88 



Notes on Sjpecies of Corbiculadce. 



The shell is transverse, subtrigonal, inequilateral, and some- 

 what inflated. The anterior side is produced and the posterior 



Fig. 36. 



Cyrena ponderosa. 



side is somewhat truncated. The valves are very ponderous. 

 The interior is white. The beaks are small and oblique, they are 

 often very much eroded. The striae are close, coarse, and indis- 

 tinct. The epidermis is dusky brown without polish. The 

 hinge is angular, broad and strong. The cardinal teeth are 

 somewhat flattened and nearly parallel. The lateral teeth are 

 not much raised, the anterior tooth is short and conical, the 

 posterior is a little longer and not quite so much raised. 



This species is somewhat allied to Cyrena Bengalica, it is 

 however smaller, a little more transverse, and the beaks are 

 much less raised and less inflated. 



5. Cyrena Cyprinseforniis, Prime. 



Cyrena Cyprinceformis, Prime. Acad. N. S. Phil. Proc. 125. 1861. 



Prime Cat. 6. 1863. 



C. testa magna, transversa, ovato-subtrigona, suborbiculari, inaequi- 

 laterali, in medio ventricosa, solida, crassa ; latere antico breviore, rotnn- 

 dato, postico angustiore, snbtruncato ; pagina interna candidissima ; 



