NEW FRESH WATER AND LAND SHELLS. 215 



thick; ligament small, linear; epidermis yellow, with numerous or large dark 

 green rays over nearly the whole disk ; umbonial slope carinate ; cardinal teeth 

 large, pointed ; lateral teeth oblique and straight; anterior cicatrices distinct; 

 posterior cicatrices distinct, the smaller one being placed on the end of the lateral 

 tooth ; dorsal cicatrices small, placed on the upper side of the cavity of the beaks ; 

 cavity of the shell very shallow; cavity of the beaks small and angular ; nacre 

 white and iridescent. 



Remarhs. — Two specimens only were received by me from Mr. Edgar, to 

 whom I dedicate it. It is an interesting little species, and is remarkable for its 

 form and the dark green rays, which almost cover the yellow ground. The 

 larger specimen has a wide furrow nearly down the centre of the valve from 

 the beak — the smaller one is only flattened there. In both specimens the pos- 

 terior slope is devoid of rays. 



Unio DOLABELLOIDES. Plate 15, Fig. 31. 



Testa subrotundd, subinjlatd; valvulis crassissimis ; natibus valde elevatis ; epidermide fused, radiatd ; 

 dentibus cardinalibus minimis; lateralibus brevibus rectisque; margaritd alba et iridescente. 



Shell rather round, somewhat inflated; valves very thick; beaks ranch elevated; epidermis brown, 

 radiated; cardinal teeth very small; lateral teeth short and straight; nacre white and iridescent. 



Hab. Holston River, Tenn. S. M. Edgar. 



My Cabinet, and Cabinet of Mr. Edgar. 

 Diam. .9, Length 1.3, Breadth 1.3 inches. 



Shell rather round, somewhat inflated, flat before the umbonial slope; sub- 

 stance of the shell very thick; beaks very much elevated and thick; ligament 

 very short; epidermis brown, with broad interrupted rays behind the umbonial 

 slope; umbonial slope sub-carinate; cardinal teeth very small and rather flat- 

 tened; lateral teeth short and straight, with a broad plate intervening between 

 them and the cardinal tooth; anterior cicatrices distinct; posterior cicatrices dis- 

 tinct, the smaller one being placed on the end of the lateral tooth ; dorsal cica- 

 trices very small and placed on the upper side of the cavity of the beaks; cavity 

 of the shell shallow; cavity of the beaks angular; nacre white and iridescent. 

 VIIL — 3 E 



