30 



AMERICAN CORBICULAD^E. 



species. In outline it offers some resemblance with C. colorata, 

 it is, however, larger, more inflated and very much more solid. 



33. Cyrena colorata, PKIME. Shell very small, fragile, elongated, 

 cuneiform, very inequilateral, compressed, ante- 

 Fig. 23. r j or gi( je broader, rounded ; posterior side longer, 

 produced, subabrupt at extremity ; beaks small, 

 acute ; stria? very fine, hardly visible ; color 

 variable, whitish with zones of purple, or 

 orange ; epidermis wanting ; hinge-margin 

 nearly straight, narrow, teeth small and deli 

 cate ; cardinal teeth unequal, divergent, anterior 

 tooth rudimentary, posterior ones bifid ; lateral 

 teeth unequal, elongated, narrow. 

 Long. 0.80; Lat. 0.52; Diam. 0.28 inches. 



20 ; &quot; 13 ; &quot; 7 mill. 



Hob. The West Indies, in the Island of New Providence. 

 the Smithsonian Institution, Cooper, Browne and Prime.) 



C. colorata. 



(Cabinets of 



The external appearance of this species presents all the charac 

 ter of a marine shell, its denticulation, however, places it without 

 a question in the genus Cyrena. Mr. W. Cooper, of Hoboken, 

 its discoverer, found several specimens of it in a brackish pond, 

 living in company with some Cerithia. It is smaller, more fra 

 gile, less inflated and more regular in outline than either C. flori- 

 dana, C. salmacida or C. cubensis. 



34. Cyrena anomala, DESHAYES. Shell trigonal, very much in 

 flated, heart-shaped, very inequilateral, striae very 

 Fig. 24. fi ne? regular, hardly perceptible ; epidermis light 



grayish green ; beaks large, acute, inclined inwards; 

 anterior side short, broadly semi-circular ; posterior 

 side extended, conical, acute and angular at ex 

 tremity ; valves very fragile, interior grayish with 

 markings of violet ; hinge-margin rounded, verv nar 

 row; cardinal teeth very small, approximate, sub- 

 equal, divergent, the central tooth bifid ; lateral teeth 

 C. anomala. subequal, distant, compressed ; sinus very small, 



barely visible. 

 Long. 2.00; Lat. 1.60; Diam. 1.36 inches, 



&quot; 50; &quot; 40; &quot; 34 mill. 

 Hab. South America, in Peru. (Cabinets of Cuming and Prime.) 



Cyrena anomala, DESH. Proc. Zool. XXII, 1854, 21. 

 Cyrena peruviana, DESH. Bivalv. Brit. Mus. 1854, 257. 



