. 21-24. Species named in the Portland catalogue. Nautilus, vol. 34, pp. 97-100, 124-132. Fossils of the Olympia Peninsula. Amer. Jour. Sci., ser. 5, vol. 4, pp. 305-314. Notes on Drupa and Morula. Acad. Nat. Sci. Philadelphia, Proc., vol. 75, pp. 203-206. Note on the species of Petricolaria of the eastern coast of the United States. Biol. Soc. Washington, Proc., vol. 38, p. 90. A new Margarites from Greenland. Biol. Soc. Washington, Proc., vol. 39, p. 59. 428 BULLETIN 204 1926b. a, new Pecten from Colombia. Biol. Soc. Washington, Proc., vol. 61-62. Dall, William bedly. and Bartsch, Paul 1903. The paleontology and stratigraphy of the Marine Pliocene and Pleistocene of San Pedro, California. LXIV. Family Pyramidel- lidae. California Acad. Sci.. Mem., vol. 37, pp. 269-366, pls. 1-2. 1913. New species of mollusks from the Atlantic and Pacific coasts of Canada. Victoria Mem. Mus., Bull., vol. 1, pp. 139-146, pl. 10. Daudin, F. M. 1800. Recueil de mémoires et de notes sur les espéces inédites ou peu connes de mollusques, der vers et de zoophytes. Paris, 50 pp., 4 pls. Dautzenberg, Philippe 1889. Contribution a la faune malacologique des Iles Acores. [In] Résultats des campagnes scientifiques accomplies sur son yacht par Albert Ier, Prince de Monaco. Monaco, fasc. 1, 112 pp., 4 pls. 1892. Description d’une espéece nouvelle du genre Chama provenant des cétes océaniques de France. Soc. Sci. Nat. de l’ouest de la France, Bull., vol. 2. 1895. De lexistence du genre Berthelinia Crosse a l’epoque actuelle. Soc. Zool. France, Bull., vol. 20, pp. 37-38, text figs. A, B. 1896. Liste de mollusques du Chili. Soc. Sci. Chile, Actas, vol. 6, pp. Ixiv-lxvii. 1900. Croisiéres du yacht Chazalie dans l’Atlantique. Mollusques. Soc. Zool. France, Mém., vol. 13, pp. 145-265, pls. 9-10. 1923. Liste préliminaire des mollusques marins de Madagascar. Jour. Conchyl., vol. 68, pp. 21-74. 1935. Résultats scientifiques du voyage aux Indes Orientales Néerlandats de LL. AA. RR. le Prince et la Princesse Léopold de Belgique. Gasteropodes marins. I, famille Terebridae. II, famille Mitridae. Mus. Roy. Hist. Nat. Belgique, Mém., hors sér., vol. 2, pp. 1-208, pls. 1-4. Dautzenberg, Philippe, and Bavay, A. 1912. Les Lamellibranches de VExpedition du Siboga. Mollusca III. Lamellibranchiata. Partie systématique I. Pectinidés. Siboga- Expeditie, vol 29, 41 pp., 2 pls. Dautzenberg, Philippe, and Bouge, J.-L. 1933. Les mollusques testacés marins des éstablissements Frangaise de VOcéanie. Jour. Conchyl., vol. 77, pp. 41-108, 145-326, 351-469. Dautzenberg, Philippe, and Dollfus, G. F. 1904. Etudes critiques sur la nomenclature avec examen des genres Pectunculus et Glycimeris. Jour. Conchyl., vol. 52, No. 2, pp. 109- 122. Dautzenberg, Philippe, and Fischer, Pierre Marie Henri 1897. Dragages effectués par l’Hirondelle et par la Princess-Alice, 1888-1896. Soc. Zool. France, Mém., vol. 10, pp. 139-234, pls. 3-7. 1905. Mollusques provenant des dragages effectués a Vouest de lAf- rique. [In] Résultats des campagnes scientifiques accomplies sur son yacht par Albert Ier, Prince de Monaco. Monaco, fasc. 32, pp. 1-125, 5 pls. 1913. Sur quelques types de Garidés de la collection de Lamarck existant au Muséum de Paris. Jour. Conchyl., vol. 41, pp. 215-228, pls. 6-7. Davenport, C. B. 1903. Comparison of some Pectens from the east and west coasts of the United States. Mark Anniversary Volume, art. 6, pp. 121-136, pl. 9. VENEZUELAN CENOZOIC PELECYPODS: WEISBORD 429 Davidson, T. 1874. Note on two Tertiary species of Brachiopoda from the island of St. Bartholomew, one of the N.E. West Indian islands. Geol. Mag., ser. 2, vol. 1, pp. 158-159, pl. 8, figs. 11-12. Davies, A. Morley 1933. The basis of classification of the Lamellibranchiata. Malac. Soc. London, Proc., vol. 20, pt. 6, pp. 322-326. Davis, C. Abbott 1904. Notes on the Mollusca of the Bermuda Islands. Nautilus, vol. 17, No. 11, pp. 125-130, pl. 4. De Kay, J. E. 1843. Zoology of New York, or the New York fauna. Pt. 5, Mollusca. Albany, 271 pp., 40 pls. Dell, R. K. 1950a. Notes on the taxonomy and distribution of some New Zealand Mollusca with description of four new species. Dominion Mus., Rec. Zool., vol. 1, No. 3, pp. 21-28, figs. 1-10. 1950b. A Tertiary molluscan fauna from Waikowhai, Manukau Harbour, Auckland. Dominion Mus., Rec. Zool., vol. 1, No. 4, pp. 29-37, figs. 1-10. 1950c. The molluscan genus Venustas in New Zealand waters. Dominion Mus., Rec. Zool., vol. 1, No. 5, pp. 39-54, figs. 1-12. 1951. A deep water molluscan fauna from off Banks Peninsula. Canter- bury Mus., Rec., vol. 6, No. 1, pp. 53-60, figs. 1-17. 1952a. A revision of the molluscan fauna of the Hurupi beds, southern Wairarapa. Dominion Mus., Rec. Zool., vol. 1, No. 8, pp. 71-86, figs. 1-21. 1952b. A deep water molluscan fauna from the Tasman Sea. Dominion Mus., Rec. Zool., vol. 1, No. 10, pp. 99-107, figs. 1-11. 1952c. New marine Mollusca from the Cook Strait area and southern New Zealand. Roy. Soc. New Zealand, Trans., vol. 79, pts. 3-4, pp. 412-418, pls. 84-85, text fig. 1. 1953. A molluscan fauna from the Chatham Rise, New Zealand. Domin- ion Mus., Rec. Zool., vol. 2, pt. 1, pp. 37-50, figs. 1-22. 1955. A synopsis of the Nuculanidae with check lists of the Australasian Tertiary and Recent species. Dominion Mus., Rec. Zool., vol. 2, pt. 3, pp. 123-134. 1956. Some new off-shore Mollusca from New Zealand. Dominion Mus., Rec. Zool., vol. 3, pt. 1, pp. 27-59, figs. 1-65. Deshayes, Gérard Paul 1863. Catalogue des mollusques de V’Ile de la Réunion (Bourbon). [In] Maillard, L., Notes sur Ile de Réunion (Bourbon). Paris, pt. 2, annexe E, 144 pp., 14 pls. Des Moulins, Charles 1832. Description d’une nouveau genre de coquille vivante, bivalve, des mers du Chili. Soc. Linnéenne Bordeaux, Actes, vol. 5, pp. 83-92. Detweiler, John D. 1915. Preliminary notes on the Mollusca of St. Andrews and vicinity, New Brunswick. Dept. Marine and Fisheries, Fisheries Branch, Sessional Paper No. 39b, Contrib. Canadian Biol., Suppl., pp. 43-46. Dexter, Ralph W. 1942. Notes on the marine Mollusca of Cape Ann, Massachusetts. Nauti- lus, vol. 56, No. 2, pp. 57-61. DeLong, James H., Jr. 1941. The paleontology and stratigraphy of the Pleistocene at Signal Hill, Long Beach, California. San Diego Soc. Nat. Hist., Trans., vol. 9, pp. 229-252, 4 figs. 430 BuLueTin 204 Dias da Rocha, Francisco 1908. Boletim do Muzeu Rocha. Vol. 1, No. 1, xviii + 155 pp. 1911. Boletim do Muzeu Rocha. Vol. 1, No. 2, xi + 119 pp. Dixon, C. J. 1955a. Geology of southern British Honduras, with notes on adjacent areas. Belize, B. H., 85 pp. + bibliog. + index, 21 photos, 1 col. geol. map, 4 maps. Dodge, Henry 1950. Hiatella Daudin versus Saxicava Fleuriaude Bellevue. Nautilus, vol. 64, No. 1, pp. 27-33. 1956. A historical review of the mollusks of Linnaeus. Pt. 4. The genus Buccinum and Strombus of the class Gastropoda. Amer. Mus. Nat. Hist., Bull., vol. 101, art. 3, pp. 153-312. 1958. A historical review of the mollusks of Linnaeus. Pt. 6. The genus Trochus of the class Gastropoda. Amer. Mus. Nat. Hist. Bull., vol. 116, art. 2, pp. 157-223. 1959. Evidential factors in the identification of the Linnaean Mollusca. Linnean Soc. London, Jour., Zoology, vol. 44, pp. 170-179. Doello-Jurado, Martin 1915. Algunos moluscos marinos Terciarios procedentes de un pozo sur- gente cerca de La Plata. Physis, vol. 1, pp. 592-598. 1917a. Notas sobre “Acanthina Calcar” (Martyn). Physis, vol. 3, No. 14, pp. 271-283, figs. 1-3. 1917b. Nota sobre “Turritella americana” (Bavard). Physis, vol. 3, No. 14, pp. 283-287. 1918a. Nota preliminar sobre la presencia de algunas especies de la fauna Magalldnica frente a mar del Plata. Physis, vol. 4, pp. 119-125. 1918b. Dos nuevas especies de bivalvos marinos. Physis, vol. 4, pp. 259- 273, figs. 1-10. 1919a. Dos nuevas especies de bivalvos marinos. Mus. Hist. Nat. Monte- video, Comunic., Zool., vol. 3, No. 57, pp. 1-8, 1 fig., 1 pl. 1919b. Une nouvelle espece de “Miltha” du Tertiaire de l’Argentine. Physis, vol. 4, pp. 558-562, 2 figs. 1922. Un nuevo “Mytilus” fésil del Terciario de Patagonia. Soc. Cientif. Argentina, An., vol. 94, 7 pp., 2 figs. Dollfus, A., and Mont-Serrat, E. de 1868. Voyage géologique dans les Républiques de Guatemala et de Salvador. Paris, ix+539 pp., 18 pls. Dolifus, Gustave F. 1909. Etude critique sur quelques coquilles fossiles du Bordelais. Soc. Linnéenne, Actes, vol. 62, pp. 335-379, pls. 11-15. Doty, Maxwell S. 1957. Rocky intertidal surfaces. Geol. Soc. Amer., Mem. 67, vol. 1, pp. 535-585, 18 figs., 1 pl. Douglas, James Archibold 1933. The geology of the Marcapata valley in eastern Peru. Geol. Soc. London, Quart. Jour., vol. 89, pp. 308-348, pls. 27-33. Douvillé, Henri 1912. Classification des lamellibranches. Soc. Géol. France, Bull., sér. 4, vol. 12, pt. 7, pp. 419-467. Ducros de Saint-Germain, A. M. P. 1857. Revue critique du genre Oliva de Bruguiére. Ann. Scient., vol. 30, pp. 289-402. Duméril, André Marie Constant 1806. Zoologie analytique ou méthode naturelle de classification des animaux. Paris. VENEZUELAN CENOZOIC PELECYPODS: WEISBORD 431 Dunker, Wilhelm Bernhard Rudolph Hadrian 1852. Aviculacea nova. Zeitschr. f. Malakozool., yr. 9, pp. 73-80. 1853a. Diagnoses molluscorum novarum. Zeitschr. f. Malakozool., yr. 10, pp. 58-60, 95-96, 110-112. 1953b. Index molluscorum quae in itinere ad Guineem inferiorem collegit Georgius Tams. Novitates Conchologicae, Abbild. u. Beschr. neuer Conchylien, Suppl. 2, 74 pp., 10 pls. 1857a. Mollusca nova collectonis Cumingiana. Zool. Soc. London, Proc. for 1856, pp. 354-358. 1857b. Mytilacea nova collectonis Cumingiana. Zool. Soc. London, Proc. for 1856, pp. 358-366. 1861. Solenacea nova collectonis Cumingiana. Zool. Soc. London, Proc., pp. 418-427. 1862. Species nonnullae Bursarum vel Ranellarum collectonis Cumingi- ana. Zool. Soc. London, Proc., pp. 238-240. 1858-70. Mollusca Marina. Novitates Conchologicae, Abtheil 2, pp. iv + 144, 45 col. pls. 1871. Mollusca nova Musei Godeffroy Hamburgensis. Malakozool. Blat- ter, vol. 18, pp. 150-175. 1872-80. Die Gattung Avicula. Syst. Conchylien-Cabinet, vol. 7, pt. 3, pp. 1-58, pls. 1-18 (1872) ; pp. 59-68, pls. 19-24 (1879) ; pp. 69-84, pls. 25-27 (1880). Durham, John Wyatt, and Allison, Edwin C. 1960. Symposium. The biogeography of Baja California and adjacent seas. Pt. 1. The geologic history of Baja California and its marine faunas. Syst. Zool., vol. 9, No. 2, pp. 47-91, 7 figs., 9 tables. Duval, A. 1840. Réflexions sur le genre Planaxe, et indication de deux especes d’une variété nouvelle. Zool. Soc. Cuvierienne, Rev., vol. 3, p. 107. Eales, Nellie B. 1923. British Antarctic (“Terra Nova”) Expedition, 1910. Natural his- tory report. Mollusca. Pt. 1-Gastropoda, Prosobranchia, Scaphopoda, and Pelecypoda. British Mus. (Nat. Hist.), Zoology, vol. 7, No. 1, pp. 1-46, 42 figs. Eames, F. E., and Cox, L. R. 1956. Some Tertiary Pectinacea from East Africa, Persia, and the Medi- terranean region. Malac. Soc. London, Proc., vol. 32, pp. 1-68, 20 pls. Emerson, William K. 1951b. Nomenclatural notes on the Scaphopoda: The subgenus Dentale Da Costa. Nautilus, vol. 65, No. 1, pp. 17-20. 1954. Notes on the scaphopod mollusks: Rectification of nomenclature. Biol. Soc. Washington, Proc., vol. 67, pp. 183-188. 1956c. Upwelling and associated marine life along Pacific Baja Cali- fornia, Mexico. Jour. Paleont., vol. 30, pp. 393-397, 1 fig. 1957. Three new Tertiary scaphopods, with a review of extinct western North American Siphonodentaliidae. Jour. Paleont., vol. 31, No. 5, pp. 985-991, pl. 126, figs. 1-5. 1958. Notes on the scaphopod mollusks: Rectifications of nomenclature II. Biol. Soc. Washington, Proc., vol. 71, pp. 91-94. 1960a. Results of the Puritan-American Museum of Natural History Ex- pedition to western Mexico. 2. Pleistocene invertebrates from Cer- alvo Island. Amer. Mus. Novitates, No. 1995, pp. 1-6. 1960b. Pleistocene invertebrates from near Punta San José, Baja Cali- fornia. Amer. Mus. Novitates, No. 2002, pp. 1-7. 1960c. Pliocene and Pleistocene invertebrates from Punta Rosalia, Baja California. Amer. Mus. Novitates, No. 2004, pp. 1-8. 432 BuL_eTiIn 204 1960. Remarks on some Eastern Pacific muricid gastropods. Amer. Mus. Novitates, No. 2009, pp. 1-15, figs. 1-7. Emerson, William K., and Addicott, Warren O. 1958. Pleistocene invertebrates from Punta Baja, Baja California, Mexico. Amer. Mus. Novitates, No. 1909, 11 pp., 2 figs. Emerson, William K., and Chace, Emery ’P. 1959. Pleistocene mollusks from Tecolate Creek, San Diego, California. San Diego Soc. Nat. Hist., Trans., vol. 12, pp. 335-346, 3 figs. Engelmann, Wilhelm 1846. Bibliotheca Historico-Naturalis. Reprinted 1960, Engelmann and Wheldon & Wesley Ltd., viii + 786 pp. Eudes-Deslongchamps, Jacques Amand 1859. Catalogue des cirrhipédes, des mollusques et des rayonnés re- cueillis par M. E. Déplanche, chirurgien auxilliaire de la Marine Impériale, pendant la campagne de laviso a vapeur le Rapide. Soc. Linnéenne Normandie, Bull., vol. 4, 50 pp. Falconer, J. D. 1902. Se of the Antilles. Scottish Geogr. Mag., vol. 18, pp. 369- 379, 1 pl. Faustino, Leopoldo A. 1928. Summary of Philippine marine and freshwater mollusks. Philip- pine Bur. Sci., Mon. No. 25. Feruglio, Egidio 1936. Nota preliminar sobre algunas nuevas especies de moluscos del supracretaceo y Terciario de la Patagonia. Inst. Mus. Univ. Nace. La Plata, Notas Mus. La Plata, vol. 1, Paleontologia, No. 6, pp. 277-300, pls. 1-2. Férussac, André Etienne Just Paschal Joseph Francois d’Audebord 1820-22. Tableaux systématique des animaux mollusques classés en familles naturelles, dans lesquels on a établi la concordance de tous les systémes; suivis d’un prodrome générale pour tous les mollusques terrestres ou fluviatiles, vivants ou fossiles. Paris, xiii --110 pp. Férussac, André Etienne, and Deshayes, Gérard Paul 1819-51. Histoire naturelle générale et particuliére des mollusques ter- restres et fluviatiles tant des espéces que lon trouve aujourd’hui vivantes, que des dépouilles fossiles de celles qui n’existent plus; classés d’aprés les charactéres essentiels que presentent ces ani- maux et leurs coquilles. Vol. 1, pp. 1-40 (1839), 41-376 (1850), 377-402 (1851), pls 1-30 (1819). Vol. 2, pp. 1-96 (1819), 96a-3 (1823), 96’-96-24 (1851), 97-100 (1820 or 1821), 101-128 (1832?), 129-152 (1839?), 153-184 (1851); pt. 2, pp. 1-260 (1851). Atlas, vol. 2, pt. 4, pls. 1-166; fossiles, pls. 1-5. Ferreira, Candido Simoes 1960. Contribuicgado a paleontolgia do Estado do Para. Revisao da familia Pectinidae formacao Pirabas (Miocene Inferior) com a descricao de novas espécies. VI. Mollusca-Pelecypoda. Mus. Nac., Arq., vol. 50, pp. 135-166, pls. 1-4. Ferreira, Candido Simoes, and Rodrigues da Cunha, Osvaldo 1957. Contribuicao a paleontologia do Estado do Para. Novos inverte- brados fésseis e redescrigdes de mais duas espécies da formag¢dao Pirabas. III, Mollusca-Gastropoda. Mus. Paraense Emilio Goeldi, Bol., nov. ser., Geologia, No. 4, pp. 1-33, pls. 1-2. Field, Richard M. 1931. Geology of the Bahamas. Geol. Soc. Amer., Bull., vol. 42, pp.759- 784, maps, photographs. VENEZUELAN CENOZOIC PELECYPODS: WEISBORD 433 Filice, F. P. 1958. Invertebrates from the estaurine portion of San Francisco Bay and some factors influencing their distribution. Wasmann Jour. Biol., vol. 16, pp. 159-211. Finlay, H. J. 1924a. New shells from New Zealand Tertiary beds. New Zealand Inst., Trans., vol. 55, pp. 450-479, pls. 48-50. 1924b. Some necessary changes in New Zealand Mollusca. Malac. Soc. London, Proc., vol. 16, pt. 2, pp. 99-107. 1926. New shells from New Zealand Tertiary beds. Pt. 2. New Zealand Inst.. Trans., vol. 56, pp. 227-258, pls. 55-60. 1927. A further commentary on New Zealand molluscan systematics. New Zealand Inst., Trans., vol. 57, pp. 320-485, pls. 18-23. 1928. The Recent Mollusca of the Chatham Islands. New Zealand Inst., Trans., vol. 59, pp. 232-286, pls. 28-43. 1930a. ars Molluscan names. New Zealand Inst., Trans., vol. 61, 37-48. 1930b. Nees shells from New Zealand Tertiary beds. Pt. 3. New Zealand Inst., Trans., vol. 61, pp. 49-84, pls. 1-6. 1930c. Notes on recent papers dealing with the Mollusca of New Zealand. New Zealand Inst., Trans., vol. 61, pp. 248-258, pl. 46. 1931. On Austrosassia, Austroharpa, and Austrolithes, new genera: with some remarks on the gastropod protoconch. New Zealand Inst., Trans., vol. 62, pp. 7-19. Fischer, Paul 1857. Etudes sur un groupe de coquilles de la famille des Trochidae. Jour. Conchyl., vol. 2, pp. 42-53, 168-176, 284-288. 1858a. Etudes sur les Pholades. Jour. Conchyl., vol. 3, pp. 47-58, 169-177, 242-253. 1858b. Enumération monographique des espéces du genre Dreissena. Jour. Conchyl., sér. 2, vol. 7, pp. 123-124, pl. 1858c. Descriptions d’espéces nouvelles. (Helix, Achatina, Solenomya, and Anomalocardia]. Jour. Conchyl., vol. 3, pp. 184-187. 1861. Ueber das Thier der Gattung Perna. Jour. Conchyl., vol. 9, pp. 19-28. 1864. Note sur le genre Pernostrea. Jour. Conchyl., vol. 12, pp. 362- 368. 1873. Sur la coquille embryonnaire des Xenophora. Jour. Conchyl., vol. 21, pp. 123-124. 1875. Remarques sur la coloration générale des coquilles de la céte occidentale d’Amérique. Jour. Conchyl., vol. 29, pp. 31-35. 1881. Note sur le genre Olivella. Jour. Conchyl., vol. 29, pp. 31-35. 1882. Diagnoses d’espéeces nouvelles de mollusques recueillis dans le cours des expéditions scientifiques de l’aviso le Travailler (1880- 1882). Jour. Conchyl., vol. 30, pp. 49-53, 273-277. 1883. Diagnoses d’espéeces nouvelles de mollusques recueillis dans le cours de Vlexpédition scientifique du Talisman (1883). Jour. Conchyl., vol. 31, pp. 391-394. Fischer, Paul-Henri 1958. Un lamellibranche a répartition “bipolaire’, Mytilus edulis L. Soc. Biogéogr., Compte Rendu, vol. 35, No. 303, pp. 12-15. 1960. Sur lontogénése des gastéropodes. Géol. Soc. France, Bull., sér. 7, vol. 1, No. 7, pp. 734-737, fig. 1. Fischer-Piette, E., and Fischer, Paul-Henri 1939. Révision des espéces vivantes de Sunetta du Muséum National @’Histoire Naturelle. Jour. Conchyl., vol. 83, Nos. 2-3, pp. 181- 213, 1 text fig., pl. 6, figs. 39-43. 434 BuLieTin 204 1942. Revision des espéces vivantes de Tivela et Eutivela du Muséum National d’Histoire Naturelle. Jour. Conchyl, vol. 85, pp. 1-49, figs. 1-2. Fleming, C. A. 1944. Molluscan evidence of Pliocene climate change in New Zealand, Roy. Soc. New Zealand, Trans., vol. 74, pt. 3, pp. 207-220. 1948. New species and genera of marine Mollusca from the Southland Fiords. Roy. Soc. New Zealand, Trans., vol. 77, pt. 1, pp. 72-92, pls. 4-8, 1 fig. 1950a. The genus Pecten in the West Pacific. Jour. Conchyl., vol. 90, pp. 276-282, pl. 1. 1950b. New Zealand Recent Thyasiridae (Mollusca). ape Soc. New Zealand, Trans., vol. 78, pts. 2-3, pp. 251-254, pl. 1951. Some Australian Mollusca in the British Museum Awl His- tory). Roy. Soc. New Zealand, Trans., vol. 79, pp. 126-139, pls. 15-20. Fleuriau de Bellevue, C. 1802. Extrait d’un mémoire sur quelques nouveau genres de mollusques. Jour. Phys., vol. 54, pp. 345-355. Flores, G. 1952. Geology of northern British Honduras. Amer. Assoc. Petrol Geol., Bull., vol. 36, No. 12, pp. 404-409, 1 fig., 3 tables. Fluck, H. W. 1906. Shell-collecting on the Mosquito Coast of Nicaragua-VI. Nautilus, vol. 20, No. 1, pp. 1-4. Foerste, Aug. F. 1893. Studies on the Chipola Miocene of Bainbridge, Georgia, and of Alum Bluff, Florida, with an attempt at correlation of certain one Gulf group beds with marine Miocene beds eastward. Amer. Jour. Sci., vol. 46, No. 274, ser. 3, pp. 244-254. de Folin, A. G. Léopold 1885. Constitution méthodique rationelle et naturelle de la famille des Chemnitzidae. Soc. d’Agric., Hist. Nat. et Arts Utiles de Lyon, séance 20 mars 1883, 16 pp. Fontannes, C. F. 1878. Les terrains Tertiaires du Basin de Visan. [Etudes stratigraphiques et paléontologiques pour servir a histoire de la période Tertiaire dans le basin du Rhone]. Pt. 3. Soc. Agric. Lyon, An., vol. 5, No. 1, pp. 11-26, pls. 1-4. Ford, John 1889. Notes on Crepidula. Acad. Nat. Sci. Philadelphia, Proc., vol. 41, pp. 345-346. Foster, Richard W. 1935. Arca barbata Linn. Nautilus, vol. 49, No. 2, p. 64. 1937. Notes on Anomia aculeata Miiller. Nautilus, vol. 50, No. 3, pp. 102-103. 1946a. The genus Mya in the Western Atlantic. Johnsonia, vol. 2, No. 20, pp. 29-35, pls. 17-21. Frenguelli, Joaquin 1935. El género “Conus” en el Patagoniano inferior de Comodoro Rivadavia (Chubut). Inst. Mus. Univ. Nac. La Plata, Notas Mus. La Plata, vol. 1, Paleontologia, No. 4, pp. 151-157, 2 figs. Freneix, Suzanne 1960. Remarques sur Vontogénie du ligament et de la charniére de quelques espéeces de lamellibranches (Noetidae et Carditidae). Soc. Géol. France, Bull., sér. 7, No. 7, pp. 719-729, pls. 33-34. VENEZUELAN CENOZOIC PELECYPODS: WEISBORD 435 Friele, Herman 1882. The Norwegian North-Atlantic Expedition. Mollusca. I. Buc- cinidae. Christiania, pp. 1-38, pls. 1-6. 1886. The Norwegian North-Atlantic Expedition. Mollusca. II. Chris- tiania, pp. 1-44, pls. 7-12. Friele, Herman, and Grieg, James A. 1876-78. Den Norske Nordhaus Exped. Vol. 7, Zoology. Mollusca 3., viii + 131 pp., map. 1877. Preliminary report on Mollusca from the Norwegian North At- lantic Expedition in 1876. Nytt Mag. Natur., vol. 23, No. 3, pp. 110sbpliub. 1886. The Norwegian North-Atlantic Expedition. Mollusca. III. Chris- tiania, pp. 1-132. Frierson, L. S. 1914. A new pearly freshwater mussel of the genus Hyria from Brazil. U. S. Nat. Mus., Proc., vol. 47, No. 2053, p. 363, pl. 12. Fulton, Hugh Coomber 1915. A list of the Recent species of Spondylus Linné. Quart. Jour. Con- chol., vol. 14, pp. 331-338, 353-362. 1922. A list of the species and genera of recent Mollusca first described in “Le Naturaliste.” Malac. Soc. London, Proc., vol. 15, pp. 19-31. Gabb, William More 1860a. Descriptions of new species of American Tertiary and Cretaceous fossils. Acad. Nat. Sci. Philadelphia, Jour., ser. 2, vol. 4, pp. 375- 406, pls. 67-69. 1874a. Notes on the geology of Costa Rica. Amer. Jour. Sci., ser. 3, vol. 7, pp. 438-439. 1874b. Notes on the geology of Costa Rica. Amer. Jour. Sci., ser. 3, vol. 8, pp. 388-390. 1895. Informe sobre la exploracién de Talamanca verificada durante los anos de 1873-74. Inst. Fis. Geog. Nac. Costa Rica, An., vol. 5 (1892), pp. 67-90. Gale, H. R. 1928. West coast species of Hinnites. San Diego Soc. Nat. Hist., Trans., vol. 5, pp. 91-94. Ganong, W. F. 1886. The marine Mollusca of New Brunswick. Nat. Hist. Soc. New Brunswick, Bull., No. 6, pp. 1-16. Gardner, Julia Anna 1940. New Rangia from upper Miocene of western Gulf Province. Amer. Assoc. Petrol. Geol., Bull., vol. 24, No. 3, pp. 476-477, figs. 1-2. Gaskoin, J. S. 1848. Descriptions of new species of the genus Cypraea. Zool. Soc. London, Proc., pp. 90-98. 1849. Descriptions of seven new species of Marginella and two of Cypraea. Zool. Soc. London, Proc., pp. 17-23. 1852. Descriptions of twenty species of Columbella, and one species of Cypraea. Zool. Soc. London, Proc., pp. 2-14. Gatliff, J. H., and Gabriel, C. J. 1911. On some new species of Victorian marine Mollusca. Roy. Soc. Victoria, Proc., new ser., vol. 24, pt. 1, pp. 187-192, pls. 46-47. Gazin, C. L. 1957. Exploration for the remains of giant ground sloths in Panama. Smithsonian Inst., Ann. Rept for 1956, pp. 341-354, 7 figs., 8 pls. 436 ButteTin 204 Gibson, Thomas G. 1961. Revision of the Turridae of the Miocene St. Mary’s formation of Maryland. Jour. Paleont., vol. 36, No. 2, pp. 225-246, pls. 40-42, 7 text figs. Gignoux, Maurice 1913. Les formations marines Pliocénes et Quaternaires de l’Italie du sud et de Sicile. Lyon Univ., Ann., new ser., sect. 1, No. 26, 693 pp., 42 text figs., 21 pls. Gigoux, Enrique Ernesto 1934. Los moluscos de Altacama. Rev. Crilena Hist. Nat., aflo 38, pp. 274-286. 1937. La Oliva peruviana Lamarck. Mus. Nac. Hist. Nat., Bol., vol. 16, pp. 3-10, figs. 1-60. Gillett, Suzette 1960. Observations sur de jeunes coquilles de mollusques du Pliocene saumdtre du Llobregat (Barcelone). Soc. Géol. France, Bull., sér. 7, vol. 1, No. 7, pp. 731-733, pls. 35-36. Ginsburg, Robert N. 1953. Intertidal erosion of the Florida Keys. Bull. Marine Sci. Gulf and Caribbean, vol. 3, No. 1, pp. 55-69. Glen, William 1959. Pliocene and lower Pleistocene of the western part of the San Francisco Peninsula. Univ. California Publ., Dept. Geol. Sci., vol. 36, No. 2, pp. 147-198, pls. 15-17, 5 text figs. 1960. Pliocene fresh-water gastropods from San Mateo County, Cali- fornia. Jour. Paleont, vol. 34, No. 6, pp. 1207-1209, text fig. 1. Glibert, Maxime 1945. Faune malacologique du Miocene de la Belgique. I. Pélécypodes. Mus. Roy. Hist. Nat. Belgique, Mém. 103, 266 pp., 12 pls. 1954. Pleurotomes du Miocéne de la Belgique et du Bassin de la Loire. Inst. Roy. Sci. Nat. Belgique, Mém. 129, 75 pp., 7 pls. Goldfuss, G. A. 1833-36. Petrefacta Germaniae. Dusseldorf, vol. 2, pt. 4, pp. 1-68, pls. 72-96 (1833); pt. 5, pp. 69-140, pls. 97-121 (1836). Gould, Augustus Addison 1855. Descriptions of shells from the Gulf of California and the Pacific coasts of Mexico and California. Boston Soc. Nat. Hist., Jour., vol. 6, art. 24, pp. 1-35, pls. 14-16. Grateloup, J. P. S. de 1840-47. Conchyliologie fossile des terrains Tertiaires du Bassin del’- Adour. Bordeaux, vol. 1, Univalves, xx + 84 + 12 pp., 48 pls. Grau, Gilbert 1959. Pectinidae of the Eastern Pacific. Allan Hancock Pacific Expedi- tions, Univ. Southern California Press, Los Angeles, vol. 23, pp. i-viii + 308, 57 pls. 1960. A new Chlamys from the South Pacific. Nautilus, vol. 74, No. 1, pp. 15-18, pl. 2. Gray, George Melton 1933. Observations on Montacuta percompressa Dall. Nautilus, vol. 46, No. 3, pp. 76-79. Gray, John Edward 1842. Synopsis of the Contents of the British Museum. London, 4th ed. Gregg, Wendell Oliver 1938. Pecten pugetensis at Newport Bay, California. Nautilus, vol. 51, No. 4, pp. 118-119. VENEZUELAN CENOzOIC PELECYPOoDS: WEISBORD 437 de Gregorio, Antonio 1883. Moderne nomenclature des coquilles des gastéropodes et des pélécypodes. Palerme, 20 pp., 1 pl. 1884. Studi su talune conchiglie Mediterranee viventi e fossili con una rivista del gen. Vulsella. Soc. Malac. Italiano, Bull., vol. 10, pp. 36-288, pls. 1-5. 1890. Monographie de la faune Eocénique de Alabama. Ann. Géol. et Paleont., pt. 7, pp. 1-156, pls. 1-17; pt. 8, pp. 157-316, pls. 18-46. Gregory, John Walter 1889. Cystechinus crassus, a new species from the radiolarian marls of Barbados, and the evidence it affords as to the age and origin of these deposits. Geol. Soc. London, Quart. Jour., vol. 45, pp. 640-650. 1892a. The relations of the American and European echinoid faunas. Geol. Soc. Amer., Bull., vol. 3, pp. 101-108. 1892b. Archaeopneustes abruptus, a new genus and species of echinoid from the Oceanic series in Barbados. Geol. Soc. London, Quart. Jour., vol. 48, pp. 163-168, pl. 4. 1892c. The microscopic structure of some Trinidad rocks. Geol. Soc. London, Quart. Jour., vol. 48, pp. 538-541. 1895. Contributions to the paleontology and physical geography of the West Indies. Geol. Soc. London, Quart. Jour., vol. 51, pp. 255-312, ple 1929a. The theory of permanent oceans and continents. Geol. Soc. Lon- don, Quart. Jour., vol. 85, pp. 68-122. 1929b. Dendroseris n. gen. and other corals from Trinidad. Geol. Mag., vol. 66, pp. 65-68, pl. 8. de Greve, Leonard 1938. Eine Mollusken fauna aus dem Neogen von Iquitos am Oberen Amazonas in Peru. Schweizerischen Palaeont. Gesell., Abhandl., vol. 61, pp. 1-133, pls. 1-10. Grieg, James A. 1921. Remarks on Verrill’s North American Alvania (Cingula) jan- mayenit (Friele). Bergens Mus. Aarbok, Naturvidensk Raekke No. 8, pp. 2-9, figs. 1-4. Gunter, Gordon 1948. The genera of living oysters. Anat. Rec., vol. 101, No. 4, p. 39. 1950. The generic status of living oysters and the scientific name of the common American species. Amer. Midland Naturalist, vol. 43, No. 2, pp. 438-449. 1951. The species of oysters of the Gulf, Caribbean and the West Indian region. Bull. Marine Sci. Gulf and Caribbean, vol. 1 No. 1, pp. 40-45. Haas, Fritz 1930-31. Versuch einer Kritischen Sichtung der siidamerikanischen Najaden, hauptsdchlich an Hand der Sammlung des Senckenberg- Museums. I. Senckenbergiana, vol. 12, pp. 175-195, figs. 1-23; vol. 13, pp. 87-110, figs. 33-37. 1932. Beitrdge zur Kenntnis der Verbreitung siidamerikanischer Najaden. Arch. Molluskenk., vol. 64, Nos. 4-5, pp. 167-170, pl. 12. 1941. Malacological notes-II. Field Mus. Nat. Hist. Zoology, vol. 24, No. 17, pp. 167-174, pl. 2. 1949. On some deepsea mollusks from Bermuda. Inst. Catalana Hist. Nut. Butil., vol. 37, pp. 69-72, figs. 1-6. Habe, Tadashige 1951. Genera of Japanese Shells. Pelecypoda. No. 1. Pp. 1-96, 192 text figs. ’ 438 BuLueTin 204 Hagg, Richard 1910. Interglaziale und postglaziale Meeresmollusken aus Feuerland und Siidpatagonien als beweis fiir ein warmeres Klima als das jetzige. Arkiv for Zoologi, K. Svenska Vetenskapsakad. i Stockholm, vol. 7, No. 1, pp. 1-26. Hamlin, Charles E. 1884. Results of an examination of Syrian molluscan fossils, chiefly from the Range of Mount Lebanon. Mus. Comp. Zool., Mem., vol. 10, No. 3, pp. 1-68, pls. 1-6 Hancock, Albany 1846. A list of shells dredged on the west coast of Davis’s Strait; with notes and descriptions of eight new species. An. and Mag. Nat. Hist., ser. 1, vol. 18, pp. 323-338, pl. 5. Hanley, Sylvanus 1843a On new species of Donax and Mya. Zool. Soc. London, Proc., Dial eppso- 7. 1843b. On new species of Solen and Mesodesma. Zool. Soc. London, Proc., pt. 11, pp. 101-102. 1844.2. Descriptions of new species of Mytilacea, Amphidesma, and Odostomia. Zool. Soc. London, Proc., pt. 12, pp. 14-18. 1844b. Descriptions of new species of Cytherea. Zool. Soc. London, Proc., pt. 12, pp. 109-110. 1844c. Descriptions of new species of Cyrena, Venus, and Amphidesma. Zool. Soc. London, Proc., pt. 12, pp. 159-162. 1860c. On some new species of Nuculaceae in the collection of Hugh Cuming, Esq. Zool. Soc. London, Proc., pp. 370-371. Hanna, G. Dallas 1939. Exotic Mollusca in California. Dept. Agric. State of California, Bull., vol. 28, No. 5, pp. 298-321, pls. A-D. Hanna, G. Dallas, and Hertlein, Leo George 1961. Large Terebras (Mollusca) from the Eastern Pacific. California Acad. Sci., Proc., ser. 4, vol. 30, No. 3, pp. 67-80, pls. 6-7. Hanna, Marcus A. 1926. Geology of the La Jolla quadrangle, California. Univ. California Publ., Bull. Dept. Geol. Sci., Vol. 16, pp. 187-246, 7 pls., 1 map. Harrison, J. V. 1953. The Geology of the Santa Elena Peninsula in Costa Rica, Cen- tral America. Seventh Pacific Sci. Congress, Proc., vol 2, pp. 102- 114. Hart, C. F. 1872. On the Tertiary basin of the Maranén. Amer. Jour. Sci. and Arts, ser. 3, vol. 4, pp. 53-58. Hayasaka, Shozo 1960. Large-sized oysters from the Japanese Pleistocene and their paleoecological implications. Science Reports Tohoku Univ., Sen- dai, Japan, 2d ser. (Geology), special vol. No. 4, pp. 356-370, pls. 37-38, 7 figs. table 1. Hedley, Charles 1899a. The Mollusca of Funafuti. Pt. 2. The Pelecypoda and Brachiopoda. Australian Mus., Mem., No. 3, pp. 489-510, figs. 50-57. 1899b. A zoogeographic scheme of the mid-Pacific. Linnaean Soc. New South Wales, Proc., vol. 24, pp. 391-417. 1902. Scientific results of the trawling expedition of H. M. C. S. “Thetis.” Mollusca. Part I. Australian Mus., Mem., vol. 4, pp. 287- 324, figs. 39-60. VENEZUELAN CENozoIc PELECYPoDsS: WEISBORD 439 1906. The Mollusca of Mast Head Reef, Capricorn Group, Queensland. Linnaean Soc. New South Wales, Proc. for 1906, vol. 31, pt. 1, pp. 453-479, pls. 36-38. 1909. Mollusca from the Hope Islands, North Queensland. Linnaean Soc. New South Wales, Proc., vol. 34, pp. 420-466, pls. 36-44, 1 map. 1911. Mollusca. British Antarctic Expedition (1907-9), Biology, vol. 2, pt. 1, pp. 1-8, 1 pl. 1913. Studies on Australian Mollusca. Part XI. Linnaean Soc. New South Wales, Proc., vol. 38, No. 2, pp. 258-339, 4 pls. 1915. A preliminary index of the Mollusca of Western Australia. Roy. Soc. Western Australia, Jour., vol. 1, 77 pp. 1916. Mollusca. Australian Antarctic Expedition., ser. C., Zoology and Botany, vol. 4, pt. 1, pp. 1-80, pls. 1-9. 1917. Studies on Australian Mollusca. Pt. 13. Linnaean Soc. New South Wales, Proc., vol. 41 (1916), pt. 4, pp. 680-719, pls. 46-52. 1918. A check-list of the marine fauna of New South Wales. Pt. 1. Mollusca. Roy. Soc. New South Wales, Jour. and Proc., vol. 51, 120 pp. 1920. Concerning Edenttelina. Malac. Soc. London, Proc., vol. 14, pp. 74-76, figs. 1-8. 1922. A revision of the Australian Turridae. Australian Mus., Rec., vol. 13, pp. 213-359, pls. 42-56. 1934. Revision of the Australian Pinnidae. Australian Mus., Rec., vol. 14, pp. 141-153, 3 pls. Heilprin, Angelo 1881. Remarks on the molluscan genera Hippagus, Verticordia and Pecchiolia. Acad. Nat. Sci. Philadelphia, Proc. vol. 33, pp. 423- 428. 1886. A new species of Aplysia. Acad. Nat. Sci. Philadelphia, Proc., vol. 38, p. 364. 1888. Contributions to the natural history of the Bermuda Islands. Acad. Nat. Sci. Philadelphia, Proc., vol. 40, pp. 302-328, pls. 14-16. 1889a. The Bermuda Islands. Philadelphia, 231 pp., 19 pls. 1889b. On some new species of Mollusca from the Bermuda Islands. Acad. Nat. Sci. Philadelphia, Proc., vol. 41, pp. 141-142, pl. 8. Henderson, John B., and Bartsch, Paul 1914. Littoral marine mollusks of Chincoteague Island, Virginia. U. S. Nat. Mus., Proc., vol. 47, No. 2055, pp. 411-421, pls. 13-14. Herrmannsen, August Nicolaus 1853. On some genera of shells, established in 1807 by the late H. F. Link. Zool. Soc. London, Proc. for 1851, pp. 228-233. Hertlein, Leo George 1928a. Preliminary report on the paleontology of the Channel Islands, California. Jour. Paleont., vol. 2, No. 2, pp. 142-157, pls. 22-25. 1928b. Pecten (Patinopecten) lohri, new name for Pecten oweni Arnold, a Pliocene species from California. Nautilus, vol. 47, pp. 62-64. 1929. Three new specific names for west American Mollusca. Jour. Paleont., vol. 3, No. 3, pp. 295-296. 1931a. Additional Pliocene and Pleistocene fossils from Lower California. Jour. Paleont., vol. 5, No. 4, pp. 365-367. 1933a. Three preoccupied names in the Pectinidae. Nautilus, vol. 47, No. 2, pp. 62-64. 1936c. The dates of publication of C. H. Kiister and W. Kobelt’s mono- graph of Spondylus and Pecten, in volume 7, part 2, of the Systematisches Conchylien-Cabinet. An. Mag. Nat. Hist., ser. 10, vol. 17, pp. 158-160. 440 BuLLeTiIn 204 1940. Additions to the range of Pecten caurinus Gould. Nautilus, vol. 54, No. 2, pp. 68-69. 1957. Pliocene and Pleistocene fossils from the southern portion of the Gulf of California. Southern California Acad. Sci., Bull., vol. 56, DEEZ Ippo 7-755) ply 13. Hertlein, Leo George, and Emerson, William K. 1956. Marine Pleistocene invertebrates from near Puerto Penasco, Sonora, Mexico. San Diego Soc. Nat. Hist., Trans., vol. 12, pp. 154-178, pl. 12, 2 maps. 1957. Additional notes on the invertebrate fauna of Clipperton Island. Amer. Mus. Novitates, No. 1859, 9 pp., 1 fig. 1959. Pliocene and Pleistocene megafossils from the Tres Marias Islands. Amer. Mus. Novitates, No. 1940, 15 pp., 5 figs. Hertlein, Leo George, and Strong, A. M. 1947. Description of a new species of Trophon from the Gulf of Cali- fornia. Southern California Acad. Sci. Bull., vol. 46, pt. 2, pp. 79-80, pl. 18. 