234 



Notes on Species of Corliculadoe. 



The shell is orbicular, trigonal, compressed, inequilateral, 



and light. The anterior side 

 is rounded. The superior mar- 

 gin is convex and the inferior 

 is curved. The beaks are 

 small, depressed, oblique, and 

 approximate. The valves are 

 delicate, the color of the 

 interior is white. The epi- 

 dermis is green and polished. 

 The striae are more or less ob- 

 solete. The hinge is narrow 

 and slight. 



This species is very closely- 

 allied to Cyrena nittda, from 

 the same locality, of which it is very possible it may be the 

 young ; it differs in being smaller, more compressed, and gene- 

 rally more delicate. 



Cyrena laevis. 



9. Cyrena triangularis, Metcalfe. 



Cyrena triangularis, Metcalfe. Proe. Zool. xix. 74. 1851. 

 Biv. Brit. Mus. 242. 1854. 



C. testa orbiculato-trigona, solida, compressiuscula, subaequilaterali ; 

 margine anteriore rotundato, posteriore subobtuso, superiore angulato, 

 inferiore arcuato ; umbonibus brevibus, approximatis ; valvis crassis, 

 intus candidis ; striis irregularibus, epidermide fuscovirescente vestita ; 

 cardine lato, anguloso. 



Long. 80 ; lat. 74 ; diam. 44 mill. 



Sab. — Borneo. Collect. Metcalfe et Prime. 



The shell is orbicular-trigonal, solid, somewhat compressed, 

 and subequilateral. The anterior margin is rounded, the pos- 

 terior somewhat obtuse, the superior angular, and the inferior 

 rounded. The beaks are small and approximate. The valves 



