20 NEAV UNIONIDiE OF THE 



Shell smooth, oblong, compressed, flat at the sides, biangular behind, rounded before, 

 very inequilateral; valves rather thin; beaks a little i^rominent and undulate at the 

 tips ; epidermis brownish green, striate, obsoletely radiate ; cardinal teeth small, 

 striate, crenulate ; lateral teeth very long, lamellar and nearly straight ; nacre white, 

 salmon, often purple and very iridescent. 

 Proc. Acad. Nat. Sci. 1859, p. 170. 



Hah. — Near Columbus, Georgia. G. Hallenbeck. 



My cabinet and cabinet of Mr. Hallenbeck. 

 Diara. -5, Length -9, Breadth 2 inches. 



Shell smooth, oblong, compressed, flattened at the sides, biangular behind, rounded 

 before, very inequilateral ; substance of the shell thin ; beaks a little prominent, with 

 small transverse undulations at the tips ; ligament long, thin and light brown ; epider- 

 mis brownish green, striate, obscurely radiate, with distant obscure lines of growth ; 

 umbonial slope slightly raised and rounded ; posterior slope carinate, with two indis- 

 tinct lines in each valve from the beaks to the margin; cardinal teeth small striate, 

 crenulate, slightly raised; lateral teeth very long, lamellar and nearly straight; 

 anterior cicatrices distinct and moderately well impressed ; posterior cicatrices conflu- 

 ent and slightly impressed ; dorsal cicatrices situated under the plate posterior to the 

 cardinal teeth ; cavity of the shell very shallow and wide ; cavity of the beaks very 

 shallow and rounded ; nacre usually purplish, sometimes white or salmon and very 

 iridescent. 



Remarlcs. — Mr. Hallenbeck sent me a number of specimens of this species, but no 

 soft parts were received. In outline it is very near to salebrosus (nobis), but is a much 

 smaller and thinner shell, and it differs in the color of the epidermis, which is green- 

 ish and not yellowish or reddish brown, and it is more oblique. It is also near to 

 viridiradiaius (nobis), being greenish and about the same size and thickness, but it is 

 more oblong, that species being more elliptical and more radiate. 



Unio quadratus. pi. 54, fig. 163. 



Testa Isevi, quadrata, compressa, ad latere planulatft, insequilaterali, postice obtuse biangulatfl; valvuHs sub- 

 crassis ; natibus prominulis ; epidermide vel rufo-fusca vel tenebroso-fusca et obsolete radiatil ; denti- 

 bus cardinalibus subcrassis, compresso-conicis, crenulatis, in utroque valvulo duplicibus ; lateralibus 

 longis, lamellatis, crassis curvisquej margarita vel albS, vel purpurescente et iridescente. 



Shell smooth, quadrate, compressed, flattened at the sides, inequilateral, obtusely 

 biangular behind ; valves rather thick ; beaks a little prominent ; epidermis reddish 

 brown or dark brown and obsoletely rayed ; cardinal teeth rather thick, compressed 

 conical, crenulate, double in both valves; lateral teeth long, lamellar, thick and 

 curved ; nacre white or purplish and iridescent. 

 Proc. Acad. Nat. Sci. 1859, p. 172. 



