BIOLOGICALRESULTS OF THE UNIVERSITY OF MIAMI DEEP-SEA EXPEDiTIONS. 77. MOLLUSKS FROM THE GULF OF PANAMA COLLECTED BY R/V JOHN ELLIOTT PILLSBURY, 19671 AXEL A. OLSSON Coral Gables, Florida ABSTRACT Forty-one species of mollusks from the Panamic-Pacific faunal province are described. The following new species are described and figured: Chama corallina, Tellina argis, Terebra argosyia, Glyphostoma bayeri, Carino- drillia dariena, Engina macleani, Phymorhynchus speciosus, Austrotrophon panamensis, Natica inexpectans, Calliostoma pillsburyae, C. insignis, C. joanneae, C. decipiens, Turcica panamensis, and Pectinodonta gilbertvossi. One new genus is proposed, Bayerius (type-species, Fusinus fragilissimus Dall), and the new subgenus Cantharus (Muricantharus) (type-species, Pseudoneptunea panamica Hertlein & Strong), both in the family Buc- cinidae. Relationships in the broad family Turridae are discussed, and the radular characters of several genera are described and illustrated. It is shown that Strombinoturris crockeri Hertlein & Strong belongs to the genus Brachytoma Swainson and is a junior synonym of Brachytoma stromboides (Sowerby). Dall's Cocculina nassa is shown to be a species of Pectinodonta allied to P. gilbertvossi, n. sp. INTRODUCTION Together with Dr. Frederick M. Bayer of the Rosenstiel School of Marine and Atmospheric Sciences of the University of Miami, the author has been engaged in a general study of the molluscan collections obtained during the cruise of the R/V JORN ELLIOTT PILLSBURYin the Gulf of Panama in 1967 and of the yacht ARGOSYin 1961 from Panama southward along the coast of Ecuador to Isla la Plata. Hitherto, our principal information on Panamic-Paci1ic mollusks has been largely restricted to shore fOnTIS readily obtainable in tidal waters; therefore the PILLSBURY and ARGOSY mollusks from offshore stations have added much needed information concerning abundance and distribution, data which later may be useful in the assess- ment of changes in ecology which may result through the construction of a sea-level canal across the Isthmus of Panama. The original plan of the PILLSBURY cruise called for midwater and bottom trawling throughout the gulf, not only on the shelf and slope, but also beyond the Continental Shelf. Unfortunately, due to mechanical difficulties, only a single bottom haul was taken in deep water (station 526) south of the fault scarp which marks the 1 Contribution No. 1310, from the University of Miami, Rosenstiel School of Marine and Atmospheric Sciences. This paper is one of a series resulting from the National Geographic Society-University of Miami Deep-Sea Biology Program. 36 Bulletin of Marine Science [21(1) south edge of the shelf. The results of this haul were so spectacular in all groups that further exploration in the general area would be desirable. In the bottom operations of the PILLSBURY,the standard 10- and 40- foot otter trawls were used, so that mainly medium to large sized mollusks were taken, most of the smaller ones being lost. It is hoped that in any future operation in the gulf, especially near the Pearl Islands, some dredging will be made for the recovery of the smaller forms which are known to abound in that area. It is the purpose of this paper to record some of the most interesting highlights from the collection of mollusks obtained by RjV PILLSBURY, with a few from that of the ARGOSY,and the unexpected discovery of some forms hitherto unknown in Panamic waters, along with the description of some new species, comments on others, and some observations on radulae. A list of the molluscan species obtained in the Bay of Panama during the PILLSBURY cruise will be given in another paper, along with other inverte- brates, etc. A separate report on the ARGOSYmollusks will appear else- where. ACKNOWLEDGMENTS The opportunity to work with the molluscan collection secured by the PILLSBURYand ARGOSYcruises in Panamic and Ecuadorian waters has been a special privilege for which I am deeply indebted to Dr. Gilbert L. Voss, who was Chief Scientist aboard Research Vessel JOHN ELLIOTT PILLSBURYduring its cruise in the Gulf of Panama and under whose direc- tion the collections were so carefully preserved, and especially to Dr. Frederick M. Bayer, in charge of the invertebrate collections at the School, for our close cooperation in all phases of this study. Also, I am pleased to thank Mrs. Jo Anne Romfh, former assistant in the Deep-Sea Biology Project, for her assistance during my visits to the laboratory. Research has been supported by a grant from the National Geographic Society for in- vestigations of deep-sea biology, and the operation of RjV PILLSBURY was supported by NSF grant GB-5776. Class PELECYPODA Family Nuculidae Genus Nuculana Link, 1807 Type-Species.-Arca rostrata Chemnitz (= Mya pernula Muller), by mono- typy. Recent, Europe. Subgenus Costelloleda Hertlein & Strong, 1940 Type-Species.