1955a. Essays in the natural sciences in honor of Captain Allan Hancock on the occasion of his birthday July 26, 1955. Marine mollusks collected at the Galapagos Islands during the voyage of the Velero III, 1931-1932. Univ. Southern California Press, Los Angeles, pp. 111-145, pl. A. 1957. Pliocene and Pleistocene fossils from the southern portion of the Gulf of California. Southern California Acad. Sci., Bull., vol. 56, pt. 2, pp. 57-75, pl. 13. Higgins, H. H. 1877. Mollusca of the Argo Expedition to the West Indies, 1876. Literary and Philos. Soc. Liverpool, Proc., vol. 31, pp. 405-423, pl. 1. Hill, Howard R. 1954. Variation in the olive shells of tropical west America. Nautilus, vol. 68, No. 2, pp. 66-69. Hinds, Richard Brinsley 1843¢. On new species of Neaera. Zool. Soc. London, Proc., pp. 75-79. 1844h. Descriptions of new species of Triton, Solarium, and Corbula. Zool. Soc. London, Proc., pt. 12, pp. 21-26. 18441. Descriptions of new species of Ringicula and Neaera from the cabinets of Sir E. Belcher and Hugh Cuming, Esq. Zool. Soc. London, Proc., pt. 12, pp. 96-98. 1844j. Description of a new species of Solarium, from the collection of Mr. Cuming. Zool. Soc. London, Proc., pt. 12, p. 158. Hoffmeister, William S. 1938. Aspect and zonation of the molluscan fauna in the La Rosa and Lagunillas formations, Bolivar Coastal Fielda, Venezuela. Bol. Geol. y Mineria, vol. 2, Nos. 2-4, pp. 103-122 (English ed.). Hoffstetter, Robert 1948. Notas sobre el Cuaternario de la Peninsula de Santa Elena (Ecuador). II. Pelecypoda de tercer Tablazo. Bol. Informacién Ciencia Nac., vol. 2, Nos. 13-14, pp. 67-83. 1949. Moluscos subfésiles de los estanques de sal de Salina (Pen. de Santa Elena, Ecuador). Comparacién con la fauna actual del Ecuador. Inst. Cienc. Nac., Bol., ato 1, No. 1, pp. 3-79, figs. 1-19. 1952. Moluscos subfésiles de los estanques de sal del Salinas (Pen. de Santa Elena, Ecuador). Inst. Cienc. Nac., Bol., aio 1, No. 1, pp. 5-79, 19 figs. Hoffstetter, Robert, et al. 1960. Lexique Stratigraphique International, vol. 5, Amérique Latine, No. 2a, Amérique Centrale, 366 pp., 8 geol. maps. VENEZUELAN CENOZOIC PELECYPODS: WEISBORD 44] Hubbard, J. W., and Smith, Sanderson 1865. Catalogue of the Mollusca of Staten Island, N. Y. Lyc. Nat. Hist. New York, Ann., vol. 8, pp. 3-5. Hubendick, Bengt 1956. A conchological survey of the genus Plecotrema (Gastropoda, Ellobiidae). Malac. Soc. London, Proc., vol. 32, pt. 3, pp. 110-126, plee23: Hutton, Frederick Wollaston 1873. Catalogue of the marine Mollusca of New Zealand, with diagnoses of the species. Colonial Mus. and Geol. Survey Dept., Wellington, 116 pp. 1880. Manual of the New Zealand Mollusca. A systematic and descrip- tive catalogue of the marine and land shells of the soft mollusks and Polyzoa of New Zealand and the adjacent islands. Colonial Mus. and Geol. Survey Dept., Wellington, 223 pp. 1884a. Revision of the Recent Lamellibranchiata of New Zealand. Linnaean Soc. New South Wales, Proc., vol. 9, pp. 511-534. 1884b. Revision of the marine taeniglossate and ptenoglossate Mollusca of New Zealand. Linnaean Soc. New South Wales, Proc., vol. 9, pp. 932-944. 1885. Revision of the toxoglossate Mollusca of New Zealand. Linnaean Soc. New South Wales, Proc., vol. 9, pp. 115-118. Hyatt, Alphaeus 1892. Remarks on the Pinnidae. Boston Soc. Nat. Hist., Proc., vol. 35 pp. 335-346. von Ihering, Hermann 1896. Zur Kenntnis der siidamerikanischen Voluta und ihrer Geschichte. Deutsch. Malakozool., Gesell., Nachrichtsblatt, Nos. 7-8, pp. 93-99. 1897b. 4d Ilha de S. Sebastoao. Mus. Paulista, Rev., vol. 2, pp. 129-170, pl. 2, text figs. 1899. Die Conchylien der patagonischen Formation. N. Jahrb. f. Min., Geol. u. Palaeont., vol. 2, pp. 1-46, pls. 1-2. 1902a. Die Photinula-Arten der Magellan Strasse. Deutsch. Malako- zool. Gesell., Nachrichtsblatt, Nos. 5-6, pp. 97-104. 1902b. Historia de los Ostras Argentinas. Mus. Nac. Buenos Aires, An., vol. 7, pp. 109-123, figs. 1-9. 1902c. On the molluscan fauna of the Patagonian Tertiary. Amer. Philos. Soc., Proc., vol. 41, No. 169, pp. 132-137, pl. 19. 1905. Les mollusques fossiles du Tertiaire et du Crétacé Supérieur de Argentine. I. Les mollusques de lVétage Rocanéen. Mus. Nac. Buenos Aires, An., ser. 3, vol. 7, pp. 1-36, pls. 1-3. 1908a. Lotorium felipponei sp. n. Malacologie de Uruguay, Buenos Aires, pp. 5-6, figs. a,b. 1908b. Mollusques du Pampéen de Mar del Plata et Chapalmaldn re- cueillis par M. le Dr. Florentino Ameghino en 1908. Mus. Nac. Buenos Aires, An., ser. 3, vol. 10, pp. 429-438. 1909. Nouvelles recherches sur la formation Magellanienne. Mus. Nac. Buenos Aires, An., ser. 3, vol. 12, pp. 27-43. 1914. Catalogo de moluscos cretaceos e terciarios da Argentina da collecgao do autor. Rev. Mus. Paulista, Notas Preliminares, vol. 1, No. 3, pt. 1, pp. 1-113, pls. 1-3. 1921. Die Geschichte der Venus-Muscheln. Archiv. f. Molluskenkunde, No. 3, pp. 125-139. 1927b. Die Gattung Mesodesma Desh. Archiv. f. Molluskenkunde, vol. 59, pp. 250-255. Imbrie, John 1956. Biometrical methods in the study of invertebrate fossils. Amer. Mus. Nat. Hist., Bull., vol. 108, art. 2, pp. 217-252. 442 BuLLeTIN 204 Ingram, William Marcus 1949. A check list of the Limacidae, Endodontidae, Arionidae, Succinei- dae, Pupillidae, Valloniidae, Carychiidae, and Truncatellidae of California. Southern California Acad. Sci., Bull., vol. 48, pt. 1, pp. 19-34. Iredale, Tom 1913. A collation of the molluscan parts of the synopses of the contents of the British Museum, 1838-1845. Malac. Soc. London, Proc., vol. 10, pt. 4, pp. 294-309. 1916. On some new and old molluscan generic names. Malac. Soc. Lon- don, Proc., vol. 12, No. 1, pp. 27-37. 1925. Mollusca from the continental shelf of eastern Australia. Aus- tralian Mus., Rec., vol. 14, pp. 243-270, pls. 41-43, 1 map. 1929b. Queensland molluscan notes, No. 1. Queensland Mus., Mem., vol. 9, pp. 261-297, pls. 30-31. 1930a. More notes on the marine Mollusca of New South Wales. Aus- tralian Mus., Rec., vol. 17, pp. 384-407, pls. 62-65. 1930b. Queensland molluscan notes, No. 2. Queensland Mus., Mem., vol. 10, pp. 73-88, pl. 9. 1931. Australian molluscan notes, No. 1. Australian Mus., Rec., vol. 18, pp. 201-235, pls. 22-25. 1936. Australian molluscan notes, No. 2. Australian Mus., Rec., vol. 19, pp. 267-340, pls. 20-24. 1937. The Middleton and Elizabeth Reefs, South Pacific Ocean. Mol- lusca. Australian Zool., vol. 8, pp. 232-261, pls. 15-17. Iredale, Tom, and Laseron, C. F. 1957. The systematic status of Ctiloceras and some comparative genera. Roy. Zool. Soc. New South Wales, Proc., pp. 97-109, pls. 1-2. Jackson, Henry, Jr. 1908. The Mollusca of North Haven, Maine. Nautilus, vol. 21, No. 12, pp. 142-144. Jackson, Robert Tracy 1890. The phylogeny of the Pelecypoda. The Aviculidae and their allies. Boston Soc. Nat. Hist.,. Mem., vol. 4, pp. 277-400. 1918. Fossil Echini of the Panama Canal Zone and Costa Rica. U. S. Nat. Mus., Bull. 103, pp. 103-116, pls. 46-52. Jacobson, Morris K., and Emerson, William K. 1961. Shells of the New York City Area. Larchmont, pp. i-xviii + 142, text figs. Jacot, Arthur Paul 1919. Some marine Mollusca about New York City. Nautilus, vol. 30, pp. 90-94. 1920a. On the marine Mollusca of Staten Island, N. Y. Nautilus, vol. 33, pp. 111-115. 1920b. Notes on marine Mollusca about New York City. Nautilus, vol. 34, pp. 59-60. 1921. Some marine molluscan shells of Beaufort and vicinity. Elisha Mitchell Sci. Soc., Jour., vol. 36, pp. 129-145, pls. 11-13. Jameson, H. L. 1901. On the identity and distribution of the mother-of-pearl oysters; with a revision of the subgenus Margaritifera. Zool. Soc. London, Proc., pp. 372-394, figs. 92-95. Jay, John C. 1857. Report on the shells collected by the Japanese Expedition. [In] Perry, M. C., Narrative of the Expedition of an American Squad- ron to the China Seas and Japan. Washington, vol. 2, pp. 291-297, 5 pls. VENEZUELAN CENOZOIC PELECYPODS: WEISBORD 443 Jeannet, A. 1928. Contribution a l'étude des Echinides tertiaires de la Trinité et du Vénézuéla. Soc. Paléont. Suisse, Mém., vol. 48, pp. 1-48, 6 pls., 12 text figs. Jeffreys, John Gwyn 1874. On some species of Japanese marine shells and fishes, which in- habit also the North Atlantic. Linnean Soc. London, Jour., Zoology, vol. 12, pp. 100-109. 1876a. New and peculiar Mollusca of the Pecten, Mytilus, and Arca fami- lies procured in the “Valorous” Expedition. Ann. Mag. Nat. Hist., ser. 4, vol. 18, pp. 424-436. 1876b. Preliminary report of the biological results of a cruise in H.M.S. “Valorous” to Davis Strait in 1875. Roy. Soc. London, Proc., vol. 25, pp. 177-230, pls. 2-4. 1877. New and peculiar Mollusca of the Eulimidae and other families of Gastropoda, as well as of the Pteropoda, procured in the “Valor- ous” Expedition. Ann. Mag. Nat. Hist., ser. 4, vol. 19, pp. 317-339. 1878-1885. On the Mollusca procured during the “Lightning” and “Porcu- pine” Expeditions, 1868-1870. Zool. Soc. London, Proc. for 1878, pt. 1, pp. 393-416, pls. 22-23; for 1879, pt. 2, pp. 553-588, pls. 45-46; for 1881, pts. 3-4, pp. 693-724, 922-962, pls. 61, 70- 71; for 1882, pt. 5, pp. 656-687, pls. 49-50; for 1883, pt. 6, pp. 88-115, pls. 19-20; for 1884, pt. 7, pp. 111-149, pls. 9-10; for 1884, pt. 8, pp. 341-372, pls. 26-28; for 1885, pt. 9, pp. 27-63, pls. 4-6. Johnson, Charles Willison 1890. An annotated list of the shells of St. Augustine, Fla. Nautilus, vol. 3, pp. 103-105. 1903. Some notes on the genus Fulgur. Nautilus, vol. 17, pp. 73-75. 1904. Panopea bitruncata Conrad. Nautilus, vol. 18, pp. 73-75, pl. 4. 1905. On the species of Martesia of the eastern United States. Nautilus, vol. 18, pp. 100-103, figs. 1-3. 1915a. Fauna of New England. List of the Mollusca. Boston Soc. Nat. Hist., Occas. Papers, vol. 7, No. 13, 231 pp. 1918. The Avicula candeana of d’Orbigny, from Bermuda. Nautilus, vol. 32, pp. 37-39, pl. 3. Johnson, J. Harlan 1961. Limestone-building Algae and Algal Limestones. Colorado School of Mines, xi + 297 pp., 139 pls. Johnson, Richard I. 1949. Jesse Wedgwood Mighels, with a bibliography and a catalogue of his species. Occas. Papers on Mollusks, vol. 1, No. 4, pp. 213-231, pl. 27. Jonas, J. H. 1844a. Newe Trochus-Arten. Zeitschr. f. Malakozool., pp. 113-116. 1844b. Bemerkungen iiber einige der von Lamarck in seiner “Histoire naturelle des animaux sans vertébres” aufgefiihrten Conchylien- Arten mit besonderer Riicksicht auf die Zusatze des Herrn De- shayes. Zeitschr. f. Malakozool., pp. 135-39. 1844c. Neue Trochoideen. Zeitschr. f. Malakozool., pp. 181-185. 1844-45. Vorldufige Diagnosen neuer Conchylien, welche ausfihrlicher beschrieben und abgebildet nachstens erscheinen werden. Zeitschr. f. Malakozool., pp. 33-37, 185-186 (1844); pp. 65-67, 168-173 (1845). 1845. Conchyliologische Notizen. Zeitschr. f. Malakozool., pp. 181-185. 1846a. Molluskologische Beitrdge. Geb. Naturw. Hamburg, Abhandl., vol. 1, pp. 99-130, pls. 7-11. 444 BuLueTin 204 1846b. Descriptions of new species of shells. Zool. Soc. London, Proc., vol. 14, pp. 34-36. 1846c. Descriptions of two new shells [Pyrula ideolum, Anomia navi- formis]. Zool. Soc. London, Proc., vol. 14, pp. 120-121. 1849. Description of a new species of Thracia [T. magnifica]. Zool. Soc. London, Proc., p. 170, pl. 6, fig. 7. Jones, J. Matthew 1877. Mollusca of Nova Scotia. Nova Scotian Inst. Nat. Sci., Proc. and Trans., vol. 4, pp. 321-330. Jordan, Eric Knight 1932. A new species of Crassatellites from the Gulf of California. Nauti- lus, vol. 46, No. 1, pp. 9-10. 1936. The Pleistocene of Magdalena Bay, Lower Sires Dept. Geol. Stanford. Univ., Contrib., vol. 1, pp. 101-173, 3 pls. Jordan, Eric Knight, and Hertlein, Leo George 1926a. Expedition to the Revillagigedo Islands, Mexico, in 1925. No. 4. A Pliocene fauna from Maria Madre Island, Mexico. California Acad. Sci., Proc., ser. 4, vol. 15, pp. 195-207, pl. 22. Jousseaume, Félix Pierre 1884a. Monographie des Triforidae. Soc. Malac. France, Bull., vol. 1, pp. 217-270, pl. 4. Jukes-Browne, Alfred John 1908. Genera of Veneridae in Cretaceous and older Tertiary deposits. Malac. Soc. London, Proc., vol. 8, pt. 3, pp. 148-177, pl. 6. 1909. The application of the names Gomphina, Marcia, Hemitapes, and Katelysia. Malac. Soc. London, Proc., vol. 8, pt. 4, pp. 233-246, pl. 10. Jukes-Browne, A. J., and Harrison, J. B. 1889. Tertiary chalk in Barbados. Nature, vol. 39, p. 607. Kanakoff, George P. 1953. A new fossil shell [Diodora constantiae] from the Palos Verdes sand. Southern California Acad. Sci., Bull., vol. 52, pt. 2, pp. 67-70, pls. 12-13. Kaspar, Josef 1913. Beitrdége zur Kenntnis der Familie der Eryciniden und Carditiden. Zool. Jahrb., Suppl. 13, pp. 545-625, figs. A-Z, A’-F’. Kay, Alison 1960. Generic revision of the Cypraeinae. Malac. Soc. London, Proc., vol. 33, pt. 6, pp. 278-279, 8 text figs., table 1. Keen, Angeline Myra 1936. A new pelecypod genus of the family Cardiidae. San Diego Soc. Nat. Hist., Trans., vol. 8, No. 17, pp. 119-120. 1943. New mollusks from the Round Mountain silt (Temblor) Miocene of California. San Diego Soc. Nat. Hist., Trans., vol. 10, No. 2, pp. 25-60, pls. 3-4, figs. 1-5. 1960a. A bivalve gastropod. Nature, vol. 186, No. 4722, pp. 406-407. 1960c. Vermetid gastropods and marine intertidal zonation. The Veliger, Vol. .3snNo. 1982) ipps 1960d. New Phyllonotus from the Eastern Pacific. Nautilus, vol. 73, No. 3, pp. 103-109, pl. 10. 1961a. What is Anatina anatina? The Veliger, vol. 4, No. 1, pp. 9-12, figs. 1-5. 1961b. A proposed reclassification of the gastropod family Vermetidae. British Mus. (Nat. Hist.), Bull., Zoology, vol. 7, No. 3, pp. 183- 213, figs. 1-33, pls. 54-55. 1962. Nomenclatural notes on some west American mollusks, with pro- posal of a new species name. The Veliger, vol. 4, No. 4, pp. 178- 180. VENEZUELAN CENOZOIC PELECYPODS: WEISBORD 445 Keen, A. Myra, and Morton, J. E. 1960. Some new African species of Dendropoma (Vermetidae: Mesogas- tropoda). Malac. Soc. London, Proc., vol. 34, No. 1, pp. 36-51, 5 figs., 3 pls. Keen, A. Myra, and Smith, Allyn G. 1961. West American species of the bivalved gastropod genus Berthelinia. California Acad. Sci., Proc., ser. 4, vol. 30, No. 2, pp. 47-66, figs. 1-33, 1 pl. Keep, Josiah 1935. West Coast Shells. Revised by J. L. Baily, Jr. Stanford University, 350 pp., 334 text figs. Kindle, E. M. 1917. Notes on the bottom environment of the marine invertebrates of western Nova Scotia. Ottawa Naturalist, vol. 30, No. 12, pp. 149-154. 1918. Notes on the habits and distribution of Teredo navalis on the Atlantic coast of Canada. Biol. Contrib., Sessional Papers, No. 38a, pp. 93-101, figs. 1-2. Kindle, E. M., and Whittaker, E. J. 1918. Bathymetric check-list of the marine invertebrates of eastern Cana- da with an index to Whiteaves’ Catalogue. Dept. Naval Service, Sessional Papers, No. 38a, pp. 229-294. Kingsley, J. S. 1901. Preliminary catalogue of the marine invertebrates of Casco Bay, Maine. Portland Soc. Nat. Hist. Proc., vol. 2, 159-183. Kira, Tetsuaki 1955. Coloured Illustrations of the Shells of Japan. Osaka, 204 pp., 67 pls., text figs. Kisch, B. S. 1959. La collection de Chemnitztidae du marquis De Folin au Muséum National d’Histoire Naturelle. Description de Turbonilla corpulens. Catalogue des espéces publiées par De Folin. Jour. Conchyl., vol. 99, No. 3, pp. 89-112. 1960. Les mollusques décrits par De Folin - a part les Caecidae et Chemnitzitidae - avec catalogue. Jour. Conchyl., vol. 100, pp. 137-162. Klein, Jacobi Theodori 1753. Tentamen Methodi Ostracologicae sive dispositio naturalis Cochli- dum et Concharum in suas classes, genera et species, iconibus singulorum Generum aeri incilis illustrata accedit Lucubratiuncula de formatione, cremento et coloribus testarum quae sunt Cochlidusm et Concharum. Tum Commentariolum in locum Plinii Hist. Nat. Libr. IX. Cap. XXXIII de Concharum differentiis denique scia- graphia Methodi ad Genus Serpentium ordinate digerendum. Dedicatio, 1 p; Praefatio 3 pp.; Cochlidum. Tabula Synoptica, 3 pp.; Methodus Ostracologica, 177 pp.; Indiculus, 2 pp.; Nom- enclator, 3 pp.; Index Rerum, 6 pp.; Index Rerum Polyglottus, 12 pp.; Clavis Figurarum, 4 pp.; Lucubratiuncula de Formatione, Cremento et Coloribus Testarum: Praefatio, 5 pp.; Summaria, 1 p.; Cochlidum et Concharum, 44 pp.; Commentariolum in locum Plinii, 16 pp.; Sciagraphia Methodi, 2 pp., pls. 1-12. Knorr, Georg Wolfgang 1757-1772. Vergnugen der Angen und des Gemiiths in vorstellung einer allgemeinen Sammlung von Schnecken un Muscheln und andern Geschipfen welche im Meer gefunden verden. Nirnberg. First ed. (1757), pp. 1-39, pls. 1-30. Zweyter Theil (1764), 56 pp., + Systematischer Register 15 pp., + Nachschrift 1 p., 30 pls. 446 BuLLeTin 204 Dritter Theil (1768), 52 pp., 30 pls. Vierter Theil (1769), pp. 1-48 + Systematischen Registers 14 pp., 30 pls. Funfter Theil (1771), 46 pp., + Vorbericht wegen des Linnaischen Registers 4 pp., + Linnaisch Register, pp. 5-13, 30 pls. Sech- ster Theil (1772), 76 pp., + Systematischen Registers 18 pp., + Linnaischen Registers 11 pp., + Allgemeines Register 100 pp., 40 pls. Kobelt, Wilhelm 1881-86. Die Gattung Crassatella Lam. Syst. Conchylien-Cabinet, vol. 10, pt. 1A, pp. 1-16, pls. 1-6 (1881); pp. 17-41, pls. 7-9 (1886). 1886-88. Die Gattungen Spondylus und Pecten. Syst. Conchylien-Cabinet, vol. 7, pt. 2, pp. 129-296, pls. 37-72. 1891. Die Gattung Arca L. Syst. Conchylien-Cabinet, vol. 8, pt. 2, pp. 1-238, pls. 1-49. Kornicker, Louis S., and Armstrong, Neal 1959. Mobility of partially submerged shells. Inst. Marine Sci. Univ. Texas, Publ., vol. 6, pp. 171-185, 14 figs. Kornicker, Louis S., Bonet, F., Cann, Ross, and Haskin, Charles M. 1959. Alacran Reef, Campeche Bank, México. Inst. Marine Sci. Univ. Texas, Publ., vol. 6, pp. 1-22, 20 figs. Korobkovy, I. A. 1954. Handbook on, and systematic guide to the Tertiary Mollusca. Lamellibranchia. State Sci-Tech. Publishing Agency Oil and Mineral Fuel Literature, Leningrad, 444 pp., 96 pls. (In Russian). Kotaka, Tamio 1960. Similarity in the turritellid phylogeny in the later Cenozoic. Tohoku Univ., Sendai, Japan, Sci. Reports, 2d ser. (Geology), Special vol. No. 4, pp. 301-308, 4 text figs. Kuroda, Tokubei 1928. Catalogue of the shell-bearing Mollusca of Amami-Oshima (Oshi- ma, Osumi). Kagoshima, 126 pp. 1929-35. An Illustrated Catalog of the Japanese Shells. Parts 1-16. 154 pp. 1960. A Catalogue of Molluscan Fauna of the Okinawa Islands. Pp. 1- 106, pls. 1-3. Kuroda, Tokubei, and Habe, Tadashige 1952. Check List and Bibliography of the Recent Marine Mollusca of Japan. Tokyo, 210 pp., 1 chart, 1 map. Kuster, H. C. 1842-59. Die Gattung Spondylus und Pecten. Syst. Conchylien-Cabinet, vol. 7, pt. 2, pp. 1-128, pls. 1-36. Kuster, H. C., and Kobelt, W. 1839-78. Die Geschwdantzen und bewehrten Purpurschnecken (Murex, Ranella, Tritonium, Trophon, Hindsia). Syst. Conchylien-Cab- inet, vol. 3, pt. 2, pp. 1-336, pls. 1-83. Kuster, H. C., and Weinkauff, H. C. 1837-75. Die Familie der Coneae oder Conidae. Syst. Conchylien-Cabinet, vol. 4, pt. 2, pp. 1-413, pls. A, 1-71. Ladd, Harry S. 1934. Geology of Vitilevu, Fiji. Bernice P. Bishop Mus., Bull., No. 119, pp. 1-263, figs. 1-11, pls. 1-44. Lahille, F. 1895. Contribucién al estudio de las Volutas Argentinas. Mus. La Plata, Rev., vol. 6, pp. 293-332, pls. 1-12. Lamy, Edouard 1903. Sur une variété de lArca rhombea Born. Mus. Nat. Hist. nat. Paris, Bull., vol. 9, No. 8, pp. 393-397, figs. 1-4. VENEZUELAN CENOZOIC PELECYPODS: WEISBORD 447 1905. 1906a. 1906b. 1907a. 1907b. 1908a. 1908b. 1908c. 1910a. 1910b. 1910c. 1910d. 191la. 1911b. 1912a. 1912b. 1912c. 1912d. 1912e. Gastropodes prosobranches recueillis par l Expedition Antarctique Frangais du Dr. Charcot. Mus. Nat. Hist. nat. Paris, Bull., vol. 11, No. 6, pp. 475-483, figs. 1-5. Lamellibranches recueillis par VExpedition Antarctique Francais du Dr. Charcot. Mus. Nat. Hist. nat. Paris, Bull., vol. 1, pp. 44-52. Sur quelques mollusques des Orcades du Sud. Mus. Nat. Hist. nat. Paris, Bull., vol. 12, No. 2, pp. 121-126. Liste des coquilles marines recueillies par M. Ch. Gravier a I’lle San Thome. Mus. Nat. Hist. nat. Paris, Bull., vol. 13, No. 2, pp. 145-154, 1 fig. Coquilles marines recueillies par M. le Dr. Nevu-Lemaire pendant la mission de Créqui Montfort et Sénéchal de la Grange dans Amérique du Sud. Mus. Nat. Hist. nat. Paris, Bull., vol. 13, No. 7, pp. 530-539. Coquilles marines recueillies par M. le Dr. Neveu-Lemaire pendant la mission de Créqui-Montfort et Sénéchal de la Grange dans VAmérique du Sud. Mus. Nat. Hist. nat. Paris, Bull., vol. 14, No. 1, pp. 44-53. Description d’un lamellibranche nouveau des Iles Malouines. Mus. Nat. Hist. nat. Paris, Bull., vol. 14, No. 2, pp. 128-129. Liste des mollusques recuellis par M. Ch. Gravier a Bergen (Norvége). Mus. Nat. Hist. nat. Paris, Bull., vol. 14, No. 7, pp. 380-383. Mollusques marins recueillis par le Dr. Rivet a Payta (Pérou). [In] Mission du Service Géographique de l’Armée pour la mésure d’un arc de méridien équatorial en Amérique du Sud, 1899-1906. Paris, vol. 9, Zoologie, No. 3, pp. C79-C91. Mollusques recueillis par M. Rallier du Baty aux Iles Kerguelen. Mus. Nat. Hist. nat. Paris, Bull., vol. 16, No. 4, pp. 198-204, fig. 1. Mission dans l’Antarctique dirigée par M. le Dr. Charcot (1908- 1910). Collections recueillies par M. le Dr. Liouville. Gastropodes prosobranches et Scaphopode. Mus. Nat. Hist. nat. Paris, Bull., vol. 16, No. 6, pp. 318-324. Mission dans l’Antarctique dirigée par M. le Dr. Charcot (1908- 1910). Collections recueillies par M. le Dr. Jacques Liouville. Pélécypodes. Mus. Nat. Hist. nat. Paris, Bull., vol. 16, No. 7, pp. 388-394. Sur quelques mollusques de la Géorgie du Sud et des Iles Sand- wich du Sud. Mus. Nat. Hist. nat. Paris, Bull., vol. 17, No. 1, pp. 22-37, figs. 1-3. Liste des Pectunculus conservées avec étiquettes de Lamarck dans les collections du Muséum de Paris. Mus. Nat. Hist. nat. Paris, Bull., vol. 17, No. 6, pp. 431-435. Notes synonymiques sur les Amphidesma de Lamarck. Mus. Nat. Hist. nat. Paris, Bull., vol. 18, No. 3, pp. 159-165. Sur les espéces de Lamarck appartenant au genre Mesodesma Deshayes. Mus. Nat. Hist. nat. Paris, Bull., vol. 18, No. 4, pp. 245-253, 1 fig. Note sur le Mesodesma mactroides Deshayes. Mus. Nat. Hist. nat. Paris, Bull., vol. 18, No. 5, pp. 312-316, figs. 1-3. Note sur les espéces rapportées au sous-genre Capsa H. et A. Adams, 1856. Mus. Nat. Hist. nat. Paris, Bull., vol. 18, No. 6, pp. 369-372. Sur le genre Pleurodon ou Nucinella S. Wood, avec description d’une espéce nouvelle. Mus. Nat. Hist. nat. Paris, Bull., vol. 18, No. 7, pp. 429-433, figs. 1-3. 448 BuL_eTin 204 1912f. Sur deux espéces de lamellibranches appartenant au genre Liti- giella Monterosato. Mus. Nat. Hist. nat. Paris, Bull., vol. 18, No. 8, pp. 511-513, 2 figs. 1913a. Notes sur les espéces Lamarckiennes de Garidae. Mus. Nat. Hist. nat. Paris, Bull., vol. 19, No. 1, pp. 19-25, 57-65. 1913b. Mollusques et Brachiopodes de la croisiére du Pourquoi-Pas? dans les mers du Nord. Mus. Nat. Hist. nat. Paris, Bull., vol. 19, No. 1, pp. 21-24. 1913c. Note sur quelques coquilles du genre Crassatella déterminés par Lamarck. Mus. Nat. Hist. nat. Paris, Bull., vol. 19, No. 2, pp. 99-105. 1913d. Note sur les espéces rangées par Lamarck dans son genre Lutraria. Mus. Nat. Hist. nat. Paris, Bull., vol. 19, No. 6, pp. 343-349. 1913e. Note sur le Cyclas australis Lamarck. Mus. Nat. Hist. nat. Paris, Bull., vol. 19, No. 7, pp. 466-468. 1913f. Mollusques testacés et Brachiopodes de la croisiére 1913 du Pourquoi-Pas? dans l’Atlantique et dans les mers boréales. Mus. Nat. Hist. nat. Paris, Bull., vol. 19, No. 8, pp. 594-603. 1913g. Révision des Scrobicularidae vivants du Muséum d’Histoire Natur- elle de Paris. Jour. Conchyl., vol. 61, pp. 243-368, No. 3, pl. 8, text figs. 1914a. Notes sur les espéces Lamarckiennes de Garidae. Mus. Nat. Hist. nat. Paris, Bull., vol. 20, No. 1, pp. 19-25; No. 2, pp. 57-65. 1914b. Notes sur les espéces du genre Mactra décrites par Lamarck. Mus. Nat. Hist. nat. Paris, Bull., vol. 20, No. 3, pp. 127-135; No. 4, pp. 239-247. 1914c. Notes sur les espéeces rangées par Lamarck dans ses genres Donax et Capsa. Mus. Nat. Hist. nat. Paris, Bull., vol. 20, No. 5, pp. 286-292; No. 6, pp. 338-346. 1915a. Note sur le Semele nuculoides Conrad. Mus. Nat. Hist. nat. Paris, Bull., vol. 21, No. 1, pp. 17-18, fig. 1. 1915b. Mollusques recueuillis aux Iles Kerguelen par M. Loranchet (Mis- sion Rallier du Baty, 1913-1914). Mus. Nat. Hist. nat. Paris, Bull., vol. 21, No. 2, pp. 68-76. 1915c. Notes sur les espéeces Lamarckiennes appartenant au genre Lucina Bruguiére. Mus. Nat. Hist. nat Paris, Bull. vol. 21, No. 4, pp. 130-136; No. 5, pp. 154-155. 1915d. Sur quelques espéeces de Cardita figurées par Valenciennes. Mus. Nat. Hist. nat. Paris, Bull., vol. 21, No. 6, pp. 195-200. 1915e. Notes sur les espéces Lamarckiennes des genres Cyprina, Cypri- cardia, Hiatella et Isocardia. Mus. Nat. Hist. nat. Paris, Bull., vol. 21, No. 7, pp. 244-252. 1916a. Notes sur les espéeces rangées par Lamarck dans les genres Venericardia et Cardita. Mus. Nat. Hist. nat. Paris, Bull., vol. 22, No. 1, pp. 50-58, 116-121. 1916b. Description d’un lamellibranche nouveau du Golfe de Californie. Mus. Nat. Hist. nat. Paris, Bull., vol. 22, No. 8, pp. 443-445, figs. 1-3. 1916c. Révision des Crassatellidae vivants du Muséum d’Histoire Natur- elle de Paris. Jour. Conchyl., vol. 62, pp. 197-270, pl. 6. figs. 1917a. Notes sur les espéeces Lamarckiennes du genre Chama. Mus. Nat. Hist. nat. Paris, Bull., vol. 23, No. 3, pp. 201-207, 265-271. 1917b. Notes sur les especes du genre Spondylus décrites par Lamarck. Mus. Nat. Hist. nat. Paris, Bull. vol. 23, No. 5, pp. 318-324; No. 6, pp. 403-409. 1917c. Réwision des Mactridae vivants du Muséum d’Histoire Naturelle de Paris. Jour. Conchyl., vol. 63, No. 3, pp. 173-275; No. 4, pp. 291- 411, pls. 6-7, figs. VENEZUELAN CENOZOIC PELECYPODS: WEISBORD 449 1918. 1919a. 1919b. 1919c. 1919d. 1919e. 1920a. 1920b. 1920c. 1921a. 1921b. 1921c. 1922a. 1922b. 1922c. 1922d. 1922e. 1922f. 1923. 1924a. 1924b. 1925a. 1925b. Notes sur quelques espéces de Purpura déterminées par Blainville dans la collection du Muséum de Paris. Mus. Nat. Hist. nat. Paris, Bull., vol. 24, No. 5, pp. 352-357; No. 6, pp. 425-430. Les Moules et les Moidioles de la Mer Rouge (d’aprés les matériaux recueillis par M. le Dr. Jousseaume). Mus. Nat. Hist. nat. Paris, Bull., vol. 25, pp. 40-45, 109-114, 173-178. Les Lithodomes de la Mer Rouge (d’aprés les matériaux re- cueillis par M. le Dr. Jousseaume). Mus. Nat. Hist. nat. Paris, Bull., vol. 25, pp. 252-257. Notes sur les espéces Lamarckiennes du genre Lima Bruguiére, 1792. Mus. Nat. Hist. nat. Paris, Bull., vol. 25, No. 6, pp. 480-486. Notes sur les espéces du genre Plicatula décrites par Lamarck. Mus. Nat. Hist. nat. Paris, Bull., vol. 25, No. 7, pp. 510-513. Révision de Astartidae vivants du Muséum d’Histoire Naturelle de Paris. Jour. Conchyl., vol. 64, pp. 70-119, figs. Notes sur les espéces rangées par Lamarck dans son genre Modiola. Mus. Nat. Hist. nat. Paris, Bull., vol. 26, No. 1, pp. 61-67; No. 2, pp. 149-154; No. 3, pp. 232-238. Notes sur les espéces de Mytilus décrites par Lamarck. Mus. Nat. Hist. nat. Paris, Bull., vol. 26, No. 4, pp. 330-335; No. 5, pp. 415- 421; No. 6, pp. 520-526. Révision des Cypricardiacea et des Isocardiacea vivants du Muséum d’Histoire Naturelle de Paris. Jour. Conchyl., vol. 64, pp. 259-307, pl. 8, figs. Sur guelques Pholades figurées par Valenciennes. Mus. Nat. Hist. nat. Paris, Bull., vol. 27, No. 2, pp. 178-183. Notes sur les espéces de Saxicava décrites par Lamarck. Mus. Nat. Hist. nat. Paris, Bull., vol. 27, pp. 361-365. Notes sur les espéces rangées par Lamarck dans son genre Petricola. Mus. Nat. Hist. nat. Paris, Bull., vol. 27, pp. 432-436. Notes sur les espéces rangées par Lamarck dans son genre Venerupis. Mus. Nat. Hist. nat. Paris, Bull., vol. 28, pp. 82-86. Notes sur les espéces Lamarckiennes de Teredo (Taret). Mus. Nat. Hist. nat. Paris, Bull., vol. 28, pp. 177-181. Notes sur les espéces Lamarckiennes de Pholas. Mus. Nat. Hist. nat. Paris, Bull., vol. 28, pp. 243-245. Notes sur les espéces Lamarckiennes appartenant a la famille des Gastrochaenidae. Mus. Nat. Hist. nat. Paris, Bull. vol. 28, pp. 307-311. Note sur les Mytilus strigatus Hinds, falcatus d’Orbigny et sinuatus Dunker. Mus. Nat. Hist. nat. Paris, Bull. vol. 28, pp. 373-375. Révision des Carditacea vivants du Muséum d’Histoire Naturelle de Paris. Jour. Conchyl., vol. 66, pp. 218-368, pls. 7-8, figs. Révision des Venerupis et des Petricola vivants du Muséum d’Histoire Naturelle de Paris. Jour. Conchyl., vol. 67, pp. 275- 358, pl. 3, figs. Notes sur les espéces Lamarckiennes d’Ostrea. Mus. Nat. Hist. nat. Paris, Bull., vol. 30, pp. 92-99, 151-158, 231-238, 316-320. Révision des Saxicavidae et des Gastrochaenidae vivants du Muséum National d’Histoire Naturelle de Paris. Jour. Conchyl., vol. 68, pp. 218-248, 261-319. Notes sur les espéces rangées par Lamarck dans le genre Mya Linné. Mus. Nat. Hist. nat. Paris, Bull., vol. 30, pp. 494-496. Notes sur les espéeces rangées par Lamarck dans son genre Anatina. Mus. Nat. Hist. nat. Paris, Bull., vol. 31, pp. 372-378. 450 BuLLETIN 204 1925c. Révision des Pholadidae vivants du Muséum National d’Histoire Naturelle de Paris. Jour. Conchyl., vol. 69, pp. 19-51, 79-103, 136-168, 193-222, figs. '1925d. Révision des Gastrochaenidae vivants du Muséum National @’Histoire Naturelle de Paris. Jour. Conchyl., vol. 68, pp. 284-319. 1926a. Notes sur le espéeces rangées par Lamarck dans le genre Corbula Bruguiére. Mus. Nat. Hist. nat. Paris, Bull., vol. 32, pp. 81-85. 1926b. Mollusques testacés de la croisiére 1925 du Pourquoi-Pas? dans Atlantique et des Mers Boréales. Mus. Nat. Hist. nat. Paris, Bull., vol. 32, pp. 179-181. 1926c. Note sur le genre Basterotia Mayer 1859 (Mollusques Lamelli- branches). Mus. Nat. Hist. nat. Paris, Bull. vol. 32, pp. 503-508, 1 fig. 1926d. Révision des Myidae vivants du Muséum National d’Histoire Natur- elle de Paris. Jour. Conchyl., vol. 70, pp. 151-185, figs. 1928a.Révision de Lyonsiidae vivants du Muséum National d’Histoire Naturelle de Paris. Jour. Conchyl., vol. 70, pp. 237-264, 2 text figs. 1928b. Révision des Chama vivants du Muséum National a’Histoire Naturelle de Paris. Jour. Conchyl., vol. 71, pp. 293-383. 1928c. Les Huitres de la Republique Argentine. Mus. Nat. Hist. nat. Paris, Bull., vol. 34, pp. 101-104. 1929a. Notes sur quelques lamellibranches de la Martinique. Mus. Nat. Hist. nat. Paris, Bull., ser. 2, vol. 1, No. 3, pp. 201-208. 1930b. Coquilles recueillies au Pérou, par M. le Dr. Vergne. Rev. Chilena Hist. Nat., pp. 95-97. 1931c. Liste de coquilles recueillies par M. E. Aubert de rue aus Iles Kerguelen, St. Paul et la Nouvelle-Amsterdam. Mus. Nat. Hist. nat. Paris, Bull., sér. 2, vol. 3, No. 6, pp. 517-520. 1932a. Notes sur les espéces Lamarckiennes de Tridacnidae. Mus. Nat. Hist. nat. Paris, Bull., sér. 2, vol. 4, No. 3, pp. 307-312. 1932b. Notes sur les espéces Lamarckiennes de Solenidae. Mus. Nat. Hist. nat. Paris, Bull., sér. 2, vol. 4, No. 4, pp. 427-437. 1932c. Notes sur les especes Lamarckiennes du genre Pinna Linné. Mus. Nat. Hist. nat. Paris, Bull., sér. 2, vol. 4, No. 7, pp. 895-902. 1933. Notes sur les espéeces Lamarckiennes du genre Pinna. Mus. Nat. Hist. nat. Paris, Bull., sér. 2, vol. 5, No. 5, pp. 393-399. 1934b. Révision des Pandoridae vivants du Muséum National d’Histoire Naturelle de Paris. Jour. Conchyl., vol. 78, pp. 95-124. 1934c. Révision des Anatina vivants du Muséum National d’Histoire Naturelle de Paris. Jour. Conchyl., vol. 78, pp. 145-168, pl. 1. 1935a. Notes sur les espéces Lamarckiennes des genres Crenatula, Malleus et Vulsella. Mus. Nat. Hist. nat. Paris, Bull., sér. 2, vol. 7, No. 1, pp. 64-70. 1935b. Notes sur les espéces Lamarckiennes des genres Avicula et Meleagrina. Mus. Nat. Hist. nat. Paris, Bull., sér. 2, vol. 7, No. 2, pp. 127-134. 1935¢c. Les genre Chamostrea Roissy. Jour. Conchyl., vol. 80, pp. 322-328. 1936. Note sur le Cytherea callosa Conrad (Moll. Lamellibr.). Mus. Nat. Hist. nat. Paris, Bull., sér. 2, vol. 8, No. 2, pp. 158-159. 1937a. Sur le dimorphisme sexuel des coquilles. Jour. Conchyl., vol. 81, pp. 283-301, figs. 1-10. 1937b. Notes sur les espéces Lamarckiennes de Katelysia (Moll. Lamel- libr.). Mus. Nat. Hist. nat. Paris, Bull., sér. 2, vol. 9, No. 1, pp. 73-76. VENEZUELAN CENOZOIC PELECYPoDS: WEISBORD 451 1940. Notes sur les espéces Lamarckiennes d’Anomia (Moll. Lamellibr.). Mus. Nat. Hist. nat. Paris, Bull., sér. 2, vol. 12, No. 6, pp. 344-347. 1940-41. Révision des Corbulidae vivants du Muséum National d’Histoire Naturelle de Paris. Jour. Conchyl., vol. 84, No. 1, pp. 5-33, 6 text figs.; No. 2, pp. 121-141; No. 3, pp. 211-254. 1941. Note sur la distribution géographique du Columbella cribraria (Moll. Gastrop.). Mus. Nat. Hist. nat. Paris, Bull., sér. 2, vol. 13, No. 4, pp. 306-308. 1941-42. Notes sur les espéces Lamarckiennes de Cardium (Moll. Lamel- libr.). Mus. Nat. Hist. nat. Paris, Bull., sér. 2, vol. 13, No. 5, pp. 458-463; No. 6, pp. 561-566; vol. 14, No. 1, pp. 63-68; No. 2, pp. 126-129; No. 3, pp. 228-232; No. 5, pp. 346-348. Lamy, Edouard: and André, Marc 1932. Notes sur les espéces Lamarckiennes de Cirripédes. Soixante- cinquiénne Congrés des Sociétés Savantes, pp. 212-228. Lamy, Edouard, and Fischer-Piette, E. 1937a. Notes sur les espéces Lamarckiennes de Tivela (Moll. Lamellibr.). Mus. Nat. Hist. nat. Paris, Bull., sér. 2, vol. 9, No. 1, pp. 77-81. 1937b. Notes sur les espéces Lamarckiennes de Meretrix (Moll. Lamel- libr.). Mus. Nat. Hist. nat. Paris, Bull., sér. 2, vol. 9, No. 2, pp. 156-158. 1937c. Notes sur les espéces Lamarckiennes de Callista (Moll. Lamellibr.). Mus. Nat. Hist. nat. Paris, Bull., sér. 2, vol. 9, No. 3, pp. 212-216. 1937d. Notes sur les espéces Lamarckiennes d’A miantis, d’Hysteroconcha et de Lioconcha (Moll. Lamellibr.). Mus. Nat. Hist. nat. Paris, Bull., sér. 2, vol. 9, No. 4, pp. 270-271. 1937e. Notes sur les espéces Lamarckiennes de Pitar (Moll. Lamellibr.). Mus. Nat. Hist. nat. Paris, Bull., sér. 2, vol. 9, No. 5, pp. 326-329. 1937f. Notes sur les espéces Lamarckiennes de Circe (Moll. Lamellibr.). Mus. Nat. Hist. nat. Paris, Bull., sér. 2, vol. 9, No. 8, pp. 384-386. 1938a. Notes sur les espéces Lamarckiennes de Crista (Moll. Lamellibr.). Mus. Nat. Hist. nat. Paris, Bull., sér. 2, vol. 10, No. 1, pp. 82-85. 1938b. Notes sur les espéces Lamarckiennes d’Anomalocardia (Moll. Lamellibr.). Mus. Nat. Hist. nat. Paris, Bull., sér. 2, vol. 10, No. 2, pp. 173-175. 1938c. Notes sur les especes Lamarckiennes d’Antigona (Moll. Lamellibr.). Mus. Nat. Hist. nat. Paris, Bull., sér. 2, vol. 10, No. 3, pp. 292- 297. 1938d. Notes sur les espéeces Lamarckiennes de Venus s. str. et de Chione (Moll. Lamellibr.). Mus. Nat. Hist. nat. Paris, Bull., sér. 2, vol. 10, No. 4, pp. 401-405. 1938e. Notes sur les espéces Lamarckiennes de Timoclea (Moll. Lamel- libr.). Mus. Nat. Hist. nat. Paris, Bull., sér. 2, vol. 10, No. 5, pp. 509-511. 1938f. Notes sur les especes Lamarckiennes de Clausinella, de Salacia, de Protothaca, et de Samarangia (Moll. Lamellibr.). Mus. Nat. Hist. nat. Paris, Bull., sér. 2, vol. 10, No. 6, pp. 611-614. 1939a. Notes sur les espéeces Lamarckiennes de Venus (Moll. Lamellibr.). Mus. Nat. Hist. nat. Paris, Bull., sér. 2, vol. 11, No. 1, pp. 140-141. 1939b. Notes sur les espéces Lamarckiennes de Marcia et d’Hemitapes (Moll. Lamellibr.). Mus. Nat. Hist. nat. Paris, Bull., sér. 2, vol. 11, No. 2, pp. 258-262. 1939c. Notes sur les espéces Lamarckiennes de Paratapes et de Tapes (Moll. Lamellibr.). Mus. Nat. Hist. nat. Paris, Bull. sér. 2, vol. 11, No. 3, pp. 314-317. 