CYREXA. 29 



Huh. Noi'tli America, at Tampa Bay, in the State of Florida. (Cabinets 

 of Phillips and Prime.) 



Cyrena Jloridana, Conkad, Proc. Ac. N. S. Phil. Ill, 184G, 23, pi. 1, 

 f. 1. 



This species has no epidermis, and presents many of the cha- 

 racters of a marine shell ; compared with G. i-almacida, which is 

 about of the same size, it differs in being irregular in outline, less 

 elongated and of a somewhat different color ; it is smaller and 

 coarser than G. maritima, and larger than either G. colorata or 

 C. cubensis. 



31. Cyrena cubensis, Prime. — Shell small, trigonal, compressed ; 

 anterior side short, rounded ; posterior side produced, subangular ; beaks 

 small, raised, inclined towards the anterior, not eroded ; stripe fine ; epider- 

 mis wanting ; color violet ; hinge-margin broad ; cardinal teeth diverging ; 

 valves solid, interior salmon color. 



Long. 0.60 inch. 

 " 15 mill. 



Hab. North America, in the Island of Cuba. (Cabinet of ?.) 



Cydas maritima, D'Okb. Moll. Cuba, II, 1853, 280, pi. xxi, f. 47-50. 



This species presents the appearance of a marine shell ; com- 

 pared with G. Jloridana it is smaller and more regular in outline ; 

 it is larger and more solid than G. colorata ; it is smaller, less in- 

 flated and more highly colored than G. maritima, and smaller and 

 more inflated than G. salmacida. 



32. Cyrena salmacida, Morelet.— Shell inequilateral, oval, 

 solid, elongated ; anterior side short, rounded ; 



posterior elongated, subabrupt at end ; beaks Fig. 22. 



small ; striae irregular, not heavy ; epidermis 

 wanting, exterior of valves whitish or flesh- 

 colored ; hinge-margin narrow ; cardinal teeth 

 small ; lateral teeth small, elongated. 



Long. 1.08; Lat. 0.76 inches. 



" 27; " 19 mill. 



. ~. , O. salmacida. 



Hah. Central America, near the Port of Sisal, 



in Yucatan. (Cabinets of Morelet and Cuming.) 



Cyrena salmacida, Morelet, Test. nov. Cub. pt. 2, 1851, 26. 



The specimens collected by the author, which have passed 

 through my hands, were found in salt-water marshes. A rare 



