230 Notes on Species of Corbiculadce. 



epidermicle atro-fuscescente vestita; valvis intus albis ad margines inferne 

 posticeque violaceis ; cardine incrassato. 



Long. 97 ; lat. 7S ; diam. 40 mill. 



Hah. — Nicobar. Collect. Prime. 



The shell is large, transversely oval, insequilateral, heavy, and 

 somewhat compressed. The anterior side is short and rounded, 

 the posterior is broader. The beaks are placed obliquely. The 

 epidermis is blackish. The interior of the valves is white with 

 violet on the inferior and posterior margins. The shell is mode- 

 rately broad and strong. 



Comparing this species with Batissa Keraudrenia we find 

 that it is transversely longer and smaller, that the posterior 

 margin is more rounded, and that the primary teeth are broader 

 and shorter ; the color of the epidermis, moreover, is different. 



3. Batissa triquetra, Deshayes. 



Batissa triquetra, Deshayes. Proc. Zool. xxii. 13. 1854. 

 Biv. Brit, Mus. 236. 1854. 

 Prime Cat. 5. 1863. 



B. testa parva, trigona, obliqua, insequilaterali, compressiuscula ; mar- 

 FlG 61. gi ne antico dilatato, postico obtuso, in- 



feriore vix arcuato ; umbonibus brevi- 

 bus ; valvis tenuibus intus albis ; epi- 

 dermide nigro, viridescente vestita ; 

 cardine angusto, dentibus lateralibus 

 elongatis, angnstis, subseqnalibus. 



Long. 39 ; lat. 36 ; diam. 11 mill. 



Ilab. — Insulse Philippinenses, 

 Australia. Collect. Cuming et 

 Prime. 



Batissa triquetra. ml i n • n l ' l i 



The shell is small, trigonal, ob- 

 lique, inequilateral, and somewhat compressed. The anterior 

 margin is produced, the posterior is obtuse, and the inferior 