1939d. Notes sur les espéces Lamarckiennes de Polititapes (Moll. Lamel- libr.). Mus. Nat. Hist. nat. Paris, Bull., sér. 2, vol. 11, No. 4, pp. 405-408. 452 BuLueTIN 204 1939e. Notes sur les espéces Lamarckiennes d’Amygdala et de Pullastra at oat Lamellibr.). Mus. Nat. Hist. nat. Paris, Bull., sér. 2, vol. 11, No. 5, pp. 461-466. Langdon, Daniel W., ar. 1889. Some Florida Miocene. Amer. Jour. Sci., ser. 3, vol. 38 (138), No. 226, art. 44, pp. 322-324. Lange de Morretes, Frederico 1938. 1940a. 1940b. 1943. 1949. Duas especoies novas de moluscos marinhos do Brasil. Livro Jubilar do Prof. Lauro Travassos, Rio de Janeiro, pp. 329-332, pl: 1. Algunas palavras sobre novas ocoriéncias e maior distribuicgao de moluscos na costa do Brasil. Rey. Industria Animal, nov. ser., vol. 3, No. 4, pt. 131, pp. 184-187. Novos moluscos marinhos do Brasil. Arg. Zoologia Estado Sao Paulo, vol. 2, art. 7, pp. 251-256, pls. 1-2. Contribuicgado ao estudo da fauna Brasileira de moluscos. Resultados de uma pequena colecao de moluscos obtida pela excursao cientifica realizada pelo Instituto Oswaldo Cruz em Outubro de 1938. Papéis Alvulsos Dept. Zool. Secretaria Agric., pp. 111-126. Ensaio de catdlogo dos moluscos do Brasil. Mus. Paranaense, Arq., VOlom/seanty leppeys-216- Laseron, Charles F. 1954. 1956. 1957. Revision of the New South Wales Turridae (Mollusca). Roy. Zool. Soc. New South Wales, Australian Zoological Handbook, 56 pp., 12 pls. The families Rissoinidae and Rissoidae (Mollusca) from the Solanderian and Dampierian zoogeographical provinces. Australian Jour. Marine and Freshwater Research, vol. 7, No. 3, pp. 384- 484, figs. 1-227. A new classification of the Australian Marginellidae (Mollusca), with a review of species from the Solanderian and Dampierian zoogeographical provinces. Australian Jour. Marine and Fresh- water Research, vol. 8, No. 3, pp. 274-311, figs. 1-84. 1958a. The care of small shells in the collection. Roy. Zool. Soc. New South Wales, Proc., pp. 92-94. 1958b. Liotiidae and allied molluscs from the Dampierian xzoogeo- Laws, C. R. 1930. 1932. 1933. 1935. graphical province. Australian Mus., Rec., vol. 24, No. 11, pp. 165-182, figs. 1-87. New Tertiary Mollusca from New Zealand. No. 1. New Zealand Inst., Trans., vol. 61, pp. 547-553, pls. 89-91. New Tertiary Mollusca from New Zealand. No. 2. New Zealand Inst., Trans., vol. 62, pp. 183-202, pls. 26-32. New Tertiary Mollusca from Timaru District, South Canterbury, N. Z. Roy. Soc. New Zealand, Trans., vol. 63, pp. 315-329, pls. 29- 33. The genus Erato in the Tertiary of New Zealand. Roy. Soc. New Zealand, Trans., vol. 65, pp. 17-22, pl. 3. 1937a. Review of the Tertiary and Recent Neozelanic pyramidellid mol- luscs. No. 1. The genus Turbonilla. Roy. Soc. New Zealand, Trans., vol. 66, pp. 402-422, pls. 32-33. 1937b. Review of the Tertiary and Recent Neozelanic pyramidellid molluscs. No. 2. The genus Chemnitzia. Roy. Soc. New Zealand, Trans., vol. 66, pp. 47-70, pls. 13-14. 1937c. Review of the Tertiary and Recent Neozelanic pyramidellid molluscs. No. 3. Further turbonillid genera. Roy. Soc. New Zealand, Trans., vol. 67, pp. 166-184, pls. 34-35. VENEZUELAN CENOZOIC PELECYPoDS: WEISBORD 453 1937d. Review of the Tertiary and Recent Neozelanic pyramidellid molluscs. No. 4. The syrnolid genera. Roy. Soc. New Zealand, Trans., vol. 67, pp. 303-315, pls. 43-44. 1938a,. Review of the Tertiary and Recent Neozelanic pyramidellid molluscs. No. 5. The eulimellid genera. Roy. Soc. New Zealand, Trans., vol. 68, pp. 51-59, pl. 9. 1938b. Review of. the Tertiary and Recent Neozelanic pyramidellid molluscs. No. 6. The genus Odostomia. Roy. Soc. New Zealand, Trans., vol. 69, pp. 191-209, pls. 16-18. 1939. The molluscan faunule et Pakaurangi Point, Kaipara. No. 1. Roy. Soc. New Zealand, Trans., vol. 68, pp. 468-503, pls. 42-47. 1940a. Paleontological study of Nukumaruan and Waitotaran rocks near Wanganui. Roy. Soc. New Zealand, Trans., vol. 70, pt. 1, pp. 34- 56, pls. 5-7. 1940b. Review of the Tertiary and Recent Neozelanic pyramidellid molluscs. No. 7. Further odostomid genera. Roy. Soc. New Zealand, Trans., vol. 70, pp. 150-160, pls. 13-14. 1941a. Review of the Tertiary and Recent Neozelanic pyramidellid molluscs. No. 8. The pyrgulinid genera and the genus Evalea. Roy. Soc. New Zealand, Trans., vol. 71, pp. 6-22, pls. 1-2. 1941b. The molluscan faunule at Pakaurangi Point, Kaipara. No. 2. Roy. Soc. New Zealand, Trans., vol. 71, pt. 2, pp. 134-151, pls. 16-19. 1944. The molluscan faunule at Pakaurangi Point, Kaipara. No. 3. Roy. Soc. New Zealand, Trans., vol. 73, pt. 4, pp. 297-312, pls. 43-45. Lea, Henry Carey 1844. Descriptions of some new species of marine shells, inhabiting the coast of the United States. Boston Jour. Nat. Hist., vol. 5, No. 2, pp. 285-290, pl. 24. 1847. Description of eight new species of shells, native to the United States. Amer. Jour. Sci. and Arts, vol. 42, pp. 106-112, pl. 1. Leidy, Joseph 1888. Remarks on the fauna of Beach Haven, N. J. Acad. Nat. Sci. Phila- delphia, Proc., vol. 40, pp. 329-333. Lemche, Henning 1959. Neopilina. Univ. Madrid, Rev., vol. 8, Nos. 29-31, pp. 411-442, figs. 1-12. Lermond, Norman Wallace 1909a. A catalogue of the land, fresh-water, and marine Mollusca of Maine. Fourth An. Rept. State Entomologist, Maine, pp. 217-262. 1909b. Shells of Maine. A catalogue of the land, fresh-water and marine Mollusca of Maine. State Entomologist of Maine, An. Rept., vol. 5, pp. 25-70. 1936. Check List of Florida Marine Shells. Gulfport, 56 pp. Lermond, Norman Wallace, and Horton, A. H. 1930. A bibliography of the Recent Mollusca of Maine, 1605-1930. Maine Naturalist, vol. 10, pp. 49-73, 100-121. Letson, Elizabeth 1905. Check list of the Mollusca of New York. New York State Mus., Bull. 88, Zoology, 112 pp. Linsley, James H. 1845. Catalogue of the shells of Connecticut. Amer. Jour. Sci. and Arts, 1st ser., vol. 48, No. 2, art. 6, pp. 271-286, 5 figs. in text. Liver, J. 1958. Quantitative beach research. I. The “left-right phenomenon”: sorting of lamellibranch valves on sandy beaches. Basteria, vol. 22, pp. 22-51. 454 BuLueTIN 204 Lobbecke, Th. 1881-87. Cancellaria. Nebst Anhang, Admete, von W. Kobelt. Syst. Conchylien-Cabinet, vol. 4, pt. 4, pp. 1-108, pls. 1-24. Locard, Arnould 1888. Contributions a la fauna malacologique Francaise. Pt. XI. Mono- graphie des espéces appartenant au genre Pecten. Soc. Linn. Lyon, Ann., new ser., vol. 34, pp. 133-287. 1898. Mollusques testacés. [In] Expéditions scientifiques du Travailleur et du Talisman pendant les années 1880, 1881, 1882, 1883. Paris, vol. 2, pp. 369-482, pls. 15-18, 1 map. Ludbrook, N. H. 1954a. Scaphopoda. British Mus. (Nat. Hist.). The John Murray Ex- pedition 1933-1934, Scientific Reports, vol. 10, No. 2, pp. 91-120, Diswel.. 1954b. The molluscan fauna of the Pliocene strata underlying the Ade- laide Plains. Pt. 1. Roy. Soc. South Australia, Trans., vol. 77, 64 pp. 1955. The molluscan fauna of the Pliocene strata underlying the Adelaide Plains. Pt. 2-Pelecypoda. Roy. Soc. South Australia, Trans., vol. 78, pp. 18-87, pls. 1-6. 1957. The Molluscan fauna of the Pliocene strata underlying the Adelaide Plains. Pt. ¢-Gastropoda (Turritellidae to Struthiolari- idae). Roy. Soc. South Australia, Trans., vol. 80, pp. 17-58, pls. 1-4. Ludbrook, N. H., and Steel, T. M. 1961. A late Tertiary bivalve gastropod from South Australia. Malac. Soc. London, Proc., vol. 34, pt. 4, pp. 228-230, pl. 12. Lyell, Charles 1833. Principles of Geology, being an attempt to explain the former changes of the earth’s surface, by reference to causes now in operation. London, John Murray, pp. i-xxxi + 398 + Appendix I, pp. 2-52, Appendix II, pp. 53-83, Index, pp. 85-109, 93 Figs., 4 pls. 1 geol. map. Lynge, H. 1909. The Danish Expedition to Siam 1899-1900. IV. Marine Lamel- libranchiata. K. Danske Vidensk. Selskabs., Skr., ser. 7, Nat. Math. Afd., vol. 5, pp. 97-299, pls. 1-5, 1 map. Mabille, Jules, and Rochebrune, A. T. 1889. Mollusques. [In] Mission scientifique du Cap Horn. Paris, vol. 6, pt. 2, 143 pp., 9 pls. MacDonald, D. F. 1819a. Notes on the stratigraphy of Panama and Costa Rica. Amer. Assoc. Petrol. Geol., Bull., vol. 3, pp. 363-366. MacGintie, Nettie 1959. Marine Mollusca of Point Barrow, Alaska. U. S. Nat. Mus., Proc., vol. 109, No. 3412, pp. 59-208, 27 pls. MacNeil, F. Stearns 1935. Fresh-water mollusks from the Catahoula Sandstone (Miocene) of Texas. Jour. Paleont., vol. 9, No. 1, pp. 10-17, pls. 3-5. 1936. A new crassatellid from the Waccamaw formation of North and South Carolina and the Caloosahatchee marl of Florida. Washington Acad. Sci., Jour., vol. 26, No. 12, pp. 528-529, figs. 1-3. 1951. Cenozoic megafossils ) northern Alaska. U. S. Geol. Sur., Prof. Paper 294-C, pp. 99-126, 7 pls. Macpherson, J. Hope 1959. New gasteropods from North Australia. Nat. Mus. Melbourne, Mem., No. 24, pp. 51-57, 1 pl. VENEZUELAN CENOozoIc PELECYPODS: WEISBORD 455 Mallard, A. E. 1903. Sur un lamellibranche nouveau, parasite des Synaptes. Mus. Nat. Hist. nat. Paris, Bull., vol. 9, pp. 342-346. Manger, G. Edward 1934. The geology of San Quintin Bay. Johns Hopkins Studies Geol., No. 11, pp. 273-303, 1 pl. Mansfield, Wendell Clay 1932c. Faunal zones in the Miocene Choctawhatchee formation of Florida. Washington Acad. Sci., Jour., vol. 22, pp. 84-88. 1936a. Additional notes on the molluscan fauna of the Pliocene Croatan Sand of North Carolina. Jour. Paleont., vol. 10, No. 7, pp. 665-668. Marchant, Stephen 1961. A photogeological analysis of the structure of the western Guayas Province, Ecuador: with discussion of the stratigraphy and Tablazo Formation, derived from surface mapping. Geol. Soc. London, Quart. Jour., vol. 17, pt. 2, pp. 215-232, figs. 1-3, pl. 8, (photogeological map). Marchesini Santos, Maria Eugenia C. 1958. Equindides miocénicos du formacdo Pirabas. Dept. Nac. Prod. Min., Div. Geol. e Min., Bol. No. 79, pp. 1-24, pls. 1-5. Marcus, Eveline and Ernst 1960a. On Hastula cinerea. Fac. Fil., Cién., Letr. Univ. §. Paulo, Bol. No. 260, Zoologia No. 23, pp. 25-66, 5 pls. 1960b. On Siphonaria hispida. Fac. Fil., Cién., Letr. Univ. S. Paulo, Bol. No. 260, Zoologia No. 23, pp. 107-140, 4 pls. 1960c.Ox Tricolia affinis cruenta. Fac. Fil., Cién. Letr. Univ. S. Paulo, Bol. No. 260, Zoologia No. 23, pp. 171-211, 6 pls. Marcus, E. 1956a.On some Prosobranchia from the coast of Sado Paulo. Inst. Oceanogr. Sao Paulo, Bol., vol. 7, pts. 1-2, pp. 3-29. 1956b. Notes on Opisthobranchia. Inst. Oceanogr. Sao Paulo, Bol., vol. 7, pts. 1-2, pp. 31-78, 8 pls. 1958. On Western Atlantic opisthobranchiate gastropods. Amer. Mus. Novitates, No. 1906, pp. 1-82, 111 figs. Marks, J. Glenn 1952. Especies vivientes de moluscos que se encuentran en las for- maciones Terciarias de Venezuela. Acta Cientifica Venezolana, vol. 3, No. 4, pp. 135-136, figs. 1-8. Marrat, Frederick Price 1876. Descriptions of five new Marginellae. Jour. Conch., vol. 1, pp. 136-137. Marshall, William Blanchard 1915. Three new species of Anodontites from Brazil. U.S. Nat. Mus., Proc., vol. 49, No. 2122, pp. 527-529, pls. 67-69. 1917. New and little-known species of South America fresh-water mussels of the genus Diplodon. U.S. Nat. Mus., Proc., vol. 53, No. 2209, pp. 381-388, pls. 50-55. 1922. New pearly fresh-water mussels from South America. U.S. Nat. Mus., Proc., vol. 61, No. 2437, art. 16, 9 pp., 3 pls. 1924a. New pearly fresh-water mussels from Mexico and Uruguay. U.S. Nat. Mus., Proc., vol. 63, No. 2485, art. 16, 4 pp., 3 pls. 1924b. New species of mollusks of the genus Chilina. U.S. Nat. Mus., Proc:, vol; 66, No. 2550, °5 pp., 1 ‘pl: 1924c. New Uruguayan mollusks of the genus Corbicula. U.S. Nat. Mus., Proc., vol. 66, No. 2552, 12 pp., 2 pls. 1925. Microscopic sculpture of pearly fresh-water mussel shells. U.S. Nat. Mus., Proc., vol. 67, No. 2576, art. 4, 14 pp. 4 pls. 456 BuLLeTIN 204 1926a. New fossil fresh-water mollusks from Florida. U.S. Nat. Mus., Proc., vol. 68, art. 11, 4 pp., 1 pl. 1926b. New land and fresh-water mollusks from Central and South America. U.S. Nat. Mus., Proc., vol. 69, No. 2638, art. 12, 12 pp., 3 pls. 1927a.4 new genus and two new species of South American fresh- water mussels. U.S. Nat. Mus., Proc., vol. 71, No. 2678, 4 pp., 2 pis. 1927b. New specics of mollusks of the genus Corbicula from Uruguay and Brazil. U.S. Nat. Mus., Proc., vol. 72, No. 2699, 7 pp., 1 pl. 1928a. New fossil pearly fresh-water mussels from deposits on the upper Amazon of Peru. U.S. Nat. Mus., Proc., vol. 74, art. 3, pp. 1-6, plist 1928b. New fresh-water and marine shells from Brazil and Uruguay. U.S. Nat. Mus., Proc., vol. 74, art. 17, pp. 1-7, pls. 1-4. 1929. New fossil and fresh-water mollusks from the Reynosa formation of Texas. U.S. Nat. Mus., Proc., vol. 76, No. 2798, art. 1, pp. 1-6, Dials 1930a. New land and fresh-water mollusks from South America. U.S. Nat. Mus., Proc., vol. 77, No. 2825, art. 2, pp. 1-7, pls. 1-2. 1930b. Type of Anodontites Bruguiére. Nautilus, vol. 43, No. 4, pp. 128- 130. 1930c. Former and present terms used in describing fresh-water mussels. Nautilus, vol. 44, No. 2, pp. 41-42. 1931a. Anodontites: A genus of South and Central American and Mexican pearly fresh-water mussels. U.S. Nat. Mus., Proc., vol. 79, No. 283895, ant. 23; pp: 1-116, pl. 1. 1931b. Ruganodontites, a new subgenus of South American pearly fresh-water mussels. Nautilus, vol. 45, No. 1, pp. 16-20. 1933. New fresh-water gastropod mollusks of the genus Chilina of South America. U.S. Nat. Mus., Proc., vol. 82, No. 2949, art. 8, pp. 1-6, pl. 1. Marshall, William B., and Bowles, Edgar O. 1932. New fossil fresh-water mollusks from Ecuador. U.S. Nat. Mus., Proc., vol. 82, No. 2946, art. 5, pp. 1-7, pl. 1. von Martens, C. E. 1881. Mittheilungen iiber Mehrere von Sr. Maj. Schiff Gazelle von der Magalhaenstrasse-Insel_ mitgebrachte Meeres-Conchylien. Gesell. Naturf. Freunde zu Berlin, Sitzungs-Bericht, vol. 17, No. 5, pp. 75-80. von Martens, Eduard, and Pfeffer, Georg 1886. Die Mollusken von Siid-Georgien nach der Ausbeute der Deut- schen Station 1882-83. Wissensch. Anstalten Hamburg, Jahrb., vol. 3, pp. 65-135, pls. 1-4. Martin, Bruce 1916. The Pliocene of middle and northern California. Univ. California Publ., Bull. Dept. Geol. Sci. vol. 9, No. 15, pp. 215-259. Martin, Karl 1879-80. Die Tertiadrschichten auf Java. Palaeontologischer Theil. Leiden, 164 pp. 28 pls. 1 geol. map, Allgemeiner Theil, 51 pp., Anhang, 6 pp. 1895-1906. Die Fossilien von Java. Mollusca. Gasteropoda. Samml. Geol. Reichs-Mus. Leiden, neue Folge, vol. 1, pts. 1-5, Bulla- Murex, pp. 1-132, pls. 1-20 (1895); pts. 6-8, Ocinebra-Tele- scopium, pp. 133-220, pls. 21-33 (1899); pt. 9, Modulus-Del- phinula, pp. 221-281, pls. 34-41 (1905); Nachtray zu den Gastropoden, pp. 282-325, pls. 42-45. VENEZUELAN CENOZOIC PELECYyPopsS: WEISBORD 457 1909-1922. Die Fossilien von Java. Lamellibranchiata. Samml. Geol. Reichs-Mus. Leiden, neue Folge, vol. 1, pt. 2, No. 1, Ostrea- Pinna, pp. 333-356, pls. 46-50 (1909); No. 2, Pinna-Cucullaea, pp. 357-386, pls. 51-54 (1910); No. 3, Die Mollusken der Njalindungschichten, pp. 446-470, pls. 58-59 (1921); No. 4, pp. 471-496, pls. 60-61 (1922). Martins, E. von 1880. Beitrage zu Meeresfauna der Insel Mauritius und der Seychellen. Mollusken. Pp. 181-346, pls. 19-22. Martin-Kaye, P. H. A. 1951. Sorting of lamellibranch valves on beaches in Trinidad, B. W. 1. Geol. Mag., vol. 88, pp. 432-434. Marwick, John 1923. The genus Glycymeris in the Tertiary of New Zealand. New Zealand Inst., Trans., vol. 54, pp. 63-80, 7 pls. 1924a. Paleontological notes on some Pliocene Mollusca from Hawke's Bay. New Zealand Inst., Trans., vol. 55, pp. 191-201, pls. 16-17. 1924b. The Tertiary and Recent Naticidae and Naricidae of New Zealand. New Zealand Inst., Trans. vol. 55, pp. 545-579, pls. 55-60. 1926a. New Tertiary Mollusca from North Taranaki. New Zealand Inst., Trans., vol. 56, pp. 317-331, pls. 73-75. 1926b. The Veneridae of New Zealand. New Zealand Inst. Trans., vol. 57, pp. 567-635, pls. 34-54, 3 figs. 1928. The Tertiary Mollusca of the Chatham Islands, including a generic revision of the New Zealand Pectinidae. New Zealand Inst., Trans. vol. 58, pp. 432-506, 148 figs. 1931. The Tertiary Mollusca of the Gisborne District. Dept. Sci. and Indust. Research, Geol. Survey Branch, Palaeont. Bull. No. 13, pp. 1-77, pls. 1-18. 1934. Some New Zealand Tertiary Mollusca. Malac. Soc. London, Proc., vol. 21, pt. 1, pp. 10-21, pls. 1-2. 1938. Notocallista and its allies. Roy. Soc. New Zealand, Trans., vol. 68, pp. 60-81, pls. 10-14. 1944. New Zealand fossil and Recent Cardiidae (Mollusca). Roy. Soc. New Zealand, Trans., vol. 74, pt. 3, pp. 255-272, pls. 35-37. 1953. A Pliocene fossil found living by the Galathea Expedition. New Zealand Jour. Sci. and Tech., Section B, vol. 35, No. 1, pp. 109- 112, figs. 1-6. 1957. Generic revision of the Turritellidae. Malac. Soc. London, Proc., vol. 32, pt. 4, pp. 144-166, figs. 1-53. Maton, William George, and Rackett, Thomas 1807. A descriptive catalogue of the British testacea. Linnean Soc. London, Trans., vol. 8, pp. 17-250, pls. 1-5. Matson, George Charleton 1916. The Pliocene Citronelle formation of the Gulf Coastal Plain. U. S. Geol. Sur., Prof. Paper 98-L, pp. 167-192. Mattox, N. T. 1949. Studies on the biology of the edible oyster Ostrea rhizophorae Guilding in Puerto Rico. Ecol. Monogr., vol. 19, pp. 339-356. May, W. L. 1921. A Check-list of the Mollusca of Tasmania. Hobart, 114 pp. 1923. W. L. May’s Illustrated Index of Tasmanian Shells. Hobart, 2 pp., 47 pls. Maycock, James D. 1821. Geological description of Barbados, with a map of the island. Quart. Jour. Sci., Lit. and Arts, vol. 11, pp. 10-20, pl. 1. 458 Mazyck, Wi BuL.eTin 204 lliam Gaillard 1915. Oliva litterata Lamarck. Nautilus, vol. 28, No. 12, pp. 139-140. McLean, Richard A. 1935. Panomya arctica Lamarck. Nautilus, vol. 49, No. 1, pp. 34-35. 1936a.A new deep-water Lucina from Maryland. Nautilus, vol. 49, 1936b. 193 6c. 1939a. 1939b. 1939c. 1941. 1942. 1951 ING:835 4p: 37. Panope bitruncata Conrad at Sanibel, Florida. Nautilus, vol. 49, No. 3, p. 104. Some marine bivalves from the Bahama Islands. Nautilus, vol. 49, No. 4, pp. 116-119. Note on the genus Lucina in the Western Atlantic. Nautilus, vol. 52, No. 3, pp. 88-89. Ostrea virginica Gmelin from Cape Breton Island. Nautilus, vol. 5S2naNo; 35 ps 07- The Cardiidae of the Western Atlantic. Soc. Cubana Hist. Nat. “Felipe Poey,” Mem., vol. 13, No. 3, pp. 157-173, pls. 23-26. The oysters of the Western Atlantic. Acad. Nat. Sci. Philadelphia, Notulae Naturae, No. 67, pp. 1-14. The sculpture of inaequivalve mollusks. Nautilus, vol. 55, No. 4, pp. 142-143. The Pelecypoda or bivalve mollusks of Porto Rico and the Virgin Islands. New York Acad. Sci., Scientific Survey of Porto Rico and the Virgin Islands, vol. 17, pt. 1, pp. 1-183, pls. 1-26. McLean, Richard A., and Schwengel, Jeanne 1944. Meek, Field 1876. 1877. A new Modiolaria from Florida. Nautilus, vol. 58, No. 1, pp. 16-17, plaice 105 ing Badford A report on the invertebrate Cretaceous and Tertiary fossils of the upper Missouri country. Report of the United States Geological Survey of the Territories (Hayden), vol. 9, pp. i-lxiv + 629, pls. 1-45. Paleontology. Report of the geological exploration of the fortieth parallel (King), vol. 4, pt. 1, pp. 1-197, pls. 1-17. Melvill, James Cosmo 1881. 1900. 1904. 1906. 1917. 1923. 1925. List of Mollusca obtained in South Carolina and Florida, princi- pally in the Island of Key West, 1871-1872. Jour. Conch., vol. 3, Nos. 5-6, pp. 155-173. Descriptions of two species of Cypraea, both of the subgenus Trivia, Gray. An. Mag. Nat. Hist. ser. 7, vol. 6, pp. 207-210, 4 figs. Description of twenty-three species of Gastropoda from the Persian Gulf of Oman, and Arabian Sea, dredged by M. F. W. Townsend, of the Indo-European telephone service, in 1903. Malac. Soc. London, Proc., vol. 6, pp. 51-60, pl. 5. A revision of the species of Cyclostremidae and Liotiidae oc- curing in the Persian Gulf and north Arabian Sea. Malac. Soc. London, Proc., vol. 7, pp. 20-28, pl. 3. A revision of the Turridae (Pleurotomidae) occurring in the Persian Gulf, Gulf of Oman, and north Arabian Sea, as evidenced mostly through the results of dredgings carried out by F. W. Townsend 1893-94. Malac. Soc. London, Proc., vol. 12, pp. 140- 201, pls. 8-10. Descriptions of twenty-one species of Turridae (Pleurotomidae) from various localities, in the collection of Mr. E. R. Sykes. Malac. Soc. London, Proc., vol. 15, pp. 162-171, pls. 4-5. Descriptions of nine new species of Mitridae. Malac. Soc. London, Proc., vol. 16, pt. 5, pp. 215-219, pl. 10. VENEZUELAN CENOZOIC PELECYPOoDS: WEISBORD 459 1927. Descriptions of eight new species of the family Turridae and of a new A N of Mitra. Malac. Soc. London, Proc., vol. 17, pp. 149-155, pl. Melvill, James Cosmo, jad Standen, Robert 1898. Notes on a collection of marine shells from Lively Island, Falk- lands, with a list of species. Jour. Conch., vol. 9, pp. 97-105. 1899. Report on the marine Mollusca obtained during the first expedi- tion of Prof. A. C. Hadden to the Torres Straits, in 1888-89. Linnean Soc. London, Jour., vol. 27, pp. 150-206, pls. 10-11. 1901. Mollusca collected by Mr. Rupert Vallentin at Stanley Harbour, Falkland Isles. Jour. Conch., vol. 10, pp. 43-47. 1907. The marine Mollusca of the Scottish National Antarctic Expedi- tion. Roy Soc. Edinburgh, Trans., vol. 46, pp. 119-157, 1 pl. 1912. The marine Mollusca of the Scottish National Antarctic Expedi- tion. Pt. 2, Roy. Soc. Edinburgh, Trans., vol. 48, pp. 333-366, 1 pl. 1916a. Note on Trichotropis antarctica Melvill and Standen (non Thiele.). Jour. Conch., vol. 15, p. 90. 1916b. Description of a new rissoid shell from the Antarctic region. Jour. Conch., vol. 15, pp. 120-121. Melvill, James Cosmo, and Sykes, E. R. 1898. Notes on a second collection of marine shells from the Andaman Islands, with descriptions of new forms. Malac. Soc. London, Proc., vol. 3, pp. 35-38, pl. 3. Menard de La Groye, F. J.-B. 1807. Mémoire sur un nouveau genre de coquille bivalve-équivalve de la famille des Solenoides, intermédiaire aux Solens et aux Myes, voisin par conséquent des Glyciméres; sur deux grandes espéces qui s’y rapportent; et accessoirement sur une riche dépot de fossiles d’Italie, ou se trouve celle qui a donne lieu a Vlestablisement de ce genre. Mus. Hist. Nat. Paris Ann., vol. 9, 37 pp., pl. 12. Mermod, G. 1950. Les types de la collection Lamarck au Muséum Genéve. Mol- lusques vivants. I. Rev. Suisse Zool., vol. 57, pp. 687-756, figs. 1-50. 1953. Les types de la collection Lamarck au Muséum de Genéve. Mol- lusques vivant. IV. Rev. Suisse Zool., vol. 60, pp. 131-204, figs. 154-300. Merrill, George P. 1897. Notes on the geology and natural history of Lower California. Rept. U. S. Nat. Mus. for 1895, pp. 969-994, pls. 1-10. Mestayer, M. K. 1916. Preliminary list of Mollusca from dredgings taken off the northern coasts of New Zealand. New Zealand Inst., Trans., vol. 48, pp. 122-128, pl. 12. 1918. The occasional occurrence of Australian and South Sea Island Mollusca in New Zealand. New Zealand Jour. Sci. and Tech., pp. 102-104. 1919. New species of Mollusca, from various dredgings taken off the coast of New Zealand, the Snares Islands, and the Bounty Islands. New Zealand Inst., Trans., vol. 51, pp. 130-135, pl. 8. Metcalf, Maynard M. 1904. Neritina virginea variety minor. Amer. Naturalist, vol. 38, Nos. 451-452, pp. 565-569, 1 pl. Meuschen, F. C. 1787. Museum Geversianum, sive index rerum naturalium continens instructissimam copiam pretiossimerum omnis generis ex tribus 460 BuL.eTIN 204 regnis naturae obiectorum quam dum in vivis erat magna dili- gentia multaqgue cura comparavit vir amplissimus Abrahamus Gevers. Rotterdam, iv + 659 pp. Mickleborough, J. 1893. A check-list of mollusks (Pelecypoda and Gasteropoda) found in waters adjacent to Long Island. Brooklyn Inst. Arts and Sci., Zool. Dept., 16 pp. Mighels, Jesse W. 1841-44. Descriptions of six species of shells regarded as new. Boston Soc. Nat. Hist. vol. 1, pp. 129-130. Boston Jour. Nat. Hist. 5.pp., pie 16: Descriptions of new N. American shells. Boston Soc. Nat. Hist., Proc., vol. 1, pp. 187-190. Boston Jour. Nat. Hist. vol. 4, pp. 345-349. 1843. Catalogue of the marine, fluviatile, and terrestrial shells of the State of Maine. Boston Jour. Nat. Hist. vol. 4, pp. 308-344. Mighels, Jesse W., and Adams, Charles Baker 1841. Descriptions of twenty-five new species of New England shells. Boston Soc. Nat. Hist., Proc. vol. 1, pp. 48-51. 1842. Description of twenty-four species of the shells of New England. Boston Jour. Nat. Hist., vol. 4, No. 1, pp. 37-54, pl. 4. Mitchell, G. J. 1922. Geology of the Ponce District. New York Acad. Sci. Scientific Survey of Porto Rico and the Virgin Islands, vol. 1, pp. 229-300, map, sections. Mitchell, J. D. 1894. List of Texas Mollusca collected by J. D. Mitchell. Victoria, pp. 1-22. Mittre, H. 1850a. Notice sur le genre Cypricarde. Jour. Conchyl., vol. 1, pp. 277- 288. 1850b. Description de Natices nouvelles. Jour. Conchyl., vol. 1, pp. 379-402, pl. 12, figs. 6-7; pl. 13, figs. 6-7, 9-10; pl. 14, figs. 1-11. Monterosato, T. A. Marchese di 1869. Description d’un Dolium méditteranéen nouveau. Jour. Conchyl., vol. 17, pp. 228-230, pl. 12. 1874. Recherches conchyliologiques, effectuées au Cap Santo Vito, en Sicile, et supplément. Jour. Conchyl., vol. 22, pp. 243-282, 359-364. 1875. Poche nota sulla conchiologia Mediterranea. Palermo, 15 pp. 1878a. Note sur quelques coquilles draguées dans les eaux de Palerme. Jour. Conchyl., vol. 26, pp. 143-160. 1878b. Note sur quelques coquilles provenant des cétes d’Algerie (supplément). Jour. Conchyl., vol. 26, pp. 313-321. 1878c. Enumerazione e sinonimia delle conchiglie mediterranee. Sci. Nat. Econ. Palermo, Giorn., vol. 13, pp. 61-115. 1883. Conchiglie littorali mediterranee. Nat. Siciliano, vol. 3, pp. 87-91. 1889. Coguilles marines Marocaines. Jour. Conchyl., vol. 37, pp. 20-40. 1892a. Monografia dei Vermeti del Mediterraneo. Soc. Malac. Italiana, Bull., vol. 17, Nos. 1-3, pp. 7-48, 7 pls. 1899. Revision de quelques Pecten des mers d’Europe. Jour. Conchyl., vol. 47, pp. 182-193. Moore, Donald R. 1957. A note on Cuna dalli. Nautilus, vol. 70, No. 4, pp. 123-125, pl. 8, figs. 3-4. 1958a. Additions to Texas marine Mollusca. Nautilus, vol. 71, No. 4, pp. 124-128. 1958b. Notes on Blanquilla Reef, the most northerly coral formation in the western Gulf of Mexico. Inst. Marine Sci. Univ. Texas, Publ., vol. 5, pp. 151-155. VENEZUELAN CENozoIcC PELECYPoDS: WEISBORD 461 1961. The marine and brackish water Mollusca of the State of Missis- sippi. Gulf Research Reports, vol. 1, No. 1, pp. 1-56, 3 figs., 1 map. Moore, Hilary 1958. Marine Ecology. New York, John Wiley & Sons, xi +491 pp., figs., tables. Moore, Raymond C., Lalicker, Cecil G., and Fischer, Alfred G. 1952. Invertebrate Fossils. New York, Toronto, London, xiii + 766 pp., figs. Morch, Otto Andreas Lowson 1868. Faunula Molluscorum Islandiae. Oversigt Islands Bliddyr. Vi- densk Meddel. Naturhist., Forening i Kjébenhavn 1868, pp. 185-227. 1870. Ubersicht der von Lorentz Spengler beschriebenen Conchylien. Malakozool. Blatter, vol. 17, pp. 99-124. 1874. Synopsis Familiae Scalidarum Indiarum Occidentalium. Over- sigt over Vestindiens Scalarier. Vidensk Meddel. Naturhist., For- ening i Kjobenhavn, No. 17, pp. 1-19. Morrison, J. P. E. 1943. A new type of fresh-water clam from British Guiana. Nautilus, vol. 57, No. 2, pp. 46-52, pl. 8. Morse, Edward S. 1869. Appendix to report on Mollusca. Peabody Acad. Sci. First Ann. Rept. for 1869, pp. 76-77, 2 figs. 1871. Remarks on the relations of Anomia. Boston Soc. Nat. Hist., Proc., vol. 14, pp. 150-153. 1919b. New forms of Caecum in New England. Nautilus, vol. 32, pp. 73-77, pl. 5: 1920. On certain fossil shells in the Boulder Clay of Boston Basin. Amer. Jour. Sci., 4th ser., vol. 49, No. 291, pp. 157-165, figs. 1-3. Morton, J. E. 1953. Vermicularia and the turritellids. Malac. Soc. London, Proc., vol. 30, No. 3, pp. 80-86, 3 figs. Miller, O. F. 1776. Zoologiae Danicae prodromus seu animalium Daniae et Nor- vegiae indigenarum, characteres, nomina, et synonyma imprimis popularium. Havniae, xxxii + 82 pp. Miullerried, F. K. G. 1945. Contribucién a la geologia de México y Noroeste de la América Central. México, viii + 80 pp., 11 figs. Murray, Grover E. 1961. Geology of the Atlantic and Gulf Coastal Province of North Ameri- ca. Harper and brothers, xvii + 692 pp., figs. Nickles, Maurice 1950. Mollusques testacés marins de la céte occidentale d’Afrique. Man- uels Ouest-Africains, vol. 2, x + 269 pp., 464 figs. 1955. Scaphopodes et lamellibranches récoltés dans l'Ouest Africian. At- lantide Rept., No. 3, pp. 93-237, 9 pls. Newell, Norman D., Imbrie, John, Purdy, Edward G., and Thurber, David L. 1959. Organism communities and bottom facies, Great Bahama Bank. Amer. Mus. Nat. Hist., Bull., vol. 117, art. 4, pp. 181-228, figs. 1-17, 6 tables, pls. 58-69. Nicol, David : 1950a. Recent species of the lucinoid pelecypod Fimbria, Washington Acad. Sci., Jour., vol. 40, No. 3, pp. 82-87, figs. 1-9. 1950b. Recent species of the prionodont pelecypod Cucullaea. Washington Acad. Sci., Jour., vol. 40, No. 10, pp. 338-343, figs. 1-9. 462 BuLLeTiIn 204 1951a. Recent species of the veneroid pelecypod Arctica. Washington Acad. Sci., Jour., vol. 41, No. 3, pp. 102-106, figs. 1-4. 1951b. Recent species of the cyrenoid pelecypod Glossus. Washington Acad. Sci., Jour., vol. 41, No. 4, pp. 142-146, figs. 1-5. 1954a. Nomenclatural review of genera and subgenera of Cucullaeidae. Jour. Paleont., vol. 28, No. 1, pp. 76-101. 1955. Morphology of Astartella, a primitive heterodont pelecypod. Jour. Paleont., vol. 29, pp. 155-158. 1956a. The taxonomic significance in gaps in pelecypod morphology. Syst. Zool., vol. 5, p. 143. 1958a. A survey of inaequivalve pelecypods. Washington Acad. Sci., Jour., vol. 48, pp. 56-62. 1958b. The pelecypod Euloxa: Observations on new localities. Washington Acad. Sci., Jour., vol. 48, pp. 153-157, 1 fig. 1958c. Trends and problems in pelecypod classification (the genus and subgenus). Washington Acad. Sci., Jour., vol. 48, pp. 285-293, 2 figs. 1958d. Notes on prionodont pelecypods. Washington Acad. Sci., Jour., vol. 48, p. 309. Nilsson-Cantell, C. A. 1939. Recent and fossil balanids from the north coast of South America. Capita Zoologica’s Gravenhage, vol. 8, pt. 4, No. 3, pp. 1-7, map. Nobre, Augusto 1905. Mollusques et Brachiopodes du Portugal. I Céphalopodes, Gastro- podes, Scaphopodes, Sciencias Naturaes, Annaes, vols. 3-8 (1896- 1903), 147 pp. 1930a. Materiais para o estudo da fauna dos Acores. Inst. Zool. Univ. Porto, pp. 1-108, pls. 1-80, 24 figs. 1930b. Moluscos terrestres, fluviais e das aguas salobras de Portugal. Ministério da Agricultura. Direccao Geral dos Servicos Florestais e Aguicolas, pp. 1-259, pls. 1-21, 42 text figs. 1931. Moluscos terrestres, fluviais e das aguas salobras do Arquipélago da Madeira. Inst. Zool. Univ. Pérto, pp. 1-208, pls. 1-4, 95 text figs. 1932a. Brachiopodes de Portugal. Anais da Faculdade de Ciéncias do Porto, vol. 17, pp. 1-20, pl. 1. 1932b. Moluscos marinhos de Portugal. Inst. Zool. Univ. Pérto, pp. 1-463, pls. 1-80, 9 text figs. Nomura, Sitihei 1935a. On some Tertiary Mollusca from northeast Honsyit, Japan. Pt. 2. Fossil Mollusca from the vicinity of Ogino, Yama-gun, Hukusima- ken. Saito Ho-On-Kai Mus., Res. Bull. No. 5, Geol., No. 2, pp. 101- 130, pls. 5-7. 1935b. Catalogue of the Tertiary and Quartery Mollusca from the Island of Taiwan (Formosa) in the Institute of Geology and Paleontology, Tohoku Imperial University, Sendai, Japan. Pt. 2. Scaphopoda and Gastropoda. ‘Tohoku Imperial Univ., Sendai, Japan, Sci. Rept., ser. 2, Geol., vol. 18, pp. 53-228, pls. 6-10. North, F. K. 1951. On the type of Pseudamussium and other notes on pectinid nomen- clature. Jour. Paleont., vol. 25, pp. 231-236. Nyst, Pierre Henri 1862. Notice sur deux coquilles nouvelles du genre Crassatelle, suive d’un tableau des especes vivantes et fossiles décrites par les quteurs, avec Vindication des depots dans lesquels ces derniéres ont été recucillies. Acad. Roy. Belgique, Bull., vol. 14, No. 8, 13 pp. VENEZUELAN CENOZzOIC PELECYPODS: WEISBORD 463 Ockelmann, W. K. 1958. The zoology of East Greenland. Marine Lamellibranchiata. Med- delser om Grgnland, vol. 122, No. 4, 256 pp., 3 pls., 28 figs. Odhner, Nils Hjalmar 1919. Contribution a la fauna malacologique de Madagascar. K. Svensk. Vetenskaps. Akad., Ark. f. Zool., vol. 12, No. 6. 1924. New Zealand Mollusca. Papers from Dr. Th. Mortensen’s Pacific Expedition 1914-1916. Saertryk Vidensk. Medd. Dansk Naturh., Foren., vol. 77, pt. 19, pp. 1-90, 24 figs., 2 double pls. 1926. Die Opisthobranchien, Wiss. Ergebn. Schwed. Siidpolar-Exped., vol. 2, pp. 1-100. 1931a. Die Scaphopoden, Wiss. Ergebn. Schwed. Siidpolar-Exped., vol. 2, No. 5, pp. 1-8. 1931b. Beitrage zur Malakozoologie der Kanarischen Inseln: Lamelli- branchien, Cephalopoden, Gastropoden, Ark. f. Zool., vol. 23A, No. 14, pp. 1-116, pls. 1-2. 1953. Identifications of Linnaean shells in Museum Ludovicae Ulricae. Mimeographed, pp. 1-27. Okada, Y. K. 1960. Encyclopedia Zoologica illustrated in Colors. Vol. III. Tokyo, 200 pp., + 38 pp. of Index, 91 pls., 21 pp. of text figs. Oken, Lorenz 1815. Okens Lehrbuch der Naturgeschichte. Leipzig, Jena, vol. 3, Zo- ologie, sect. 1, Fleischose Thiere, 842 pp., 40 pls. Oleksyshyn, John 1960. Some new species of Miocene Mollusca from Maryland and Vir- ginia, Pennsylvania Acad. Sci., Proc., vol. 34, pp. 101-106, 8 figs. de Oliveira, Lejeune 1950. Levantamento biogeografico da Baia de Guanabara. Inst. Oswaldo Cruz, Mem., vol. 48, pp. 363-391, figs. 1-19. de Oliveira Roxo, M. G. 1924. Breve noticia sobre os fosseis terciarios do Alto Amazonas. Serv. Geol. e Min. Brasil, Bol. No. 1, pp. 41-62, 1 pl. 1937. Fosseis Pliocenios do Rio Jurud, Estado do Amazonas. Serv. Geol. do Brasil, Bol. No. 11, pp. 1-52. Oliver, W. R. B. 1915. The Mollusca of the Kermadec Islands. New Zealand Inst., Trans., vol. 47 (1914), pp. 509-568, pls. 9-12. 1923. Notes on New Zealand Pelecypods, Malac. Soc. London, Proc., vol. 15, pt. 4, pp. 179-188, 2 figs. Olsson, Axel A. 1961. Mollusks of the tropical Eastern Pacific particularly from the southern half of the Panamic-Pacific faunal province (Panamé to Peru). Panamic-Pacific Pelecypoda. Paleont. Research Inst., 574 pp., 86 pls. Olsson, Axel A., and Wurtz, C. B. 1951. New Colombian naiades, with observations on other species. Acad. Nat. Sci. Philadelphia, Notulae Naturae, No. 239, pp. 1-9, figs. 1-12. Oostingh, C. H. 1925. Report on a collection of Recent shells from Obi and Halmahera (Molluccas). Landbouwhoogeschoo] Wageningen Meded., vol. 29, pt. 1, pp. 1-362. Orcutt, C. A., and Dall, W. H. 1885. Notes on the mollusks of the vicinity of San Diego, Cal., and Todos Santos Bay, Lower California. U.S. Nat. Mus., Proc., vol. 8, pp. 534-552, 1 pl. 464 BULLETIN 204 Ortmann, Arnold E. 1898. Preliminary report on some new marine Tertiary horizons dis- covered by Mr. J. B. Hatcher near Punta Arenas, Magellanes, Chile. Amer. Jour. Sci., vol. 6, art. 49, pp. 478-482. 1899. The fauna of the Magellanian beds of Punta Arenas, Chile. Amer. Jour. Sci., vol. 8, art. 49, pp. 427-432. 