CALLISTA. 



425 



Shell transverse, ovate, inequilateral, closed ; margins of 

 valves entire, often obtuse. Hinge tri-dentate in the left 

 valve, the anterior lateral tooth united to the lunular tooth. 

 Pallial line with a wide, deep, semi-ovate sinus. 



Sy?i. Chione, Gray, not Muhlfeldt. Dione, Gray. 



Ex. C. Chione, Linnceus, pi. 108, fig. 1. Shell, C. 

 Dione, Linnaeus, fig. 1, a, I, b. 



In this genus the form of the animal is ovate-oblong; the 

 labial appendages are triangular, narrow, and acuminated; 

 the gills are elongated, unequal, transverse, posteriorly 

 united and acuminate, the outer ones the narrowest; and 

 the foot is large, compressed, and linguiform. The shell is 

 either sub-orbicular and inflated, or ovate and trigonal ; and 

 the surface of the valves is either smooth, sulcated, striated, 

 or lamellose. 



Species of Callista. 



acuminata, Sow. 

 affinis, Brod. 

 albida, List. 

 albocincta, Soic. 

 angulifera, Sow. 

 aurautia, Hanley. 

 Belcheri, Sow. 

 brevispinata, Sow. 

 bullata, Soiv. 

 Candida, Desk. 

 Chinensis, Chem. 

 Chione, Linn. 

 circinata, Born. 

 citrina, Lain. 

 concinna, Sow. 

 consanguinea, Sow. 

 convexa, Say. 

 cor, Wood. 



cordiforinis, Dhr. 

 costata, Chem. 

 crocea, Desh. 

 cygnus, Lam. 

 Diemensis, Hanley. 

 Dione, Linn. 

 disrupta, Sow. 

 Erycina, Linn. 

 festiva, Sow. 

 florida, Lam. 

 floridella, Gray. 

 fluctuata, Sow. 

 gibbosula, Desh. 

 gigantea, Chem. 

 grata, Desh. 

 Grayi, Desh. 

 Hagenowi, Dkr. 

 hebrosa, Lam. 



