22 NEW UNIONID^ OF THE 



behind ; valves rather thin, thicker before, beaks slightly prominent, undulated at 

 the tips ; epidermis yellow, with interrupted rays ; cardinal teeth rather small, erect, 

 conical ; lateral teeth rather long, lamellar and straight ; nacre either white or salmon 

 color and very iridescent. 



Proc. Acad. Nat. Sci. 1859, p. 171. 



Hah. — Euharlee Creek, Georgia. J. Postell. 



My cabinet and cabinet of Mr. Postell. 

 Diam. -7, Length 1-1, Breadth 1-9 inches. 



Shell smooth, elliptical, slightly inflated, very inequilateral, obtusely angular be- 

 hind and i-egularly rounded before ; substance of the shell rather thin, thicker before ; 

 beaks slightly prominent, with small, irregular, transverse undulations at the tips ; 

 ligament rather long, thin and brown, epidermis light yellow, having distant marks of 

 growth, with numerous rays interrupted at the marks of growth ; umbonial slope 

 rounded ; posterior slope narrow, slightly raised ; cardinal teeth rather small, erect, 

 conical, crenulate ; lateral teeth rather long, lamellar, straight ; anterior cicatrices 

 distinct and well impressed ; posterior cicatrices confluent and slightly impressed ; 

 dorsal cicatrices situated on the underside of the plate and across the base of the 

 cardinal tooth ; cavity of the shell rather deep and rounded; cavity of the beaks shal- 

 low and subangular ; nacre either white or slightly salmon color and very iridescent. 



Remarlcs. — I have three specimens of this small shell before me. They were sent 

 by Mr. Thomas Jones to Mr. Postell, and I dedicate it to the former as the discoverer. 

 It is very closely allied to CumbeTlandicmus (nobis), and proximus (nobis). It is 

 nearly of the same outline as the latter, but not so transverse as the former. The 

 cardinal teeth are more conical and thicker than in either of them. In all the three 

 specimens the rays are interrupted at the lines of growth. This is not usually the 

 case with the other two species. The specimen figured is the largest of the three and 

 evidently a female. 



Unio discrepans. pi. 55, fig. 165. 



Testa Isevi, elliptica, subinflata, ad latere subplanulata, vald6 inaequilaterali; postic^ obtuse biangulatu, antice 

 rotundata; valvulis subtenuibus, antice crassioribus ; natibus prominulisj epidermide luteo-oliva, mi- 

 cante, radiata; dentibus cardinalibus parvis, compre^so-conicis crenulatisque ; lateralibus longis, ]amol- 

 latis subcurvisque ; margarita vel alba vel purpurea et valde iridescente. 



Shell smooth, elliptical, somewhat inflated, slightly flattened at the sides, very 

 inequilateral, obtusely biangular behind, rounded before ; valves rather thin, thicker 

 before; beaks slightly prominent; ei^idermis yellowish olive, shining, radiate, cardinal 

 teeth small, compressed-conical and crenulate ; lateral teeth long, lamellar and slightly 

 curved ; nacre white or purplish and very iridescent. 

 Proc. Acad. Nat. Sci. 1860, p. 92. 



Hah. — North Alabama. Prof Tuomey. 



My cabinet. 

 Diam. -6, Length 1, Breadth 1-8 inches. 