1900. Synopsis of the collections of invertebrate fossils made by the Princeton Expedition to southern Patagonia. Amer. Jour. Sci., vol. 10, art. 37, pp. 368-381. Oyama, Katura 1944. Classification of the genus Propeamussium. Venus, vol. 13, pp. 240-254. Pace, S. 1902a. On the anatomy and relationships of Voluta musica Linn.; with notes upon certain other supposed members of the Volutidae. Malac. Soc. London, Proc., vol. 5, pp. 21-31. Packard, Earl L. 1916. Mesozoic and Cenozoic Mactrinae of the Pacific coast of North America, Univ. California Publ., Bull. Dept. Geol., vol. 9, No. 16, pp. 261-360, pls. 12-35. Paetel, Friedrich 1890. Die Acephalen und die Brachiopoden. [In] Catalog der Conchylien- Sammlung von Fr. Paetel. Berlin, vol. 3, 256 pp. + Index of XxXxli pp. Pallary, Paul 1900. Coguilles marines du littoral du Départment d’Oran. Jour. Conchyl., vol. 48, PP. 211-422, pls. 6-8. 1904. Addition ala faune malacologique Golfe de Gabés. Jour. Conchyl., vol. 52, pp. 212-248. 1938. Les molhisques marins de la Syrie. Jour. Conchyl., vol. 82, pp. 5-58. Palmer, E. Laurence 1940. Atlantic and Gulf Coast shells. Nature Mag., vol. 33, No. 6, pp. 341,248, pls. 1-4. Palmer, Katherine Van Winkle 1938. Neocene Spondylii from the southern United States and tropical America. Palaeontographica Americana, vol. 2, No. 8, pp. 147- 156, pls. 16-18. Parker, Robert H. 1956. Macro-invertebrate assemblages as indicators of sedimentary en- vironments in East Mississippi Delta region. Amer. Assoc. Petrol. Geol., Bull., vol. 40, No. 2, pp. 295-376, 32 figs., 8 pls. Parodiz, Juan José 1939. Las especies de “Crepidula” de las costas Argentinas. Physis, vol. 17, pp. 685-709, figs. 1-8, 1 pl. 1942. Transgressiones ocednicas y fauna del mar epicontinental Argen- tino. Geografica Americana Rev., ano 9, vol. 18, pp. 203-211, figs. 1948. Sobre “Ostrea” actuales y Pleistocénicas de Argentina y su ecologia. Mus. Argentino Cienc. Nat. “Bernardino Rivadavia”’, Comunica- ciones, ser. Cienc. Zool., No. 6, pp. xiv + 22, pls. 1-3. 1955. Una nueva especie de Triphora del Uruguay (Moll. Prosobr.) Neotropica, vol. 1, No. 4, pp. 59-60, 1 fig. Pearse, A. S. 1936. Estuarine animals at Beaufort, North Carolina. Elisha Mitchell Sci. Soc., Jour., vol. 52, No. 2, pp. 174-222, pls. 15-16. Pearse, A. S., and Williams, Louis G. 1951. The biota of the reefs off the Carolinas. Elisha Mitchell Sci. Soc., Jour., vol. 67, No. 1, pp. 133-161. VENEZUELAN CENOZOIC PELECYPODS: WEISBORD 465 Pelseneer, P. 1903. Résultats du voyage du §. Y. ‘Belgica.’ Zoologie. Mollusques (Am- phineures, Gastropodes, et Lamellibranches). Anvers, 85 pp., pls. 1-9. Perkins, George 1869. Molluscan fauna of New Haven. Pt. 1, Cephalopoda and Gastero- poda. Pt. 2, Acephala and Bryozoa. Boston Soc. Nat. Hist., Proc., vol. 13, pp. 109-164, 2 figs. Perry, Louise M. 1936. A marine tenement. Science, vol. 84, No. 2172, pp. 156-157. Petit de la Saussaye, S. 1850a. Notice sur le genre Cyclostoma, et catalogue des especes appar- tenant a ce genre. Jour Conchyl., vol. 1, pp. 36-55, pl. 3, figs. 2, 5-7, 10; pl. 4, figs. 2-3,7. Petterd, W. F. 1886. New species of Tasmanian marine shells. Roy Soc. Tasmania, Papers and Proc. for 1885, pp. 320-321. Pfeffer, G. 1866. Mollusken, Krebse und Echinodermen von Cumberland-Sund nach der Ausbeute der Deutschen Nordexpedition, 1882 und 1883. Jahr. Wiss. Anst. Hamburg, vol. 3, pp. 25-50, figs. 1-6. Pfeiffer, Louis 1840a. Kritisches Register zu Martini und Chemnitz’s Systematischen Konchylien-Kabinet, Kassel, viii + 112 pp. 1849a. Descriptions of twelve new species of Vitrina and Succinea, from the collection of H. Cuming, Esq. Zool. Soc. London, Proc., pp. 132-134. 1849b. Descriptions of thirty new species of Tornatellina, Cylindrella, and Clausilia, from the collection of H. Cuming, Esq. Zool. Soc. London, Proc., pp. 134-141. 1841-72. Die Familie der Venus Muscheln, Veneracea. Nebst einem An- hange, enthaltend die Chemnitz’schen Lucinen, Galateen und Cor- bis. Syst. Conchylien-Cabinet, vol. 11, pt. 1, pp. 1-3, pls. 1-3, 5-10 (1841); pls. 11-15 (1842); pp. 32-56, pls. 4, 16-24 (1868) ; pp. 57-160, pls. 25-34 (1869); pp. 161-224, pls. 35-38 (1870); pp. 225-302, pls. 39-42 (1872). Philippi, E. 1900. Beitraége zur Morphologie und Phyogenie der Lamellibranchier. Pt. 2. Zur Stammesgeschichte der Pectiniden. Deutsch. Geol. Gessel., Zeitschr., vol. 52, pp. 64-117, 24 text figs. Philippi, Rudolphus Amandus 1836. Beschreibung einiger neuen Conchylien-Arten (Vermetus spiratus, Diplodonta semiaspera, Tellina sulcata, Corbula aequivalvis, Chama cancellata) und Bemerkungen iiber die Gattung Lacuna, Turton, Archiv f. Naturg., vol. 2, pp. 337-368. 1837. Pododesmus, ein neues Genus der Acephalen. Archiv f. Naturg., vol. 3, pp. 385-387, pl. 9, figs. la-d. 1841. Bemerkungen iiber einige Linnéische Conchylien-Arten welchen von den Spaten Conchyliologen verkannt sind. Archiv f. Naturg., vol. 7, pp. 258-276. ) 1845b. Bemerkungen iiber einige Muschelgeschlechter, deren Thiere wenig bekannt sind. Archiv f. Naturg., vol. 11, pp. 185-196. i 1845c. Bemerkungen iiber die Mollusken-Fauna von Massachusetts. Zeit- schr. f. Malakozool., yr. 2, pp. 68-79. 466 BuL.eTin 204 1856. Ueber die Conchylien der Magellans-Strasse. Malakozool. Blatter, vol. 3, pp. 157-173. 1868. Conchylia nova potissimum Magellanica. Malakozool. Blatter, vol. 15, pp. 222-226. 1893. Die Mactra-Arten Chiles. Mus. Nac. Chile, An., pp. 1-9, pls. 1-3. Pijpers, P. J. 193la. The occurrence of foreign pebbles on the isle of Bonaire, Konink. Akad. Wetensch. Amsterdam, Proc., vol. 34, No. 1, pp. 169-174, 1 map. 1931b. Some remarks on the geology of the surroundings of “Ronde Klip” (East Curacao). Konink. Akad. Wetensch. Amsterdam, Proc., vol. 34, No. 7, pp. 1023-1027, geol. sketch map. 31, pp. 1023-1027. 1931c. Bonaire, Leidsche Geol. Meded., vol. 5 (Martin Feestbundel), pp. 704-708, sketch-map. 1931d. Over de geologie van het eiland Bonaire. Handel 23ste Nederl. Nat. en Geneesk. Congress, pp. 265-266. 193le. Over de geologie van Bonaire. Geol. en Mijnbouw., vol. 10, pp. 144-145. 1933. Geology and paleontology of Bonaire (D. W.1.). Geogr. en Geol. Meded., Physiogr.-Geol. Reeks No. 8, 103 pp., 11 pls., map. Pilsbry, Henry Augustus 1889. Littoral mollusks from Cape Fairweather, Patagonia. Amer. Jour. Sci., vol. 17, pp. 126-128, pl. 1. 1890. Trochidae, new and old. Acad. Nat. Sci. Philadelphia, Proc., vol. 42, pp. 343-344, text figs. 1-2. 1891a. Sea shells of the Jersey Shore. Asbury Park, 40 pp., figs. 1897a. Patagonian Tertiary fossils. Acad. Nat. Sci. Philadelphia, Proc., vol. 49, pp. 329-330, 1 fig. 1898a. Margarita sharpii, a new Alaskan gastropod. Acad. Nat. Sci. Philadelphia, Proc., vol. 50, pp. 486-487, fig. 1. 1900a. A new Calliostoma from Florida. Nautilus, vol. 12, pp. 129-130. 1900b. Purpura coronata Lamarck in America. Nautilus, vol. 12, p. 130. 1900c. Species of Chlorostoma of southern and eastern Patagonia. Nauti- lus, vol. 13, No. 10, pp. 110-112. 1905a. A new brackish-water snail from New England. Nautilus, vol. 19, pp. 90-91, 1 fig. 191la.4 new Ecphora of the Chesapeake Miocene. Acad. Nat. Sci. Philadelphia, Proc., vol. 63, pp. 438-439. 1919. Mollusca from Central America and Mexico. Acad. Nat. Sci. Philadelphia, Proc., vol. 71, pp. 212-223, pl. 11. 1924. Miocene and Pleistocene Cirripedia from Haiti, U.S. Nat. Mus., Proc., vol. 65, art. 2, 3 pp., 1 pl. 1930. List of land and freshwater mollusks collected on Andros, Bahamas. Acad. Nat. Sci. Philadelphia, Proc., vol. 82, pp. 297-302, figs. 1-2. 1931g. A new race of Neritina reclivata Say. Nautilus, vol. 45, No. 2, pp. 67-68, 1 fig. 1934d. Notes on the gastropod genus Liotia and its allies. Acad. Nat. Sci. Philadelphia, Proc., vol. 85, pp. 375-381, pl. 13. Pilsbry, Henry Augustus, and Olsson, Axel A. 1935b. Tertiary fresh-water mollusks of the Magdalena Embayment, Co- lombia. Acad. Nat. Sci. Philadelphia, Proc., vol. 87, pp. 7-39, pls. 2-5. Reprinted in Spanish, Acad. Colombiana Cienc. Exactas, Fis. y Nat., Rev., vol. 4, pp. 410-417, without plates, 1941. Pittier, H. 1890. Apuntamientos para la historia natural de Costa Rica. Mollusca, Inst. Fis. Geogr. Mus. Nac. Costa Rica, An., vol. 3, pp. 123-126. VENEZUELAN CENOZOIC PELECYPODS: WEISBORD 467 Plate, L. 1908a. Die Solenoconchen der “Valdivia Expedition.’ Wissenschaftliche Execpnisee Deutschen Tiefsee-Exped., vol. 9, No. 3, pp. 339-361, pl. 30. 1908b. Die Scaphopoden der Deutschen Siidpolar Exped. (1901-3). Wissen- schaftliche Ergebnisse Deutschen Siidpolar Exped., vol. 10, pp. 1-6. 1908c. Scaphopoden. Résultats du Voy. du S. Y. ‘Belgica’ en 1895-9, pp. 1-4. Platt, Rutherford 1949. Shells take you over world horizons. Nat. Geogr. Mag., vol. 96, pp. 33-84, 31 col. pls. Powell, A. W. B. 1927b. Deep-water Mollusca from south-west Otago, with descriptions of 2 new genera and 22 new species. Canterbury Mus., Rec., vol. 3, pt. 2, pp. 113-124, pls. 21-23. 1929. The Recent and Tertiary species of the genus Buccinulum in New Zealand, with a review of related genera and families. New Zea- land Inst., Trans., vol. 60, pp. 57-101, 132 figs., 4 pls. 1931a. Waitotaran faunules of the Wanganui System, and descriptions of Mollusca from the New Zealand Pliocene. Auckland Inst. Mus., Rec., vol. 1, No. 2, pp. 85-112, pls. 10-14. 1931b. Descriptions of some new species of Recent Mollusca mainly from the sub-Antarctic islands of New Zealand. Canterbury Mus. Rec., vol. 3, pp. 371-376, 2 figs., pls. 52-53. 1932a. On some New Zealand pelecypods. Malac. Soc. London, Proc., vol. 20, pt. 1, pp. 65-72, pl. 6. 1932. The Recent Marginellidae of New Zealand, with descriptions of some new species. New Zealand Inst., Trans., vol. 62, pp. 203-214, pls. 33-36. 1933b. On five new species of Recent New Zealand Mollusca. Malac. Soc. London, Proc., vol. 20, pt. 4, pp. 194-198, figs. 1-4, pl. 16. 1933c. New pelecypod Mollusca from northern New Zealand, Malac. Soc. London, Proc., vol. 20, pt. 4, pp. 199-206, text fig. 16, pls. 17-18. 1933d. The marine Mollusca of the Chatham Islands, Auckland Inst. Mus., Rec., vol. 1, No. 4, pp. 181-208, pls. 33-36. 1933e. Marine Mollusca from the Bounty Islands. Canterbury Mus., Rec., vol. 4, pp. 29-39, pl. 6. 1933f. Two new molluscs of the Pectinidae from 600 to 700 fathoms, four hundred miles west of New Plymouth. New Zealand Inst., Trans., vol. 63, pp. 370-372, pl. 40. 1933g. New species of marine Mollusca from the subantarctic islands of New Zealand. Malac. Soc. London, Proc., vol. 20, pt. 5, pp. 232- 236, figs. 1-4, pl. 20. 1934a. New Recent and Tertiary Nuculanidae from New Zealand. Malac. Soc. London, Proc., vol. 21, pt. 4, pp. 252-255, pl. 27. 1934b. Five new species of pelecypod Mollusca from New Zealand. Malac. Soc. London, Proc., vol. 21, pt. 4, pp. 255-258, pl. 28. 1934c. Gasteropods new to the New Zealand fauna; with descriptions of six new species and a new subspecies. New Zealand Inst., Trans., vol. 64, pp. 154-160, pls. 21-22. 1934d. Upper Pliocene fossils from Cape Runaway. Auckland Inst. Mus., Rec., vol. 1, No. 6, pp. 327-240, pls. 76-78. 1937. New species of marine Mollusca from New Zealand. [In] Great Britain. Discovery Committee. Discovery Reports, Cambridge, vol. 15, pp. 153-222, pls. 45-56. @) 1938a. A Pliocene molluscan faunule from Castle Point, and Additions to the Recent molluscan fauna of New Zealand. Auckland Inst. Mus., Rec., vol. 2, No. 3, pp. 157-164, 3 text figs., pls. 38-39; pp. 165-170, pl. 40. 468 BuLLeTin 204 1938b. Tertiary molluscan faunules from the Waitemata beds. Roy. Soc. New Zealand, Trans., vol. 68, pp. 362-379, pls. 38-40. 1938¢c. Additions to the Recent molluscan fauna of New Zealand. Auckland Inst. Mus., Rec., vol. 2, No. 3, pp. 167-170, pl. 40. 1939. The Mollusca af Stewart Fstand! Auckland Inst. Mus., Rec., vol. 2, No. 4, pp. 211-238. 1940. The marine Mollusca of the Aupourian Province, New Zealand. Roy. Soc. New Zealand, Trans., vol. 70, pt. 3, pp. 205-208, 1 text fig., pls. 28-33. 1944. The Australian Tertiary Mollusca of the family Turridae. Auck- land Inst. Mus., Rec., vol. 3, No. 1, 68 pp., 7 pls. 1946a. New species of New Zealand Mollusca from the South Island, Stewart Island, and Chatham Islands. Auckland Inst. Mus., Rec., vol. 3, No. 2, pp. 137-144, pls. 11-12. 1946b. The Shellfish of New Zealand. Second ed., 106 pp., 26 pls. 1950. Mollusca from the continental shelf, eastern Otago. Auckland Inst. Mus., Rec., vol. 4, No. 1, pp. 73-81, pl. 7. 1951. Antarctic and subantarctic Mollusca. Pelecypoda and Gastropoda. Discovery Reports, vol. 26, pp. 47-196, text figs. A-N, pls. 5-10. Powers, Sydney 1918. Notes on the geology of eastern Guatemala and northwestern Spanish Honduras Jour. Geol., vol. 36, pp. 507-523. Prashad, B. 1932. The Lamellibranchia of the Siboga Expedition. Pelecypoda. Mol- lusca III. Systematic part II. Pelecypoda (exclusive of the Pectini- dae). Siboga- Expeditie, vol. 29, 334 pp., 9 pls. Preston, H. B. 1912. Characters of six new pelecypods and two new gastropods from the Falkland Islands. Ann. Mag. Nat. Hist., ser. 8, vol. 9, pp. 636- 640, pl. 21. 1913. Descriptions of fifteen new species and varieties of marine shells from the Falkland Islands. Ann. Mag. Nat. Hist., ser. 8, vol. 11, pp. 218-223, pl. 4. 1916. Descriptions of eight new species of marine Mollusca from the South Shetland Islands. Ann. Mag. Nat. Hist., ser. 8, vol. 18, pp. 269-272, pl. 13. Prime, Temple 1860a. Synonymy of the species of Cyrenella, a genus of Mollusca belong- ing to the family of the Lucinidae. Boston Soc. Nat. Hist., Proc., vol. 7, pp. 1-3. 1860b. Synonymy of the known species of Rangia, a genus of the family Mactracea. Boston Soc. Nat. Hist., Proc., vol. 7, pp. 3-4. 1862. Description of a new species of Melluita of the genus Venus. Lyc. Nat. Hist. New York, Ann., vol. 7, pp. 3-4. Priolo, O. 1956a. Molluschi del porto di Catania. Soc. Tosc. Sci. Nat. (B), Atti, vol. 63, pp. 9-13. 1956b. Nuova revisione delle conchiglie marine de Sicilia. Accad. Gioenia, Atti, ser. 6, vol. 10, pp. 55-97, 219-254, 1 pl. Pulteney, Richard 1799. Catalogues of the Birds, Shells, and some of the more rare Plants of Dorsetshire. From Hutchins, History of that county. London, 2d ed., 1813, folio. Quayle, D. B. 1960. The intertidal bivalves of British Columbia. British Columbia Pro- vincial Mus., Dept. Education, Handbook No. 17, 104 pp., pls. Rafinesque, Constantine Schmaltz 1820. Monografie des coquilles bivalves fluviatiles de la riviére Ohio. Gén. Sci. Phys. Bruxelles, Ann., vol. 5, pp. 287-322, 3 pls. VENEZUELAN CENOzoIC PELECYPoDS: WEISBORD 469 Ramirez, Ricardo 1950. Descripcién de algunos moluscos del Miocene del Valle del Cibao de la Republica Dominicana, Publ. Univ. Santo Domingo, ser. 4, No. 1, 58 pp. 1956. Paleontologia Dominicana, Publ. Uniy. Santo Domingo, ser. 4, No. 2, pp. 1-26, pls. 1-8. Rang, Sander 1832. Notice sur la Galathée, genre de mollusque acéphale du la famille des Conchacés Ann. Sciences Naturelles, vol. 24, 13 pp., pl. 5. Ranson, Gilbert 1939. Le provinculum de la prodissoconque de quelques Ostréides. Mus. Nat. Hist. nat. Paris, Bull., vol. 11, No. 3, pp. 318-331, 4 fig., 1 pl. 1942. Note sur la classification des Ostréides. Soc. Géol. France, Bull., sér. 5, vol. 12, pp. 161-164. 1943. Observation sur quelques Ostréides actuels et fossiles. Soc. Géol. France, Bull., sér. 5, vol. 13, pp. 289-294, pl. 11. 1948. Prodissoconques et classification des Ostréides vivants. Mus. Roy. Hist. Nat. Belgique, Bull., vol. 24, No. 42, 12 pp., figs. 1-7. 1950. La chambre promyaire et la classification zoologique des Ostréides. Jour. Conchyl., vol. 90, pp. 195-200. Rathbun, M. J. 1918. Decapod crustaceans from the Panama region. U.S. Nat. Mus., Bull. 103, pp. 123-184, pls. 54-66. Raven, Chr. P. 1958. Morphogenesis. The Analysis of Molluscan Development. New York, i-xii + 311 pp., 66 figs. Ravenel, Edmund 1834. Catalogue of Recent Shells in the Cabinet of Edmund Ravenel. Charleston, 20 pp. 1848. Echinidae, Recent and fossil, of South Carolina. Amer. Paleont., Tertiary, pp. 1-4. 1859. Description of three new species of univalves, Recent and fossil. Elliott Soc., Proc., pp. 280-282. 1860. Tellinidae of South Carolina. Elliott Soc., Proc., pp. 33-40. Récluz, C. A. 1842a. Description de neuf especes de Nérites nouvelles, suive d’observa- tions sur les N. cornea et dubia. Soc. Zool. Cuviérienne Rev., vol. 5, pp. 73-79. 1842b. Description de plusieurs especes de Nérites nouvelles vivantes. Soc. Zool. Cuviérienne, Rev., vol. 5, pp. 177-184. 1843a. On new species of Nerita. Zool. Soc. London, Proc., pt. 11, pp. 71-73. 1843b. On new species of Narica. Zool. Soc. London, Proc., pt. 11, pp. 136- 141. 1843c. Descriptions of new species of Navicella, Neritina, Nerita and Natica, in the collection of Hugh Cuming, Esq. Zool. Soc. London, Proc., pt. 11, pp. 197-214. 1843d. Description de deux coguilles nouvelles. Soc. Zool. Cuviérienne, Rev., vol. 6, p. 261. 1843e. Monographie du genre Syndosmya, et examen des genres Ligule, Abra, et Amphidesme. Soc. Zool. Cuviérienne, Rev., vol. 6, pp. 292-299, 359-369. 1844a. Monographie du genre Ervilla, Turton. Soc. Zool. Cuviérienne, Rev., vol. 7, pp. 85-86, pls. 95-96 [in Mag. Zool.]. 1844b. Prodrome d’une monographie du genre Erycina. Soc. Zool. Cuviér- ienne, Rev., vol. 7, pp. 291-299, 325-336. 1845. Description de quelques nouvelles Nérites fluviatile du cabinet de Hugh Cuming. Zool. Soc. London, Proc., pp. 119-122. 470 BuLLETIN 204 1846a. Description de plusieurs animaux mollusques bivalves, soit nou- veaux, soit incomplétement connus. Soc. Zool. Cuviérienne, Rev., vol. 9, pp. 8-12, 48-55, 146-151. 1846b. De la famille des Lithophages, Lam. Soc. Zool. Cuviérienne, Rev., vol. 9, pp. 405-425. 1847. Description de plusieurs animaux mollusques, soit nouveaux, soit pee amen connus. Soc. Zool. Cuviérienne, Rev., vol. 10, pp. -343. 1848. Description d’un nouveau genre de coquilles bivalve nommé Septi- feére. Soc. Zool. Cuviérienne, Rev., vol. 11, pp. 275-279. 1850a. Des Neéritines, section des Crépidiformes. Jour. Conchyl., vol. 1, pp. 58-75. 185la. Catalogue des espéces du genre Sigaret (Sigaretus, Lk.). Jour. Conchyl., vol. 2, pp. 163-191, pl. 6, figs. 1-6, 12-14. 1851b. Description de quelques coquilles nouvelles. Jour. Conchyl., vol. 2, pp. 194-216. 1851c. Notice sur la Natica canrena des auteurs. Jour. Conchyl., vol. 2, pp. 251-254. 1852. oie ie de coquilles nouvelles. Jour. Conchyl., vol. 3, pp. 249- Z56-apl 0: 1854. Description de plusieurs coquilles nouvelles. Jour. Conchyl., vol. 3, pp. 408-414. 1856. Histoire du genre Natica. Jour. Conchyl., vol. 1, pp. 43-64. 1857. Note sue la famille des Lithophages, Lamarck. Jour. Conchyl., vol. 2, pp. 15-24. Reeve, Lovell Augustus 1842a. Monograph of Crassatella, a genus of acephalous mollusks. Zool. Soc. London, Proc., pt. 10, pp. 42-46. 1842c. Monograph of the genus Tornatella. Zool. Soc. London, Proc., pt. 10, pp. 58-62. 1842d. On the genus Phorus, a group of agglutinating mollusks of the family Turbinacea. Zool. Soc. London, Proc., pt. 10, pp. 160-163. 1842e. Descriptions of new species of shells belonging to the genera Tro- chus and Turbo. Zool. Soc. London, Proc., pt. 10, pp. 184-186. 1842f. Descriptions of new species of shells figured in the ‘Conchologica Systematica’ Zool. Soc. London, Proc., pt. 10, pp. 187-202. 1843a. On new species of Pleurotoma and Pectunculus. Zool. Soc. London, Proc., pt. 11, pp. 31-34. 1843b. On a new species of Cyclostoma. Zool. Soc. London, Proc., pt. 11, p. 46. 1843c. On new species of Conus and Pectunculus. Zool. Soc. London, Proc., pt. 11, pp. 79-81. 1843d. On new species of Delphinula and a new Voluta. Zool. Soc. Lon- don, Proc., pt. 11, pp. 141-144. 1843e. On new species of Conus, Pleurotoma, Pectunculus, Cardita, and Cypricardia, Zool. Soc. London, Proc., pt. 11, pp. 168-197. 1843f. Descriptions by Mr. Lovell Reeve of new species of shells figured in the ‘Conchologica Systematica’. Zool. Soc. London, Proc. for 1842, pp. 197-200. 18444. Descriptions of thirty-three new species of Arca. Zool. Soc. Lon- don, Proc., pt. 12, pp. 39-48. 1844b. Monograph of the genus Myadora. Zool. Soc. London, Proc., pt. 12, pp. 91-94. 1844c. Descriptions of new species of Triton, collected chiefly by Hugh Cuming, Esq. Zool. Soc. London, Proc., pt. 12, pp. 109-122. 1844d. Descriptions of new species of Arca, from the cabinet of Hugh Cuming, Esq. Zool. Soc. London, Proc., pt. 12, pp. 123-128. VENEZUELAN CENOZOIC PELECYPODS: WEISBORD 471 1844e. Descriptions of new species of Ranella. Zool. Soc. London, Proc., pt. 12, pp. 136-137. 1844f. Descriptions of new species of Mitra and Cardium. Zool. Soc. London, Proc., pt. 12, pp. 167-187. 1848a. On Fastigiella, a new genus of shells of the Lamarckian family Canalifera. Zool. Soc. London, Proc., pp. 14-15. 1848b. Descriptions of new species of Turbo, chiefly from the collection of Hugh Cuming, Esq. Zool. Soc. London, Proc., pp. 49-52. van Regteren Altena, C. O. 1941. The marine Mollusca of the Kendeng beds (East Java). Gastro- poda, pt. 2 (families Planaxidae-Naticidae inclusive). Leidsche Geol. Meded., vol. 12, No. 1, pp. 1-86, figs. 1-24. 1961. The Mollusca from the limestone of Brimstone Hill, St. Kitts, and Sugar Loaf and White Wall, St. Eustatius, Lesser Antilles. aoe Nederl. Akad. Wetensch.-Amsterdam, Proc., ser. B, vol. No. 2, pp. 288-304, 1 pl. Rehder, Harald Alfred 1950. Congeria leucopheata (Con.) in the Hudson River. Nautilus, vol. 50, No. 4, p. 143. 1952. The publication dates of Kobelt’s “Illustriertes Conchylienbuch.” Nautilus, vol. 66, No. 2, pp. 59-60. Richards, Horace Gardiner 1930a. Notes on barnacles from Cape May, New Jersey. Acad. Nat. Sci. Philadelphia, Proc., vol. 82, pp. 143-144. 1936b. Fauna of the Pleistocene Pamlico formation of the southern At- lantic Coastal Plain, Geol. Soc. Amer., Bull., vol. 47, pp. 1611-1656, 4 pls., 1 fig. 1939a. Marne Pleistocene of the Gulf Coastal Plain: Alabama, Mississippi, and Louisiana. Geol. Soc. Amer., Bull., vol. 50, pt. 1, pp. 297-316, 3 pls. 1939b. Marine Pleistocene of Texas. Geol. Soc. Amer., Bull., vol. 50, pt. 2, pp. 1885-1898, pls. 1-3. 1948. T ertiary invertebrate fossils from newly discovered localities in North and South Carolina. Pt. 1, Acad. Nat. Sci. Philadelphia, Notulae Naurae, No. 207, pp. 1-11, pls. 1-4. 1950. Geology of the coastal plain of North Carolina. Amer. Philos. Soc., Trans., new ser., vol. 40, pt. 1, 83 pp., 76 figs. 1955. The geological ‘history of the Cayman Islands, Acad. Nat. Sci. Philadelphia, Notulae Naturae, No. 284, pp. 1-11, 1 fig. Ricketts, E. F., and Calvin, J. 1948. Between Pacific Tides. Stanford University, rev. ed., xxvii -+- 365 pp., 46 pls., 129 figs. Rivera, R. 1953. Pleistocene mollusks from Ecuador and Peru, Conchological Club Southern California, Minutes, No. 129, pp. 5-15. Riveros-Zuniga, Francisco 1951a. Catdlogo descriptivo de Fisurelidos Chilenos, Rev. Biol. Marina, vol. 3, pp. 89-148, 54 figs. 1951b. Cypraca (Aricia) caput serpentis Linne en la Isla Pascua. Rev. Biol. Marina, vol. 3, pp. 154-156. 1951c. El area de Hutpbiciin de Chorus giganteus Less., 1829 y algunas de sus diferencias morfoldgicas. Rev. Biol. Marina, vol. 3, pp. 157- 161, 2 figs. Riveros-Zufiga, Francisco, and Gonzalez Reyes, Juan 1950. Catdlogo descriptivo de veneridos Chilenos. Rev. Biol. Marina, vol. 2, pp. 117-160, figs. 22-44. 472 BULLETIN 204 Rivers, J. J. 1891. 4 new wvolutid shell (Scaphella arnheimi) from Monterey Bay. California Acad. Sci., Proc., ser. 3, vol. 3, p. 107. Roberts, R. J., and Irving, E. M. 1957. Mineral deposits of Central America with a section on manganese deposits of Panama, by F. §. Simons. U.S. Geol. Sur., Bull. 1034, 205, pp., 16 pls. 15 figs. Robertson, Robert 1957a. A study of Cantharus multangulus (Philippi), with notes on Can- tharus and Pseudoneptunea (Gastropoda: Buccinidae). Acad. Nat. Sci. Philadelphia, Notulae Naturae, No. 300, pp. 1-10, figs. 1-19. 1957b. Publication dates of Troschel’s “Das Gebiss der Schnecken.” Nau- tilus, vol. 70, No. 4, pp. 136-138. 1958b. The family Stenacmidae, Nautilus, vol. 72, No. 2, pp. 68-69. 1959b. The subgenus Halopsephus Rehder, with notes on the Western Atlantic species of Turbo and the subfamily Bothropomatinae Thiele. Washington Acad. Sci., Jour., vol. 47, pp. 316-319, 3 figs. 1959c. Observations on the spawn and veligers of conchs (Strombus) in the Bahamas. Malac. Soc. London, Proc., vol. 33, pt. 4, pp. 164-171, pl. 11, text figs. 1-2. 1959d. The mollusk fauna of Bahamian mangroves. Amer. Malac. Union, Bull., No. 26, pp. 22-23. 1961a. Review of pyramidellid hosts, with notes on an Odostomia parasitic on a chiton. Nautilus, vol. 74, No. 3, pp. 85-91, figs. 1-9. 1961b. A second Western Atlantic Rissoella and a list of species in the Rissoellidae. Nautilus, vol. 74, No. 4, pp. 131-136, pl. 9. 1961c. The feeding of Strombus and related herbivorous marine gastro- pods: With a review and field observations. Acad. Nat. Sci. Phila- delphia, Notulae Naturae, No. 343, pp. 1-9, 1 fig. de Rochebrune, A. T., and Mabille, J. 1885. Diagnoses de mollusques nouveaux, recueillis par les membres de la mission du Cap Horn. Soc. Phil. Paris, Bull., vol. 9, pp. 100-111. 1889. Cephalopoda, Gastropoda et Lamellibranchiata. Mission Scienti- fique du Cap Horn (1882-3), vol. 6, Zool., pp. 1-126, pls. 1-8. Romanes, J. 1912a. Geological notes on the peninsula of Nicoya, Costa Rica. Geol. Mag., ser. 5, vol. 9, No. 6, pp. 258-265, 1 fig. Romer, Eduard 1841, 1869-70. Die Familie der Dreiecks—oder Stumpfmuscheln, Dona- cidae. Syst. Conchylien-Cabinet, vol. 10, pt. 3, pp. 1-8, pl. 1 (1841); pp. 1-32, pls. 2-7 (1869); pp. 33-122, pls. 8-21a (1870). 1857. Kritische Untersuchung der Arten des Molluskengeschlechts Venus bei Linné und Gmelin mit Beriicksichtigung der spater beschrie- benen Arten. Marburg, xiii + 135 pp. 1867. Kritische Uebersicht aller zum Subgenus Chione gehirenden Arten von Venus. Malakozool. Blatter, vol. 14, pp. 28-62, 92-126. 1870-73. Die Familie der Tellmuscheln, Tellinidae. Syst. Conchylien- Cabinet, vol. 10, pt. 4, pp. 1-291, pls. 1-52. Rosewater, Joseph 1961. The family Pinnidae in the Indo-Pacific. Indo-Pacific Mollusca, vol. 1, No. 4, pp. 175-226, pls. 135-171. Rossmassler, E. A., and Kobelt, W. 1835-1913. Iconographie der Land-und Susswasser-Mollusken. Vols. 1-21. Rosso, Samuel W. 1952. Some differences in the bivalve fauna of Ocean Springs, Missis- sippi, and Grand Isle, Louisiana. Louisiana Acad. Sci., Proc., vol. 15, pp. 62-64. VENEZUELAN CENozoIc PELECyPops: WEISBORD 473 Roux, Polydore 1828. Iconographie conchyliologique ou recueil de planches lithographiées et colorées représentant les coquilles marines, fluviatiles, terrestres et fossiles, décrit par de Lamarck, Sowerby, Swainson, de Ferrus- sac, de Blainville, Risso, etc., et autres inédites, Vol. 1, 8 pp., 9 pls. Rutsch, Rolf F. 1942. Bettrdge zur Kenntnis tropisch-amerikanischer Tertidrmollusken. VII. Larkinien (Arcidae) aus dem jungtertiar von Trinidad. Eclo- gae Geol. Helvetiae, vol. 35, No. 2, pp. 213-223, pl. 8. Rutten, L. M. R. 1931c. Our paleontologic knowledge of the Netherlands West Indies. Leidsche Geol. Meded., vol. 5, pp. 651-672. 1934. Oude Land en Zee-Verbindingen in midden-Amerika en West- Indié. Koninkl. Neder]. Aardrijks. Genootschap, Tijdschr., vol. 51, pp. 351-600, 5 figs., map, table. 1935a. Alte Land-und Meeresverbindungen in West-Indien und Zentral- amerika, Geol. Rundschau, vol. 26, Nos. 1-2, pp. 65-94, 3 figs., 1 pl. 1935b. Uber den Antillenbogen, Koninkl. Akad. Wetensch. Amsterdam, Proc., vol. 38, No. 10, pp. 1046-1058, 3 figs. 1938. Bibliography of West Indian geology. Geogr. en Geol. Meded., Physiogr.-Geol. Reeks No. 16, 103 pp. 1940c. New data on the smaller islands north of Venezuela. Nederl. Akad. Wetensch. Amsterdam, Proc., vol. 43, pp. 820-827, figs. Salisbury, A. E. 1929. A twice pre-occupied generic name. Malac. Soc. London, Proc., vol. 18, p. 255. 1953. Mollusca of the University of Oxford Expedition to the Cayman Islands, 1938. Malac. Soc. London, Proc., vol. 30, pp. 39-54. Sapper, K. 1937. Mittelamerika. Handbuch regionalen Geologie, vol. 8, No. 29, pt. 4a, 160 pp., 10 pls., 15 figs. Sars, G. O. 1872. On some remarkable forms of animal life from the great deeps off the Norwegian coast. I. Univ. Programm K. Norske Univ. Christi- ania for 1869, vol. 1, vii + 82 pp., 6 pls. 1878. Mollusca regionis articae Norvegiae. Bijdrag til Kundskalen om Norges Arktiske Fauna, I, Christiania, xvi + 466 pp., 52 pls., 1 map. Sars, Michael 1861. Om Siphodentalium vitreum en ny slaegt og art af Dentalidernes demilie. Christiania Univ.-Program for Fgrste Halvaar, 29 pp., 3 pls. 1870. Bidrag til kundskab om Christianiafjordens fauna. II, Nytt Mag. Nat., vol. 17, pp. 113-226, pls. 8-13. Sassi [as Sasso], A. 1827. Saggio geologico sopra il bacino terziario di Albenga. G. Ligust. Sci. Lett. Art. Genova, vol. 1, No. 5, pp. 467-484. Schaufelberger, P. 1933. Un estudio geolégico de la Meseta Central occidental. Apuntes de geologia. San José, 15 pp. Scheltema, Rudolf S., and Truitt, R. V. 1954. Ecological factors related to the distribution of Bankia gouldi Bartsch in Chesapeake Bay. Chesapeake Biol. Lab., Publ. No. 100, pp. Schenck, Hubert G. L 1961. Guiding principles in stratigraphy. Geol. Soc. India, Jour., vol. 2, 10 pp. 474 BuLieTin 204 Schepman, M. M. 1908-13. Mollusca II. The Prosobranchia of the Siboga Expedition. Siboga-Expeditie, vol. 28. Pt. 1. Rhipidoglossa and Docoglossa, with an appendix by Prof. R. Bergh, 107 pp., 9 pls., 3 text figs. Pt. 2. Taenioglossa and Ptenoglossa, 123 pp., 7 pls. Pt. 3. Gymno- glossa, 13 pp., 1 pl. Pt. 4. Rhachioglossa, 117 pp., 4 pls. Pt. 5. Toxoglossa, 88 pp., 6 pls., 1 text fig. Pt. 6. Pulmonata and Opis- thobranchia Tectibranchiata tribe Bullomorpha, 42 pp., 2 pls. Schepman, M. M., and Nierstrasz, H. F. 1909. Mollusca II. Parasitische Prosobranchia der Siboga-Expedition. Siboga-Expeditie, vol. 28, 76 pp., 6 pls., 39 text figs. Schilder, F. A. 1935. Revision of the Tertiary Cypraeacea of Australia and New Zea- land. Malac. Soc. London, Proc., vol. 21, pt. 6, pp. 325-355, figs. 1-50. Schilder, F. A., and Tomlin, J. R. le Brocton 1931. Re-discovery of a rare cowry. Malac. Soc. London, Proc., vol. 19, pt. 6, pp. 274-275. Schmidt, F. C. 1818. Versuch iiber die beste Einrichtung zur Aufstellung, Behandlung und Aufbewahrung der verschiedenen Naturkorper und Gegen stinde der Kunst, verziiglich der Conchylien-Sammlungen, Gotha, Viiv 52eppe Schramm, A. 1869. Catalogue des coquilles et des crustacées de la Guadeloupe, envoyés a lexposition universelle de 1867. Basse-Terre, Imprimerie du Gouvernement, 2 pp. Schwengel, Jeanne S. 1942c. A new Floridan Calliostoma (Astele). Acad. Nat. Sci. Philadelphia, Notulae Naturae, No. 106, 2 pp., 1 fig. Scopoli, Giovanni Antonio 1777. Introductio ad historium naturalem sistens genera Lapidum, Plan- tarum et Animalium hactenus detecta, caracteribus essentiabilus donata, in tribus divisa, subinde ad leges naturae, Prague, Mol- lusca, pp. 386-400. Scudder, H. 1864. Notes on the geology of Cuba and the Isle of Pines. Boston Soc. Nat. Hist., Proc., vol. 10, pp. 47-49. Seguenza, Giuseppe 1862. Paleontologia malacologica della rocce terziarie del distretto di Messina studiata vei suoi rapporti zodlogici e geognostici. Accad. Asperanti Nat. Napoli, Ann., ser. 3, vol. 2, pp. 77-95. 1876a. Cenne intorno alle Verticordie fossili del Plioceno Italiano. R. Accad. Sci. Napoli, Rend., vol. 15, pp. 104-115, map. 1876b. Studii stratigrafici sulla formazione Pliocenica dell’Italia meridion- ale, R. Comitato Geol. Italia, Bol., vol. 7, pp. 7-15, 179-189. 1877. Nuculidi terziare rinvenute nelle provincie meridionali d’Italia. R. Accad. Lincei Roma, Mem., ser. 3, vol. 1, pp. 1163-1200, pls. 1-5. 1880. Le formazione terziarie nella provincia di Reggio (Calabria). R. Accad. Lincei Roma, Mem., ser. 3, vol. 6, pp. 1-446, pls. 1-17. Semmes, Douglas R. 1919. The geology of the San Juan District, Porto Rico. New York Acad. Sci. Scientific Survey of Porto Rico and the Virgin Islands, vol. 1, pt. 1, pp. 1-110, 23 figs., geol. map. Sharff, R. F. 1922. On the origin of the West Indian fauna. Dierk Amsterdam Bijdr., Weber Feestbundel., pp. 65-72. VENEZUELAN CENOZOIC PELECYPODS: WEISBORD 475 Sherborn, Carolo Davies 1936. An index to the authors (other than Linnaeus) mentioned in the Catalogue of the Works of Linnaeus preserved in the libraries of the British Museum. London, 2d ed., 1933, pp. 1-59. Shimer, H. A., and Shrock, R. R. 1944. Index Easels of North America. New York, London, ix + 837 pp., 303 pls. Shrock, Robert R., and Twenhofel, William H. 1953. Principles of Invertebrate Paleontology. New York, Toronto, Lon- don, 2d ed., xx + 816 pp., figs. Shuttleworth, Robert James 1856. Description de nouvelles espéces. Premiére décade: especes nou- velles pour la faune des Antilles. Jour. Conchyl., sér. 2, vol. 5, pp. 168-175. Sievers, W. 1895. Zur Kenntniss Puerto Rico’s. Geogr. Gesell. Hamburg, Mitth. 1891- 92, pp. 217- 236, map. 1903. Siid und Mittelamerika. Hamburg, 2d ed., xii + 665 pp., 144 figs., 11 maps, 20 pls. 1914. Stid und Mittelamerika. Hamburg, 3d ed., xi + 567 pp., 54 figs., maps, sections, diagrams, 26 pls. Simpson, Charles T. 1887a. Record of a two-day’s dredging cruise in Tampa Bay, Florida. Conch. Exchange, vol. 1, pp. 44, 52-53. 1887b. On a new Florida Natica. Conch. Exchange, vol. 2, p. 51. 1895. Distribution of land-and freshwater mollusks in the West Indian region and their evidence with regard to past changes of land and sea, U. S. Nat. Mus., Proc., vol. 17, pp. 423-450, pl. 16. Smith, Allyn G. 1961a. Note on the bivalved gastropod Berthelinia limax (Kawaguti and Baba). The Veliger, vol. 3, No. 3, pp. 80-81. 1961b. Notes on the habitat of Berthelinia spec. nov. from the vicinity of La Paz, Baja California, Mexico. The Veliger, vol. 3, No. 3, pp. 81-82. Smith, Edgar A. 1875b. Descriptions of some new shells from Kerguelen’s Island. Ann. Mag. Nat. Hist., ser. 4, vol. 16, pp. 62-73. 1877a. On the Mollusca collected during the Arctic Expedition of 1875- 76. Ann. Mag. Nat. Hist., ser. 4, vol. 20, pp. 131-146, 2 figs. 1877b. Account of the zoological collection made during visit of H. M. S. ‘Petrel’ to the Galapagos Islands. Mollusca. Zool. Soc. London, Proc., pp. 69-73, pl. 11, figs. 6-8. 1879. Transit of Venus Expeditions. Mollusca. Roy. Philos. Soc. London, Trans., vol. 168, pp. 167-192. 1880b. On oe genus Myodora Gray. Zool. Soc. London, Proc., pp. 578- 587, pl. 53. 1880c. Descriptions of five new species of shells from Uruguay. Ann. Mag. Nat. Hist., ser. 5, vol. 6, pp. 319-322. 1881c. On the genus Gouldia of C. B. Adams, and on a new species of Crassatella. Zool. Soc. London, Proc., No. 32, pp. 498-491. 1890a. Report on the marine molluscan fauna of the Island of St. Helena. Zool. Soc. London, Proc., pp. 247-317, pls. 21-24. 1891b. Descriptions of new species of shells from the ‘Challenger Expedi- tion, Zool. Soc. London, Proc., pp. 436-445, pls. 34-35. 1891c. Remarks upon the genus Pythina of Hinds and the species which have been referred to it, upon Mysella of Angas, and the descrip- tion of a new species of Mylitta. Ann. Mag. Nat. Hist. for 1891, Ppp. 227-236, pl. 13A. 476 BuLLeTIN 204 1892. Descriptions of shells from Mauritius and California. Ann. Mag. Nat. Hist., ser. 6, vol. 9, No. 51, art. 39, pp. 255-256, 2 figs. 1893. Observations on the genus Sphenia, with descriptions of new species. Ann. Mag. Nat. Hist., ser. 6, vol. 12, pp. 277-281, pl. 15A. 1895a. Natural history notes from H. M. Indian Marine Survey steamer “Investigator,’ Commander C. F. Oldham, R. N. Series 2, No. 20. Report upon some Mollusca dredged in the Arabian Sea during the season 1894-95. Ann. Mag. Nat. Hist., ser. 6, vol. 16, pp. 1-19, 262-265, pls. 1-12. 1895b. A list of land and freshwater Mollusca of Trinidad. Jour. Conch., vol. 8, pp. 231-251. 