FRESHWATER AND LAND SHELLS. 79 



Shell elliptical, inflated, very much radiated, inequilateral; valves thin ; beaks some- 

 what prominent and undulated at the tip ; epidermis smooth ; nacre bluish. 



Hab. head waters of the Little Beaver, Ohio. J. P. Kirtland, M. D. 



My Cabinet. 

 Cabinet of Dr Kirtland. 

 Cabinet of Mr Hyde. 

 Cabinet of Dr Jay. 

 Diam. 1-1, Length 15, Breadth 3 inches. 



Shell elliptical, inflated, very much radiated, inequilateral ; substance 

 of the shell thin ; beaks somewhat prominent and furnished with ra- 

 ther large undulations at the tip; ligament rather short and thin; epi- 

 dermis smooth, shining and furnished with numerous dark green rays, 

 which diverge to the whole margin, the larger ones being generally 

 about the centre of the valve; anterior cicatrices confluent; posterior 

 cicatrices confluent ; dorsal cicatrices placed on the interior of the curve 

 at the point of the beaks ; cavity of the shell deep and large ; cavity of 

 the beak small and angular; nacre bluish. 



Memarks. — I owe to Dr Kirtland this beautiful ^nodonta, which 

 he has recently discovered in the Little Beaver, in considerable 

 quantities. In the interior it very much resembles .^n. Ferussacia- 

 na (nobis) and has, like that shell, an incipient tooth at the immediate 

 point of the beak. In the exterior it is distinguished from all the 

 species with which I am acquainted, by its numerous and very beau- 

 tiful dark green rays, which so much pervade as to give the disk, in 

 some individuals, almost a black appearance. 



Anodonta Newtoniensis. Plate XXI. fig. 66. 



Testa elliptica, inflata, incequilaterali ; vahulis crassis; nalibus subprominentibus, ad apices 

 undulatis ; epidermide fulgida ; margariia alba. 



Shell elliptica], inflated, inequilateral ; valves thick ; beaks rather prominent and un- 

 dulated at the tip ; epidermis shining ; nacre white. 



