302 MR. E. A. SMITH ON THE [Ap""' ^> 



re[)resent varieties and different stages of the same shell. The loca- 

 lity " Indian Ocean " given hy Reeve to Am. cordiformis, which he 

 assigns to Sowerby, is evidently incorrect. Say's species were from 

 Georgia and E. Florida, A. reticulata,- subtruncata, and decussata 

 from the West Indies, A. lenticularis from West Colombia, and A, 

 modesta from West Africa. 



The shells from St. Helena are only young specimens, 18 millim. 

 in length, and agree with A. modesta as figured by Reeve (Conch. 

 Icon. fig. 35 b). 



Ervilia subcancellata, Smith. 



Ervilia subcancellata, Smith, 'Challenger' Lamellibr. p. 80, 

 pi. vi. figs. 2-2 b. 



Hab. West Indies ; Fernando Noronha ; Brazil ; 25-675 fathoms. 



The concentric sculpture is much coarser in some specimens than 

 in others, and the radiating striae, as formerly pointed out, also vary. 

 Young specimens, whicli are pellucid, exhibit on each side towards 

 the end of the dorsal margin a small brown spot, also occasionally 

 observable in more adult shells. 



CoRBULA swiftiana, C. B. Adams. 



Corbula siciftiana, C. B. Adi^ms, Contrib. Conch, p. 236. 



Hab. Jamaica, St. Thomas, Hayti. 



Cardium (Fragum) sPECiosuM, Adams & Reeve. 



Cardium speciosuni, Adams & Eeeve, Voy. * Samarang,' p. 77, 

 pi. xxii. fig. 9. 



Hab, China Sea (Ad. 4' Rve.). 



After a very careful comparison of the St. Helena specimens with 

 the type of this species preserved in the British Museum, I liave no 

 hesitation in jironouncing them one and the same form. In shape 

 and sculpture they are identical, but differ in having about three 

 more ribs. The locality assigned to' this species is possibly, or 

 probably, erroneous, and I think it likely it may have been obtained 

 at St. Helena on the voyage home, for, as stated by Mr. Adams in 

 the preface to the 'Voyage,' p. vi, the ' Samarang' touched at St. 

 Helena. Whether this species should or should not be regarded 

 merely as a variety of the West-Indian C. medium, Linne, I cannot 

 now determine, not having a sufficient series of either for studying 

 tlieir variation or constancy. C. 7nedium, however, has a less oblique 

 form, and seems to be a broader shell, or, in other words, has a 

 longer ventral margin, which is not so obliquely upsloping in front. 

 The ribs, too, are usually flatter, and sculptured with much coarser 

 curved striae. 



Cardium (Papyridea) bullatum, Chemnitz. 



Eab. West Indies, Brazil, and west coast of Central America. 

 St. Vincent, Cape Verde Islands {Bunker). 



The synonymy of this species I have given in the Eeport of the 