1898. On a small collection of marine shells from New Zealand and Mac- Quarie Island, with descriptions of new species. Malac. Soc. Lon- don, Proc., vol. 3, pt. 1, pp. 20-25, figs. 1-9. 1900. On Callocardia and Vesicomya. Malac. Soc. London, Proc., vol. 4, pt. 2, pp. 81-83, 2 figs. 1902a. Description of a new species of Gomphina from New Zealand. Jour. Malac., vol. 9, No. 4, pp. 109-110, 2 figs. 1902b. Report on the collections of Mollusca made in the Antarctic during the voyage of the ‘Southern Cross, Pt. 7, Mollusca, pp. 201-213, pls. 24-25. 1905a. On a small collection of Mollusca from Tierra del Fuego. Zool. Soc. London, Proc., pp. 333-339. 1905b. Mollusca from Tierra del Fuego. Malac. Soc. London, Proc., vol. 6, pt. 6, pp. 333-339, figs. 1-7. 1906. Natural history notes from R. I. M. 8. “Investigator.” On Mollusca from the Bay of Bengal and the Arabian Sea. Ann. Mag. Nat. Hist., ser. 7, vol. 18, pp. 157-175, 245-264. 1907a. Mollusca and Brachiopoda. Nat. Antarctic Exped. (‘Discovery’), Nat. Hist., vol. 2, pp. 1-112, pls. 1-3. 1907b. Lamellibranchiata. Nat. Antarctic Exped. (‘Discovery’), Nat. Hist., vol. 2, pp. 1-7, pls. 2-3. 1915b. Mollusca. Pt. 1. Gastropoda, Prosobranchia, Scaphopoda and Pele- cypoda. British Antarctic (‘Terra Nova’) Exped. (1910), Zoology, vol. 2, No. 4, pp. 61-112, pls. 1-2. 1915c. A list of Australian Mactridae, with a description of a new species. Malac. Soc. London, Proc., vol. 11, pp. 137-151. Smith, Ernest Rice 1923. Three new brackish-water Pliocene Mollusca from Louisiana. In- diana Acad. Sci., Proc., pp. 135-136. Smith, Lillian C. 1945. Notes on the family Cardiidae. Occas. Papers on Mollusks, No. 4, pp. 29-32. Smith, Maxwell 1909. A Sicilian collection. Nautilus, vol. 22, pp. 128-135. 1960. Universal Shells. Marine-freshwater-land. Asheville, 254 pp. Smith, Sanderson 1860. On the Mollusca of Peconic and Gardiner’s Bays, Long Island, New York. Lyc. Nat. Hist. New York, Ann., vol. 7, pp. 147-168. 1865. Catalogue of the Mollusca of Little Gull Island, Suffolk County, New York. Lyc. Nat. Hist. New York, Ann; vol. 7, 2 pp. 1870. Report on the Mollusca of Long Island, N. Y., and of its dependen- cies. Lyc. Nat. Hist. New York, Ann., vol. 9, pp. 377-407, figs. 1-6. (With Temple Prime) Solem, Alan 1954. Living species of the pelecypod family Trapeztidae, Malac. Soc. London, Proc., vol. 31, pt. 2, pp. 64-84, pls. 5-7. VENEZUELAN CENOzOoIC PELECYPOoDS: WEISBORD 477 Soot-Ryen, Tron 1932a. The Norwegian zoological expedition to the Galapagos Islands 1925, conducted by Alf Wolleback. II. Pelecypods from Floreana (Sancta Maria), Galapagos Islands. Meddel. Zool. Mus. Oslo, No. 27, pp. 313-324, pls. 1-2. 1932b. Pelecypoda, with a discussion of possible migrations of Arctic pelecypods in Tertiary times. [In] The Norwegian North Polar Expedition with the “Maud” 1918-25, Scientific Results, vol. 5, No. 12, 135 pp., 2 pls. 1951a. Scientific results of the Norwegian expeditions 1927-1928 et sqq., instituted and financed by Consul Lars Christensen. No. 32. Ant- eee pelecypods. Norske Videnskaps-Akademi i Oslo, pp. 1-46, 1 1952a. Choromytilus, a new genus in the Mytilidae. Soc. Malacolégica, vol. 8, No. 3, pp. 121-122. 1952b. Laternula elliptica (King and Broderip 1831) from the Pecten- conglomerate, Cockburn Island. Kung}. Svenska Vetenskapsakad., Ark f. Zoologi, ser. 3, vol. 4, No. No. 9, pp. 163-164, pl. 1. 1952c. New Tertiary Pelecypoda from Punta Arenas. Arkiv f. Zoologi, vol. 4, No. 15, pp. 307-310, pl. 1. 1957b. Preliminary diagnoses of new genera and species of pelecypods from Chile. Astarte, No. 16, 5 pp. 1959. Reports of the Lund University Chile Expedition 1948-49. Pele- cypoda, Lund Univ. Arsskrift, ser. 2, vol. 55, No. 6, pp. 1-86, pls. 1-4. 1960. Pelecypods from Tristan da Cunha, Results Norwegian Sci. Exped. to Tristan da Cunha, No. 49, 47 pp., 3 pls., 9 figs. Soulsby, B. H. 1903-40. Catalogue of the books, manuscripts, maps and drawings in the British Museum (Natural History). British Museum, vol. 1 (A- D), pp. 1-500 (1903); vol. 2 (E-K), pp. 501-1038 (1904); vol. 3 (L-O), pp. 1039-1494 (1910); vol. 4 (P-SN), pp. 1495-1956 (1913) ; vol. 5, pp. 1957-2403 (1915); vol. 6, Supplement (A-I), pp. 1-511 + Addenda and Corrigenda of vols. 1 and 2, 48 pp. (1922); vol. 7, Supplement (J-O), pp. 1-967 (1933); vol. 8, Supplement, pp. 1-1480 (1940). 1933. A catalogue of the works of Linnaeus (and publications more im- mediately relating thereto) preserved in the libraries of the British Museum (Bloomsbury) and the British Museum (Natural History) (South Kensington). London, 2d ed., xi+ 246 pp., + addenda and corrigenda 65 pp., + index pp. 67-68. de Souza Lopes, H. 1958. Sobre “Turbonilla (Pyrgiscus) dispar” Pilsbry, 1897 (Gastropoda, Pyramidellidae). Brasil Biol. Rev., vol. 18, No. 1, pp. 17-21, figs. la-11c. de Souza Lopes, H., and Alvarenga, M. 1955. Contribuicgao ao conhecimento dos moluscos da Ilha Fernando de Noronha-Brasil. Inst. Oceanografico Bol., vol. 6, Nos. 1-2, pp. 157- 196, pls. 1-3. de Souza Lopes, H., and de Sa Cardoso, Paulo 1958. Sobre um novo gastrépodo Brasileiro do género “Solariella” Wood, 1842 (Trochidae). Brasil Biol. Rev., vol. 18, No. 1, pp. 59-64, figs. 1-3. Sowerby, George Brettingham (first of name) 1828. Observations on the shells of an acephalous molluscum of the family Pectinidae, for which the generic name of Hinnites has been proposed by M. DeFrance; together with the characters of several species. Zool. Jour., vol. 3, pp. 67-72. 478 BuLLeTIN 204 1843. On new species of Cyclostoma in the collection of H. Cuming, Esq. Zool. Soc. London, Proc., pt. 11, pp. 29-31, 59-66. 1844a. Descriptions of new species of Columbella, from the collection of High Cuming, Esq. Zool. Soc. London, Proc., pt. 12, pp. 48-53. 1844b. Descriptions of six new species of Voluta. Zool. Soc. London Proc., pt. 12, pp. 149-152. Sowerby, George Brettingham, Jr. (second of name) 1841c. Description of eight new species of Ranella. Zool. Soc. London, Proc., pt. 9, pp. 51-53. 1842. Descriptions of new species of the genus Pecten, figured in Sower- by’s ‘Thesaurus Conchyliorum’ Zool. Soc. London, Proc., pt. 10, pp. 163-165. 1843. Descriptions of new species of Lima. Zool. Soc. London, Proc., pt. ii ipe ase 1844a. Descriptions of new species of Scalaria collected by Hugh Cuming, Esq. Zool. Soc. London, Proc., pt. 12, pp. 10-14. 1844b. Continuation of descriptions of Scalaria. Zool. Soc. London, Proc., pt. 12, pp. 26-31. 1846a. Descriptions of Tertiary fossil shells from South America. [In] Darwin, Charles R., Geological observations on South America, being the third part of the geology of the Voyage of the Beagle ... during the years 1832 to 1836. Appendix, pp. 249-264. 1848a. Descriptions of some new species of Ovulum in the collection of Mr. Cuming. Zool. Soc. London, Proc., pp. 135-136. 1848b. Descriptions of some new species of Cancellaria in the collection of Mr. Cuming. Zool. Soc. London, Proc., pp. 136-138. 1849a.On a new species of Pholadidae, with notices of several new species and of a remarkable specimen of Pholas calva in Mr. Cuming’s collection. Zool. Soc. London, Proc., pp. 160-162, pl. 5. 1888. Descriptions of fourteen new species of shells. Linnean Soc. Lon- don, Jour., Zoology, vol. 20, pp. 395-400, pl. 25. 1897. On three new shells from the collection of Mr. B. C. Thomas of Brest, Malac. Soc. London, Proc., vol. 2, No. 4, pp. 137-138, pl. 11. 1900. Descriptions of two new species of shells—Murex marcoensis and Cassis booleyi. Jour. Malac., vol. 7, pp. 162-163, 2 figs. 1904 Mollusca of South Africa. Dept. Agric., Marine Investigations in South Africa, vol. 2, pp. 93-100, pl. 2; pp. 213-232, pls. 3-5. Springer, J. W. 1924. A Tertiary crinoid from the West Indies. U. S. Nat. Mus., Proc, vol. 65, art. 3, 8 pp., 1 pl. Staadt, J. L. 1956. Observations on the subgeneric classification of Calliostoma. Jour. Conchyl., Vol. 96, pp. 119-120. Stahl, Augistin 1882. Fauna de Puerto Rica. Imprenta del Boletin Mercantil, p. 242. Stearns, Robert Edwards Carter 1867d. Shells collected at San Juanico, Lower California, by William M. Gabb. California Acad. Sci., Proc., vol. 5, pp. 131-132. 1867e. Shells collected at Loreto, Lower California by W. M. Gabb, in February 1867. California Acad. Sci. Proc., vol. 5, p. 132. 1869. On a new species of Pedipes from Tampa Bay, Florida. Boston Soc. Nat. Hist., Proc., vol. 13, pp. 108-109, 1 fig. 1872. Descriptions of new species of marine mollusks from the coast of Florida, Conch. Memoranda, No. 11, pp. 2-4. 1873e. Descriptions of new marine shells from the west coast of Florida. Acad. Nat. Sci. Philadelphia, Proc., vol. 25, pp. 344-347, figs. 1-4. 1893e. Scientific results of explorations by the U. S. Fish Commission steamer Albatross. U. S. Nat. Mus., Proc., vol. 16, pp. 353-450, pls. 51-52. VENEZUELAN CENOZOIC PELECYPODS: WEISBORD 479 Steinbeck, J., and Ricketts, E. F. 1941. Phylum Mollusca. [In] Sea of Cortez. New York, x + 598 pp., 40 pls., 2 charts. Steinmann, G., and Wilckens, Otton 1908. Kreide-und Tertidrfossilen aus den Magellanslaindern gesammelt von der Schwedischen Expedition 1895-1897. K. Svenska Vetenskap- sakad. Stockholm, Ark. f. Zool., vol. 4, No. 6, pp. 1-118, pls. 1-7, 7 text figs. Stenzel, H. B. 1947. Nomenclatural synopsis of supraspecific groups of the family Ostreidae (Pelecypoda, Mollusca). Jour. Paleont., vol. 21, No. 2, pp. 165-185. Stephenson, T. A., and Stephenson, Anne 1949. The universal features of zonation between tide-marks on rocky coasts. Jour. Ecology, vol. 37, No. 2, pp. 289-305. 1950. Life between tide-marks in North America. I. The Florida Keys. Jour. Ecology, vol. 38, No. 2, pp. 354-402. 1954. The Bermuda Islands. Endeavor, vol. 13, No. 50, pp. 72-80, 4 pls. Stimpson, William 185la. Descriptions of two new species of shells from Massachusetts Bay, namely: Spiralis gouldii and Thracia couthouyi, and a Holothuria. Boston Soc. Nat. Hist., Proc., vol. 4, pp. 7-9. 1863. Synopsis of the marine Invertebrata collected by the late Arctic Expedition, under Dr. I. I. Hayes. Acad. Nat. Sci. Philadelphia, Proc., vol. 15, pp. 138-142. 1865a. Review of the northern Buccinums and remarks on some other northern marine mollusks. Part. 1, Canadian Naturalist, vol. 2, pp. 364-389. Stoliczka, Ferdinand 1868. The Gastropoda of the Cretaceous of southern India. Geol. Survey India, Mem., Paleont. Indica, Cretaceous fauna, vol. 2, xiii + 498 pp., pls. 1-28. 1870-71. The Pelecypoda, with a review of all known genera of this class, fossil and Recent, Geol. Survey India, Mem., Paleont. Indi- ca, Cretaceous fauna, vol. 3, xxii + 538 pp., pls. 1-50. Storer, D. H. 1838. Description of a new species of Nucula from Massachusetts Bay. Boston Jour. Nat. Hist., vol. 2, pp. 122-125, 1 fig. Strebel, H. 1904-07. Beitraége zur Kenntnis der Mollusken Fauna der Magalhaen- Provinz. Zool. Jahrb., Abt. Systemat., vol. 21, pp. 171-248, pls. 3-4 (1904); vol. 21, suppl. 8, pp. 121-166, pl. 5 (1905); vol. 22, pp. 575-666, pls. 21-24 (1905); vol. 24, pp. 91-174, pls. 7-13 (1906) ; vol. 25, pp. 79-196, pls. 1-8 (1907). 1908. Die Gastropoden. Wiss. Ergeb. Schwed. Siidpolar-Exped. (1901- 03), vol. 6, pp. 1-112, pls. 1-6. Stuardo B., José 1960. La familia Glycimeridae (Bivalvia) en Chile. Biol. Marina Rev., vol. 10, Nos. 1-3, pp. 133-142, 1 pl. Stutchbury, Samuel 1837. On Cypraecdssis, a proposed new genus of univalve shells, for the reception of certain species of Bruguiére’s genus Cassis. Mag. Nat. Hist., new ser., vol. 1, pp. 214-217, 2 figs. Sumner, F. B., Osburn, R. C., and Cole, L. J. 1913. A biological survey of the waters of Woods Hole and vicinity. Pt. I, Sect. 1, Physical and zoological. U. S. Bur. Fisheries, vol. 31, pt. 1, pp. 1-441, 227 charts. Pt. II, Sect. 3. A catalogue of the marine fauna, Vol. 31, pt. 2, pp. 545-794. 480 BuLuetTin 204 Suter, Henry 1908. Descriptions of new species of New Zealand Mollusca. New Zea- land Inst., Trans., vol. 40, pp. 360-373, pls. 28-30. 1913. Descriptions of two new marine shells from New Zealand. Canter- bury Mus., Rec., vol. 2, No. 1, pp. 57-58, figs. 1-2. 1913-15. Waeuak of the New Zealand Wiolloscas Wellington, xxiii + 1120 pp., Atlas 72 pls. Sverdrup, H. U., Johnson, M. W., and Fleming, R. H. 1942. The Oceans, their Physics, Chemistry and General Biology. New Work. existe 1087 pp., 265 text figs. Sykes, E. R. 1906. On the dates of publication of Sowerby’s “Mineral Conchology” and “Genera of Recent and Fossil Shells’? Malac. Soc. London, Proc., vol. 7, pp. 191-194. Tegland, Nellie May 1929. Correlation and affinities of certain species of Pitaria. Univ. California Publ., Bull. Dept. Geol. Sci., vol. 18, No. 10, pp. 275- 290, pls. 21-23. Teisseire, Augusto 1928. Contribucién al estudio de la geologia y de la paleontologia de la Repiblica del Uruguay. Region de Colonia. Montevideo, 153 pp., 27 photogr., 12 pls., 2 maps. von Teppner, Wilfried 1922. Lamellibranchiata tertiaria, Anisomyaria, 2. Fossilium Catalogus, vol. 1, pt. 15, pp. 67-296. Thalmann, Hans E. 1935. Die miozine Tuxpan-Stufe im Gebiete zwischen Rio Tuxpan und Rio Tecolutla (Staat Veracruz, Ost-Mexico). Eclogae Geol. Helve- tiae, vol. 28, No. 2, pp. 543-546. Thiele, Johannes 1903 Die beschalten Gastropoden der Deutschen Tiefsee-Expedition, 1898-99. Wiss. Ergebn. ‘Valdiva,’ vol. 7, pp. 147-174, pls. 6-9 1912a. Scissureliden und Fissurelliden. Syst. Conchylien- Cabinet, wol.ti2, pt. 4a, pls. 1-4. 1912b. Die antarktischen Schnecken und Muscheln. [In] Deutsche Siid- polar-Exped. 1901-03, vol. 13, pp. 183-285, 9 pls. 1920. Eamélic Limidae. Syst. Conchylien-Cabinet, vol. 7, pt. 2a, 66 pp., 10 pls. 1924a. Revision des Systems Trochacea. Zool. Mus. Berlin, Mitteil., vol. 11, No. 1, pp. 47-74. 1924b. Ueber die Systematic der Columbelliden. Archiv f. Molluskenfunde, vol. 56, pp. 200-210, 1 pl. 1925. Gastropoda der Deutsche Tiefsee-Expedition. 2. Wiss. Ergebn. ‘Valdivia,’, vol. 17, No. 2, pp. 26-382, pls. 13-46. 1929-35. Handbuch der systematischen Weichtierkunde. Jena, vol. 1, pt. 1, pp. 1-376 (1929) ; pt. 2, pp. 377-778, figs. 1-783 (1931); vol. 2, pt. pe 779-1022 (1934); pt. 4, pp. 1023-1154, figs. 784-879 (1935). Thomas, Abram Owen 1919. Notes on the geology of Barbados and Antigua. Iowa Univ. Studies in Nat. Hist., vol. 8, pp. 127-136, 213-219. Thompson, Fred G. 1957. A collection of mollusks from northern Venezuela, Mus. Zool. Univ. Michigan, Occas. Papers, No. 591, pp. 1-10, pls. 1-2. Thompson, J. M. 1954. The genera of oysters and the Australian species. Australian Jour. Marine and Freshwater Research, vol. 5, No. 1, pp. 132-168, pls. 1-11. VENEZUELAN CENOZOIC PELECYPODS: WEISBORD 481 Thomson, J. H. 1867. Description of a new species of Montacuta. Amer. Jour. Conch., vol. 3;:pt. 1, No. '8;"p!.33, pli 1) figs 15: Tippenhauer, L. Gentil 1893. Die Insel Haiti. Leipzig, xviii + 693 pp., 30 figs., 35 pls. 1899. Geologische Studien in Haiti. Peterm. Mitth. J. Aus der siidwest- lichen Halbinsel, pp. 26-29, pl. 3. IJ. Aus der nordwestlichen Hal- binsel, pp. 153-155, pl. 10. III. Geologische Studien zavischen Port au Prince, Jacmel, Baient und Grand Goave, pp. 201-204, pl. 13. 1901. Beitrage zur Geologie Haitis. Peterm. Mitth. IV. Die Erzfundstatten von Terre Neuve und Gonaives, pp. 121-127, pl. 10. V. Das La Selle Gebirge, die Cul de Sac Ebene und das Salzseengebiet, pp. 169-178, pls. 13-14. VI. Das Lignitlager von Maissade und der Aufstieg wm eee aon und Gonaives und von Norden aus, pp. 193-199, pls. 15-16 1909. Neuer Beitrag zur Topographie, Ee RE es Eee und Geologie Haitis. Peterm. Mitth., pp. 49-57, pl. 5 Tomlin, J. R. le Brocton 1916a. Notes on Marginella. Jour. Conch., vol. 15, p. 43. 1931a. Notes from the British Museum-I. Dates of certain species of Donax and Mesodesma. Malac. Soc. London, Proc., vol. 19, No. 3, pp. 295-308, pls. 46-47. 1945. Hawaiian types [of| Terebra. Conch. Club Southern California, Minutes, No. 43, p. 40. Tomlin, J. R. le Brocton, and Shackleford, L. J. 1914-15. The marine Mollusca of Sado Thomé. I. Jour. Conch., vol. 14, pp. 239-256 (1914) ; pp. 267-276 (1915). Townsend, Charles Haskins 1916. Scientific results of the expedition to the Gulf of California in charge of C. H. Townsend, by the U.S. Fisheries steamship “Alba- tross” in 1911, Commander G. H. Burrage, U.S.N., commanding. Voyage of the Albatross to the Gulf of California in 1911. Amer. Mus. Nat. Hist., Bull., vol. 35, art. 24, pp. 399-476. Trechmann, C. T. 1932a. Notes on Brimstone Hill, St. Kitts. Geol. Mag., vol. 69, pp. 241- 258, pls. 12-13. 1932b. Brimstone Hill, St. Kitts. Geol. Mag., vol. 69, p. 430. Troschel, F. H. 1856-93. Das Gebiss der Schnecken zur Begriindung einer Natiirlichen Classification untersucht von Dr. F. H. Troschel. Vol. 1, pt. 1, pp. 1-72, pls. 1-4 (1856) ; pt. 2, pp. 73-112, pls. 5-8 (1857); pt. 3, pp. 113-152, pls. 9-12 (1858) ; pt. 4, pp. 153-196, pls. 13-16 (1861) : pt. 5, pp. 197-252 +- i-viii, pls. 17-20 (1863); vol. 2, pt. 1, pp. 1-48, pls. 1-4 (1865); pt. 2, pp. 49-96, pls. 5-8 (1867); pt. 3, pp. 97-132, pls. 9-12 (1869); pt. 4, pp. 133-180, pls. 13-16 (1875); pt. 5, pp. 181-216, pls. 17-20 (1878); pt. 6, pp. 217-246, pls. 21-24 (1879); pt. 7, pp. 249-334, pls. 25-28 (1891, by Thiele); pt. 8, pp. 337-409 + title + i-ix, pls. 29-32, (1893, by Thiele). Tryon, George Washington, Jr. 1862a. On the classification and synonymy of the Recent species of Phola- didae. Acad. Nat. Sci. Philadelphia, Proc., vol. 14, pp. 191-221. 1862b. Description of a new genus and species of Pholadidae. Acad. Nat. Sci. Philadelphia, Proc., vol. 14, pp. 449-451, 1 fig. 1862c. Monograph of the Fantily Teredidae. Acad. Nat. Sci. Philadelphia, Proc., vol. 14, pp. 453-482. 1872j. Descriptions of new species of marine bivalve Mollusca, Acad. Nat. Sci. Philadelphia, Proc., vol. 2, p. 130, pl. 6. 482 BuLLETIN 204 1873. American Marine Conchology: or, descriptions of the shells of the Atlantic coast of the United States from Maine to Florida. Philadelphia, vi + 208 pp., 44 pls. 1886. Family Vermetidae. [In] Man. Conch., vol. 8, pp. 163-191, pls. 49-58. Tucker-Rowland, Helen I. 1938a. A preliminary survey of the nomenclatural units of the Tertiary Pectinidae. Mus. Roy. Hist. Nat. Belgique, Bull., vol. 14, No. 49, pp. 1-15. 1938b. New subgenus and genus of Tertiary pectinids. Jour. Conch., vol. 21, pp. 81-82. Turner, Ruth D. 1955a. Scaphopods of the Atlantis dredgings in the Western Atlantic with a catalogue of the scaphopod types in the Museum of Comparative Zoology. Woods Hole Oceanagr. Inst., Contrib. No. 779, pp. 309- 320. 1956c. Notes on Xylophaga Washingtona Bartsch and on the genus. Nauti- lus, vol. 70, No. 1, pp. 10-12. 1961. Pleurotomariidae in Bermuda waters. Nautilus, vol. 74, No. 4, pp. 162-163. Turner, Ruth D., and Rosewater, Joseph 1958. The family Pinnidae in the Western Atlantic. Johnsonia, vol. 3, No. 38, pp. 285-326, pls. 149-171. Turton, William 1819. A Conchological Dictionary of the British Islands. London, xxvit Z7i2= pp: 28 pls: Turton, W. H. 1932. The Marine Shells of Port Alfred, §. Africa. Oxford Univ. Press, xvi + 331 pp., 70 pls. Vaillant, Leon 1865. Recherches sur la faune malacologique de la baie de Suez. Jour. Conchyl., vol. 13, pp. 97-127. 1871. Recherche sur la synonymie des espéeces placées par de Lamarck dans les genres Vermet, Serpule, Vermilie. Mus. Nat. Hist. nat. Paris, Nouv. Arch., sér. 1, vol. 7, pp. 181-201. Valentine, James W. 1956. Upper Pleistocene Mollusca from Potrero Canyon, Pacific Pali- sades, California. San Diego Soc. Nat. Hist., Trans., vol. 12, pp. 181-205, pl. 13, 1 map. 1960. Pleistocene molluscan notes, 3. Rocky coast faunule, Bahia San Quentin, Mexico. Nautilus, vol. 74, No. 1, pp. 18-23. 1961. Paleoecologic molluscan geography of the Californian Pleistocene. Univ. California Publ. Geol. Sci., vol. 34, No. 7, pp. 309-442, 16 text figs. Vanatta, Edward G. 1899b. Melampus floridanus Shuttl. Nautilus, vol. 12, p. 107. 1914. Modiolus demissus Dillw. and var. granosissimus Shy. Nautilus, vol. 28, p. 35. Van der Schalie, Henry 1933. Notes on the brackish water bivalve Polymesoda caroliniana (Bosc). Mus. Zool. Univ. Michigan, Occas. Papers, No. 258, pp. 1-8, pl. 1, map. 1948. The land and fresh-water mollusks of Puerto Rico. Mus. Zool. Univ. Michigan, Misc. Publ. No. 70, 134 pp., 14 pls. Van Hyning, Thompson 1945. A new Strombus from Florida. Mollusca, vol. 1, No. 7, pp. 95-98, 4 figs. Vaughan, Thomas Wayland 1899. Some Cretaceous and Eocene corals from Jamaica. Mus. Comp. Zool., Bull., vol. 34, pp. 227-250, pls. 36-41. VENEZUELAN CENOzoIC PELECYPoDS: WEISBORD 483 1900. 1902. 1905. 1913a. 1913b. 1914¢. 1914d. 1914e. A Tertiary coral reef near Bainbridge, Georgia. Science, n. s., vol. 12, pp. 873-875. Earliest Tertiary coral reefs in the Antilles and the United States. Science, n. s., vol. 15, pp. 506-507. A critical review of the literature on the simple genera of Madre- poraria Fungida, with a tentative classification. U. S. Nat. Mus., Proc. vol. 28, pp. 371-424. Studies of the geology and of the Madreporaria of the Bahamas and of southern Florida. Carnegie Inst. Washington, Yearbook, vol. 11, pp. 153-162. Remarks on the geology of the Bahamas and on the Bahamian oolites. Washington Acad. Sci., Jour., vol. 3, pp. 302-304. The platform of barrier coral reefs. Amer. Geogr. Soc., Bull., vol. 46, pp. 426-429. Sketch of the geologic history of the Florida coral reef tract and comparison with other coral reef areas. Washington Acad. Sci., Jour., vol. 4, pp. 26-34. Memorandum on the geology of the groundwater of the island of Antigua (B.W.I.). West Indian Bull. 14, pp. 276-279. 1914f. Investigations of the geology and geologic processes of the reef 1914g. 1915a. 1915b. tracts and adjacent areas in the Bahamas and Florida. Carnegie Inst. Washington, Yearbook, vol. 12 for 1913, pp. 183-184. Coral reefs and reef corals of the southeastern United States, their geologic history and significance. Geol. Soc. Amer., Bull., vol. 26, pp. 58-60. The geologic significance of the growth rate of the Floridan and Bahaman shoal-water corals. Washington Acad. Sci. Jour., vol. 5, pp. 591-600. Geological investigations in the Bahamas and southern Florida. Carnegie Inst. Washington, Yearbook, vol. 13 for 1914, pp. 227-233. 1915-18. Study of the stratigraphic geology and of the fossil corals and 1916a. 1916b. 1917a. 1918a. 1919a. 1919b. 1920a. 1920b. 1921. 1922. associated organisms in several of the smaller West Indian is- lands. Carnegie Inst. Washington, Yearbook, vol. 13 for 1914 (1915), pp. 358-369; vol. 14 for 1915 (1916), pp. 368-373; vol. 15 for 1916 (1917), p. 359; vol. 16 for 1917 (1918), p. 319. The corals and coral reefs of the Gulf of Mexico and the Carib- bean Sea. Science, n. s., vol. 43, pp. 250-251. Some littoral and sublittoral physiographic features of the Virgin and northern Leeward Islands and their bearing on the coral reef problem. Washington Acad. Sci., Jour., vol. 6, pp. 53-66. Chemical and organic deposits of the sea. Geol. Soc. Amer., Bull., vol. 28, pp. 935-944, pls. 47-48. Correlation of the Tertiary geologic formations of the southeastern United States, Central America, and the West Indies. Washing- ton Acad. Sci., Jour., vol. 8, pp. 268-276. Corals and formation of coral reefs. Smithsonian Inst. Washing- ton, An. Rept. for 1917, pp. 189-276, 37 pls. Fossil corals from Central America, Cuba, and Porto Rico, with an account of the American Tertiary, Pleistocene and Recent coral reefs. U. S. Nat. Mus., Bull., vol. 103, pp. 189-524, pls. 68-153. Study of the stratigraphic geology and of the fossil corals and as- sociated organisms in several of the smaller West Indian islands. Carnegie Inst. Washington, Yearbook, vol. 18 for 1919, pp. 345-346. Stratigraphy of the Virgin Islands of the U. 8. and Culebra and Vieques Island, Geol. Soc. Amer., Bull., vol. 31, pp. 216-217. Correlation of the Tertiary formations of Central America and the West Indies. First Pan-Pacific Sci. Conf., Proc., pp. 819-844. Stratigraphic significance of the species of West Indian fossil Echini. Carnegie Inst. Washington, Publ. No. 306, pp. 107-122. 484 BuLieTiIn 204 1923a. On the relative value of species of smaller Foraminifera for the recognition of stratigraphic zones. Amer. Assoc. Petrol. Geol., Bull., vol. 7, pp. 517-531. 1925a. Recent progress in the study of the tectonic features of the West Indies and Central America. Pan-Pacific Sci. Congress, Proc. for 1923, vol. 1, pp. 735-741. 1925b. Recent additions to knowledge of the correlation of the Tertiary geologic formations of northeast Mexico, Central America, the West Indies, northern South America, and Lower California, Pan- Pacific Sci. Congress, Proc. for 1923, vol. 1, pp. 864-870. 1925¢c. Coral reefs and submerged platforms. Second Pan-Pacific Sci. Congress, Proc., vol. 2, pp. 1128-1134. 1926. Notes on the igneous rocks of the northeast West Indies and of the geology of the island of Anguilla. Washington Acad. Sci., Jour., vol. 16, pp. 345-358. Vaughan, T. Wayland, and Hofmeister, John Edward 1925. New species of fossil corals from the Dominican Republic. Mus. Comp. Zool., Bull., vol. 67, pp. 315-326, 4 pls. 1926. Miocene corals from Briidad: Carnegie Inst. Washington, Publ. No. 344, pp. 105-134, 5 pls. Vayssiére, A 1917. Recherches zoologiques et anatomiques sur les mollusques amphin- eures et gastéropodes (opisthobranches et prosobranches). Deuxi- éme Expéd. Antarctique Francaise (1908-10), pp. 1-50, pls. 1-4. Vélain, Charles 1876. Sur la faune malacologique des ile Saint-Paul et Amsterdam. Acad. Sci. Paris, Comptes Rendus, vol. 83, pp. 284-287. 1877a. Observations générales sur la faune des deux iles suivies d’une description des mollusques. Arch. Zool. Expér. Gén., vol. 6, pp. 1- 144, pls. 1-5, figs. 1-9. 1877b. Expédition francaise aux iles Saint-Paul et Amsterdam. Zoologie. Description des mollusques. Arch. Zool. Expér. Gén., vol. 6, pp. 96- 144, 4 pls. Verany, J. B. 1846. Catalago degli animali invertebrati marini del golfo di Genova e Nizza. Genova, 30 pp., 3 pls. Verastegui, Pedro 1953. The pelecypod genus Venericardia in the Paleocene and Eocene of western North America. Palaeontographica Americana, vol. 3, No. 25, pp. 395-506, pls. 40-61, charts 1-3. Verkriizen, T. A. 1877. Mollusca dredged and collected by T. A. Verkriizen in 1876, in the neighborhood of St. John’s, Newfoundland, including a few species obtained from the Bay of Fundy. St. John’s, N. F., 10 pp. 1881. Bericht iiber meinen Besuch der grossen Bank von Neufundland in eet eitay 1880. Deutsch. Malakozool. Gesell., Jahrb., vol. 8, pp. 2-20, pls. 3-4 Vermunt, L. W. J., and Rutten, M. G. 193la. Geology of central Curacao. Konink. Akad. Wetensch. Amsterdam, Proc., vol. 34, pp. 271-276. 1931b. Geology of the surroundings of “St. Martha” and “St. Kruis,” cepa: Konink. Akad. Wetensch. Amsterdam, Proc., vol. 34, pp. 558-563. 1931c. Some remarks on the geology of N. Curacao. Konink. Akad. Weten- sch. Amsterdam, Proc., vol. 34, pp. 1028-1031. r VENEZUELAN CENOozoIC PELECYPODS: WEISBORD 485 Verrill, Addison E. 1873a. Results of recent dredging expeditions on the coast of New Eng- land, Amer. Jour. Sci., ser. 3, vol. 5, pp. 1-16, 98-106. 1873b. Report upon the invertebrate animals of Vineyard Sound and the adjacent waters with an account of the physical characters of the region. Rept. U. S. Fish Com., vol. 1, pp. 295-778, 38 pls., 1 map. 1878a. Notice of recent additions to the marine faunas of the eatern coast of North America, Amer. Jour. Sci., ser. 3, vol. 16, pp. 207-215. 1878b. Notice of recent additions to the marine fauna of the eastern coast of North America. No. 2, Amer. Jour. Sci., ser. 3, vol. 16, pp. 371-378. 1879a. Notice of recent additions to the marine fauna of the eastern coast of North America. No. 3. Amer. Jour. Sci. ser. 3, vol. 17, pp. 239-243. 1879b. Notice of recent additions to the marine fauna of the eastern coast of North America. No. 7. Amer. Jour. Sci., ser. 3, vol. 18, 18, pp. 468-470. 1880a. Notice of recent additions to the marine fauna of the eastern coast of North America. Pts. 2-3. U. S. Nat. Mus., Proc., vol. 3, pp. 356-409. 1880b. Notice of recent additions to the marine fauna of the eastern coast of North America. No. 8. Amer. Jour. Sci., ser. 3, vol. 19, pp. 137-140. 1880c. Notice of the remarkable marine fauna occupying the outer banks off the southern coast of New England, Amer. Jour. Sci., ser. 3, vol. 20, pp. 390-403. 1882a. Notice of recent additions to the marine fauna of the eastern coast of North America. Pt. 4. Additions to the deep-water Mollusca, taken off Martha’s Vineyard, in 1880 and 1881, U. S. Nat. Mus., Proc., vol. 5, pp. 315-343. 1882b. Notice of the remarkable fauna occupying the outer banks off the southern coast of New England, No. 7, and of some additions to the fauna of Vineyard Sound. Amer. Jour. Sci., ser. 3, vol. 24, pp. 360-371. Verrill, Addison E., and Smith, S. I. 1873. Report upon the invertebrate animals of Vineyard Sound and the adjacent waters, with an account of the physical characters of the region. U. S. Fish Com., Rept. for 1871-1872, pt. 1, pp. 295-778. Vignon, P. 1931. Les dents du labre et les raports qu’elles nouent avec les sillons, les cordons et les varices chez les gastéropodes. Jour. Conchyl., vol. 75, pp. 242-267, pls. 1-2. Vinson, G. L. 1962. Upper Cretaceous and Tertiary stratigraphy of Guatemala, Amer. Assoc. Petrol. Geol., Bull., vol. 46, No. 4, pp. 425-456, 14 figs. Vokes, Harold Ernest 1941. Geological observations in the Lebanon Mountains of western Asia. Geol. Soc. Amer., Bull., vol. 52, pp. 1715-1732, 3 figs. 1944. The validity of the molluscan genus Caestocorbula Vincent. Amer. Jour. Sci.. No. 242, pp. 614-623, pl. 1. 1945. Protodonax, a new Cretaceous molluscan genus. Jour. Paleont., vol. 19, No. 3, pp. 295-308, pls. 46-47. 1956. Notes on, and rectifications of, pelecypod nomenclature. Jour. Paleont., vol. 30, No. 3, pp. 762-765. 1957a. Geography and geology of Maryland. Indiana Dept. Geol., Bull., vol. 19, xiv + 243 pp., 28 pls., figs. 1957b. Miocene fossils of Maryland, Indiana Dept. Geol., Bull., vol. 20, vii + 85 pp., 31 pls. 1957c. Miocene fossils of Maryland. Maryland Dept. Geol. Mines, and Water Resources, Bull., vol. 20, 85 pp., 30 pls. 486 BuLueTIn 204 Vredenburg, E. W. 1925. Description of Mollusca from the post-Eocene Tertiary formation of northwestern India. Cephalopoda, Opisthobranchiata, Siphono- stomata. Geol. Sur. India, Mem., vol. 50, pp. 1-350, pls. 1-13. 1928. Descriptions of Mollusca from the post-Eocene Tertiary formation of northwestern India. Gastropoda (in part) and Lamellibranchi- ata, Geol. Sur. India, Mem., vol. 50, pt. 2, pp. i-xiii, 351-462. Warmke, Germaine, and Abbott, R. Tucker 1953. The gross anatomy and occurrence in Puerto Rico of the pelecypod Yoldia perprotracta. Washington Acad. Sci., Jour., vol. 43, No. 8, pp. 260-261, figs. 1-2. 1961. Caribbean Seashells. Livingston Publishing Co., Narberth, Pa., i-x + 346 pp., 44 pls., 19 distrib. maps. Watson, Robert Boog 1879. Mollusca of the “Challenger’ Expedition, pts. 2-4. Linnean Soc. London, Jour., vol. 14, pp. 508-529, 586-605. 1881. Mollusca of H.M.S. ‘Challenger’ Expedition, pt. 7. Linnean Soc. London, Jour., vol. 15, pp. 245-274. 1883. Mollusca of H.M.S. ‘Challenger Expedition, pt. 6. Linnean Soc. London, Jour., vol. 17, pp. 26-40, 1 fig. 1886. Report on the Scaphopoda and Gasteropoda collected by H.MS. Challenger during the years 1873-76. Voyage of H.M.S. Challenger, Zoology, vol. 15, pp. 1-675; appendix, pp. 676-680; geographical distribution, pp. 691-722; index, pp. 723-756; pls. 1-50. Weaver, Charles Edward 1949. Geology of the coast ranges immediately north of the San Fran- cisco Bay region, California. Geol. Soc. Amer., Mem. 35, ix + 242 pp, 10 pls. Weber, Maurice 1915. seg sl des hirudinées Sud-Americains. Neuchatel, 134 pp., 6 pls. Weinkauff, H. C., and Kobelt, Wilhelm 1875-87. Die Familie Pleurotomidae. Syst. Conchylien-Cabinet, vol. 4, pt. 3, pp. 1-248, pls. A, 1-42. Weisbord, Norman E. 1962. Late Cenozoic gastropods from northern Venezuela. Bull. Amer. Paleont., vol. 42, No. 193, 672 pp., 48 pls., 2 text figs. Wells, Harry W. and Mary Jane 1961. Three species of Odostomia from North Carolina, with description of a new species. Nautilus, vol. 74, No. 4, pp. 159-157, figs. 1-7. Wells, John W. d 1960. A Pleistocene marine mollusk in central New York. Nautilus, vol. 74, No. 1, pp. 26-28. Wenz, W. 1938-60. Handbuch der Paldozoologie Gastropoda. Allgemeiner Teil und Prosobranchia, vol. 6, pt. 1, viii + 240 pp., 471 pp. (1938); pt. 2, Prosobranchia, pp. 241-480, figs. 472-1235 (1938); pt. 3, Pro- sobranchia, pp. 481-720, figs. 1236-2083 (1939); Pt. 4, Proso- branchia, pp. 271-960, figs. 2084-2787 (1940); pt. 5, Prosobran- chia, pp. 961-1200, figs. 2788-3416 (1941); pt. 6, pp. 1201-1506, figs. 3417-4211 (1943); pt. 7, Prosobranchia, xii+ pp. 1507- 1639 (1944); vol. 6, pt. 2, Euthyneura, xii + 600 pp., figs. 1- 211 (1959); pp. 601-834, figs. 212-824 (1960). Weyl, B. 1953. Geologische streifziige durch Westindien und Mittelamerika. Frankfurt, 96 pp., 96 figs. 1957. Contribucién a la geologia de la Cordillera de Talamanca de Costa Rica (Centro América). Inst. Geogr., ii + 77 pp., 15 figs. 2 photos. VENEZUELAN CENOZzOIC PELECYPoDS: WEISBORD 487 Wheat, S. C. 1913. A Long Island Acmaea, and a new variety of Urosalpinx cinerea. Brooklyn Inst. Arts and Sci., Bull., vol. 2, pp. 17-20, pl. 1. White, Charles A. 1882-83. d review of the fossil Ostreidae of North America. U. S. Geol. Sur., Ann. Rept. for 1882-83, pp. 273-333. White, F. A. 1896. Some notes on Florida Mollusca. Nautilus, vol. 10, p. 40. Whiteaves, Joseph Frederick 1872. Notes on a deep-sea dredging expedition around the island of Anticosti, in the Gulf of St. Lawrence. Ann. Mag. Nat. Hist., vol. 4, No. 10, pp. 341-354. 1893. Notes on some marine Invertebrata from the coast of British Columbia. Ottawa Naturalist, vol. 7, pp. 133-137, 1 pl. 1901. Catalogue of the marine Invertebrata of Eastern Canada. Geol. Survey Canada, 272 pp. Wiedenmayer, C. 1938. Comparison of Maturin and Maracaibo sedimentary basins, Vene- zuela, Bol. Geol. Min., vol. 1, Nos. 2-4, pp. 209-235. Wiedey, L. W. 1928. Notes on the Vaqueros and Temblor formations of the California Miocene, with descriptions of new species. San Diego Soc. Nat. Hist., Trans., vol. 5, pp. 95-182, pls. 9-21. 1929. Some previously unpublished figures of type mollusks from Calif- ornia. Nautilus, vol. 43, No. 1, pp. 21-26, pl. 1. Wilbur, Karl M. 1960. Shell structure and mineralization in molluscs. Amer. Assoc. Adv. Sci., Publ. No. 64, pp. 15-40. Wilkens, Guy L. 1954. The Cracherode shell collection. British Mus. (Nat. Hist.) His- torical Series, Bull., vol. 1, No. 4, pp. 123-184, pls. 23-25, figs. 1-5. Willet, George 1931. Three new marine mollusks from Catalina Island, California. Nau- tilus, vol. 45, pp. 65-678, pl. 4. 1946a. Additional notes on the Pliocene molluscan fauna of Los Angeles City. Southern California Acad. Sci., Bull., vol. 45, pt. 1, pp. 28-32. 1946b. A new mollusk of the genus Solariella from Alaska. Southern California Acad. Sci., Bull., vol. 45, pt. 1, pp. 32-33, pl. 7. 1948. Four new gastropods from the upper Pleistocene of Newport Bay Mesa, Orange County, California. Southern California Acad. Sci., Bull., vol. 47, pt. 1, pp. 17-21, pl. 4. Willis, T. R. 1861. Catalogue of the marine shells of Nova Scotia. Boston Soc. Nat. Hist., Proc., vol. 8, pp. 61-62. Wilson, J. Howard 1905. The Pleistocene formations of Sankaty Head, Nantucket. Jour. Geol., vol. 13, No. 8, pp. 713-734, figs. 1-11. Winckworth, R. 1929a. Notes on nomenclature, pt. 3. The genotypes selected by Fleming in 1818 and 1822. Malac. Soc. London, Proc., vol. 18, pp. 224-228. 