NEW UNIONIU.E OF THE UNITED STATES. 75 



Unio Lewisii. pi, 8, fig. 220. 



Testa lasvi, subrotunda, suborbiculari, subasquilaterali ; valvulis crassissimis, anticfi cras.sioribus ; natibus 

 elcvatis, turaiJis incurvisque; epidcrmide luteola, punctata; dentibus cardinalibus crassissimis, erectis 

 crenulatisquo; lateralibus crassissimis, brevibus et obliquisj margarita alba et iridescente. 



Shell smooth, subrotund, suborbicular, nearly equilateral ; valves very thick, thicker 

 before; beaks raised, swollen and incurved; epidermis yellowish and with spots; 

 cardinal teeth very thick, erect and crenulate; lateral teeth very thick, short and 

 oblique ; nacre white and iridescent. 



Proc. Acad. Nat. Sci. 1861, p. 40. 



Hah. — Coosa River, Alabama. E. R. Showalter, M. D. 



My cabinet and cabinets of Dr. Showalter, Dr. Lewis and Dr. Hartman. 

 Diam. -9, Length 1-3, Breadth 1-3 inch. 



Shell smooth, sulirotund, subglobose, nearly equilateral ; suljstance of the .shell very 

 thick, thicker before ; beaks very much raised, swollen and incurved ; ligament very 

 short, thick and light brown ; epidermis yellowish, inclining to horn color, with 

 regular rather close lines of growth, without ray.s, with two or three small, well de- 

 fined dark spots at the intersection of the lines of growth before the umbonial 

 slope; umbonial slope raised and rounded; posterior slope broad, cordate, very 

 slightly raised, with two indistinct impressed lines in each valve; cardinal teeth very 

 thick, elevated, somewhat compressed and crenulate ; lateral teeth very thick, short 

 and oblique; anterior cicatrices distinct, small and deeply impressed; posterior 

 cicatrices distinct, small and well impressed ; dorsal cicatrices small, placed on the 

 plate within the cavity of the beaks ; cavity of the shell somewhat deep and 

 rounded ; cavity of the beaks very shallow and rounded ; nacre white and iridescent. 



i2e»iar/iw.— Several specimens of this species are before me. It is a remarkably solid 

 species, having high solid massive beaks and teeth. It is nearly allied to cor, Con., 

 but is more rotund than that species, with less elevated beaks. All the specimens 

 before me are without any ray or spot, except the younger and more perfect ones, 

 which have a single pointed, green spot at the intersection of the first two or three 

 lines of growth in each valve before the umbonial slope. These are remarkable for 

 their small size and distinctness. In one specimen these are elongate, and make an 

 obscure line. In all the old individuals these spots have disappeared. I have "-reat 

 pleasure in naming this species after my friend, James Lewis, M. D., of Mohawk, 

 New York, who has done so much to promote a knowledge of the fresh water and 

 land MoUu-sca of our country, and to whom I am under very many obligations in 

 sending me new species, with his valuable notes, on all occasions. 



Unio stabilis. pi. 8. fig. 221. 



Testa loevi, triangulari, valde tumida, valde inacquilaterali, postic6 subbiangulari, antici> rotundata ; valvulia 

 percrassis,antici^crassioribus; natibus valde promiDcutibus, tumidis, solidissimis, incurvis; epidcrmide 



