18 NEW UNIONID^, MELANIDiE, ETC., 



large, striate and crenulate; lateral teeth lamellar and corrugate ; nacre whitish or 

 purplish and very iridescent. 



Proc. Acad. Nat. Soi., 1863, p. 19J. 



Eab. — Near Charlotte, Mecklenberg County, North Carolina, E. Emmons, M. D. 



My cabinet and cabinet of Dr. Emmons. 

 Diam. 1-2, Length 2-2, Breadth 3-8 inches. 



Shell smooth, elliptical, slightly compressed, inequilateral, slightly flattened at the 

 sides, biangular behind and rounded before ; substance of the shell thick, thicker 

 before; beaks slightly prominent; ligament large and dark brown; epidermis dark 

 brown, obscurely rayed, with rather distant marks of growth ; umbonial slope 

 slightly raised and obtusely angular; posterior slope rather narrow and slightly 

 carinate ; cardinal teeth rather large, striate and crenulate, double in the right and 

 disposed to be treble in the left valve ; lateral teeth long, lamellar, somewhat curved 

 and corrugate ; anterior cicatrices distinct, large and well impressed ; posterior cica- 

 trices confluent, large and slightly impressed ; dorsal cicatrices placed immediately 

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

 the beaks shallow and obtusely angular; nacre whitish or purple and very 

 iridescent. 



Remarlcs.— There were but three specimens of this . species from Dr. Emmons, 

 diflfering much in size. It belongs to the complanatm group, and is nearest perhaps 

 to Savannahensis (nobis), but is not so high nor angular on the umbonial slope, is 

 more elliptical in the outline, difiers in the teeth, has closer marks of growth, 

 and has a darker epidermis. The beaks were not perfect enough to observe any 

 undulations at the tips. 



Unio perlucens. PL 5, fig. 16. 



Testa lasvi, elliptioa, subinflata, valde insequilaterali ; valvulis subtenuibus, antice parum crassioribus ; 

 natibus prominulis; epid^rmide luteo-virente, perlutescens et radiis indutis; dentibus cardinalibus 

 parvis, compressis, crenulatis. in utroque valvulo duplicibus ; lateralibus longis, lamellatis subrec- 

 tisque; margarita caeruleo-alba et valde iridescente. 



Shell smooth, elliptical, somewhat inflated, very inequilateral ; valves rather thin, 

 rather thicker before ; beaks a little prominent ; epidermis yellowish green, very 

 bright and covered with rays ; cardinal teeth small, compressed, crenulate, double in 

 both valves; lateral teeth long, lamellar and nearly straight; nacre bluish white and 

 very iridescent. 



Proc. Acad. Nat. Sci., 1863, p. 193. 



S"a6.— Six Runs, Sampson County, North Carolina, E. Emmons, M. D. 



My cabinet and cabinet of Dr. Emmons. 

 Diam. -7, Length 1, Breadth 2 inches. 