1929b. Marine Mollusca from South India and Ceylon. III. Pinna. With an index to the Recent species. Malac. Soc. London, Proc., vol. 18, pp. 276-297. 1930a. Notes on nomenclature. 5. Some new names for British marine bi- valves, Malac. Soc. London, Proc., vol. 19, pp. 14-16. 488 ButueTin 204 1930b. Notes on nomenclature. 6. Lima and allied genera. Malac. Soc. London, Proc., vol. 19, pt. 3, pp. 115-116. 1932. The British marine Mollusca. Jour. Conch., vol. 19, pp. 211-252. 1934. Names of British Mollusca—llI. Jour. Conch., vol. 20, pp. 9-15, 51-53. 1936. Marine Mollusca from South India and Ceylon. X. Further notes on Pinna. Malac. Soc. London, Proc., vol. 22, pp. 20-23. Winkley, H. W. 1908. A new Caecum. Nautilus, vol. 22, p. 54. 1909. New England Pyramidellidae with description of a new species. Nautilus, vol. 23, pp. 39-40, 1 fig. Wolf, Teodoro 1892. Geografia y Geologia del Ecuador, publicada por orden del su- premo gobierno de la Repiblica. Leipzig, 671 pp. Wood, Searles V. 1848-56. 4 monograph of the Crag Mollusca, or descriptions of shells from the middle and upper Tertiaries of the east of England. Pt. 1, Univalves; pts. 2-4, Bivalves. Palaeontographical Soc., pt. 1, vol. 1, xii + 208 pp., 21 pls. (1848); pt. 2, vol. 4, 150 pp., 12 pls. (1850) ; pt. 3, vol. 7, pp. 151-216, pls. 13-20 (1853); pt. 4, pp. 217-341, pls. 21-31 (1856). Wood, Willard M., and Raymond, William T. 1891. Mollusks of San Francisco County. Nautilus, vol. 5, No. 5, pp. 54-58. Woodring, Wendell P. 1958a. Geology of Barro Colorado Island, Canal Zone. Smithsonian Misc. Collections, vol. 135, No. 3, publ. 4304, 39 pp., 3 pls. Woodring, Wendell P., and Malavassi V., Enrique 1961. Miocene Foraminifera, mollusks, and a barnacle from the Valle Central, Costa Rica. Jour. Paleont., vol. 35, No. 3, pp. 489-497, pls. 69-70, 1 text fig. Woolman, Lewis S. 1898. Fossil mollusks and diatoms from the Dismal Swamp, Virginia and North Carolina; indication of the geological age of the deposit. With notes on the diatoms, by Charles §. Boyer. Acad. Nat. Sci. Philadelphia, Proc., vol. 50, pp. 414-428. Wurtz, Charles B. 1950. Quadrula (Quincuncina) guadalupensis sp. nov. (Unionidae: Pele- cypoda). Acad. Nat. Sci. Philadelphia, Notulae Naturae, No. 224, pp. 1-3, figs. 1-5. Yen, T.-C. 1942. A review of Chinese gastropods in the British Museum, Malac. Soc. London, Proc., vol. 24, pp. 170-289, pls. 11-28. Zetek, James, and McLean, Richard Alfred be 1936. Hiata, a new genus of the family Pholadidae, from the Pacific at Panama, with a description of a new species. Nautilus, vol. 49, No. 4, pp. 110-111. PLATES 490 Figure 1-6. 7-10. 11-17. BuLLETIN 204 Explanation of Plate 1 Page Nucula (Nucula) venezuelana Weisbord, n. Sp. ...............ccceeeeeeeee Figs. 1, 2, holotype (G479a). 26465 PRI. Exterior and interior of left valve. Length 2.7 mm.; height 2.1 mm., thickness 0.75 mm. Upper Mare formation. Figs. 2-4, paratype (G479b). 26466 PRI. Exterior and interior of young left valve. Length 2.1 mm.; height 2 mm.; thickness 0.6 mm. Upper Mare formation. Figs. 5, 6, paratype (G479c). 26467 PRI. Exterior and interior of right valve. Length 1.8 mm.; height 1.6 mm.; thickness 0.6 mm. Upper Mare formation. Nucula (Ennucula) mareana Weisbord, Nn. Sp. ...............0cc000eeeee Figs. 7, 8, holotype (G478a). 26468 PRI. Exterior and interior of left valve. Length 4.4 mm.; height 3.3 mm.; thickness 0.9 mm. Upper Mare formation. Figs. 9, 10, paratype (G478b). 26469 PRI. Exterior and interior of right valve. Length 4 mm.; height 3.1 mm.; thickness 0.75 mm. Upper Mare formation. Nuculana (Saccella) karIlmartini Weisbord, n. sp. ...................... Fig. 11, holotype (1473a). 26470 PRI. Attachhed valves. Length 12.2 mm.; height 6.8 mm.; thickness 5 mm. Lower Mare for- mation. Figs. 12, 13, paratype (1473b). 26471 PRI. Interior and exterior of right valve. Length 10.2 mm.; height 5.5 mm.; thickness 2.1 mm. Lower Mare formation. Figs. 14, 15, paratype (1473c). 26472 PRI. Interior and exterior of left valve. Length 11.4 mm.; height 6.8 mm.; thickness 2 mm. Lower Mare formation. Figs. 16, 17, paratype (G473c). 26473 PRI. Exterior and interior of young left valve. Length 4.1 mm.; height 2.6 mm.; thickness 0.8 mm. Upper Mare formation. 36 39 41 BuLL. AMER. PALEONT., VOL. 45 PLATE 1 >>, BULL. AMER. PALEONT., VOL. 45 PLATE 2 Figure 1-4. 5-10. 112 13. 14,15. 16,17. 18,19. VENEZUELAN CENOZzOIC PELECYPODS: WEISBORD Explanation of Plate 2 49] Page Nuculana (Saccella) karlmartini Weisbord, n. sp. .................... Figs. 1, 2, paratype (G473d). 26474 PRI. Exterior and interior of left valve. Length 8.8 mm.; height 4.9 mm.; thickness 2 mm. Upper Mare formation. Figs. 3, 4, paratype (G473e). 26475 PRI. Exterior and interior of right valve. Length 9.5 mm.; height 5.1 mm.; thickness 2 mm. Upper Mare formation. Nuculana (Saccella) axelolssoni Weisbord, N. SDP. ...............0 Figs. 5, 6, holotype (G474a). 26476 PRI. Exterior and interior of left valve. Length 6.3 mm.; height 3.5 mm.; thickness 0.8 mm. Upper Mare formation. Figs. 7, 8, paratype (G474b). 26477 PRI. Exterior and interior of young right valve. Length 4.5 mm.; height 2.4 mm.; thickness 0.8 mm. Upper Mare forma- tion. Figs. 9, 10, paratype (G474c). 26478 PRI. Exterior and interior of juvenile left valve. Length 2.4 mm.; height 1.3 mm.; thickness 0.3 mm. Upper Mare formation. Nuculana (Saccella) marella Weisbord, Nn. sp. ..................0005. Holotype (F475a). 26479 PRI. Exterior and interior of juvenile right valve. Length of broken specimen 1.3 mm.; width 0.9 mm. Upper Mare formation. Nuculana (Saccella) SDCCIES ......:......6..c...ccecccccsseeseseseeretessceeeeneeesecenes Specimen 0476a. 26480 PRI. Internal mold of left valve. Length 4.5 mm.; height 2.9 mm. Playa Grande formation (Catia mem- ber). Adrana Cf. tellinoides (SOWeLrDY) ..................0cccccccceesscceeeeeeeensntscceeee Specimen T544a. 26481 PRI. Exterior and interior of broken right valve. Length 9.5 mm.; height 2.7 mm. Upper Mare formation. Arca’ (Area) zebra: SwWailson 3.2.0 5..520.266- 55.005 eecaensseeeeeeeeteos: Specimen A369aa. 26482 PRI. Interior and exterior of right valve. Length 50 mm.; height 20.3 mm.; thickness 12.2 mm. Recent. Arca (Arca) zebra abisiniana Weisbord, n. subsp. ...............0...... Holotype (D368a). 26483 PRI. Interior and exterior of right valve. 41 45 45 47 54 Length 61 mm.; height 34 mm.; thickness 20.5 mm. Abisinia forma- tion. £3 = 492 Figure 1-8. 9-14. 15,16. Bu.ueTin 204 Explanation of Plate 3 Arca (Arca) imbricata Bruguiére .....000..000000000..c0ccccecccsssccssceseceeeees Figs. 1, 2, specimen A369a. 26484 PRI. Exterior and interior of right valve. Length 50 mm.; height 24.5 mm.; thickness 16 mm. Recent. Figs. 3, 4, specimen A371a. 26485 PRI. Exterior and interior of left valve. Length 37.8 mm.; height 32.3 mm.; thickness 19.8 mm. Recent. Figs. 5, 6, specimen C369a. 26486 PRI. Exterior and interior of right valve. Length 66.6 mm.; height 33.6 mm.; thick- ness 18 mm. Guaiguaza clay. Figs. 7, 8, specimen D371la. 26487 PRI. Exterior and interior of left valve. Length 40 mm.; height 29 mm.; thickness 18.8 mm. Abisinia formation. Barbatia (Barbatia) candida (Helbling) .........00.0.0.0000ccceeeee Figs. 9, 10, specimen A391al. 26488 PRI. Young right valve of pair, exterior and interior views. Length 13.4 mm.; height 7.2 mm. Recent. Figs. 11, 12, specimen A391a2. 26489 PRI. Young left valve of same pair as above, exterior and interior views. Length 13.4 mm.; height 7.2 mm.; thickness of both valves attached 5.6 mm. Recent. Figs. 13, 14, specimen A388a. 26490 PRI. Ex- terior and interior of left valve. Length 29 mm.; height 19.5 mm.; thickness 8 mm. Recent. Barbatia (Barbatia) candida (Helbling) ? ............0000 es Specimen D381la. 26491 PRI. Exterior and interior of right valve. Length 31 mm.; height (base broken away) 17.9 mm.; thick- ness 9.6 mm. Abisinia formation. 58 58 BULL. AMER. PALEONT., VOL. 45 PLATE 3 BULL. AMER. PALEONT., VOL. 45 PLATE 4 "i BY Pat ANN a PA noe ee Figure 1-9. 10-13. 14-17. VENEZUELAN CENOzOIC PELECYPODS: WEISBORD 493 Explanation of Plate 4 Page Barbatia (Acar) dominguensis (Lamarck) .................0...00..000.0005 61 Figs. 1, 2, specimen A385a. 26492 PRI. Exterior and interior of right valve. Length 13.5 mm.; height 10.3 mm.; thickness 5.7 mm. Recent. Figs. 3, 4, specimen A385b. 26493 PRI. Exterior and inter- ior of left valve. Length 20 mm.; height 12 mm.; thickness 5.8 mm. Recent. Fig. 5, specimen A385c. 26494 PRI. Exterior of attached valves. Length 12 mm.; height 9 mm.; thickness of paired valves 7.4 mm. Recent. Figs. 6, 7, specimen D385a. 26495 PRI. Exterior and interior of right valve. Length 12 mm.; height 6 mm.; thickness 3.4 mm. Abisinia formation. Figs. 8, 9, specimen D385b. 26496 PRI. Exterior and interior of left valve. Length 12.9 mm.; height 7.5 mm.; thickness 4.1 mm. Abisinia formation. Barbatia (Fugleria) tenera C. B. Adams ........0...0 ee Figs. 10, 11, specimen A389al. 26497 PRI. Exterior and interior of right valve of pair. Length 19 mm.; height 13 mm.; thickness of paired valves 9.5 mm. Recent. Figs. 12, 13, specimen A389a2. 26498 PRI. Exterior and interior of left valve of same pair as above. Recent. Arcopsis adamsi “Shuttleworth” (E. A. Smith) .....0..000000000000...... Figs. 14, 15, specimen A386al. 26499 PRI. Exterior and interior of right valve of pair. Length 11.6 mm.; height 11.6 mm.; thick- ness of paired valves 6.7 mm. Recent. Figs. 16, 17, specimen A386a2. 26500 PRI. Exterior and interior of left valve of same pair as above. Recent. 64 65 i] oO — we » ——— ~ags 494 Figure 1-6. 7-10. 11,12. 13-16. BuLLeTin 204 Explanation of Plate 5 Arcopsis adamsi “Shuttleworth” (E. A. Smith) ...........000000..... Figs. 1, 2, specimen C386a. 26501 PRI. Exterior and interior of right valve. Length 9.7 mm.; height 6.2 mm.; thickness 3 mm. Guaiguaza clay. Figs. 3, 4, specimen C386b. 26502 PRI. Exterior and interior of right valve. Length 10.1 mm.; height 6.8 mm.; thickness 3.5 mm. Guaiguaza clay. Figs. 5, 6, specimen C396a. 26503 PRI. Exterior and interior of right valve of juvenile. Length 2.4 mm.; height 1.5 mm. Guaiguaza clay. Anadara (Larkinia) notabilis (R6ding) ...000000....0 ee. Figs. 7, 8, specimen A382a. 26504 PRI. Exterior and interior of right valve. Length 30 mm.; height 22.3 mm.; thickness 9.5 mm. Recent. Figs. 9, 10, specimen $382a. 26505 PRI. Exterior and in- terior of left valve. Length 40 mm.; height 28.2 mm.; thickness 13.5 mm. Playa Grande formation (Maiquetia member). Anadara (Larkinia): species: ))0.0.0-4..0) eee Specimen M367a. 26506 PRI. Internal mold of attached valves. Length 67 mm.; height 42 mm.; thickness 38 mm. Fig. 11, view of right valve and beak of left valve. Fig. 12, view of left valve of pair. Playa Grande formation (Catia member). Anadara (Lunarca) ovalis (Bruguiére) ......000.00.0..0...0ccceccee Figs. 13, 14, specimen A372a. 26507 PRI. Exterior and interior of right valve. Length 35 mm.; height 27 mm.; thickness 12 mm. Recent. Figs. 15, 16, specimen A372b. 26508 PRI. Exterior and interior of left valve. Length 32.5 mm.; height 25 mm.; thick- ness 10 mm. Recent. 69 72 72 BULL. AMER. PALEONT., VOL. 45 PLATE 5 oe PREETI IAG t TELE \ BULL. AMER. PALEONT., VOL. 45 PLATE 6 Figure 1-4. 9-12. 13-16. VENEZUELAN CENOZOIC PELECYPODS: WEISBORD Explanation of Plate 6 Anadara (Lunarca) ovalis (Bruguiére) .................00.ccccccccecsseeeeees Figs. 1, 2, specimen T384a. 36509 PRI. Exterior and interior of right valve. Length 39 mm.; height 27 mm.; thickness 11 mm. Upper Mare formation. Figs. 3, 4, specimen T384b. 26510 PRI. Exterior and interior of left valve. Length 33 mm.; height 20.5 mm.; thickness 10 mm. Upper Mare formation. Anadara (Lunarca ?) caboblanquensis Weisbord, n. sp. ............ Figs. 5, 6, holotype (Q394a. 26511 PRI. Exterior and interior of left valve. Length 2.1 mm.; height 1.8 mm.; thickness 0.8 mm. Playa Grande formation (Maiquetia member). Figs. 7, 8, para- type (T394a). 26512 PRI. Exterior and interior of left valve. Length 1.8 mm.; height 1.5 mm.; thickness 0.5 mm. Upper Mare formation. Anadara (Lunarca ?) mareana Weisbord, Nn. Sp. ...............0...0... Figs. 9, 10, holotype (J393a). 26513 PRI. Exterior and interior of right valve. Length 3.6 mm.; height 3 mm.; thickness 1.5 mm. Lower Mare formation. Figs. 11, 12, paratype (J393b). 26514 PRI. Exterior and interior of left valve. Length 3.7 mm.; height 3.4 mm.; thickness 1.3 mm. Lower Mare formation. Anadara (Cunearca) brasiliana (Lamarck) .........00...00...0...cee Figs. 13, 14, specimen A373a. 26515 PRI. Exterior and interior of right valve. Length 35 mm.; height 29 mm.; thickness 12.2 mm. Recent. Figs. 15, 16, specimen A373b. 26516 PRI. Exterior and interior of left valve. Length 39 mm.; height 32 mm.; thickness 14 mm. Recent. 495 We 78 79 496 Figure 1-6. 7,8. 9-12. 13,14. BuLietTin 204 Explanation of Plate 7 Anadara (Cunearca) cumanensis (Dall) ......0000.0......0ccccceeceeeeseeeee Figs. 1, 2, specimen R374a. 26517 PRI. Exterior and interior of right valve. Length 28.5 mm.; height 27.5 mm.; thickness 12.4 mm. Playa Grande formation (Maiquetia member). Figs. 3, 4, specimen R374b. 26518 PRI. Exterior and interior of left valve. Length 27.5 mm.; height 26 mm.; thickness 11.3 mm. Playa Grande formation (Maiquetia member). Figs. 5, 6, specimen 1377a. 26519 PRI. Exterior and interior of right valve. Length 35.6 mm.; height 37.6 mm.; thickness 18 mm. Lower Mare formation. Anadara (Cunearca) species indeterminate ...................c0ccee Specimen M370a. 26520 PRI. Internal mold of left valve. Length 25.5 mm.; height 25 mm.; thickness 10.5 mm. Playa Grande for- mation (Catia member). Glycymeris (Glycymeris) undata (Linnaeus) ..............0...00...000.... Figs. 9, 10, specimen J482a. 26521 PRI. Exterior and interior of right ? valve. Length 6.5 mm.; height 6.3 mm.; thickness 2 mm. Lower Mare formation. Figs. 11, 12, specimen S484a. 26522 PRI. Exterior and interior of right valve. Length 10.8 mm.; height 10.6 mm.; thickness 3.5 mm. Playa Grande formation (Maiquetia member). Glycymeris (Tucetona) pectinata (Gmelin) .............0...0.... Specimen G48la. 26523 PRI. Exterior and interior of left valve. Length 24.6 mm.; height 24.5 mm.; thickness 6.1 mm. Mare for- mation. 86 86 89 PLATE 7 BULL. AMER. PALEONT., VOL. 45 BULL. AMER. PALEONT., VOL. 45 PLATE 8 Figure 1-4, 11-14, VENEZUELAN CENozoIc PELECYPopDs: WEISBORD 497 Explanation of Plate 8 Page Glycymeris (Tucetona) pectinata (Gmelin) 22000000000... 89 Figs. 1, 2, specimen G481b. 26524 PRI. Exterior and interior of right ? valve. Length 16 mm.; height 16 mm.; thickness 4.2 mm. Mare formation. Figs. 3, 4, specimen G481c. 26525 PRI. Exterior and interior of young left ? valve. Length 7.2 mm.; height 7 mm.; thickness 3 mm. Mare formation. Glycymeris (Glycymerella) decussata (Linnaeus) .................... Figs. 5, 6, specimen A480a. 26526 PRI. Exterior and interior of right valve. Length 19.5 mm.; height 17 mm.; thickness 5.2 mm. Recent. Figs. 7, 8, specimen 1480a. 26527 PRI. Exterior and interior of left valve. Length 34 mm.; height 30 mm.; thickness 16 mm. Lower Mare formation. Figs. 9, 10, specimen 1480c. 26528 PRI. Exterior and interior of right valve. Length 18 mm.; height 16.8 mm.; thickness 5.4 mm. Lower Mare formation. Brachidontes (Ischadium) recurvus (Rafinesque) ...................... Specimen A556a1-2. 26529 PRI. Paired valves. Length 9.7 mm.; width 6 mm.; thickness of doublet 5.1 mm. Figs. 11, 12, exterior and interior of right valve. Figs. 13, 14, exterior and interior of left valve. Recent. 92 95 UL ‘4 > te xX 498 Figure WZ. 3-6. 13,14. BuLueTin 204 Explanation of Plate 9 Glycymeris (Glycymerella) decussata (Linnaeus) ...................... 92 Specimen J480a. 26530 PRI. Exterior and interior of large right valve. Length 58 mm.; height 57.8 mm.; thickness 21 mm. Lower Mare formation. Modiolus americanus Geach |) ti)... sect ee 98 Specimen A555a1-2. 26531 PRI. Paired valves. Length 41 mm.; width 21 mm.; thickness of doublet 18 mm. Figs. 3, 4, exterior and interior of right valve. Figs. 5, 6, exterior and interior of left valve. Recent. Musculus lateralis: (Sav) reece ree eee 100 Specimen 1514a. 26532 PRI. Exterior and interior of left valve. Length 2.1 mm.; height 1.5 mm. Lower Mare formation. Crenella divaricata (d’Orbigny) 0.0.0.0... sacle cee 102 Figs. 9, 10, specimen R487a. 26533 PRI. Exterior and interior of right valve. Length 3.1 mm.; width 2.7 mm.; thickness 0.75 mm. Playa Grande formation (Maiquetia member). Figs. 11, 12, specimen R487b. 26534 PRI. Exterior and interior of left valve. Length 2.9 mm.; width 2.4 mm.; thickness 0.7 mm. Playa Grande formation (Maiquetia member). Lioberus ? marensis WeiSbord, N. SDP. ..................ccccceeccceceesseeeeseees 105 Holotype (I511a). 26535 PRI. Interior and exterior of broken left valve. Length (incomplete) 5 mm.; max. width 3 mm.; thickness 1.3 mm. Lower Mare formation. PLATE 9 BULL. AMER. PALEONT., VOL. 45 BULL. AMER. PALEONT., VOL. 45 PLATE 10 Figure 1,2. 6-9. 10-13. VENEZUELAN CENozoIc PELEcypops: WEISBORD 499 Explanation of Plate 10 Isognomon alatus (Gmelin) .2.......0.....eooooocococecceecccccccccccccseueeeceeeceeee. 106 Specimen B560a. 26536 PRI. Exterior and interior of left valve. Height 40 mm.; width 37.8 mm.; thickness 3 mm. Recent. Pinna: att) carneasGmMelin - 2 lee 107 Specimen G359a. 26537 PRI. External view of right valve of at- tached pair. Length (broken away at ends and sides) 145 mm. Mare formation. Atrina (Servatrina) seminuda (Lamarck) .......0000000..0..cccccccsees 109 Specimen B358a. 26538 PRI. External view of left valve of attached pair. Length (anterior tip broken away) 78.5 mm. Recent. Atrina (Servatrina ?) aff. seminuda (Lamarck) ...................... 110 Atrina (Servatrina) serrata ? Sowerby 220200000 oooccecccecececceees 111 Figs. 6, 7, specimen L361a. 26540 PRI. Attached valves, broken and with rock filling. Length 54.5 mm. Fig. 6, view of right valve. Fig. 7, view of left valve. Playa Grande formation (Catia mem- ber). Figs. 8, 9, specimen L361b. 26541 PRI. Anterior end of at- tached valves. Length 40.5 mm. Fig. 8, view of right valve. Fig. 9, view of left valve. Playa Grande formation (Catia member). Plicatula:gibbosa: Lamarck 2225... ..cs0cscsscsccncis..doscendccaeoen ee 113 Figs. 10, 11, specimen $433a. 26542 PRI. Exterior and interior of right valve. Height 31 mm.; width 27 mm.; thickness 13 mm. Playa Grande formation (Maiquetia member). Figs. 12, 13, speci- men 1T434a. 26543 PRI. Exterior and interior of left valve. Height 19.5 mm.; width 17.3 mm.; thickness 6 mm. Upper Mare formation. 500 BuLtetTin 204 . Explanation of Plate 11 Figure Page 1-4. Plicatula venezuelama Weisbord, n. SP. ...........0ccccccccccceecseeeeeeeeeeee 117 Figs. 1, 2, holotype (S432a). 26544 PRI. Exterior and interior of left valve. Height 16.7 mm.; width 20.3 mm.; thickness 2.6 mm. Playa Grande formation (Maiquetia member). Figs. 3, 4, para- type (R432a). 26545 PRI. Exterior and interior of immature right ? valve. Height 1.8 mm.; width 1.9 mm.; thickness 0.5 mm. Playa Grande formation (Maiquetia member). 5-8. Plicatula caribbeama Weisbord, n. SP. ..............0eceeecceeeceeeeeeeees 118 Holotype (H431a1-2). 26546 PRI. Figs. 5, 6 (H431al1), exterior and interior of right valve of pair. Height 8.2 mm.; width 7.7 mm.; thickness of paired valves 2.6 mm. Figs. 7, 8 (H431a2), exterior and interior of left valve of pair. Mare formation. 9-13. Pecten (Pecten) catianus Weisbord, n. Sp. «0.0.0.0... eee 119 Figs. 9, 10, holotype (K330a). 26547 PRI. Attached valves with rock filling. Height 36.2 mm.; width 36.9 mm. Fig. 9, external view of right valve. Fig. 10, external view of left valve. Playa Grande formation (Catia member). Figs. 11-13, paratype (K332a). 26548 PRI. Right valve. Height 23.3 mm.; width 33.6 mm.; thickness 7.6 mm. Figs. 11, 12, views of exterior. Fig. 13, view of interior. Playa Grande formation (Catia member). PLATE 11 BULL. AMER. PALEONT., VOL. 45 PLATE 12 BULL. AMER. PALEONT., VOL. 45 Vices f Pere DI hy! | oe ncaa Figure 7,8. 9,10. VENEZUELAN CENOzOIC PELECYPODS: WEISBORD 501 Explanation of Plate 12 Page Pecten (Pecten) caribeus Weisbord, n. sp. ooo... cece 121 Holotype (G344a). 26549 PRI. Exterior and interior of right valve. Height 43.8 mm.; width 47.9 mm.; thickness 16.5 mm. Mare formation. Pecten (Pecten) maiquetiensis Weisbord, n. sp. .....000.0.0c.. 124 Figs. 3, 4, holotype (T329a). 26550 PRI. Exterior and interior of left valve. Height 34.3 mm.; width 38.2 mm. Upper Mare forma- tion. Figs. 5, 6, paratype (J329a). 26551 PRI. Exterior and in- terior of left valve. Height 22.1 mm.; width 22.4 mm. Lower Mare formation. Pecian, (recten) SDECICS 5 .0o eis ees le 126 Fig. 7 (K330b). 26552 PRI. Exterior of broken left valve. Height 35 mm. Playa Grande formation (Catia member). Fig. 8 (0330a). 26553 PRI. Interior of broken left valve. Height 53 mm. Playa Grande formation (Catia member). Pecten (Pecten ?) remulus Weisbord, n. sp. ...0.000000.0cccccee. 127 Holotype (S345a). 26554 PRI. Exterior and interior of immature left valve. Height 8 mm.; width 8.3 mm. Playa Grande forma- tion (Maiquetia member). Figure 1-6. BuLieTIn 204 Explanation of Plate 13 Page Pecten (Euvola) ziczac caboblancoensis Druckerman, n. sp. .... 128 Fig. 1, topotype (U324a). 26555 PRI. External view of right valve. Height 67 mm.; width 60 mm.; thickness 25 mm. Playa Grande formation (Catia member). Figs. 2, 3, topotype (K324a). 26556 PRI. Exterior and interior of broken right valve. Height 38 mm.; thickness 12 mm. Playa Grande formation (Catia member). Figs. 4, 5, hypotype (1327a). 26557 PRI. Exterior and interior of small left valve. Height 26.2 mm.; width 26.2 mm. Lower Mare forma- tion. Fig. 6, hypotype (H327a). 26558 PRI. Exterior of left valve. Height 37.6 mm.; width 37.6 mm. Mare formation. Pecten (Amusium) papyraceus (Gabb) ..................0...ceeeeee 131 Figs. 7, 8, specimen L326b. 26559 PRI. Interior and exterior of left valve. Height 47 mm.; thickness 5 mm. Playa Grande formation (Catia member). Fig. 9, specimen L326a. 26560 PRI. Right valve of pair, with hinge of left valve showing behind. Height of right valve 69 mm.; width 77 mm.; thickness of paired valves 14 mm. Playa Grande formation (Catia member). See Pl. 14, fig. 1 for left valve of doublet. PLATE 13 BULL. AMER. PALEONT., VOL. 45 PLATE 14 BULL. AMER. PALEONT., VOL. 45 Figure 2,3. 8-11. VENEZUELAN CENOZOIC PELECYPODs: WEISBORD 503 Explanation of Plate 14 Pecten (Amusium) papyraceus (Gabb) 2000000 131 Specimen L326a. 26560 PRI. Exterior of left valve of pair. Height 71 mm.; width 76 mm. See Pl. 13, fig. 9 for right valve of same pair. Playa Grande formation (Catia member). Pecten (Amusium) marensis Weisbord, Nn. SP. .0..........00..cccceceeeees 136 Holotype (G326a). 26562 PRI. Exterior and interior of juvenile left valve. Height 19 mm.; width 18.1 mm.; thickness 0.8 mm. Mare formation. Chlamys (Chlamys) ornata (Lamarck) 200000000.0000..00ccccccceeeeeeecceeeeeee 137 Figs. 4, 5, specimen A325a. 26563 PRI. Exterior and interior of right valve. Height 16.5 mm.; width 18.4 mm.; thickness 2.1 mm. Re- cent. Figs. 6, 7, specimen A325b. 26564 PRI. Exterior and in- terior of left valve. Height 16.3 mm.; width 14.1 mm.; thickness 2.2 mm. Recent. Chlamys (Chlamys) benedicti Verrill and Bush ........................ 139 Figs. 8, 9, specimen L337a. 26565 PRI. Exterior and interior of right valve. Height 17 mm.; width 15 mm.; thickness 2.5 mm. Playa Grande formation (Catia member). Figs. 10, 11, specimen L337b. 26566 PRI. Exterior and interior of left valve. Height 13.9 mm.; width 12.2 mm.; thickness 2.1 mm. Playa Grande formation (Ca- tia member). 504 Figure 1,2. 3-6. 7-12. BuL.eTin 204 Explanation of Plate 15 Aequipecten muscosus (W00d) .......0.....ccccceccccececeteceseteeennerenneee 142 Specimen K339a. 26567 PRI. Exterior and interior of left valve. Height 12.1 mm.; width 11.9 mm.; thickness 2 mm. Playa Grande formation (Catia member). Chlamys (Leptopecten) desultoria Weisbord, n. sp. .................. 145 Figs. 3, 4, holotype (G342a). 26568 PRI. Exterior and interior of right valve. Height 10.3 mm.; width 10.3 mm.; thickness 1.1 mm. Mare formation. Figs. 5, 6, paratype (J342a). 26569 PRI. Exterior and interior of right valve. Height 9.6 mm.; width 9.8 mm.; thickness 2 mm. Lower Mare formation. Chlamys (Argopecten) gibbus antecessor Weisbord, n. subsp... 148 Figs. 7, 8, holotype (T344a). 26570 PRI. Exterior and interior of left valve. Height 32 mm.; width 33.5 mm.; thickness 10.2 mm. Upper Mare formation. Figs. 9, 10, paratype (G344c). 26571 PRI. Exterior and interior of right valve. Height 18.7 mm.; width 18.7 mm.; thickness 6.8 mm. Mare formation. Figs. 11, 12, para- type (1344a). 26572 PRI. Exterior and interior of right valve. Height 17.5 mm.; width 17.8 mm.; thickness 4 mm. Lower Mare formation. PLATE 15 BULL. AMER. PALEONT., VOL. 45 PLATE 16 BULL. AMER. PALEONT., VOL. 45 ee al TY step teys iu etme i Figure 1-4, 5-10. VENEZUELAN CENOzOIC PELECYPODS: WEISBORD 505 Explanation of Plate 16 Page Chlamys (Argopecten) gibbus antecessor Weisbord, n. subsp... 148 Figs. 1, 2, paratype (J344a). 26573 PRI. Exterior and interior of left valve. Height 12.5 mm.; width 11.8 mm.; thickness 2 mm. Lower Mare formation. Figs. 3, 4, paratype (L340a). 26574 PRI. Exterior and interior of left valve. Height 12.2 mm.; width 11.8 mm.; thickness 2.1 mm. Playa Grande formation (Catia member). Chlamys (Argopecten) imitata Weisbord, n. Sp. .............0..0.... 152 Figs. 5-8, holotype (L331al-2). 26575 PRI. Paired valves. Figs. 5, 6, exterior and interior of right valve of pair. Height 36.9 mm.; width 36.9 mm.; thickness of valves attached 19 mm. Figs. 7, 8, exterior and interior of left valve of pair. Height 37.1 mm.; width 37.1 mm. Playa Grande formation (Catia member). Figs. 9, 10, paratype (U33la). 26576 PRI. Exterior and interior of right valve. Height 27.9 mm.; width 27.9 mm.; thickness 5.4 mm. Playa Grande formation (Catia member). 2,3. 4,5. 6-8. 9,10. BuLietTin 204 Explanation of Plate 17 Lyropecten (Nodipecten) nodosus ? (Linnaeus) .......................... 156 Specimen N322a. 26577 PRI. Right valve. Height 103 mm. Playa Grande formation (Catia member). Lyropecten (Nodipecten) Species “a7 ooo... cece ccc ccc eeeeeteeeteeees 162 Specimen 1323a. 26578 PRI. Exterior and interior of fragment. Height of fragment 66 mm. Lower Mare formation. Lyropecten (Nodipecten) species “BD? oo... ccecceecceceeeeeeeeeees 162 Specimen O321a. 26579 PRI. Exterior and interior of fragment. Width of fragment 59 mm.; height 52 mm. Playa Grande for- mation (Catia member). Spondylus americanus Hermann ........00............0ccccccceeeeeceeseeseeteeees 163 Figs. 6, 7, specimen O0441a. 26580 PRI. Exterior and interior of um- bonal area and beak of right valve. Height 42 mm. Playa Grande formation (Catia member). Fig. 8, specimen O356a. 26581 PRI. Part of umbonal area. Height 36.5 mm. Playa Grande formation (Catia member). Anomia mareana WeiSbOrd, N. SP. ooo... ccccccccceeeecceeeeseeeeeeeseeeess 169 Paratype (J444a). 26582 PRI. Exterior and interior of juvenile left valve. Height 6.3 mm.; width 7.7 mm.; thickness 1 mm. Lower Mare formation. BULL. AMER. PALEONT., VOL. 45 PLATE 17 BULL. AMER. PALEONT., VOL. 45 PLATE 18 Figure VENEZUELAN CENozoIc PELECYPODS: WEISBORD 507 Explanation of Plate 18 Lyropecten (Nodipecten) arnoldi Aguerrevere ...... Se Ea cn 159 Specimen M320a. 26583 PRI. Exterior of right valve. Height 147 mm.; width 148 mm.; length of hinge line 97 mm.; thickness 35 mm. Playa Grande formation (Catia member). Lima (Limaria) pellucida C. B. Adams ...............00000000.cccceeee 167 Specimen A559a. 26584 PRI. Exterior and interior of right valve. Height 21 mm.; width 13.5 mm.; thickness 4 mm. Recent. Anomia mareana WeiSbord, N. SP. o.oo... cece ccececceceeceeessseeeesees 169 Figs. 4, 5, holotype (T362b). 26585 PRI. Exterior and interior of left valve. Height 24.8 mm.; width 23.9 mm.; thickness 7 mm. Upper Mare formation. Figs. 6, 7, paratype (T362a). 26586 PRI. Exterior and interior of left valve. Height 36 mm.; width 40.2 mm.; thickness 15 mm. Upper Mare formation. Figs. 8, 9, paratype (G362b). 26587 PRI. Exterior and interior of left ? valve. Height 25.2 mm.; width 26.5 mm.; thickness 1.7 mm. Mare for- mation. U 508 7,8. BULLETIN 204 Explanation of Plate 19 Lyropecten (Nodipecten) arnoldi Aguerrevere ..............0..000...... 159 Specimen M320a. 26583 PRI. Interior of right valve. Height 147 mm.; width 148 mm.; length of hinge line 97 mm.; thickness 35 mm. Playa Grande formation (Catia member). Anomia, catiana Weisbord; ni sp. cbic RY Aad oO ae a rr 187 Figs. 5, 6, holotype (N346b). 26616 PRI. External views of paired valves. Height 48 mm.; width 39 mm.; thickness of pair 17 mm. Fig. 5, left valve; fig. 6, right valve. Playa Grande formation (Catia member). Figs. 7, 8, paratype (N346a). 26617 PRI. Exterior and interior of right valve. Height 44 mm.; width 31 mm.; thick- ness 9 mm. Playa Grande formation (Catia member). Figs. 9, 10, paratype (N346d). 26618 PRI. Exterior and interior of left valve. Height 63 mm.; width 57 mm.; thickness 20 mm. Playa Grande formation (Catia member). Fig. 11, paratype (N346e). 26619 PRI. Interior of left valve. Height 39 mm.; width 31 mm.; thickness 11 mm. Playa Grande formation (Catia member). Figure 1-6. 7,8. 9,10. 11-14. BuLLETIN 204 Explanation of Plate 25 Page Ostrea (Alectryonia ?) caboblanquensis Weisbord, n. sp. ........ 190 Figs. 1, 2, holotype (S346a). 26620 PRI. Exterior and interior of right valve. Height 61.5 mm.; width 59.7 mm.; thickness 14 mm. Playa Grande formation (Maiquetia member). Figs. 3, 4, para- type (0346a). 26621 PRI. Exterior and interior of right valve. Height 51 mm.; width 43 mm.; thickness 12.7 mm. Playa Grande formation (Catia member). Figs. 5, 6, paratype (M430a). 26622 PRI. Exterior and interior of juvenile right valve. Height 9 mm.; width 10 mm.; thickness 2 mm. Playa Grande formation (Catia member). Ostrea (Agerostrea ?) antecursor Weisbord, n. sp. .................... 192 Holotype (R348a). 26623 PRI. Exterior and interior of right valve. Length 44.4 mm.; width 25 mm. Playa Grande formation (Mai- quetia member). Eucrassatella (Hybolophus) antillarum (Reeve) ........................ 194 Specimen 1488a. 26624 PRI. Exterior and interior of right valve. Length 41 mm.; height 28.7 mm.; thickness 6.7 mm. Lower Mare formation. Crassinella aduncata Weisbord, M. SP. oo........0.cccecccceecececceeeseeeeeees 197 Figs. 11, 12, holotype (1485a). 26625 PRI. Exterior and interior of right valve. Height 2.3 mm.; width 2.7 mm.; thickness 0.8 mm. Lower Mare formation. Figs. 13, 14, paratype (1485b). 26626 PRI. Exterior and interior of left valve. Height 1.9 mm.; width 2.1 mm.; thickness 0.6 mm. Lower Mare formation. BuLu. AMER. PALEONT., VOL. 45 PLATE 25 BULL. AMER. PALEONT., VOL. 45 PLATE 26 VENEZUELAN CENozoIc PELEcyPops: WEISBORD 515 Explanation of Plate 26 Figure Page 1,2. Crassinella triquetra Weisbord, n. SP. ooo.......ooccccccecocceccecceececceseees 199 Holotype (1486a) 26627 PRI. Exterior and interior of left valve. Height 3 mm.; width 2.9 mm.; thickness 0.9 mm. Lower Mare formation. 3-17. Cardita (Carditamera) gracilis Shuttleworth ............................. 200 Figs. 3-6, specimen A540a1-2. 26628 PRI. Paired valves. Height 11.8 mm.; length 26 mm.; thickness of attached valves 10 mm. Figs. 3, 4, interior and exterior of right valve. Figs. 5, 6, interior and exterior of left valve. Recent. Fig. 7, specimen A540b. 26629 PRI. Dorsal view of attached valves. Height 9.1 mm.; length 19.5 mm.; thickness 6.7 mm. Recent. Figs. 8, 9, specimen D540a. 26630 PRI. Exterior and interior of right valve. Height 11 mm.; length 23 mm.; thickness 5.8 mm. Abisinia formation. Figs. 10, 11, specimen D540b. 26631 PRI. Exterior and interior of left valve. Height 7.2 mm.; length 14.4 mm.; thickness 5.1 mm. Abisinia formation. Figs. 12, 13, specimen J540a. 26632 PRI. Exterior and interior of right valve. Height 8.2 mm.; length 17.4 mm.; thick- ness 3.2 mm. Lower Mare formation. Figs. 14, 15, specimen J540b. 26633 PRI. Exterior and interior of left valve. Height 9.1 mm.; length 18.1 mm.; thickness 4.1 mm. Lower Mare formation. Figs. 16, 17, specimen [54la. 26634 PRI. Exterior and interior of juvenile left valve. Height 1.4 mm.; length 2.4 mm.; thickness 0.5 mm. Lower Mare formation. 18,19. Venericardia (Glyptoactis) wendellwoodringi Weisbord, n. sp. 203 Figs. 18, 19, holotype (T493a). 26635 PRI. Exterior and interior of right valve. Height 24.2 mm.; width 23.9 mm.; thickness 11.2 mm. Upper Mare formation. 516 Figure 11,12. 13,14. Mytilopsis leucopheatus ? Conrad Specimen B557a. 26642 PRI. Exterior and interior of right valve. BuLLeETIN 204 Explanation of Plate 27 Page 1-10. Venericardia (Glyptoactis) wendellwoodringi Weisbord, n. sp. 203 Figs. 1, 2, paratype (1493b). 26636 PRI. Exterior and interior of left valve. Height 18.2 mm.; width 20.2 mm.; thickness 7 mm. Lower Mare formation. Figs. 3, 4, paratype (T493b). 26637 PRI. Exterior and interior of young left valve. Height 11.7 mm.; width 12.1 mm.; thickness 4.1 mm. Upper Mare formation. Figs. 5, 6, paratype (1493a). 26638 PRI. Exterior and interior of young right valve. Height 11.1 mm.; width 12 mm.; thickness 4.3 mm. Lower Mare formation. Figs. 7, 8, paratype (J494a). 26639 PRI. Exterior and interior of juvenile right valve. Height 4.7 mm.; width 4.8 mm.; thickness 2 mm. Lower Mare formation. Fig. 9, paratype (1T494a). 26640 PRI. Exterial view of juvenile left valve. Height 3 mm.; width 3 mm.; thickness 1.2 mm. Upper Mare formation. Fig. 10, paratype (S494a). 26641 PRI. Internal view of juvenile left valve. Height 6.5 mm.; width 6.6 mm.; thickness 2.1 mm. Playa Grande formation (Maiquetia member). Length 32 mm.; width 14.5 mm.; thickness 6.6. mm. Recent. Diplodonta (Diplodonta) mareana Weisbord, n. sp. .................... 211 Holotype (J428a). 26643 PRI. Exterior and interior of left valve. Height 3.7 mm.; width 3.8 mm.; thickness 0.9 mm. Lower Mare formation. PLATE 27 BULL. AMER. PALEONT., VOL. 45 ee \ ] \ { PLATE 28 BULL. AMER. PALEONT., VOL. 45 Figure 1-4. 5,6. 7,8. 9-12. VENEZUELAN CENOzoIC PELECYPODS: WEISBORD 517 Explanation of Plate 28 Lucina (Cavilinga) trisulcata blanda (Dall and Simpson) ........ 214 Figs. 1, 2, specimen 1528a. 26644 PRI. Exterior and interior of left valve. Height 7.2 mm.; width 7.4 mm.; thickness 2.3 mm. Lower Mare formation. Figs. 3, 4, specimen J427a. 26645 PRI. Exterior and interior of left valve. Height 9.3 mm.; width 9.2 mm.; thick- ness 2.6 mm. Lower Mare formation. Eueinar(Gallucina’ ?)SP@Cl@S) ...5.-..05c.cccccsocenceeclepaseseesoosecessetesarees 216 Specimen R525a. 26646 PRI. Exterior and interior of broken right valve. Height of fragment 1.7 mm.; width 1.5 mm. Playa Grande formation (Maiquetia member). Lucina (Bellucina) katherinepalmerae Weisbord, n. sp. ........ 217 Holotype (H526a). 26647 PRI. Exterior and interior of right valve. Height 5 mm.; width 4.4 mm.; thickness 1.9 mm. Mare formation. Lucina (Parvilucina) ephraimi Weisbord, n. sp. ........................ 219 Figs. 9, 10, holotype (R52la). 26648 PRI. Exterior and interior of right valve. Height 4.9 mm.; width 4.9 mm.; thickness 1.8 mm. Playa Grande formation (Maiquetia member). Figs. 11, 12, para- type (R521b). 