Notes on Species of Corbicidada. 



227 



The shell is large, orbicular-trigonal, somewhat compressed 

 and subequilateral. The anterior side is rounded and obtuse, 



Fig. 59. 



Corbicula Woodiana. 



the posterior is more produced and angular. The beaks are 

 prominent and approximate, and they curve inwardly. The 

 ligament is short and narrow. The epidermis is polished but vari- 

 able in color ; it is dark green, blackish- chestnut, or yellow. The 

 valves are solid. The interior is white with yellow on the mar- 

 gins. The striae are irregular. The hinge is angular and narrow. 

 This species, the largest known of the genus, has, as may be 

 seen by the above synonymy, received quite a number of 

 names. Thanks to the kindness of Mr. Lea, the describer of 

 the original Cyrena Woodiana, 1 have been able to examine 

 his type and thereby to institute the necessary comparisons with 

 the different synonyms. The Corbicula Woodiana, I will 

 remark, exhibits great change in the color of the epidermis, 

 hence I think the numerous mistakes that have been made con- 

 cerning it. The type, the largest specimen I have seen of the 

 species, has an epidermis of a dark chestnut color which is 

 highly polished. 