-Nucula costellata Sowerby, by original designation. 1971] Olsson: Mollusks from the Gulf of Panama 37 Nuculana (Costelloleda) costellata (Sowerby) Fig. 12 Nucu/a costel/ata Sowerby, 1833, Proc. Zool. Soc. Lond., 1832: 198. "Hab. ad Panamam. Ten fathoms." Leda (Leda) costel/ata (Sowerby), DaH, 1908, Bull. Mus. Compo ZooI. Harv., 43(6): 375. N ucu/ana (Costelloleda) costellata (Sowerby), Hertlein & Strong, 1940, Zoologica, N.Y., 25(4): 398-399, pI. 2, fig. 10. Remarks.-An elongated shell with a pale olivaceous periostracum, the surface underneath white and sculptured with raised, distant concentrics. Figured specimen measures: length 15.7 mm, height 5.8 mm, thickness of paired valves 3.5 mm. Material Examined.-PILLSBURY Sta. P-488, Gulf of Panama, 8°13.I'N, 80009.6'W, depth 17 m, 1-2 May 1967. UMML 28-2297.-PILLSBURY Sta. P-543, Gulf of Panama, 8°21.4'N, 78°45.5'W, depth 62-70 m, 7 May 1967. UMML 28-2727. Genus Adrana H. & A. Adams, 1858 Type-Species.-Nucula (Adrana) lanceolata Lamarck, by subsequent des- ignation: Stoliczka, 1871. Adrana exoptata (Pilsbry & Lowe) Figs. 2, 3 Leda (Adrana) exoptata Pilsbry & Lowe, 1932, Proc. Acad. Nat. Sci. Phila- delphia, 84: 107, pI. 17, figs. 8, 9. Adrana exoptata (Pilsbry & Lowe), Olsson, 1961, Panamic-Pacitic Pelecy- poda: 71, pI. 3, fig. 6. Remarks.- The shell of this species is small, delicate, with a straight dorsal margin and weak to strong sculpture. A single paired specimen in the collection. Length 15.0 mm, height 10.0 mm. Material Examined.-PILLSBURY Sta. P-488, Gulf of Panama, 8°13.1'N, 80009.6'W, depth 17 m, 1-2 May 1967. UMML 28-2296. Adrana marella (Hertlein & Strong) Fig. 11 N ucu/ana (C ostel/o/eda) marella Hertlein & Strong, 1940, Zoologica, 25 (4) : 399, 400, pI. 2, figs. 12, 13. Remarks.-Shells of this species are fairly large, with fine concentric sculp- ture. Figured specimen, a right valve, measures: length 27.8 mm, height 10.7 mm, semidiameter 2.5 mm. Material Examined.-PILLSBURY Sta. P-S43, Gulf of Panama, 8°21.4'N, 38 Bulletin of Marine Science [21 (1) FIGURES 1-12. Panamic Pelecypoda: 1, Limopsis compress us Dall; length without periostracum 36.5 mm, height 28.8 mm, UMML 28-2717, PILLSBURY Sta. P-526.-2, 3, Adrana exoptata (Pilsbry & Lowe); paired valves, length 15 mm, UMML 28-2296, PILLSBURYSta. P-488.-4-6, Tellina (Tellina) argis, new species, holotype; 4,5, right valve, exterior and interior, length 32.1 mm; 6, magnified view of surface to show details of sculpture; ARGOSYSta. 38.- 7-10, Chama corallina, new species, holotype, paired valves; height 22.6 mm, 1971] Olsson: Mollusks from the Gulf of Panama 39 78°45.5'W, depth 62-70 m, 7 May 1967. UMML 28-2644, 6 specimens; also a fragment of a larger shell from the same station, UMML 28-2656. Family Limopsidae Genus Limopsis Sacco, 1827 Type-Species.-Arca aurita Brocchi, by monotypy. Upper Neogene of Italy. Limopsis compressus Dall Fig. 1 Limopsis compressus DaH, 1896, Proc. U.S. Nat. Museum, 18: 16; 1908, Bull. Mus. Compo Zoo!., 43(6): 392, p!. 7, figs. 7, 8. (USS ALBATROSS Sta. 3382, Gulf of Panama, 1793 fathoms = 3279 meters, mud bottom, temperature 36°F. Type, USNM 122889.) Description.- The shell is rather large, with the valves thin, compressed, obliquely ovate, the small, inconspicuous beaks closer to the anterior end; it is externally covered with a yellowish brown, pilose periostracum, the surface below white, polished, and marked with a faint reticulate pattern of concentrics and radials. Unusual for its large size. Measurements.-Length exclusive of periostracum, 35 mm, height 28 mm, diameter 9.9 mm (an average specimen). Material Examined.-PILLSBURY Sta. P-526, Gulf of Panama, 6°53'N, 79°27'W, depth 3193-3200 m, 5 May 1967. UMML 28-2717, 15 perfect specimens and one free valve. Family Chamidae Genus Chama Linne, 1758 Type-Species.-Chama gryphoides Linne, by subsequent designation: Schumacher, 1817. Mediterranean. Chama corallina, new specIes Figs. 7-10 Description.- The shell is small with rounded plump valves of a pinkish or coral red color, attached by a small area on the umbo of the left valve. length 20 mm, PILLSBURYSta. P-549.-11, Adrana marella (Hertlein & Strong); length 27.8 mm, height 10.7 mm, UMML 28-2644, PILLSBURYSta. P-543.- 12, Nuculana (Costelloleda) costellata (Sowerby); length 15.7 mm, height 5.8 mm, UMML 28-2297, PILLSBURYSta. P-488. 40 Bulletin of Marine Science [21(1) The left or attached valve is a little larger than the right, its umbonal sec- tion coiled so as to resemble a small, Cretaceous chamoid. Both valves are of nearly equal convexity. Surface sculpture consists of small, crowded, radial wrinkles and on an occasional specimen there are a few lines of small, radial, sharp spines. The internal edge of the valve margin shows two shell layers; the outer one, probably calcitic, is minutely wrinkled and pinkish, and the inner layer, also finely crenulated, is white.