NEW UNIONIDJE OF THE UNITED STATES. 85 



pyramidal and striate ; lateral teeth rather short, thick, somewhat oblique and some- 

 what curved ; nacre silver white and very iridescent. 

 Proc. Acad. Nat. Sci. 1861, p. 60. 



Hob. — Cahawba River, Alabama. E. R. Showalter, M. D. 



My cabinet and cabinet of Dr. Showalter. 

 Diam. "6, Length 1, Breadth 1*4 inch. 



Shell smooth, suboblique, rather compressed, inequilateral, rounded behind and 

 round before ; substance of the shell somewhat thick, thicker before ; beaks raised ; 

 ligament rather short, thin and light brown ; epidermis yellowish horn color, rayed 

 and shining above, striate below, and with three or four distant lines of growth ; 

 umbonial slope slightly raised and rounded ; posterior slope narrow-elliptical, slightly 

 carinate, with an obscure impressed line from the beaks to the margin ; cardinal teeth 

 small, pyramidal and striate ; lateral teeth rather short, thick, somewhat oblique and 

 slightly curved ; anterior cicatrices distinct, rather large and deeply impressed ; pos- 

 terior cicatrices distinct, rather large and well impressed ; dorsal cicatrices situated 

 above the centre of the cavity of the beaks ; cavity of the shell rather shallow and 

 wide ; cavity of the beaks rather shallow and obtusely angular ; nacre silver white 

 and very iridescent. 



Remarlcs. — Two specimens of this species are before me. It is closely allied to 

 pcdtidqfalvw, herein described ; but differs somewhat in the outline, in being devoid 

 of spots on the umbonial slope, and in being more compressed. That species has no 

 rays of any kind. This has them on the beaks, interrupted at the lines of growth, 

 and extending but a short distance. This species reminds one of Hanleyanus on one 

 side and decisus on the other. It is not so transverse as the former, and not so ob- 

 lique as the latter. The beaks are not perfect enough to give us an idea of the cha- 

 racter of the undulations. 



Unio ornatus. PI. 11, fig. 234. 



Testa, ltevi, subrotunda, compressa, inxquilaterali, postice subrotunda, antici: rotunda; valvulis crassius- 

 culis, antice crassioribus ; natibus subpromiuentibus, ad apices rugoso-undulatis ; epidertuide mellea, 

 viridiinaculata, superne nitida, inferne striata; dentibus cardinalibus parviusculis, sulcatis ; laterali- 

 bus brevibus, obliquis rectisque ; margarita argentea et valde iridescente. 



Shell smooth, subrotund, compressed, inequilateral, nearly round behind, round 

 before; valves somewhat thick, thicker before; beaks rather prominent, rugosely 

 undulate at the tips; epidermis honey yellow, green spotted, bright above, striate 

 below; cardinal teeth rather small, sulcate; lateral teeth short, oblique and straight; 

 nacre silver white and very iridescent. 

 Proc. Acad. Nat. Sci. 1861, p. 41. 



