ERVILIA. 341 



the same spot, he has never procured a second example we think it 

 most 2)rohahle that the shell came from some foreign vessel. 



ERVILIA, TuRTON. 



Shell more or less solid, equivalve, inequilateral, oblong-, 

 depressed, closed. Surface transversely striate or nearly 

 smooth. Two diverging teeth in each valve, one of them 

 in the right valve high and jirojecting : a cartilage pit in 

 each for the reception of the connecting internal cartilage. 

 No lateral teeth. Muscular impressions strong ; pallial 

 sinus large and broad. 



Animal unknown. 



This genus, which was constituted by Turton for the 

 Mya nitens of Montagu, has lately been revised and re- 

 defined by Recluz.* It has considerable relations with 

 Mesodesma^ but until the animal shall have been observed, 

 its true position can only be assigned by analogy, as indi- 

 cated by the shell alone. The species here described are 

 all which have as yet been enumerated as members of the 

 group. 



E. CASTANEA, MoutagU. 



Plate XXXI. figs. 5, 6. 



Dona<K castanea, Mont. Test. Brit. p. 573. — Linn. Trans, vol. viii. p. 77. — Turt. 



Conch. Diction, p. 42. — Dillw. Recent Shells, vol. i. p. 152. 



— Index Testae, pi. 6, Donax, f. 10. 

 Capsa cadaneu, Turt. Dithyra Brit. p. 128, pi. 10, f. 13. — Flem. Brit. Anim. 



p. 434.— Brown, 111. Conch. G. B. p. 06, pi. 39, f. 12. 

 Mesodesma castanea, Brit. ]\Iarine Conch, p. 54. 

 ErvUia castanea, Recluz, Mag. de Zool. 1845, pi. 95. — Recluz, in Chenu III. 



Conch. Ervilia, p. 3. 



The shape of this interesting and rare shell, erroneously 

 placed by Dr. Turton in the genus Capsa (which has a 



* Revue Zoologi(iue par la Soc. Cuvierienue, Marcli, 1844. 