26649 PRI. Exterior and interior of right valve. Height 4 mm.; width 4 mm.; thickness 1.7 mm. Playa Grande for- mation (Maiquetia member). 518 BuLLETIN 204 y Explanation of Plate 29 Figure Page 1-6. Lucina (Parvilucina) ephraimi Weisbord, n. sp. ........................ 219 Figs. 1, 2, paratype (R52lc). 26650 Exterior and interior of left valve. Height 4.9 mm.; width 4.9 mm.; thickness 1.6 mm. Playa Grande formation (Maiquetia member). Figs. 3, 4, paratype (G521b). 26651 Exterior and interior of juvenile right valve. Height 2 mm.; width 2.1 mm. Mare formation. Figs. 5, 6, para- type (G52Ic). 26652 PRI. Exterior and interior of juvenile left valve. Height 2.9 mm.; width 2.9 mm. Mare formation. 7,8. Lucina (Parvilucina) multilineata Tuomey and Holmes ............ 221 Specimen R524a. 26653 PRI. Exterior and interior of right valve. Height 3.1 mm.; width 3.3 mm.; thickness 1.2 mm. Playa Grande formation (Maiquetia member). 9-14. Lucina (Lucinisca) muricata (Spengler) ............000..0cccceeeeee 223 Figs. 9, 10, specimen C529a. 26654 PRI. Exterior and interior of right valve. Height 10 mm.; width 10 mm.; thickness 3 mm. Guaiguaza clay. Figs. 11, 12, specimen C518d. 26655 PRI. Ex- terior and interior of left valve. Height 7.4 mm.; width 7.5 mm.; thickness 2 mm. Guaiguaza clay. Figs. 13, 14, specimen C523a. 26656 PRI. Exterior and interior of juvenile right valve. Height 2.2 mm.; width 2 mm.; thickness 0.8 mm. Guaiguaza clay. BULL. AMER. PALEONT., VOL. 45 PLATE 29 BuLL. AMER. PALEONT., VOL. 45 PLATE 30 VENEZUELAN CENOzoIC PELECYPoDs: WEISBORD 519 Explanation of Plate 30 Figure Page 1-8. Codakia (Lentillaria) orbicularis (Linnaeus) .......................... 226 Figs. 1, 2, specimen S417a. 26657 PRI. Exterior and interior of broken right valve. Length 53.3 mm. Playa Grande formation (Maiquetia member). Figs. 3, 4, specimen S417b. 26658 PRI. Ex- terior and interior of broken right valve. Length 39.5 mm. Playa Grande formation (Maiquetia member). Figs. 5, 6, specimen S417c. 26659 PRI. Exterior and interior of young right valve. Height 30.2 mm.; length 37.2 mm.; thickness 5.2 mm. Playa Grande formation (Maiquetia member). Figs. 7, 8, specimen S$417d. 26660 PRI. Exterior and interior of broken left valve. Length 31.8 mm. Playa Grande formation (Maiquetia member). ie LOOM P Tr aoL Cle Palsy Oto) (ea ee RAE 237 Specimen L423a. 26661 PRI. Internal mold of right valve. Height 23 mm.; width 23.7 mm. Playa Grande formation (Catia mem- ber). 520 Figure 1-4. 5,6. 8. 9,10. 11-14. Bu teTin 204 Explanation of Plate 31 Codakia (Jagonia) orbiculata (Montagu) 22.000000000....cececceeee 229 Specimen A520a1-2. 26662 PRI. Paired valves. Height 12 mm.; width 12.9 mm.; thickness of pair 5.2 mm. Figs. 1, 2 (A520a1), exterior and interior of left valve. Figs. 3, 4 (A520a2), exterior and interior of right valve. Recent. Codakia (Jagonia) pectinata (C. B. Adams) ...00...0...0...00ccccceeeee 234 Specimen A426a. 26663 PRI. Exterior and interior of right valve. Height 11.4 mm.; width 12 mm.; thickness 3.2 mm. Recent. Codakia (Jagonia) umbonicostata Weisbord, n. sp. .................... 236 Holotype (1519a). 26664 PRI. Exterior and interior of right valve. Height 10 mm.; width 10.5 mm.; thickness 3.2 mm. Lower Mare formation. Bornia tacaguana WeiSbord, N. SP. o.oo... ccc cecceceecceeeseeeeeeseeeees 251 Holotype (T548a). 26665 PRI. Exterior and interior of right valve. Width 3.4 mm.; height 3.1 mm.; thickness 0.5 mm. Upper Mare formation. Chama, ‘congregata; Conrad. .....:.....2.c5-4-0 eee 238 Specimen A436al-2. 26666 PRI. Paired valves. Figs. 11, 12 (A436al), exterior and interior of left valve. Length 20 mm.; width 15 mm. Figs. 13, 14 (A436a2), exterior and interior of right valve. Length 15 mm.; width 13.7 mm.; thickness of at- tached valves 12 mm. Recent. PLATE 31 BULL. AMER. PALEONT., VOL. 45 BuLu. AMER. PALEONT., VOL. 45 PLATE 382 Figure VENEZUELAN CENOZOIC PELECYPODS: WEISBORD 521 Explanation of Plate 32 Page 1-0: (‘Chama congregata, Conrad: . 2.056)... 6. ei. ee 238 Figs. 1, 2, specimen H436b. 26667 PRI. Exterior and interior of right valve. Length 15.2 mm.; width 14.9 mm.; thickness 4 mm. Mare formation. Figs. 3, 4, specimen 1436a. 26668 PRI. Exterior and interior of right valve. Length 20.1 mm.; width 17.1 mm.; thickness 5 mm. Lower Mare formation. Figs. 5, 6, specimen J436b. 26669 PRI. Exterior and interior of right valve. Length 17.7 mm.; width 14.6 mm.; thickness 3.5 mm. Lower Mare forma- tion. Fig. 7, specimen J436a. 26670 PRI. External view of left valve, showing flattened area of attachment. Length 28 mm.; width 24.8 mm.; thickness 15.2 mm. Lower Mare formation. Figs. 8, 9, specimen H436a. 26671 PRI. Exterior and interior of left valve. Length 25 mm.; width 20.4 mm.; thickness 11.5 mm. Iden- tification uncertain. Mare formation. 10-13. Chama sinuosa bermudensis Heilprin .....0.0....0..0.000000 Figs. 10, 11, specimen C438a. 26672 Exterior and interior of left valve. Height 61 mm,; width 52 mm.; thickness 23 mm. Guai- guaza clay. Figs. 12, 13, specimen C438b. 26673 PRI. Exterior and interior of right valve. Height 40 mm.; width 41 mm.; thickness 9 mm. Guaiguaza clay. a 7) 45 w oo — 522 Figure 8,9. 10. Ai i2. BuLueTiIn 204 Explanation of Plate 33 Chama macerophylla Gmelin 22.......00000ccciccccececccceeeeeeececeeeeees 241 Specimen A436b. 26674 PRI. Exterior and interior of right valve. Length 18.9 mm.; width 18 mm.; thickness 6.6. mm. Recent. Chama cviorida Watiarcle iscsi ce sere... -i.:c.-- gee eee 244 Specimen A66la. 26675 PRI. Exterior and interior of right valve. Length 15 mm.; width 13 mm.; thickness 5.3 mm. Recent. Pseudochama radians (Lamarck) ..............0..0..ccccccceeseeeeeeeeeeeeteeeeees 246 Specimen A662a1-2. 26676 PRI. Paired valves. Fig. 5. External view of right valve of pair. Height 31.5 mm.; width 27.3 mm.; thick- ness, 17.1 mm. Fig. 6, external view of left valve of pair. Height 23.6 mm.; width 27.5 mm.; thickness 5 mm. Recent. Tivela (Planitivela) venezuelana Weisbord, n. sp. .................... 281 Paratype (T451la). 26677 PRI. Internal view of left valve. Height 3.9 mm.; length, 4.8 mm.; thickness 1.2 mm. Upper Mare forma- tion. Pitar (Pitar ?) antillensis Weisbord, n. sp. ............000..000.0008. 296 Holotype (T666a). 26678 PRI. Exterior and interior of left valve. Length 2.7 mm.; height 2.2 mm. Upper Mare formation. Pitar (Pitarella ?) scutellaris Weisbord, n. sp. .....................0...... 298 Holotype (G416a). 26679 PRI. View of umbo and hinge of right valve. Length of fragment 4.7 mm.; thickness at umbo 1.3 mm. Mare formation. Chione (Chione ?) mamoensis Weisbord, n. sp. ........................ 315 Paratype (S401b). 26680 PRI. Exterior and interior of left valve. Length 11.2 mm.; height 9.7 mm.; thickness 3.3 mm. Playa Grande formation (Maiquetia member). PLATE 33 Buu. AMER. PALEONT., VOL. 45 PLATE 34 BULL. AMER. PALEONT., VOL. 45 Figure 1-6. 8. 9,10. 11-13. VENEZUELAN CENOZzOIC PELECYPoDS: WEISBORD 523 Explanation of Plate 34 Pseudochama radians Lamarck oo.00o20oo0oo0ooocccccccccccceeceeeceeeeeees 246 Figs. 1, 2, specimen D439a. 26681 PRI. Exterior and interior of right valve. Height 50 mm.; width 39.5 mm.; thickness 33 mm. Abisinia formation. Figs. 3, 4, specimen D439b. 26682 PRI. Ex- terior and interior of left valve. Height 33 mm.; width 33 mm.; thickness 10 mm. Abisinia formation. Figs. 5, 6, specimen D440a. 26683 PRI. Exterior and interior of young right valve. Height 12.6 mm.; width 10 mm.; thickness 7.1 mm. Identification uncer- tain. Abisinia formation. Pseudochiaima® 2 SPCCICS: ...5.....c.-ccsesscseedsesceseccescesessssseceseatceseuseebecawwoe 249 Specimen D508a. 26684 PRI. Exterior and interior of immature left valve. Height 8 mm.; width 6 mm.; thickness 0.8 mm. Abisinia formation. PRVCIMOLIALSDECICS Bd, terete eee re ates ce sate oe vsan ondestend eee 249 Specimen 1T442a. 26685 PRI. Exterior and interior of broken left valve. Height 16 mm.; width 12 mm. Upper Mare formation. AGCINGILAESPECICS Ihe) eect eee seers heen ke ee be 250 Specimen G435a. 26686 PRI. Figs. 11, 12, exterior and interior of apical area of right valve. Length 14.2 mm.; width 15 mm.; thick- ness at umbo 10.3 mm. Fig. 13, view looking down on beak. Mare formation. r $ 524 BuL.LeTIn 204 Explanation of Plate 35 Figure Page 1-8. Trachycardium (Dallocardia) muricatum (Linnaeus) .............. 252 Figs. 1, 2, specimen A498a. 26687 PRI. Exterior and interior of right valve. Height 30 mm.; width 29 mm.; thickness 11.2 mm. Recent. Figs. 3, 4, specimen A498b. 26688 PRI. Exterior and in- terior of left valve. Height 28.8 mm.; width 27.9 mm.; thickness 11 mm. Recent. Figs. 5, 6, specimen 1498a. 26689 PRI. Exterior and interior of juvenile left valve. Height 4.7 mm.; width 5 mm.; thickness 1.5 mm. Lower Mare formation. Figs. 7, 8, specimen H498a. 26690 PRI. Exterior and interior of right valve. Height 48 mm.; width 44 mm.; thickness 15 mm. Mare formation. 9. Trachycardium (Trachycardium) cf. isocardia (Linnaeus) on 256 Specimen $500a. 26691 PRI. External view of anterior half of right valve. Height 66 mm.; thickness 24 mm. Playa Grande forma- tion (Maiquetia member). 10-12. Trigoniocardia (Trigoniocardia) caboblanquensis Weisbord, n. Sp. Figs. 10, 11, holotype (G496d). 26692 PRI. Exterior and interior of right valve. Height 10.2 mm.; width 8.2 mm.; thickness 4.9 mm. Mare formation. Fig. 12, paratype (G496c). 26693 PRI. External view of right valve. Height 11.3 mm.; width 10.1 mm.; thickness 4.8 mm. Mare formation. BULL. AMER. PALEONT., VOL. 45 PLATE 35 Buu. AMER. PALEONT., VOL. 45 PLATE 36 dh. . Se he i “i. 3. > 3" we: 4 AA Ash dR 2-6. 7-12. 13,14. VENEZUELAN CENOZOIC PELECYPODS: WEISBORD 525 Explanation of Plate 36 Trachycardium (Trachycardium) cf. isocardia (Linnaeus) ........ 256 Specimen $500a. 26691 PRI. Interior of same specimen illustrated on Pl. 35, fig. 9. Playa Grande formation (Maiquetia member). Trigoniocardia (Trigoniocardia) caboblanquensis Weisbord, n. Sp. Fig. 2, paratype (G496c). 26693 PRI. Interior of same specimen il- lustrated on Pl. 35, fig. 12. Mare formation. Figs. 3, 4, paratype (G496a). 26696 PRI. Exterior and interior of left valve. Height 9.1 mm.; width 8.5 mm.; thickness 3.2 mm. Mare formation. Figs. 5, 6, paratype (G496b). 26697 PRI. Exterior and interior of left valve. Height 10.9 mm.; width 9.2 mm.; thickness 5.3 mm. Mare formation. Trigoniocardia (Americardia) media (Linnaeus) ...................... 264 Figs. 7. 8, specimen A497a. 26698 PRI. Exterior and interior of left valve. Height 17.9 mm.; length 16.1 mm.; thickness 6.4 mm. Re- cent. Figs. 9-12, specimen $497a1-2. 26699 PRI. Paired valves. Figs. 9, 10 (S497a1). Exterior and interior of right valve. Figs. 11, 12 (497a2). Exterior and interior of left valve. Height 29.3 mm.; length 26.1 mm.; thickness of paired valves 24.1 mm. Playa Grande formation (Maiquetia member). aevicardiumm) 2 SPECIOS <<. sccssdccsoecesanssectoeseseeceees shies Soe ta cosh oSuce seeens 268 Specimen H550a. 26700 PRI. Exterior and interior of incomplete and juvenile right valve. Height 1.7 mm.; length 1.5 mm.; thickness 0.9 mm. Mare formation. 1531 337 526 Figure 2 3-10. BuLLeTIN 204 Explanation of Plate 37 Papyridea aff. soleniformis (Bruguiére) ...........00.0..00...00..000000000-. 268 Specimen 1[512a. 26701 PRI. Exterior and interior of broken left valve. Length 4.7 mm.; height 3.5 mm.; thickness 1.2 mm. Lower Mare formation. Dosinia (Dosinidia) concentrica prosapia Weisbord, n. subsp. 270 Figs. 3, 4, holotype (T418a). 26702 PRI. Exterior and interior of right valve. Length 75.5 mm.; height 75 mm.; thickness 14.5 mm. Upper Mare formation. Figs. 5, 6, paratype (1418a). 26703 PRI. Hinge area of left valve. Length of fragment 52 mm. Lower Mare formation. Figs. 7-10, paratype (G420a1-2). 26704 PRI. Young valves of pair. Length 36 mm.; thickness of doublet 14.5 mm. Figs. 7, 8 (G420a1). Exterior and interior of right valve of pair; figs. 9, 10 (G420a2). Exterior and interior of left valve of pair. Mare formation. PLATE 37 BULL. AMER. PALEONT., VOL. 45 BULL. AMER. PALEONT., VOL. 45 PLATE 38 Figure 1-4, 5-8. VENEZUELAN CENozoIc PELECYPoDS: WEISBORD 527 Explanation of Plate 38 Page Dosinia (Dosinidia) concentrica prosapia Weisbord, n. subsp. 270 Figs. 1, 2, paratype (R419a1-2). 26705 PRI. Paired valves. Length 67 mm.; height 70.5 mm. Fig. 1, exterior of right valve. Fig. 2, exterior of left valve. Playa Grande formation (Maiquetia member). Figs. 3, 4, paratype (R419b). 26706 PRI. Hinge area of left valve. Height of fragment 47 mm. Playa Grande forma- tion (Maiquetia member). Anomalocardia brasiliana (Gmelin) ..........0.0.0......ccccccceeeceeeeeeeeee 274 Figs. 5, 6, specimen C539a. 26868 PRI. Exterior and interior of left valve. Length 12.7 mm.; height 8.9 mm.; thickness 3.3 mm. Guai- guaza clay. Figs. 7, 8, specimen C539b. 26869 PRI. Exterior and interior of right valve. Length 10.8 mm.; height 8.8 mm.; thick- ness 3 mm. Guaiguaza clay. E 39 IE 528 Figure 1,2. 3-6. 7-13. Bu.LuetTin 204 Explanation of Plate 39 Page Dosinia (Dosinidia) concentrica prosapia Weisbord, n. subsp. 270 Paratype (K414a). 26709 PRI. Paired valves. Length 71.5 mm.; height 74 mm.; thickness of pair 28 mm. Fig. 1, exterior of right valve; fig. 2, exterior of left valve. Playa Grande formation (Catia member). Anomalocardia venezuvelana Weisbord, n. sp. ..............0.000.0000.... 276 Figs. 3, 4, holotype (C399a). 26710 PRI. Exterior and interior of right valve. Length 2.5 mm.; height 2.1 mm.; thickness 0.8 mm. Guaiguaza clay. Figs. 5, 6, paratype (C399b). 26711 PRI. Ex- terior and interior of right valve. Length 2 mm.; height 1.75 mm.; thickness 0.7 mm. Guaiguaza clay. Tivela (Tivela) mactroides (Born) ............000.0..000........ cee cceeeeeeeeeeees 278 Figs. 7-10, specimen B543a1-2. 26712 PRI. Paired valves. Figs. 5, 8 (B543al1), exterior and interior of right valve of pair. Height 37 mm.; length 42.5 mm.; thickness 12.8 mm. Figs. 9, 10 (B543a2), exterior and interior of left valve of pair. Height 37.2 mm.; length 43 mm.; thickness 12.5 mm. Recent. Fig. 11, specimen B543b. 26713 PRI. Dorsal view of attached valves. Height 41 mm.; length 48 mm.; thickness 29 mm. Recent. Figs. 12, 13, speci- men D546a. 26714 PRI. Exterior and interior of left valve. Height 8 mm.; length 9.9 mm.; thickness 3.3 mm. Abisinia forma- tion. BULL. AMER. PALEONT., VOL. 45 PLATE 39 BULL. AMER. PALEONT., VOL. 45 PLATE 40 VENEZUELAN CENOzoIC PELECYPODS: WEISBORD 529 Explanation of Plate 40 Figure Page 1-4. Tivela (Planitivela) venezuelana Weisbord, n. sp. .................... 281 Figs. 1, 2, holotype (J45la). 26715 PRI. Exterior and interior of right valve. Height 4.1 mm.; length 5 mm.; thickness 1.3 mm. Lower Mare formation Figs. 3, 4, paratype (1457a). 26716 PRI. Exterior and interior of right valve. Height 6 mm.; length 8 mm.; thickness 1.8 mm. Lower Mare formation. 5-15. Gouldia venezvelana Weisbord, n. Sp. ooo.......oo oo cooceeeeeccccseee 282 Figs. 5, 6, holotype ($533b). 26717 PRI. Exterior and interior of right valve. Length 1.6 mm.; width 1.4 mm. Playa Grande forma- tion (Maiquetia member). Fig. 7, paratype ($533a). 26718 PRI. External view of right valve. Length 1.7 mm.; height 1.5 mm. Playa Grande formation (Maiquetia member). Figs. 8, 9, para- type (S532a). 26719 PRI. Exterior and interior of right valve. Length 2.1 mm.; height 1.9 mm. Playa Grande formation (Mai- quetia member). Figs. 10, 11, paratype (S522a). 26720 PRI. Exterior and interior of right valve. Length 3.2 mm.; height 2.8 mm. Playa Grande formation (Maiquetia member). Figs. 12, 13, paratype (H527a). 26721 PRI. Hinge area of left valve. Length 4.7 mm. Mare formation. Figs. 14, 15, paratype (H421a). 26722 PRI. Exterior and interior of broken left valve. Length 5 mm. Mare formation. 16,17. Gouldia ? diffidentia Weisbord. n. sp. 2.0.00... 284 Holotype (1510a). 26723 PRI. Exterior and interior of juvenile left valve. Length 1.7 mm.; height 1.2 mm. Lower Mare formation. 530 Figure 1-8. 9,10. 11-15. BuLLeTIN 204 Explanation of Plate 41 Page Transennella caboblanquensis Weisbord, n. sp. ....................0.. 285 Figs. 1, 2, holotype (1516c). 26724 PRI. Exterior and interior of right valve. Length 4.5 mm.; height 3.6 mm.; thickness 1.8 mm. Lower Mare formation. Figs. 3, 4, paratype (1516b). 26725 PRI. Exterior and interior of right valve. Length 5.5 mm.; height 4.8 mm.; thickness 2 mm. Lower Mare formation. Figs. 5, 6, paratype (1516a). 26726 PRI. Exterior and interior of left valve. Length 3 mm.; height 2.5 mm.; thickness 1 mm. Lower Mare formation. Figs. 7, 8, paratype (T517a). 26727 PRI. Exterior and interior of broken left valve. Length 1.9 mm. Upper Mare formation. Transennela venezuelana Weisbord, n. Sp. .0........0.0..ccccceeeee 287 Holotype (S$552a). 26728 PRI. Exterior and interior of left valve. Length 6.2 mm.; height 5.5 mm.; thickness 1.7 mm. Playa Grande formation (Maiquetia member). Macrocallista maculata (Linnaeus) ....0.0000..000....ecccececceeeeeeeeees 288 Figs. 11, 12, specimen G295a. 26729 PRI. Exterior and interior of left valve. Length 64 mm.; height 50 mm.; thickness 14 mm. Upper Mare formation. Figs. 13, 14, specimen G295b. 26730 PRI. Exterior and interior of right valve. Length 72.5 mm.; height 54 mm.; thickness 12 mm. Upper Mare formation. Fig. 15, specimen E295a. 26731 PRI. Dorsal view of attached valves. Length 71 mm.; height 54 mm.; thickness of doublet 31.5 mm. Upper Mare formation. PLATE 41 BULL. AMER. PALEONT., VOL. 45 PLATE 42 BULL. AMER. PALEONT., VOL. 45 Figure 1-6. 7,8. 9,10. 11-14. 15,16. 17-19. VENEZUELAN CENOZOIC PELECYPODS: WEISBORD 531 Explanation of Plate 42 Macrocallista maculata (Linmaeus) ...00.000000.000.ccccccccccececcceeeeeeecees 288 Figs. 1, 2, specimen G295e. 26732 PRI. Exterior and interior of young left valve. Length 13.9 mm.; height 10.1 mm.; thickness 2.8 mm. Upper Mare formation. Figs. 3, 4, specimen G295f. 26733 PRI. Exterior and interior of young right valve. Length 14.6 mm.; height 11.4 mm.; thickness 3.3 mm. Upper Mare formation. Figs. 5, 6, specimen M295a. 26734 PRI. Internal mold of paired valves. Length 65 mm.; height 48 mm.; thickness of pair 26 mm. Fig. 5, left valve; fig. 6, right valve. Playa Grande formation (Catia member). Pitar (Pifar)albida (Gmelin) :->....2.:..2.....00520).- lan. cial.ce. 293 Specimen C407a. 26735 PRI. Exterior and interior of juvenile right valve. Length 1.9 mm.; height 1.7 mm. Guaiguaza clay. Pitar (Pitar) maiquetiensis Weisbord, n. sp... 295 Holotype (T515a). 26736 PRI. Exterior and interior of juvenile right valve. Length 1.9 mm.; height 1.7 mm. Upper Mare forma- tion. Pitar (Nanopitar) marensis Weisbord, n. sp. ......0...000...000.000..00.2.. 297 Figs. 11, 12, holotype (1515b). 26737 PRI. Exterior and interior of right valve. Length 1.8 mm.; height 1.5 mm. Lower Mare for- mation. Figs. 13, 14, paratype (1515a). 26738 PRI. Exterior and interior of right valve. Length 1.3 mm.; height 1.5 mm. Lower Mare formation. Pitar (Pitarella ?) scutellaris Weisbord, n. sp. ................0..00.... 298 Holotype (G416a). Exterior and interior of incomplete right valve. Length of fragment 4.7 mm.; thickness (at umbo) 1.3 mm. Mare formation. Pitar (Hysteroconcha) dione (Linnaeus) ........................cccccccceeee 300 Specimen J397a. 26740 PRI. Internal, external, and posterodorsal views of incomplete right valve. Height of fragment 18.5 mm.; thickness 6 mm. Lower Mare formation. JLL 532 Figure 1-6. 7,0. 9-11. 12,13. BuLtetin 204 Explanation of Plate 43 Ptiar (Hysteroconcha) dione (Linnaeus) |........2...00.. cece 300 Figs. 1, 2, specimen B397a. 26741 PRI. Exterior and interior of right valve. Length 31.2 mm.; height 25 mm.; thickness 7.6 mm. Recent. Figs. 3, 4, specimen B397b. 26742 PRI. Exterior and in- terior of left valve. Length 36 mm.; height 28.1 mm.; thickness 7.5 mm. Recent. Figs. 5, 6, specimen D403a. 26743 PRI. Exterior and interior of broken right valve. Length of fragment 18.4 mm.; thickness 7.3 mm. Identification uncertain. Abisinia formation Periglypta: aff. listerin(Gray): © ...............00600s.ciesee 302 Specimen 1410a. 26744 PRI. Interior and exterior of anterior end of left valve. Height of fragment 27.5 mm. Lower Mare formation. Antigona (Ventricolaria) aff. rigida (Dillwyn) .............000.0000....... 304 Figs. 9, 10, specimen M411la. 26745 PRI. Internal mold of paired valves. Length 79 mm.; height 75 mm.; thickness of doublet 53 mm. Fig. 9, left valve; fig. 10, right valve. Playa Grande forma- tion (Catia member). Fig. 11, specimen H412a. 26746 PRI. Height of fragment 27.4 mm. Identification uncertain. Mare formation. Antigona (Ventricolaria) rugatina (Heilprin) .............00...000.00..... 306 Specimen A402a. 26747 PRI. Exterior and interior of left valve. Length 19.7 mm.; height 18.3 mm.; thickness 6 mm. Recent. BULL. AMER. PALEONT., VOL. 45 PLATE 43 BULL. AMER. PALEONT., VOL. 45 PLATE 44 pee Ret gt ee thee mew ee ST A we Tht Liye VENEZUELAN CENOZOIC PELECYPODS: WEISBORD 533 Explanation of Plate 44 Figure Page 1-8. Chione (Chione) cancellata (Linnaeus) |...........0.0....000.cccccccccceeee 308 Figs. 1, 2, specimen C400a. 26748 PRI. Exterior and interior of right valve. Length 21 mm.; height 18.1 mm.; thickness 5.6 mm. Guai- guaza clay. Fig. 3, specimen J400a. 26749 PRI. External view of right valve. Length 18.2 mm.; height 15.4 mm.; thickness 3.7 mm. Lower Mare formation. Fig. 4, specimen T400a. 26750 PRI. In- ternal view of right valve. Length 23.2 mm.; height 19.4 mm.; thickness 4.6 mm. Upper Mare formation. Figs. 5, 6, specimen T400b. 26751 PRI. Exterior and interior of left valve. Length 32.1 mm.; height 26 mm.; thickness 8 mm. Upper Mare formation. Figs. 7, 8, specimen 1400b. 26752 PRI. Exterior and interior of left valve. Length 17.8 mm.; height 15.9 mm.; thickness 4 mm. Lower Mare formation. 9-11. Chione (Chione) pailasana Weisbord, n. sp. .....000000000 313 Fig. 9, holotype (P401a). 26753 PRI. Attached valves. Length 47 mm.; height 43 mm.; thickness of pair 27.5 mm. Playa Grande formation (Maiquetia member). Figs. 10, 11, paratype (R40la). 26754 PRI. Exterior and interior of left valve. Length 43.8 mm.; height 39 mm.; thickness 13.2 mm. Playa Grande formation (Maiquetia member). 12,13. Chione (Chione ?) mamoensis Weisbord, n. sp. ..................000..4. 315 Holotype (S401a). 26755 PRI. Exterior and interior of right valve. Length 13 mm.; height 11.2 mm.; thickness 4 mm. Playa Grande formation (Maiquetia member). wm =! 534 Figure 1,2. 3-6. 7,8. 9-14. 15,16. BuLLeTIN 204 Explanation of Plate 45 Page Chione (Chione ?) mamoensis Weisbord, n. sp. ........................ 315 Paratype (D401a). 26870 PRI. Exterior and interior of right valve. Length 10 mm.; height 9 mm.; thickness 3.7 mm. Abisinia forma- tion. Chione (Chione ?) laciniosa Weisbord, n. sp. ...........0.0.0.0..000..... 317 Figs. 3, 4, holotype (1401a) 26757 PRI. Exterior and interior of immature right valve. Length 2.4 mm.; height 2.3 mm.; thickness 0.7 mm. Lower Mare formation. Figs. 5, 6, paratype (1405a). 26758 PRI. Exterior and interior of broken right valve. Length of fragment 3.7 mm.; thickness 1.1 mm. Lower Mare formation. Chione (Timoclea) tacaguana Weisbord, n. sp. .......0....00ee ee. 320 Holotype (S401c). 26759 PRI. Exterior and interior of left valve. Length 13 mm.; height 11 mm.; thickness 4.2 mm. Playa Grande formation (Maiquetia member). Chione (Chionopsis) subrostrata (Lamarck) ................................ 322 Figs. 9, 10, specimen B400a. 26760 PRI. Exterior and interior of right valve. Length 21.3 mm.; height 19 mm.; thickness 5.1 mm. Recent. Figs. 11, 12, specimen B400b. 26761 PRI. Exterior and in- terior of left valve. Length 20 mm.; height 17 mm.; thickness 6 mm. Recent. Figs. 13, 14, specimen A404a. 26762 PRI. Exterior and interior of worn right valve. Length 15 mm.; height 13 mm.; thickness 5 mm. Recent. Chione (Lirophora) riomaturensis Maury ..................................... 325 Specimen H398a. 26763 PRI. Exterior and interior of right valve. Length 34.7 mm.; height 28.2 mm.; thickness (excluding height of ribs) 7 mm. Mare formation. BULL. AMER. PALEONT., VOL. 45 PLATE 45 BULL. AMER. PALEONT., VOL. 45 PLATE 46 zh ¥ belt he Ae as VENEZUELAN CENozoIc PELECYPODS: WEISBORD 535 Explanation of Plate 46 Figure Page 1,2. Chione (Timoclea) tacaguana Weisbord, n. sp. ...2...0cee.. 320 Paratype (S401d). 26764 PRI. Exterior and interior of right valve. Length 11.8 mm.; height 10.4 mm.; thickness 3.9 mm. Playa Grande formation (Maiquetia member). 3,4. Macoma (Psammacoma) hybrida Weisbord, n. sp. ......0............. 354 Holotype (1665a). 26765 PRI. Exterior and interior of right valve. Length 36.2 mm.; height 21 mm.; thickness 4.1 mm. Lower Mare formation. 5,6. Corbula (Notocorbula) bruscasensis Weisbord, n. sp. .............. 400 Holotype (R667a). 26766 PRI. Exterior and interior of left valve. Length 3 mm.; height 2.5 mm. Playa Grande formation (Mai- quetia member). 536 Figure 1-6. 7-12. 13,14. / 15. BuLietTin 204 Explanation of Plate 47 Chione (Lirophora) riomaturensis Maury ....................0...0.....0004. 325 Figs. 1, 2, specimen 1398a. 26767 PRI. Exterior and interior of left valve. Length 36.6 mm.; height 32.1 mm.; thickness (exclud- ing ribs) 10 mm. Lower Mare formation. Figs. 3, 4, specimen J398a. 26768 PRI. Exterior and interior of right valve. Length 14.6 mm.; height 12 mm.; thickness (excluding ribs) 3.1 mm. Lower Mare formation. Figs. 5, 6, specimen J398b. 26769 PRI. Exterior and interior of left valve. Length 14.3 mm.; height 12.3 mm.; thickness (excluding ribs) 4 mm. Lower Mare formation. Chione (Lirophora) cultellata Weisbord, n. sp. .........00000000....... 328 Figs. 7, 8, holotype (G409a). 26770 Exterior and interior of in- complete right valve. Length 4.3 mm. Upper Mare formation. Figs. 9, 10, paratype (G408a). 26771 Exterior and interior of left valve. Length 4.7 mm.; height 3.9 mm. Upper Mare forma- tion. Figs. 11, 12, paratype (1406a). 26772 Exterior and interior of left valve. Length 4 mm.; height 3.7 mm.; thickness (exclud- ing ribs) 1 mm. Lower Mare formation. Petricola (Naranio) lapicida (Gmelin) ...2.0000o eee 329 Specimen $549a. 26773 PRI. Exterior and interior of left valve. Length 12.0 mm.; height 11.2 mm.; thickness 3.9 mm. Playa Grande formation (Maiquetia member). Petricola (Rupellaria) typica (Jomas) ...000000..00000.000ececceeeeee 331 Specimen A506a. 26774 PRI. Dorsal view of paired valves. Length 11 mm.; height 9 mm.; thickness of doublet 8.3 mm. Recent. BULL. AMER. PALEONT., VOL. 45 PLATE 47 BULL. AMER. PALEONT., VOL. 45 PLATE 48 Figure 1-6. 7-12. 13. 14-15. VENEZUELAN CENOzoIC PELECYPOoDS: WEISBORD 537 Explanation of Plate 48 Petricola (Rupellaria) typicaS@onas)a yee ees ee eas oie 331 Figs. 1, 2, specimen A506b. 26775 PRI. Exterior and interior of left valve. Length 13.8 mm.; height 13 mm.; thickness 5.1 mm. Recent. Figs. 3, 4, specimen ’A506c. 26776 PRI. Exterior and in- terior of right valve Length 16 mm.; height 13.5 mm.; thickness 4.6 mm. Recent. Figs. 5, 6, specimen D506a. 26777 PRI. Exterior and interior of right valve. Length 13.3 mm.; height 11 mm.; thickness 5 mm. Abisinia formation. Pleiorytis venezuelensis Weisbord, n. sp. oo... eee 334 Figs. 7, 8, holotype (1507a). 26778 PRI. Exterior and interior of right valve. Length 4 mm.; height 3 mm.; thickness 1.5 mm. Lower Mare formation. Figs. 9, 10, paratype (1507b). 26779 PRI. Exterior and interior of left valve. Length 3.7 mm.; height 3.3 mm.; thickness 1.4 mm. Lower Mare formation. Figs. 11, 12, paratype (T507a). 26780 PRI. Exterior and interior of broken right valve. Length 4.5 mm. Upper Mare formation. Tellina (Tellina ?) species indeterminate .........00000000000000.... 337 Specimen Q446a. 26781 PRI. External view of right valve. Length 43 mm.; height 26 mm. Playa Grande formation (Maiquetia member). Tellina (Eurytellina) punicea Born .........00...000000.000.ccceccceceeeeeeeees 337 Specimen J448a. 26782 PRI. Exterior and interior of young right valve. Length 11 mm.; height 7 mm.; thickness 1.1 mm. Lower Mare formation. ULI Ww 538 BuLuetTin 204 Explanation of Plate 49 Figure Page 1,2. Tellina (Eurytellina) punicea Born .........0.0.000000...0.0.000ccccceeeeceees 337 Specimen 1448a. 26783 PRI. Exterior and interior of right valve. Length 44 mm.; height 28 mm.; thickness 4.6 mm. Lower Mare formation. 3-10. Tellina (Eurytellina) nitens C. B. Adams ................0...000..00.:00: 341 Figs. 3, 4, specimen G448a. 26784 PRI. Exterior and interior of right valve. Length 21.8 mm.; height 12 mm.; thickness 2.2 mm. Mare formation. Figs. 5, 6, specimen G448b. 26785 PRI. Exterior and interior of immature right valve. Length 8.1 mm.; height 4.8 mm.; thickness 0.9 mm. Mare formation. Figs. 7, 8, specimen G448c. 26786 PRI. Exterior and interior of left valve. Length 29 mm.; height 16 mm.; thickness 2.3 mm. Mare formation. Figs. 9, 10, specimen G448d. 26787 PRI. Exterior and interior of im- mature left valve. Length 10.2 mm.; height 5.6 mm.; thickness 1 mm. Mare formation. 11-12. Tellina (Eurytellina) alternata ? Say ......0.0000..0..ee 344 Specimen R447a. 26788 PRI. Exterior and interior of broken left valve. Length of fragment 34 mm.; height 21 mm. Playa Grande formation (Maiquetia member). 13,14. Tellina (Merisea) cristallina Spengler .......000..000.00000.e 345 Specimen J455a. 26789 PRI. Exterior and interior of broken left valve. Length 17.4 mm.; height 13.1 mm.; thickness 3.2 mm. Lower Mare formation. PLATE 49 BULL. AMER. PALEONT., VOL. 45 BULL. AMER. PALEONT., VOL. 45 PLATE 50 Figure 9-12. VENEZUELAN CENOzOIC PELECYPODS: WEISBORD 539 Explanation of Plate 50 Tellina (Merisca) cristallina Spengler .0o0...000.00..000ccccccceeeeeceeeee 345 Specimen T454a. 26790 PRI. Exterior and interior of right valve. Length 27 mm.; height 20.3 mm.; thickness 2.4 mm. Upper Mare formation. Strigillaopisiformis: G.innaeus)".2..2.)....0028.2082. A. Bes 348 Figs. 3, 4, specimen B466a. 26791 PRI. Exterior and interior of right valve. Length 7.8 mm.; height 7.5 mm.; thickness 2.6 mm. Recent. Figs. 5, 6, specimen B468a. 26792 PRI. Exterior and in- terior of left valve. Length 7.9 mm.; height 8 mm.; thickness 2.3 mm. Recent. Figs. 7, 8, specimen D467a. 26793 PRI. Exterior and interior of right valve. Length 5.1 mm.; height 4.6 mm.; thickness 1.2 mm. Abisinia formation. Strigilla carmaria (LiIMMAEUS) ...000.........ecceecccccccecsecceccceceecsssseeceeeseee 351 Specimen A464al1-2. 26794 PRI. Paired valves. Length 15.8 mm.; height 14.7 mm.; thickness of attached valves 7 mm. Figs. 9, 10, (A464a1), exterior and interior of right valve; figs. 11, 12 (464a2), exterior and interior of left valve. Recent. 7,8. 9-14. BuLLeTIN 204 Explanation of Plate 51 Strigilla carnaria (Linnaeus) ..002 08000222 ee NST Figs. 1, 2, specimen D464a 26795 PRI. Exterior and interior of right valve. Length 6.8 mm.; height 6 mm.; thickness 1.2 mm. Abisinia formation. Figs. 3, 4, specimen 1465a. 26796 PRI. Ex- terior and interior of young right valve. Length 4.8 mm.; height 4.2 mm.; thickness 1.4 mm. Lower Mare formation. Figs. 5, 6, specimen 1465b. 26797 PRI. Exterior and interior of young left valve. Length 4.9 mm.; height 4.05 mm.; thickness 1.2 mm. Lower Mare formation. Semele purpurascens (Gmelin) 20000000000 occ eeeees Specimen A456a. 26798 PRI. Exterior and interior of left valve. Length 16.7 mm.; height 13 mm.; thickness 3 mm. Recent. Semele proficua (Pultney) 0 a eee Figs. 9, 10, specimen B470a. 26807 PRI. Exterior and interior of right valve. Length 23.1 mm.; height 21.6 mm.; thickness 4.2 mm. Recent. Figs. 11, 12, specimen A424b. 26800 PRI. Exterior and in- terior of left valve. Length 16 mm.; height 14 mm.; thickness 2.2 mm. Recent. Figs. 13, 14, specimen J425a. 26801 PRI. Exterior and interior of left valve. Length 19.7 mm.; height 17.3 mm.; thickness 3.5 mm. Lower Mare formation. 355 358 BULL. AMER. PALEONT., VOL. 45 PLATE 51 BULL. AMER. PALEONT., VOL. 45 PLATE 52 Figure 9-17. VENEZUELAN CENOozoIc PELECYPODS: WEISBORD 541 Explanation of Plate 52 Semelina nmuculoides (Conrad) ..............00ccccccccccccccceceeccceeeceeseeeeeeeeens 361 Specimen S458. 26802 PRI. Exterior and interior of left valve. Length 4.3 mm.; height 2.9 mm.; thickness 1.1 mm. Playa Grande formation (Maiquetia member). Donax, GenticUlatos GWINNACUS ooo... oc. cccsts occ gececer- dope cacestionneat 363 Figs. 3, 4, specimen B469a. 26803 PRI. Exterior and interior of left valve. Length 29.3 mm.; height 20.5 mm.; thickness 6.9 mm. Recent. Figs. 5, 6, specimen B469b. 26804 PRI. Exterior and in- terior of right valve. Length 20.8 mm.; height 15 mm.; thickness 5 mm. Recent. Fig. 7, specimen B469c. 26805 PRI. Posterior end of left valve. Length 25.4 mm.; height 18.7 mm.; thickness 6 mm. Recent. Fig. 8, specimen B469d. 26806 PRI. Posterior end of right valve. Length 27.3 mm.; height 20.3 mm.; thickness 6.8 mm. Recent. Donax. striatus: Linnaeus,.0¢21.. 2s. BES BRON... cae: 365 Figs. 9, 10, specimen B470a. 26807 PRI. Exterior and interior of paired valves, open. Length 26.3 mm.; height 16.4 mm; _thick- ness of pair, closed 11.5 mm. Recent. Fig. 11, specimen B470b. 26808 PRI. Dorsal view of paired valves, closed. Length 12.3 mm.; height 7.9 mm.; thickness of pair 5.2 mm. Recent. Figs. 12, 13, specimen B470c. 26809 PRI. Exterior and interior of left valve. Length 25.9 mm.; height 17 mm.; thickness 5 mm. Recent. Figs. 14, 15, specimen B470d. 26810 PRI. Exterior and interior of right valve. Length 23.3 mm.; height 14.1 mm.; thickness 4.6 mm. Recent. Figs. 16, 17, specimen B470e1-2. 26811 PRI. Paired valves, detached. Length 28.1 mm.; height 18.2 mm.; thickness of at- tached valves 12.2 mm. Fig. 16, posterior end of left valve; fig. 17, posterior end of right valve. Recent. 542 Figure 1-9. 10,11. 12,13. 14-17. BuLLETIN 204 Explanation of Plate 53 Page Donax higuerotensis Weisbord, Mm. SP. oo............00cccccccccccceeeceee eee 368 Fig. 1, holotype (B471a). 26812 PRI. Dorsal view of paired valves. Length 25 mm.; height 12.2 mm.; thickness 7.5 mm. Recent. Figs. 2-5, paratype (B471b). 26813 PRI. Left valve. Length 23 mm.; height 10.7 mm.; thickness 4 mm. Figs. 2, 3, exterior and in- terior; fig. 4, dorsal view; fig. 5, enlarged view of posterior end. Recent. Figs. 6-9, paratype (B471c). 26814 PRI. Right valve. Length 22 mm.; height 10.9 mm.; thickness 4 mm. Figs. 6, 7, ex- terior and interior; fig. 8, dorsal view; fig. 9, enlarged view of posterior end. Recent. Donax vagus WeEISDOTd? 1. 1SP. 4.6......6206. 60h .cccbet Lis eden act bendeenccteneeee 370 Holotype (1542a). 26815 PRI. Exterior and interior of left valve. Length 5.1 mm.; height 3.6 mm.; thickness 1.4 mm. Lower Mare formation. Donax marensis WeiSbOrd, 1. SP. o.oo... ccccccceccececeesccceeesseeceenseeeeens 371 Holotype (T472a). 26816 PRI. Exterior and interior of right valve. Length 2.7 mm.; height 2 mm. Upper Mare formation. Sanguinolaria (Psammotella) operculata (Gmelin) .................. 372 Figs. 14, 15, specimen B445ia. 26817 PRI. Exterior and interior of right valve. Length 65.5 mm.; height 34 mm.; thickness 10.2 mm. Recent. Figs. 16, 17, specimen B445b. 26818 PRI. Exterior and interior of hinged pair. Length of larger fragment (right valve) 34 mm. Recent. PLATE 53 BULL. AMER. PALEONT., VOL. 45 as cay LID Ss SOEEET TOTS eee BuLu. AMER. PALEONT., VOL. 45 PLATE 54 paves rier tn Figure 1-4. 5,6. 7-10. 11,12: VENEZUELAN CENOzoIC PELECYPODS: WEISBORD 543 Explanation of Plate 54 Page Tagelus plebeius: (Solanden))«:::aci!..).)