Two JVew Species of MoUusca of the Genus Corbioula. 481 

 2. Corbicula iiiediocris, nov. sp. 



T. ovato-transvers&., compressiuscola, subsequi- 

 laterali, temii, latere antice subangulato, postico 

 snbtruncato ; umbonibus tumidis, brevibus, lajvi- 

 gatis ; lunula ovato-lanceolata, pallida, laevigata ; 

 transversim regulariter sulcata; epidermide flaves- 

 cente-viridi, vestit^, ad umbones atro-violascente 

 radiata ; valvis intus violaceo-rubris ; cardine an- 

 gusto inajqualiter tridentato ; dentibus lateralibus 

 brevibus, angustis, albis, teiiue striatis. 



Long. 22; lat. 17; diam. 11 mill. 



f ; ri ; tV poll- 



Hah. f (Mj Cabinet.) 



This species is comparatively delicate, it is nearly equilateral ; 

 the anterior side is somewhat distended and angular, the pos- 

 terior being abrupt, the beaks are small and not much raised, 

 the lunula is distinct and of a lighter color than the rest of the 

 shell ; the strise, though somewhat coarse, are regular and 

 close ; the epidermis is j^ellowish-green, the valves very little 

 convex are, in the interior, dark purplish-violet. 



Compared with the C. occidens, from India, to which it is 

 closely allied, the beaks are smaller, the hinge is slighter, but 

 the main difference consists in the fact that in the G. mediocris 

 the anterior side is distended and angular, whereas in C. 

 occidens it is rounded. 



