[303] 



Art. VII. — New TJnionidce, Melanidce, etc., cldefly of the United States. 



By Isaac Lea. 

 Unio Murratensis. PI. 46, fig. 115. 



Testa Isevi, obliqua, tumida, solida, valde inrequilaterali, postice rotundata, antice truncata ; valvulis 

 crassis, antice crassioribus ; natibus valde elevatis, tumidis ; epidermide luteo-fuscata, con- 

 centrico-vittata, eradiata ; dentibus cardinalibus crassis, subelevatis ; lateralibus crassis, obliquis 

 rectisque ; margarita argentea et iridescente. 



Shell smooth, oblique, swollen, solid, very inequilateral, rounded behind, truncate 

 before ; valves thick, thicker before ; beaks very much elevated, swollen ; epidermis 

 yellowish-brown, concentrically banded, without rays; cardinal teeth thick and 

 somewhat raised; lateral teeth thick, oblique and straight; nacre silver-white and 

 iridescent. 



Proc. Acad. Nat. Sci. 1868, p. 143. 



Eah. — Connesauga Creek, Whitfield Co., Georgia, Major T. C. Downie ; Etowah 

 River, Geo., Bishop Elliott. 



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

 Diam. -9, Length 1-2, Breadth 1-4 inch. 



Shell smooth, oblique, swollen, solid, very inequilateral, rounded behind, truncate 

 before; substance of the shell thick, thicker before; beaks very much elevated, 

 swollen; ligament short, rather thick and light brown; epidermis yellowish-brown, 

 concentrically and distinctly banded, without rays, and with very close marks of 

 growth; umbonial slope raised and obtusely angular; posterior slope flattened 

 and cordate ; cardinal teeth thick and somewhat raised ; lateral teeth thick, oblique 

 and straight; anterior cicatrices distinct, sm.all and deeply impressed; posterior 

 cicatrices distinct and moderately impressed ; dorsal cicatrices placed under the 

 cardinal tooth; cavity of the shell rather shallow and rounded; cavity of the beaks 

 shallow and rounded ; nacre silver-white and iridescent. 



Remarlcs. — Among the oblique group of Uniones I have had, for many years, a few 

 specimens which I could not satisfactorily place with any species of the group in 

 which there had already been many classed. The entire group so completely in- 

 osculate that it is with great difficulty that they can be made out, without complete 

 suites, which few are happy enough to possess. I have had one specimen certainly 

 twenty years. Several were received six years since, and recently, by the kindness 

 Vol. VI. 73 



