64 



Notes on Species of Coroicidadw. 



not only in respect to the flattening of the inferior margins in 

 Corbicula difficilis, but that the Corbicula cor is larger, more 

 transverse, less inequilateral, more inflated and more robust ; 

 the beaks are fuller, larger, and more prominent ; the hinge is 

 stronger and less rounded, and the stride are deeper. 



I have every reason to suppose that the Corbicula difficilis 

 comes from Northern Africa. 



7. Corbicula leriiiscnla, nov. spec 



Corbicula levinscula, Prime in litt. Cat. 4. 1863. 

 C. testa ovato-trigona, insequilaterali ; latere antico producto, rotnn- 



Fig. 9. 



ciato, postico subtruncato ; subinflata ; umbonibns 

 parvulis, depresses, apice denudato, albidis ; mar- 

 garita albido-lilaciua ; cardine angusto ; dentibus 

 minutis; lunula inconspieua ; sulcis regularibus, 

 tenuibus ; epidermide nitidissima, fuscescente, ad 

 raarginem inferiorem pallide viridi-flavescente 

 vestita. 



Long. 27 ; lat. 26 ; diam. 17 mill. 

 Hdb. — Cochinchina. Collect. Prime. 



The shell is rounded-trigonal, inequila- 

 teral. The anterior side is produced and 

 rounded, the posterior is subtruncated. The 

 beaks are small, not much raised, and when 

 denuded show a white surface. The valves 

 are. light and not much inflated. The inte- 

 rior is pale whitish lilac. The hinge is narrow and consider- 

 ably curved. The teeth are delicate and small. The lunula is 

 indistinct. The sulci are regular and close. The epidermis is 

 highly polished, the upper portion is blackish-brown, and the 

 portion near the inferior margin is pale greenish-yellow. 



This attractive species bears some resemblance to Corhimila 

 difficilis, as far as the marginal outline is concerned ; in other 



Corbicula leviuscula. 



