78 DESCRIPTION OF NEW 



Anodonta Wahlamatensis. Plate XX. fig. 64. 



Testa (data, triangulari, subinjiaia, incequilaterali ; valvulis tennibus connatisque ; natibus 

 subcompressis, ad apices undulatis ; epidermide subfulgida; margarita alba. 



Shell winged, triangular, somewhat inflated, inequilateral ; valves thin and connate ; 

 beaks rather compressed and undulated at the tip ; epidermis somewhat shining; nacre 

 white. 



Hab. Wahlamat, near its junction witli the Columbia River. Pro- 

 fessor Nuttall. 



My Cabinet. 



Cabinet of Professor Nuttall. 



Diam. '8, Length 1*8, Breadth 2-5 inches. 



Shell winged, triangular, inflated on the lower posterior part, inequi- 

 lateral ; substance of the shell thin, the valves being connate over the 

 ligament; beaks rather compressed, undulated at the tip, and yellow as 

 far as the first stage of growth ; epidermis rather smooth and shining, hav- 

 ing a small dark band at the line of growth near the margin; cicatrices 

 scarcely visible; cavity of the shell shallow; cavity of the beaks very 

 shallow; nacre white. 



Remarks. — This is one of the species brought by Professor Nuttall 

 from his late expedition to the Columbia River, over the Rocky Moun- 

 tains. It has some resemblance to the Nuttaliiana, but cannot be easily 

 mistaken for that species, being different in outline and more inflated. 

 In its outline and in the inflation of the lower posterior portion of the 

 shell, it resembles Jllas. complanata (Barnes). Professor Nuttall also 

 met with this and the above species in Lewis's River, a branch of the 

 Shoshonee. 



Anodonta pavonia. Plate XXI. fig. 65. 



Testa ellipticd, infiatH., valdh radiata, incequilaterali ; valvulis tenuibus ; natibus prominu- 

 li^y ad apices undulatis; epidermide glabra ; margarita carulea. 



