JVotes on Species of Coruiculadce. 215 



32. Corbictila Pisidiiformis, nov. spec 



C. testa minima, trigona, triangular!, obliqua, inaequilaterali, alta, 

 subinflata ; superius conica, inferius arcuata ; latere FlG 42 



antico prodncto, postico brevi, subtruncato • umbo^ 

 nibus tumidulis; lunula distincta; striis regularibus, 

 reuiotis ; epidermide viridi-flavescente, nitente vestita ; 

 valvis solidis, intus pallide violaceis; cardine incras- 

 sato. 



Long. 5; lat. 5; diam. 3 mill. 



Hab. — Siam. Collect. Wheatley et Prime. 



The shell is very small, triangular, inequi- Corbloula mdUformis " 

 lateral, and somewhat inflated. The superior portion is conical 

 and the inferior rounded. The anterior side is distended, the 

 posterior is short and somewhat truncated. The beaks are pro- 

 minent. The lunula is well marked, but not of a distinct color. 

 The striae are deep, regular, and distant. The epidermis is 

 polished and of a yellowish-green color. The valves are solid, 

 their interior is pale violet. The hinge is robust and broad. 

 Some specimens exhibit a few fine rays of a darker color, run- 

 ning from the beaks to the inferior margin. 



The Corb. Pisidiiformis is remarkable for being the smallest 

 known species of the genus. In outline and shape it bears great 

 resemblance to certain species of Pisidium. It is closely allied 

 to Corb. Lydigiana ; irrespective of size, it differs from that spe- 

 cies in being more solid, more convex, more conical, less equi- 

 lateral, and in having heavier striae. 



33. Corbicula triangularis, Desbayes. 



Corbicula triangularis, Deshayes. Proc. Zoo], xxii. 345. 1854. 



Biv. Brit. Mus. 234. 1854. 

 Prime Cat. 4. 1863. 



C. testa trigona, sequilaterali, alta, tumidula, solida ; utroque latere 