... ee ee ee ee 375 Figs. 1, 2, specimen B492a. 26819 PRI. Exterior and interior of right valve. Length 51.5 mm.; height 18.7 mm.; thickness 5.2 mm. Re- cent. Figs. 3, 4, specimen B492b. 26820 PRI. Exterior and in- terior of incomplete left valve. Length of specimen 37.7 mm.; thickness 4 mm. Recent. Solen (Solena) obliquus Spengler .o.....00.....0cccccccccccecccccccecceeeenseseeee Specimen B489a. 26821 PRI. Exterior and interior of left valve. Length 90 mm.; height 23 mm.; thickness 5 mm. Recent. SolencSpecies: .... ct eeeat sw liane re eta) ate elee Fl Figs. 7, 8, specimen 1490a. 26822 PRI. Exterior and interior of posterior portion of incomplete left valve. Length of fragment 55 mm.; height 14.3 mm.; thickness 6 mm. Lower Mare formation. Figs. 9, 10, specimen T490a. 26823 PRI. Exterior and interior of posterior portion of incomplete right valve. Length of frag- ment 42 mm.; height 14.3 mm.; thickness 6 mm. Upper Mare formation. Solecurtus cumingianus (Dunker) ........00000.........0ccccccceccceeeeseeeeeeees Specimen 1491a. 26824 PRI. Exterior and interior of right valve. Length 61 mm.; height 24.7 mm.; thickness 8.1 mm. Lower Mare formation. 378 380 544 Figure 1,2. 3-6. 7,8. 9-14. BuLueTIn 204 Explanation of Plate 55 Mactra (Mactrellona ?) iheringi (Dall) ..........00000000ccee 383 Specimen B554a. 26825 PRI. Exterior and interior of broken left valve. Length 52 mm.; thickness 21 mm. Recent. Mulinia cleryana (d’Orbigny) .......00..000.000cccceccccccceccceceeenseeseeenseeeees 384 Figs. 3, 4, specimen B545a. 26826 PRI. Exterior and interior of right valve. Length 23 mm.; height 18.3 mm.; thickness 5.2 mm. Recent. Figs. 5, 6, specimen B545b. 26827 PRI. Exterior and in- terior of left valve. Length 24.2 mm.; height 21 mm.; thickness 6.9 mm. Recent. Labiosa (Raeta) aff. plicatella (Conrad) ...0.......0000cecceceeeeeeeeeee 387 Specimen Q463a. 26828 PRI. Paired valves, incomplete. Height 26 mm.; thickness of pair 18 mm. Fig. 7, external view of left valve of pair; fig. 8, external view of right valve of pair. Playa Grande formation (Maiquetia member). Ervilia nitens venezuelana Weisbord, n. subsp. ........................ 389 Figs. 9, 10, holotype (J449a). 26829 PRI. Exterior and interior of right valve. Length 7.3 mm.; height 5.3 mm.; thickness 1.3 mm. Lower Mare formation. Figs. 11, 12, paratype (J449b). 26830 PRI. Exterior and interior of left valve. Length 9 mm.; height 5.6 mm.; thickness 1.3 mm. Lower Mare formation. Figs. 13, 14, paratype (T449a). 26831 PRI. Exterior and interior of juvenile right valve. Length 3.8 mm.; height 2.5 mm.; thickness 0.9 mm. Upper Mare formation. BuLuL. AMER. PALEONT., VOL. 45 PLATE 55 PLATE 56 BULL. AMER. PALEONT., VOL. 45 VENEZUELAN CENOzoIC PELECYPODS: WEISBORD 545 Explanation of Plate 56 Figure Page 1-8. Ervilia nitens venezuelana Weisbord, n. subsp. ........................ 389 Figs. 1, 2, paratype (G449a). 26832 PRI. Exterior and interior of right valve. Length 7.8 mm.; height 5.3 mm.; thickness 1.2 mm. Upper Mare formation. Figs. 3, 4, paratype (1449a). 26833 PRI. Exterior and interior of right valve. Length 6.7 mm.; height 4.4 thickness 1 mm. Lower Mare formation. Figs. 5, 6, paratype (G449b). 26834 PRI. Exterior and interior of young left valve. Length 4.1 mm.; height 2.8 mm.; thickness 0.9 mm. Upper Mare formation. Figs. 7, 8, paratype (T453a). 26835 PRI. Exterior and interior of juvenile left valve. Length 3.3 mm.; height 2.2 mm.; thickness 0.8 mm. Upper Mare formation. 9-12. Ervilia antilleana Weisbord, n. Sp. ooo0.......0ccccceecccccceeet eee eee 391 Figs. 9, 10, holotype (G450a). 26836 PRI. Exterior and interior of right valve. Length 3.4 mm.; height 2.3 mm.; thickness 0.8 mm. Mare formation. Figs. 11, 12, paratype (G450b). 26837 PRI. Exterior and interior of left valve. Length 2.2 mm.; height 1.5 mm.; thickness 0.7 mm. Mare formation. 13,14. Ervilia caribbeana Weisbord, n. sp. ooo... ccceeceecceeeeteeees 393 Holotype (S459a). 26838 PRI. Exterior and interior of young left valve. Length 2.6 mm.; height 1.8 mm.; thickness 0.8 mm. Playa Grande formation (Maiquetia member). 15,16. Ervilia mareana Weisbord, nN. Sp. ..........0.....00cccccccceccccecceeceeeseeeeees 394 Holotype (1452a). 26839 PRI. Exterior and interior of right valve. Length 2.85 mm.; height 2.1 mm.; thickness 1.1 mm. Lower Mare formation. 546 BuLLeTIN 204 Explanation of Plate 57 Figure Page 12. Ervilia mareana Weisbord, 0. SPov si s:cee...2.001.8.. nee 394 Paratype (J452a). 26840 PRI. Exterior and interior of right valve. Length 3.8 mm.; height 2.7 mm.; thickness 1.1 mm. Lower Mare formation. 3-6. Corbula (Juliacorbula) aequivalvis Philippi .........0....000.0000000.. 394 Figs. 3, 4, specimen C535a. 26841 PRI. Exterior and interior of right valve. Length 12.3 mm.; height 8 mm.; thickness 3.6 mm. Guaiguaza clay. Figs. 5, 6, specimen C535b. 26842 PRI. Exterior and interior of left valve. Length 10.2 mm.; height 7 mm.; thick- ness 2.8 mm. Guaiguaza clay. 7-14. Corbula (Caryocorbula) cf. lavalleana d’Orbigny ....................... 397 Figs. 7, 8, specimen C536a. 26843 PRI. Exterior and interior of right valve. Length 9.8 mm.; height 7 mm.; thickness 4 mm. Guaiguaza clay. Figs. 9, 10, specimen C536b. 26844 PRI. Exterior and in- terior of left valve. Length 10.2 mm.; height 6.1 mm.; thickness 3.9 mm. Guaiguaza clay. Figs. 11, 12, specimen T536a. 26845 PRI. Exterior and interior of young right valve. Length 5.5 mm.; height 3.8 mm.; thickness 1.7 mm. Upper Mare formation. Figs. 13, 14, specimen 1537a. 26846 PRI. Exterior and interior of young left valve. Length 5.9 mm.; height 3.8 mm.; thickness 1.9 mm. Lower Mare formation. 15-16. Corbula (Notocorbula) puntagordensis Weisbord, Nn. sp. ........ 402 Holotype (H551a). 26847 PRI. Exterior and interior of left valve. Length 2.9 mm.; height 2.6 mm.; thickness 1.3 mm. Mare forma- tion. BULL. AMER. PALEONT., VOL. 45 PLATE 57 BULL. AMER. PALEONT., VOL. 45 PLATE 58 VENEZUELAN CENOzoIC PELECYPops: WEISBORD 547 Explanation of Plate 58 one Martesia striata, (Linnaeus), 1c. s.. .c nes hae Settee 405 Specimen B505a. 26848 PRI. Exterior, and two interior views. Length 24 mm.; height 11.6 mm.; thickness 6 mm. Recent. 4-9. Periploma margaritacea (Lamarck) ............0...0....00..0..0:ccccceeess 408 Figs. 4, 5, specimen 1509a. 26849 PRI. Exterior and interior of broken right valve. Height of fragment 9 mm. Lower Mare for- mation. Figs. 6, 7, specimen A534a. 26850 PRI. Exterior and in- terior of laterally foreshortened right valve. Height 15.1 mm.; length 14.3 mm.; thickness 2.5 mm. Recent. Figs. 8, 9, specimen A558al. 26851 PRI. Exterior and interior of right valve of pair. Length 13.3 mm.; height 8.4 mm.; thickness of attached pair 5.5 mm. Recent. 10,11. Dosinia (Dosinidia) concentrica prosapia Weisbord, n. subsp. 270 Paratype (M415a). 26852 PRI. Internal mold of pair. Length 98.3 mm.; height 89 mm.; thickness of pair 33 mm. Fig. 10, right valve; fig. 11, left valve. Playa Grande formation (Catia mem- ber). 548 Figure 12: 3-6. 7,8. BuLLeETIN 204 Explanation of Plate 59 Periploma margaritacea (Lamarck) .0.........0........cccccccccceeeeeeeseeeeeee 408 Specimen A558a2. 26853 PRI. Exterior and interior of left valve of pair. Length 13.9 mm.; height 8.1 mm.; thickness of pair 5.5 mm. Recent. Cyathodonta cf. tristami OISSON oooo........ occ ccccceeeeecccceeceereseeeee 410 Figs. 3, 4, specimen L460a. 26854 PRI. Internal mold of pair. Length 34 mm.; thickness of pair 10 mm. Fig. 3, right valve; fig. 4, left valve. Playa Grande formation (Catia member). Figs. 5, 6, specimen M462a. 26855 PRI. Internal mold of paired valves. Length 62 mm.; height 50 mm.; thickness of pair 24 mm. Fig. 5, right valve; fig. 6, left valve. Playa Grande formation (Catia member). Pholadomya cf. candida Sowerby .........00.......0.......0c0cccccseceeeeseeeees 412 Specimen M357a. 26856 PRI. Internal] mold of paired valves. Length 104 mm.; height 72 mm.; thickness of pair 61 mm. Fig. 7, left valve; fig. 8, right valve. Playa Grande formation (Catia mem- ber). BULL. AMER. PALEONT., VOL. 45 PLATE 59 INDEX TO VOLUME XLV Note: Light face figures refer to pages. Heavy face figures refer to plates. A Abbott, R. Tucker .... 7 Abisinia formation .... 5, 8, 9, 18, 19, 20, 30 abnormalis, Placunanomia ......... 173 Academy of Natural Sciences of Phila- Gelphia ......200987.. 6, 7, 49 acaris, Venericardia .. 206 acetabulum, Dosinia .. Drill aculeata, Anomia ...... 173 Carditay px sse hc ccee: 202 actitay eda =. 41 INUeHana ese 43 adamsi adamsi, Arca 67 adamsi, Arcopsis ..4,5 10, 16, 17, 65-69 adamsi conradiana, ATCA se es cece, ETO S. 66 adamsi, Fossularca .... 66, 67 adamsi sawkinsi, Hossilarca es. 66 adamsi, Mytilopsis .... 208 adamsii, Arca .... 65, 66 Barbatia. ........20.%% 66 adelinae, Crassatella .. 195, 197 adsociata, Ostrea ........ 185 aduncata, Crassinella .......... 25 1p), Py 197-199, 200 aegeénsis, Nucula ...... 40 aequivalvis, Corbula (Juliacorbula) ....57 14, 17, 393-396 aequivalvis stainforthi, Corbula 396 affinis, Cardita .......... 203 Maselus: ...Aiccteee: 376 afra, Arcopsis ............ 68 aguaclarensis, Pecten (Amusium)@s............ 136 ajar Carditay...:...0.:.... 203, 205 alata, Isognoma .......... 106 MeIAGS cscs. 106 Ostrea: 2.85) aoe 106 Pedalion’ -22..2......: 106 1eYes OE Tha sen a e 106 IPtCTi ag. oes 106 alatum, Isognomon .... 106 alatus, Isognomon ..10 11, 16, 106-107 albida, Caryatis .......... 291 Cytherea’: -....005-eces-<: 291 10312) 0 aia re 291 Meretrix ....:5.008.5 291 IPIEAT AS ut. eee 42 is ae 291-293 Pitarigeee es ee 291 IWEnUSit?.2.- eee 291 alicula, Trigoniocardia 261 alouatta, Sanguinolaria ........ 372 altasebinnaw st 109 alternata, Tellina (Eurytellina) ...... 49 14, 27, 338, 342-343 ambiguus, Solen ........ 376, 377 amelea, Chlamys (Plagioctenium) ...... 15 americana, Anadara .. 76 AT CAMA a 2 0 teehee BH B Dreissena ................ 206 Glycymeris .............. 88 Martesia (Diploplax) 405 Mytiliss 206 Wolsellaye) 99 americanus, Modiolus ................ 9 11, 16, 98-100 Mytiltist eee ee, amiantus, Lucina ...... 218 aminense, Trigoniocardia ........ 260 ammondea, Callocardia 2... 297 Anadara (Cunearca) Sp: -indet:< :..2¢.0:--23 7 10, 86 speiiees... 2 10, 28, 72 angulosa, Tellina ........ 338 angustior, Chama ...... Sia anomioides, Plicatula 118 antecursor, Ostrea (Agerostrea) ........ 25 12, 26, 192-194 antiguensis, Pecten (Amusium)) 2 134 antillarum, Crassatella .............. 194, 195 Eucrassatella (Hybolophus) .25 1222; 194-197 Trigoniocardia ........ 258, 259 antilleana, Ervilia 56 14, 24, 27, 389-391, 392, 393 antillensis, Pitar ....33 13, 23 294-295 apateticum, Trigoniocardia ........ 261 approximata, Lucina .. 221 549 arachnoides, Spondylus abatasCarditaw 2. Glycymeris arborea, Ostrea .......... arcinella olssoni, Echinochama Argina be Argopecten ................ i armstrongi, Crenella Armulles formation arnoldi, Lyropecten (Nodipecten) 18, 19 Asaphis aspersa, Papyridea .... atlanticola, Chione .... Pecten atomas, Pholas ............ auberiana, Anomalocardia aurantiacus, Spondylus auriculata, Anadara 7: a Beaphnarea, ......000.0. axelolssoni, Nucu- lana (Saccella) . 2 aztecus, Pecten baccata, Nucula ......... Baja California balesi, Arca (Barbatia)) see barbadensis, Arca Bornia Plicatula Spondylus .....cet0! barretti, Pecten Beachrock ViCNUS S32 he sen oe beauiana, Pholas bellilamellatus, Pecten (Chlamys) benedicti, Chlamys 14 bermudensis, Chama . 8) eS eee bertini, Sanguinolaria .......... Beyrich, Ernest INDEX 10, 21, 25, 43, 45, 46 123 121, 125 322 blanda, Linga (Cavilinga) 214 bocasensis, Amusium) =. 135 bonaczyi, Arca ............ 59 Bappatiaees ee 59 borealis, Ostrea ........ 181, 182 botula, Petricola ........ 334 bowdenensis bow- denensis, Nuculana 47 bowdenensis, Pecten 125, 131 boweni, Pleiorytis .... 334 brasiliana, Anadara (Cuneareca) ............ 10, 16, 79-82 Anomalocardia ....38 ue Pile 272-274, 275 (ATCA: 6525 PRA 79, 81 Ostreal..:.c:haks.. BIA8 181, 185 Seapharca, 4.0.2... 79 Venus “.2......20e8 272 brevifrons, Macoma .. 353 Bruseas fault. ee 9 bruscasensis, Corbula (Notocorbula) ...... 46 15, 27, 399-401, 402 Buie, B. Frank ............ 6 bullata, Papyridea .... 266 bullatum, Cardium .... 266 bullatus, Solen ............ 266 Burica Peninsula, Patama ....68.ccccon-- 247 byronensis, Tivela .... 278 Cabo Blanco Cabo Blanco group.... 5, 36 caboblanquensis, Ana- dara (Lunarca) ....6 1Oy21, 25, 77-78, 79 Ostrea (Alectry- OTUTD) er cece nana 25 12) 22526; 29, 190-192 Transennella ........ 41 RAP sy 26, 283-285 Trigoniocardia (Tri- goniocardia) ..35, 36 1822; 26, 256-262 cabopasadum, Tri- goniocardia ............ 261 caelata, Arcall... 200% 65 Lf Ci eee 65 cahuitensis, Crassi- FU Ce RR ey 199 INUCULAI cee 38, 39 caianensis, Donax ...... Caiguire Abajo ............ caimitica, Petricola .. cala, Corbula Caleareous algae ........ californica, Gouldia .. californiensis, Chione callopleurum, Trigoniocardia ........ caloosae, Corbula ........ Caloosahatchee formation caloosana, Transennella calvertensis, Petricola campeachiensis, AT. Cal. Leet en oe” campechensis, Arca... NeUtraria MMe eu. Mactra Raeta Seapharca campechiense, Cardiumy 225.0. campechiensis, Arca campechiensis ameri- cana, Arca canadensis, Ostrea ... canaliculata, Labiosa Neer ATIA: eee. WIA CERAUS, neu ten Raeta cancellaris, Lucina .... cancellata, Chione 44 285 250 72, 73, 74 74 181 385, 386 385 385 385, 386 218 13, 16, 17, 23, 26, 306- 311313 candida, Arca Barbatia cantrainei, Gniathodon=...25.. Mulinia Carabobo, State of .... caraboboensis, Ostréa’... ¥ 208. 22,23 Caracas eardara, Nucula ........ caribaea, Corbula ..... Siliquaria caribaeus, Cultellus .. Banopea, (x. 2... ec..--.0s SOlCCUTTUS «......0.c..5. 307 306, 307, 308 58 411-413 382 384 5, 8 12-0, 180-181 5 40 398, 399 373 373 373 373 OLED et irs 373 Tagelus 1.) le es 374 caribbeana, SEV, oe: 56 14, 27, 391-392, 393 Pheatula ic 11 LOA 118-119 caribeus, Pecten 12, 23 In PAE 121-124, 126 carnaria, Lucina _..... 349 Strigillay a 50, 51 14, 16, 20, 27, 347, 349-352 Vellinary yee 349 carnea, Pinna 10 112021, k 107-109 carolinae, Trigonio- CaMiann. -..e... 260 carolinensis, Mytilus. 96 Semele ft RTT 356 SLi gu arias, 8 o4.-.:<-.:. 373 Transennella ............ 285, 286 caroniana, Pleiorytis 333 Cartagena ee 50 cartagenensis, Chione (Liroph ora) ere 3295 castaneus, Lioberus . 106 castum, brassicum, Trigoniocardia liaee os 260 castum castum, Tri- goniocardia .............. 260 Catiay LarMarient tle 9, 18 catiana, Anomia 19, 23 aT 28: ; 171-173 catianus, Pecten __11 Peas, 119-121, 123, 127 cayanensis, Donax .... 363 centenaria, Pleiorytis 334 ceramidum, Tri- goniocardia eee. 0 258 cerina, Gouldia ............ 281, 282 charapota, Petricola . 334 chazaliei, Pecten ........ 125 chemnitzi, Anadara (Cunearca) ........ 23 10, 16, 82-84 ATC. ee iS) , 83 scapharca: £2 chiclaya, Bornia .......... 250 chiriquiensis, Chione (hirophora) 325 chuckatuckensis, DONA Se sec 369 cingenda, Venus ........ 306, 307 cira, Mytilopsis ............ 209 circularis, Chlamys .... 154, 155 Pecten a. 151 circularis venezue- lanus, Pecten ........ 151, 155 551 INDEX clavata, Pholas ............ 404 Clench, William J. .... if cleryana, Mactra ........ 382 od Ec Ee ee pare 55 14, 16, 382-385 cochleatus, Mytilus .... 209 colinensis, Pecten (Nodipecten) ............ 161, 163 colombiensis, Spondylus ................ 167 columba, Hemicardium .......... 262 concentrica concen- trica, Dosinia .......... 270, 271 concentrica prosapia, Dosinia 37, 38, 39, 58 13, 23, 26, 29, 268-272 concentrica, Ervilia.... 391, 393 congregata, CGhamaiu:!:.<...... 31,32 12,16, 20, 22, 26, 235-238,241 congregatoides, Chama 2236 conoides, Pholas ........ 404 conradiana adamsi, PACATH 5, BF Fsd corte ct 2. 67 conradina, Transen- TC 12 epee 5s socncns act oe 285 consors, Trachy- Cardiimupeie... te 256 contracta, Corbula ...... 398 Cooper, G. Arthur .... “if Corallinaceae .............. 19 corallinoides, Lyropecteny «...2:.....-.:. 158 corallinus, Pecten ...... 156 corbicula, Cytherea .... 210, 200 ivelaaee. eee 277 WiGTUUISB ics esses serene 276 COLDULAESD. yee ee 407 cordiformis, Semele .. 357 cornuta, Echinochama 248 corticaria, Pholas .... 404 cortinaria, Chione ...... 317 WOstawlallltne se se 9 Costa dOAGag 31 costaricana, Tellina .... 339 costata, Naranio ........ 328 PetricOlawge 0... 328 crassa, Ostreay 225... 181 crassisquama, SMOHGYIUS v.cccccs cone, 163 crenella, Lucina ........ 222 Phacoides (Parvi- TUCINA) | etter ee cce cee 221 crenulata, Lucina ........ 216 INGIO@UW aes 38 cretatus, Pecten ........ 143 cristata, Ostrea .......... cristobalensis, WAM. ee croceus, Spondylus .... ervstallina, Tellina .... cubaniana, Aloidis (Caryocorbula) ...... Corbulay 2 Juliacorbula ............ Transennella ........... culebrensis, Nucula .. cultellata, Chione (Lirophora) ........ 47 culter) Donax Cumana eee Cumana beds ............ cumanensis, Anadara (Cunearea) “2.22. 7 ATCA nt Me ees Scapharcag 2 cumingiana, Dreissena Machag 3 Merete. cumingianus, Psammosolen Solecurtus cuneimeris, Anomalocardia ........ cupula, Pholas .......... curta, Martesia .......... cymaina, Chione ........ D IDFA NYE LS oon cence es dalli, Dreissensia ...... daphnis, Corbula ........ deadenense, Trigoniocardia ........ decipiens, Pododesmus ............ declivis, Nucula ........ iPSammobid Sol enn tt-c5- << Sees decussata, Amphidesma .......... AT CTech ee Grenellay ct i os ke Glycymeris (Glycy- merella) 317 14, 23, 343-346 277 155, 156 164 343, 344 394 393, 394, 395 14, 23, 379-281 274 405 405 326 32 209 398 261 173. 174 38 373 373 356 92, 93 104 10, 16 21, 25, 92-95 INDEX decussata, Pholas ...... 404 SGMClOR see sees 356, 357 ellina’ #22) e2nc ies 356 degenera, Pinna ....... 107 delicatissima, DOSINIA! Wx... eceisee! 272 delicatus, Pleiorytis . soo demiurgus, Chlamys 154, 155 democraciana, Corbula 2... 399 democraciana chiri- guarana, Ostrea ...... 178 densata, Plicatula ...... 116 denticulatus, OMAN 8 5 ssccceces 52 14, 16, 361-363, 365, 369 Deshayes, G. P............. 31, 32 deshayesi, Scapharca 70 deshayesii, Arca ........ 69, 70 Desnoyers, Jules ........ ol desultoria, Chlamys (Leptopecten) ...... 15 neal 145-147 De Vore, George W. .. diffidentia, Gouldiays...2.2.. 40 13, 23, 282-283, 295 digueti, Eucrassatella 197 diktyota, Lucina ........ 221 dione, Cytherea ........ 298 DIONEIS.... 52 eM... 298 IMGreCtDIX ...2.6-:-.2----- 298 Pitar (Hystero- concha) ........ 42, 43 13516; 20, 23, 298-300 WEnus>.0...te ea, 298 discors, Cardium ........ 347 disparilis, Corbula .... 400, 401, 402 Distrito Federal ........ 5, 8, 15, 18 diuturna, Crenella ...... 104 WIV ALITA... scsconecsscovinets 235 divaricata, Crenella’ ees. 9 inl. Pall. 25, 102-105 Nuculocardia .......... 102 Petricolav os 328 1D hig (oe) IE ee 235 Divaricella sp. ........ 30 3= 12, 29, 235 divergens, Venus ........ 328 divisus, Tagelus (Mesopleura) .......... 376 dodona, Nuculana ...... 45 domingensis, Arca ... 61 Barbatia (Acar) ....4 10, 16, 61-64 Dreissena, =e 209 dominica Venericardia .......... 206 dominicensis, Corbula 398 Spondylus,. 2......:,..-.. 163, 164 donacaeformis, Mactra 382 Mulinia: “.....:......20 384 d’Orbignyi, Arca ........ 82 PANNA ©. Soe. 5ec e551 109 Druckerman, Daniel .. Ff, 835 duplinensis, Crenella 104, 105 duplinensis wal- toniana, Crenella .... 104 dupliniana, Crassinella 199 Durham, J. Wyatt .... Up, BY dysera, Venus ............ 306 E eburniferum, Cardium) 94. 254 eccentricus, Pecten .... 154 echinata, Ostrea ........ 163 Placunanomia me 173 echinatus, Spondylus 163, 164, 165 Echinochama species “a” ...... 34 13, 22, 247 species <“b? 4.2 34 13, 22, 248 ecuadorina, Crenella.. 104 IPT AXIS Ue Task ee 209 effosa, Chlamys ........ 147 effosus, Pecten (Aequipecten) ........ 147 egmontianum, Trachycardium ........ 256 eldridgei, Pecten (Plagioctenium) ...... 151 elegans, Dosinia ........ 271 elegans elegans, Dosinia, AALS... 270, 271 elegans venezuelana, Doesinia, 2a... 271 elenensis, Nuculana .. 43 Pita: c cite 295 elethusa, Callocardia 297 elevata, Venus ............ 306 elliptica, Modiola ...... 100 elongata, Ostrea ........ 181 elytrum, Macoma ...... 353 Bnnuculay ee 40 ephraimi, Lucina (Parvilucina) 28, 29 IPA BPe. 26, 219-221 equestris, Ostrea ........ 177 erici, Ostrea ................ 180 erratin-hellinaa =e 34, 346 evergladensis, Pecten (Plagioctenium) ...... 152 exasperata, Chlamys .. 143 exasperatus, Pecten .. 142, 143 exigua, Nucula ............ 38 553 falcata, Pholas falconensis, Pho- ladomya fasciata, Trigona ferruginea, Chama .... Pseudochama flabellum, Pinna flexuosa, Cytherea .... Wenus 28 aliens: fluctuatus, Pitar fimbriatus, Spon- dylus fisheri, Ostrea flexuosa, Anomalo- cardia flexuosus, Donax .... florida, Chama Florida Geological versity floridana, Cardita floridensis, Ostrea .... fluctifraga, Chione .... folia-brassica, Spondylus fontis, Lucina fossor, Donax .......... fragosus, Lyropecten freudenbergeri, Ostrea fulminata, Pitar ...... funisicola, Martesia (Diploplax) ............ fuscopurpureus, Chlamys Pecten Gabbi WM. 20" .2a: gabbi, Diplodonta Ervilia galvestonense, Trigoniocardia gardnerae, Labiosa .... Garman, Phyllis ...... gatunense, Trigonio- CANTATA esses: gatunensis, Callocardia Cyathodonta Ostréa. 2. peice georgiana, Tellina es INDEX ” 163, 164 . 192 272 363 13, 16, 241-242 . 294 2 34 “¢ 212 : 391, 393 .... 338, 339, 341 gerrardi, Transen- WI GLAY oa ese te oa 285 gibba, Siliquaria ........ 373 gibbosa, Plicatula ..10 1121, 25, 113-117 gibbosus, Solecurtus 374 gibbus, Chlamys ........ 152 Pecten (Plagio- ClLenium) ne 148 SOLCCUTEUS ees ese 374 Solen”.......2..8 ees 373 Tagelus 0.7... R2ue 373, 374, 375 gibbus, antecessor, CHilamys n...).:. 15, 16 11:22, 25, 29, 148-152 carolinensis, Pecten 152 gibbus, Chlamys .... 150 nucleus, Aequipecten 151 portusregii, Pecten (Plagioctenium) ...... 152 versicolor, Chlamys 150 gigas, Pecten ............ 159, 161 glypta, Anomia .......... 171 Glyptoacuis; 2.24.2 2— 205 Goodell, H. Grant .... 6 Gorsline, Donn 6. ........ 6, 15 gossei, Cardium ........ 250 gracilis, Cardita (Carditamera) ....26 12, 20, 22, 200-203 Trapezium (Cypri- Cardia) 2 eee 200 pradata, Area. ....-079) 61 Batbatial .o8: 2ef 5. 64 grandis, Dosinia ........ QU, 22 graniferum, Trigonio- CAVGIA ge 5 cc...- Ate 261 granulata, Veneri- GBROIAR c= ccenne. ARES 205, 206 granulosa, Lucina ...... 213 PTS, CHIONE .....65c5ce5rs 320 gryphoides, Chama .... 238 guadelupensis, Gnathodone =)... 382 1716) 8 of le 3 382 Mualiniaees 382, 384 mrieonella 3s 3 Guaiguaza clay ............ RM Werou, 34, 35 guanacastense, Trigoniocardia ........ 265 guatulcoensis, Ghione".. sa¢4= 315 guineensis, Solen ........ 373 gundlachi, Dreissena. 209 guppyana, Chione ...... 317 guppyi, Plicatula ...... 116 554 H hadra, Venericardia.... haitense areciboense, Trigoniocardia ........ cercadium, Trigoniocardia ........ haitense, Trigonio- Cardia ....::::. Som haitensis, Ostrea ........ hamatus, Brachy- GONTESHE hese Mytilds. 6.2.0.0 ey hannai, Trigonio- REAR A ees se dae eceeicea ss Harbison: A. Ee ............ harfordi, Placuna- TOTES eee oe harrisi, Petricola ........ hastata, Chlamys ........ hawaiiensis, Martesia.. Heilprin, Angelo ........ helblingii, Arca ........ hemidermos, Arca .... hemphilli, Lima .......... hendersoni, Chione (Lirophora) .............. 2h 73 a heredium, Trigonio- Candia 4 oko scence: heterogena, Corbula .. hians, Lima (Limaria).... (Mantellum) ............ hiatus, Cardium ........ Papyridea ................ FIeneTOte _.BE ...ccccccce. higuerotensis, Donax: AVaCee. >. 53 fails; (Nucula |... 222 himerta. Venericardia hirtus, Pectunculus .... hiulcum, Cardium ...... holmesi, Anadara ...... hybrida, Macoma (Psammacoma) .46 ictericus, Spondylus .. iheringi, Mactra (Mactrellona) ...... 55 INDEX 205 259 259 2909 187, 188, 189, 192 14, 23, 352-353 164, 165 14, 16, 381-382 Mactrella “028 381 ilesca, Dosinia ............ 272 imbricata, Arca Anca). Sees 3 ew 15207; LAL 10: RR AED 169 Pellintal (324i tate 223 imbricatula, Lucina .. 229, 230 imitata, Chlamys (Argopecten) ...... 16 129: 152-156 impar, Nuculana ........ 45 inaequivalvis, Periplomaee....72. 407, 408, 409 incongrua, Arca ........ 79, 84 Seapharea 22.36..5.3 79 indecisa, Anomia ........ yal inequalis, Thracia ...... 407 inezae, Pseudochama.. 247 inezana, Plicatula .... 116 anrelix, Hiatai.......£0%: 405 inflata, Crenella ........ 104 | OF 00: eR 167, 168, 169 intapurpurea, Chione Sailt/ intercalata, Martesia 406 intusgranosa, Mesopholas ............ 405 irradians, Chlamys .... 154 irradians concentrica, CHTARAYS ss. scecdsccccccesat 155 irradians, Pecten 150 irremotis, Chlamys (Plagioctenium) ...... 147 isla-trinitatis, CODDUTA: ....c1:02. eee 402 isocardia, Antigona .... 304 Cardium i... 253, 254, 255 isocardia, Trachy- cardium ........ 35, 36 a3, 22, 26, 253-256 isognomon’.. 176 J jamaicensis, Arca ........ 58 Glycymeris .............. 95 Mytilopsis ................ 209 Janson, Andrew R. .... q jayanum, Amphidesma 356, 357 seannet, Av vo.)..ccc.ccscesss 36 K karlmartini, Nuculana (Saccella).......... le. I) PAL Oby 41-43, 45, 46, 47 555 INDEX katherinepalmere, Lu- cina (Bellucina) ..28 I DERPA 217-218 kjoeriana, Corbula .... 398 knoxiana, Corbula .... 393, 394, 395 knoxiana fossilis, Corbulay.. enn 396 krebsiana, Corbula .... 400 Kugler-“H. Go. 222 34 L laciniosa, Chione (Chione) iF... 14, 23, 315-318 Laevicardium ? sp. 36 fijeoe. 265-266 WarGuaira see 18 lamarckii, Donax ........ 363 lamellata, Congeria .... 209 Lamy, Edouard .......... 406 lapicida, Naranio ........ 328 Petricola (Na- FANIO). «2.25. eee 47 14,27, 327-329 Rupellariay............ 328 WiENUS = 2c ee 328 lapicidum, Choristodon 328 La Salina de Guai- BU ALA artnet 5; 8,16, 17, 130 Las Brucas, Quebrada 9 Las Pailas, formation 18, 30 Las Pailas, Quebrada 9,18 lateralis, Crenella ...... 100 Modiolariay..... 100 NMUSCULS? 3206. 9 11, 21, 100-102 Mytilus). .afes 100 latilirata, Chione @irophora) =... 323, 325 latilirata athleta, Chione (Lirophora) 325 colombiana, Chione @arophora) 326 latum, Cardium)'.:........ 266 lavalleana, Corbula (Caryocorbula) .57 iby ae 24, 396-399 lazarus, Chama ”.......... 238 leucopheata, Congeria 206, 207 Dreissena’ 206 Dreissensia .............. 206, 207 leucophaetus, Mytilopsis ............ 27 12,16, 206-211 MUGS ceca 206 levicostatus, Pecten .. 151, 155 Léxico Estratigrafico de Venezuela .......... TT libella, Ostrea (Ostrea) .......... 20, 21 pantry 176-177, 178 himariag.. Sees 169 Pimon:. DedS yc: 5:..857 34 limonensis, Gouldia .. 281 lineata, Glycymeris . 87 lineatus, Pectunculus 86 SOIEN) Ses. eee, 381 Tagelus: ..........:.28500 379 PRG DHOTAL t pect 5: 325 lisbonensis, Anomia .. 2s listeri, Antigona ........ 301 Cytherea ae 301 DOSINAl . £5 se 300 Periglypta 43 Isp esy 300-302, 304 PANN Ake ees a ete 109 Wenusisiex...£: 422 300, 301 lithophaga, Petricola .. 330 Lithothamnium .......... 9, 19, 229, 323 Litoral anticline ........ 9, 190 lixula, Ostrea .......... 22... JZ 179-180 locklini, Ostrea ............ 194 longipes, Bormia ........ 249 longitudinalis, Spondylus), --... 163, 164 lowei, Pecten (Chiamys) -... 142 Lower Mare forma- LIGHTS «3... -REveIss f) 8 unacana eee... 76 UCN ayesiac... Vane 233 Lucina (Callucina) oe ee ee ee 28 12528, 216-217 luna, Pecten CAMUSIUM)) -2....2--.. 135, 137 lunularis, Cytherea .... 272 WEDS 322.2 renee 272 lupanaria, Pitar .......... 300 Lyell, Sir Charles ...... Bike: 24, 31-32 lyoni, Pleuronectia .... 135 Lyropecten (Nodipec- ten) species “a” 17 11,22, 162 species ‘“‘b” ........ iz Li 29; 162-163 M macerophylla, Chama’ ..226i3.0t 33 13, 16, 20, 26, 238-241 macrodon, Cytherea DA POL 6: WV CMU f. eo artnet svntes 272 556 INDEX macrophylla, Chama 238, 239, 240 macroschisma, Pododesmus ............ 175 mactracea, CrassinellaX=......... 198, 199 mactroides, Bornia .... 249 Meretrix (Tivela) .... 276 PV OLA™ cccasdsssecscosse: 39 1316520: 276-278 AVIETIUS G8 ete. 52s 276 maculata, Callista ...... 286, 287 CnIONGF eee 286 Cytherea. eee. 286, 278 1D Gy ce): Ree ee eee eer 286 Macrocallista 41, 42 13, 17, 23, 26, 29, 286-291 MOCK etn iXs otc-cA si. t tee: 287 Pitabia: 205s eee... 288 DETRUSOR: onc ccczecetcosice. 286, 287, 288 maculatus, Pitar ........ 288 magnificus, Pecten .. 156 Maiquetia anticline .... 9 maiquetiensis, IPCCtenas es 12 ial, Pale 124-126, 127 Pipa 28 oes. 8c: 42 IBY PBY 293-294 mantaensis, Tellina .... 338 Mantellummes i s.--....2.: 169 manzanillense, Trigoniocardia ........ 260 mamoensis, Chione ...... 33, 44, 45 14, 20, qi olo-ot5 Mare Abajo fault ...... 9 Mare Abajo, Quebrada 8 Mare formation ........ 5, 8, 10, 18, 19, 20, 21-25, 28, 30, 32, 33, 34 mareana, Anadara (Gunarca) esc 6 10, 21, 78-79 /ANOMI1A 0 terest 17, 18 22. 169-171 Diplodonta (Diplodonta) ........ an IPED A 211-212 RE Viliay 2:35 223! 56, 57 14, 24, 392-393 Nucula (Ennucula) 1 10, 21, 39-41 marella, Nuculana (Saccella)) je..82 2 10, 21, 45-46 marensis, Donax ...... 53 14, 23 369-370 Poperus gsc 9 ial OA 105-106 Pecten (Amusium) ....... 14 it: 136, 137 Pitar (Nanopitar) 42 18} 28} 295-296 margaritacea, Corbula 407 Periploma_ ....58, 59 15, 16, 24, 407-409 marshalli, Nucula ...... 41 Martin, Keic!.... 1 er 43 martinicensis, Crassinella) =. 198, 199 matarucana, Chione (Lirophora) .............. 326 Matura formation ...... 5, 33, 34-35 maturense, Trigoniocardia ....... 261 maturensis, Pecten .... 147 Maury, Carlotta J. ...... 35 mauryae, Periglypta .. 302 mauryi, Amusium ..... 134 mazyckii, Chione ........ 315 media, Americardia .. 264 Trigoniocardia (Americardia) ..36 13, 16, 26, 262-265 mediamericana, Donaxes.....iae 368 Semele: se ee 359 medium, Cardium (Eragum))<.:........0 262, 263, 264 Corculum (Fragum) 264 megodon, Ostrea ........ 193 mendenhalli, Chlamys 155 meridionalis, AStarte: 2s... eee 275, 276 Cyathodonta ............ 411 Ostrea, 3... 190 UAC CA ee. fetch ee 408, 409 Thracia (Cyathodonta) ........ 387, 409 messor, Ostrea ............ 194 messor caimitica, Ostréar 0... FA cc 194 colombiensis, Ostreal 0 weer. 194 metastriata, Gouldia .. 282 mexicana, Codakia @asonta) ee 233 mexicanus, Pitar ........ 297 miguelensis, Ostrea .. 181 millers Praxis) ess 210 Miranda, State of ...... SROs mirandense, Trigoniocardia ........ 260 Modiolus (228486. «002.2. 100 modiolus, Modiolus .... 100 moenensis, Donax ...... 369 Moin formation .......... 5, 33, 34 Soy, INDEX montserratensis, Arana) ise 50 morchiana, Dreissena 210 mortoni, Laevicardium .......... 266 IPECtCN terre. cccess-s 131, 134, 135, 137 multicostata, Permeslypta ..0. ie esse. 302 multicostata var., Chiones 78 ae 301 multilineata, Mactra .. 379 Lucina (Parvilucina) ...... 29 =12, 26, 220, 221-223 multilineatus, Phacoides (Parvilucina) ........... 221 multispinosa, Pitar .... 300 multistriata, Petricola 333 muricata, Lucina (Lucinisea) .......... 29 1p SI 223-226 TITAS he tec cicsoccscene 112 melilinay wee 223 muricatum, Cardium 250, 251, 252 Laevicardium .......... 251 Phacoidess.... 2 224 Trachycardium (Dallocardia) ...... 35 13, 16, 17, 22, 26, 250-253 muricatus, Phacoides (Lucinisea) .............. 224 muscosa, Chlamys .... 142, 143 muscosus, Aequipecten ...... 15 11, 29, 142-145 IPE CUCHINe ssccsseecs oe 142, 143 Museum of Comparative ZOOlOSYy: wk... 6, 7 N nansemondensis, Crassinela i)... 198 manus, Pholase.....- 404 National Science Foundation .............. 5 nereidideditus, ucina Pee 218 nicholsi, Chlamys (Plagioctenium) ...... 152 nitens nitens, Ervilia 389, 393 venezuelana, ervilia’ ch 55,56. d4c3a 37: 387-389, 390, 392, 393 nitens, Tellina (Eurytellina) ...... 49 14, 23, 27, 338, 339-441 nivea, Arca .................. 59 NOAE ATCA 2) ee Ti 58: nodosa, Chlamys (Lyropecten) ............ 157 Osireat, Senate ts 156 nodosus, Lyropecten (Nodipecten) ........ 17 415 29, 156-159, 161 RECIEn: 2.2 eee: 156 noduliferus, Lyropecten .............. 158 North St. Petersburg 33, 34 notabilis, Adrana ...... 50 Anadara (Larkinia) +.:..20222 5 10, 16, 25, 69-72 PAPC. foie io Rin ee 69, 70 notata, Siliquaria ...... 373 nucicola, Mesopholas 405 nucleus, Ostrea .......... 150 Nuculana (Jupiteria) | gt nn 10, 28, 47 Nuculana (Saccella) SEIN See, ok spans 2 10, 28, 47 nuculoidea, Semele .... 359 nuculoides, Abra ........ 359 Amphidesma .......... 359 Semele (0%)... Pees 359, 360 Semelina .............. 52 14, 27 359-361 Nucwlopsis ~ .2...s26..2. 40 Nux Lucia 22 eS 218 oO obliqua, Semele .......... 354 Solenage.> 2... ....cc.c... 376 Letina ss..28%.08%....... 354 obliquus, Solen (Solena) ies. 0... 54 14, 16, 376-378 obovale, Trigoniocardia ........ 262 Oceanographic Institute, Florida State University .......00....... 15 occidentalis, Area ...... 51 EMG)... 28... .42 eer 229 occurrens, Lucina ...... 216 Olsson, Axel A. .......... 32, 33, 45 operculata, Corbula .. 400, 401, 402, 403 Sanguinolaria (Psammotella) ....53 14, 16, 558 elinal >... 5%. orbicularis, Codakia (Lentillaria) Venus orbiculata, Amphidesma ............ Codakia (Jagonia) 31 orbiculata orbiculata (Codakia) raGiata, Semele ...... orbignyi, Arca ............ ornata, Chlamys ....14 Semeleye.. ses: ornatus, Pecten .......... Oropuche River .......... Osmond, John IKONNOGth i ooh:.c eek: se SP sees rte 24 oulotricha, Chione .... ovalis, Anadara (Lunarca) PAT. CO othe ens ee Pacifica, Arca 0.005.. pailasana, Chione ..44 Paleocene ..0....00....0...... Palmer, Ephraim Laurence ................ Katherine V. W. .... palmeri, Pecten .......... panis-sacchari, Trigoniocardia ........ pannucea, Ostrea .22 paphia, Chione (Lirophora) ............ Wesco kee Papyracea, GAVIEMON) ioe sk a: Pleuronectia ............ papyraceus, Pecten INDEX 370-373 (Amusium) ....13, 14 370 Paraguana Peninsula 12, 20,26, parasitica, Ostrea ...... 26-229 parawhitfieldi, Lucina 226 pariaensis, Arca (Angina) eee b eo patagonia, Pinna ........ 299.239,'933 patagonica, Pinna ...... 230 pauperatus oligocostatus, 930 Phacoides 229, 230 (Callucina) See 356.357 ~«+ecten, Lucina ............ "999 «© Pecten sp: ti... 12 230 ~=pectinata, Arca .......... 357 Codakia (Jagonia) 31 82 1116; Glycymeris 137-139 (Tucetona) 354 OTE (criore ee 5 eevee eee 137 _ pectinatus, 35 Pectunclus .............. pectinella, Lucina ...... 6 pectiniformis, Pectunculus ............ 12,16, pellucida, Lima 184-185 (Eimaria), 6.205: 18 318 peltella, Nuculana .... oe ce oe penicillata, Plicatula .. ie) 72, penistonae, Pitar ........ 404 penistoni, Cytherea .. Pitan ee eae pennacea, Glycymeris pennaceus, Glycymeris .............. 54 Pectunculus .......0<. 13,27, perii-maris, 311-313 Trigoniocardia ........ 35 permollis, Ostrea ...... pernodosus, Pecten .... 220 perplexus, Phacoides 6,7,218 peruviana, Anomia .... 147 Petricola pexata, Anadara ........ 262 IAT CARE Pian? See 12,26, pexata holmesi, Arca 177-178 _ pfeifferi, Dreissena ................ S20 DehaAcoides, |e ee 326 philippii, Corbula ........ 385 Pholadomya 131 pictorum, Spondylus .. Pilsbry, H. A 559 11, 28, 131-136, 137 11, 28, 126-127 89 12, 16, 232-233 ? 89 220 89 115,16; 167-169 pilula, Pitar (Nanopitar) .............. pinchoti, Chione .... pisiformis, Strigilla 50 dig 210 1 i pee etre : pittieri, Pecten (Lyropecten) ..... et planulata, Tivela ........ Playa Grande Playa Grande forma- tion (Catia member) INDEX 296 313 14, 16, 20, 346-349 347 8, 10, 18, 19, 28-29, 30, 32, 33, 34 (Maiquetia member) 9, 10, 18, 19, 25-28, 30, 32, 33, 34 Playa Grande Yachting Club plebeius, Solen ........... Tagelus Pleistocene ................ plicatayATea. ...........:-. plicatella, Anatina (Raeta)s.. zee Labiosa (Raeta) . 55 utrariae. se 2... Pliocene 228 8 3s. ponderosa, Dosinia _.. ponderosa, pacali- tosana, Dosinia ........ portesiana, Chione .... WiCTUS WA AEst ores) ae. portoricensis, Mactra hi (010) 6 Ee portoricoensis, Pecten (ChIaMYyS) « <