Anatina, Lamarck. Lantern- stoll. 



Type, A. rostrata, PI. XXIIL, Fig. 7. {Anatiniis, pertain- 

 ing to a duck.) 



Synonyms, Laternula, Bolten MS. Auriscalpium, Mulilf. 

 Osteodesma, Blainyille. Cyathodonta (iindulata), Conrad ? West 

 America, 



Shell oblong, ventricose, sub^equiyalve, thin and translucent, 

 posterior side attenuated and gaping ; umbones fissured, directed 

 backwards, supported internally by an oblique plate ; hinge 

 with a spoon-ghaped cartilage process in each valye, furnished 

 in front with a transverse ossicle; pallial sinus wide and 

 shallow. 



Animal with a closed mantle and long united siphons, clothed 

 with wrinkled epidermis ; gills one on each side, thick, deeply 

 plaited ; palpi very long and narrow ; pedal opening minute, 

 foot very small, compressed. 



Distribution, 20 species. India, Philippines, New Zealand, 

 "West America. 



Fossil, 50 species. Devonian ? — Oolite — . United States, 

 Europe. 



Sub-genera, Feriploma (inequivalvis), Schum. *' Spoon- 

 hinge" of Petiver; oval, inequivalve, left valve deepest; pos- 

 terior side very short and contracted. Distrihictwn, West Indies, 

 South America. 



Cochl.odesma, Couthouy. C. preetenue, PI. XXIIL, Fig. 8. 

 (Bontia, Leach MS. Ligula, Mont., part.) Oblong, compressed, 

 thin, slightly inequivalve ; umbones fissured ; cartilage processes 

 prominent, ossicle minute ; pallial sinus deep. Animal with a 

 broad, compressed foot ; siphons long, slender, divided through- 

 out ; gills one on each side, deeply plaited, divided by an oblique 

 fiirrtfr^ into two parts, the dorsal portion being narrower, com- 

 posed of a single lamina only, and attached by its whole inner 

 surface. (Hancock.) Distribution, 2 species. United States, 

 Britain, Mediterranean. Fossil, Pliocene, Sicily. 



Cercomya, Agassiz. C. undulata, Sowerby. (=^Ehynchomya, 

 Agassiz.) Shell very thin, elongated, compressed, attenuated 

 posteriorly ; sides concentrically furrowed, umbones fissured, 

 posterior (cardinal) area more or less defined. Fossil, 12 species. 

 Oolite — Neocomian. Klurope. 



Thracia (Leach), Blainville. 



Synonyms, Odoncinetus, Costa. Corimya, Agassiz. Eupiccla 

 (concentrica"^, Bellevue. 



