FRESHWATER AND LAND SHELLS. 47 



Shell elliptical, transverse, somewhat inflated, inequilateral, at the 

 base subeniarginate, dorsal margin curved under the beak ; umbonial 

 slope rounded ; substance of the shell thin ; beaks prominent, concen- 

 trically undulated at the tip ; ligament rather short ; epidermis green, 

 disposed to be yellow on the posterior slope and the beaks ; anterior 

 cicatrices confluent ; posterior cicatrices confluent ; dorsal cicatrices in- 

 distinct ; cavity of the shell large ; cavity of the beaks angular ; nacre 

 bluish. 



Remarks.— I have from time to time received specimens of this 

 species from Ohio, but I owe the perfect ones, now before me, to Dr 

 Ward, of Chilicothe. Aware of its resemblance to ^n. Fcrussaciana 

 (nobis), and ^n. areolatus (Swainson), that gentleman gave parti- 

 cular attention to its habits, and in his letter to me, comparing it to 

 the latter, which it most resembles, he says : " It more nearly resem- 

 bles a variety of areolatus than any other species. It, like that shell, 

 has the strong bend under the beak, which in the areolatus is almost 

 a tooth. In habit, it totally differs from areolatus. It pierces deeply 

 in the clay and gravel banks, in which it resembles the Jin. ineerta, 

 while the areolatus is only found in the deep bed of the stream, and is 

 partially uncovered." In the undulations of the beaks, it more resem- 

 bles the Ferussaciana, these being larger in the areolatus. 



Anodonta Buchanensis. Plate XIV. fig. 43. 



Testa transversa, inflatd incBquilaterali, infernh emarginata, ad latus planulata ; clivo 

 umboniali elevato ; valvulis tenuibus ; natibus prominulis ; apicibus undulalis ; epidermide sub- 

 viridi; margaritd alba. 



Shell transverse, inflated, inequilateral, emarginate at base ; flattened on the side ; 

 umbonial slope elevated ; valves thin; beaks somewhat prominent, undulated at the tip ; 

 epidermis greenish ; nacre white. 



Hab. Buck Creek, Ohio. R. Buchanan, Esq. 



My Cabinet. 



