CORBULID-aE. 141 



for the purpose of supporting the cartilage, which seems likely , 

 has yet to be satisfactorily determined. 



Spheniopsis, Saudberger, 1863. 



Distr. — S. scalatHs, Braun. Tertiary; Germany (cv, 1-3). 



Shell subtrigonal, compressed, equivalve, posteriorly^ rostrate 

 and slightly gaping ; hinge of right valve with an anterior car- 

 dinal tooth, and a deep cartilage-pit behind it, a long laminar 

 tooth runs along the areal margin ; left valve edentulous, only 

 provided with a cartilage-pit ; pallial sinus deep. 



Ne^ra, Gra}^, 1834. 



Etym. — Neaera, a Roman lady's name. 



Syn. — Cuspidaria, Nardo, 1840. Sphena, d'Orb., 1846. 



Distr. — 22 sp. Norway, Britain, Mediterranean, Canaries, 

 Madeira, China, Moluccas, New Guinea, Chili ; from 12-200 

 fathoms. Fossil, 14 sp. Oolite — ; Britain, Belgium, Italy. N. 

 ornatissima, Orb. (cv, 4, 5). 



Shell globular, attenuated, and gaping behind ; right valve a 

 little the smallest ; umbones strengthened internally by a rib 

 on the posterior side ; cartilage-process spatulate, in each valve 

 (furnished with a movable ossicle — Deshayes), with an obsolete 

 tooth in front, and a posterior lateral tooth ; pallial sinus very 

 shallow. 



Animal with the mantle closed ; foot lanceolate ; siphons 

 short, united, branchial largest, anal with a membranous valve, 

 both with a few long, lateral cirri. 



Placed by Messrs. Adams in the Anatinidse, though judging 

 from the form of the shell, being in many respects similar to 

 that of Corbula, and also from the form of the small foot and the 

 short siphons of the animal, there can be little doubt that Des- 

 hayes' classification near Sphsenia, Corbula, etc., is the more 

 correct one. Almost the only character which some species of 

 the genus have in common with the Anatinidse is the presence of 

 a small ossicle at the cartilage, but as all the Anatinidse do not 

 possess the same, its presence cannot be regarded as an exclu- 

 sive character of that family. 



RHiNOMYA, A. Ad., 1864. For those forms having the surface 

 of the shells lamellar, like Nesera proper, but possessing a small 

 triangular cartilage-pit, and two lateral teeth in the right valve. 

 N. PhilijDpinensis, Hinds. 



CARDiOMYA, A. Ad., 1864. Species with the surface radiately 

 ribbed. iV. Gouldiana, Hinds. 



CoRBULOMYA, Nyst., 1846. 

 Etym. — Corbula and Mya. 



Distr. — 3 sp. Mediterranean. Fossil, 7 sp. Eocene ; France, 

 Belgium, England. C. antiqua, Desh. (cvii, 38). 



