DESCRIPTION OF FIFTY-TWO SPECIES OF UNIONID^. 4T 



Shell smooth, oblong, somewhat compressed, flattened at the sides, inequilateral, 

 subbiangular behind, rounded before ; substance of the shell rather thick, slightly 

 thicker before ; beaks a little prominent, at the tips concentrically and roughly 

 wrinkled ; ligament rather large and dark brown ; epidermis dark brown, shining 

 and radiate; umbonial slope somewhat raised and obtusely angular; posterior slope 

 carinate and rather narrow-elliptical ; cardinal teeth rather small, conical, rugose 

 and somewhat double in both valves ; lateral teeth very long, lamellar and some- 

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

 terior cicatrices confluent, rather large and slightly impressed; dorsal cicatrices 

 placed in the centre of the cavity of the beaks ; cavity of the shell shallow and 

 wide ; cavity of the beaks shallow and rounded ; nacre salmon colored and very 



iridescent. 



Bemarks.—l have four specimens before me. This species is nearly allied to 

 Catawhensis and rufusculus (nobis). It is not so wide as the former, but is higher 

 in the wing. All four are salmon colored. The old ones have no rays remaining; 

 the younger are full of obscure rays. In outline it is near to Irwinensis described 

 herein, but it is more compressed and has more distant marks of growth. It reminds 

 one of nubilus (nobis) and is close to it in outline. None were perfect at the tips. 



Unio subsquamosus. pi. 16, fig. 45. 



Testa leevi, oblongo-elliptica, compressa, ad latere subplanulata, valde inaequilaterali, postice obtuse 

 biangulari, aiitice oblique rotundata ; valvulis crassiusculis ; natibus parvis, prominulis, ad apices 

 rugoso-undulatis ; epidermide tenebroso-fusca, subsquamosa, eradiata; dentibus cardinalibus par- 

 vis, sulcatis, in utroquo valvulo duplicibus ; lateralibus prselongis, lamellatis subrectisque ; mar- 

 garita alba et valde iridescente. 



Shell smooth, oblong-elliptical, compressed, somewhat flattened at the sides, 

 very inequilateral, obtusely biangular behind, obliquely rounded before ; valves 

 somewhat thick ; beaks small, a little prominent, rugosely undulate at the tips ; 

 epidermis dark brown, somewhat squamose, without rays ; cardinal teeth small, 

 sulcate, double in both valves; lateral teeth very long, lamellar and nearly straight; 



nacre white and very iridescent. 



Proc. Acad. Nat. Sci., 1872, p. 160. 



jfa^.—Yadkin Kiver, North Carolina, C. M. Wheatley. 



My cabinet and cabinet of C. M. Wheatley. 

 piam. -8, Length 1-5, Breadth 3-1 inches. 



Shell smooth, oblong-elliptical, compressed, somewhat flattened at the sides, 

 very inequilateral, obtusely biangular behind, obliquely rounded before; substance 



