DESCRIPTION OF FIFTY-TWO SPECIES OF UNIONIDiE. 35 



Diam. 1-5, Length 2-5, Breadth 4-3 inches. 



Shell smooth, elliptical, somewhat inflated, inequilateral, obtusely angular behind 

 and rounded before ; substance of the shell thick, thicker before ; beaks somewhat 

 prominent, undulate at the tips; ligament large and dark brown; epidermis reddish- 

 brown, radiated all over the disks and with distant marks of growth ; umbonial 

 slope obtusely angular ; posterior slope narrow elliptical, rough and dark in the 

 adult; cardinal teeth rather small, crenulate, compressed conical and double in 

 both valves ; lateral teeth very long, lamellar and somewhat curved ; anterior cica- 

 trices distinct, very large and well impressed ; posterior cicatrices confluent, large 

 and slightly impressed ; dorsal cicatrices placed within the cavity of the beaks ; 

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

 obtusely angular; nacre very bright, deep salmon colored and beautifully iridescent. 



jRmarA-5. — This is another fine species obtained from North Carolina by Mr. 

 Wheatley, to whom I am indebted for a fine suite. It is closely allied to radiatus 

 Lam. Like it the rays are fine and usually cover the whole disk. The outline is 

 very nearly the same. It is rather more inflated than the radiatus of the Delaware, 

 Schuylkill and Susquehanna Rivers. It differs in the cardinal teeth being more 

 compressed. The color of the nacre of all the specimens I have seen is of a very 

 beautiful salmon. In some this color is intense. 



Unio breyis. pi. 12, fig. 32. 



Testa laevi, subtriangulari, subcompressa, ad latere subplanulata, inasquilaterali, postice obtuse bian- 

 gulata, antice rotundata ; valvulis crassiusculis, antice crassioribus ; natibus prominulia ; epider- 

 mide flavida, eradiata ; dentibus cardinalibus parviusculis, subcompressis, in utroque valvulo 

 duplicibus; lateralibus lamellatis, parviusculis obliquisque; margaritavel alba vel salmonis colore 

 tincta et valde iridescente. 



Shell smooth, subtriangular, somewhat compressed, flattish at the sides, inequi- 

 lateral, obtusely biangular behind, rounded before; valves somewhat thick, thicker 

 before; beaks somewhat prominent; epidermis yellowish and without rays; cardi- 

 nal teeth rather small, subcompressed and double in both valves; lateral teeth 

 rather small and oblique ; nacre white or salmon colored and very iridescent. 

 Proc. Acad. Nat. Sci., 1872, p. 157. 

 jlah. — Conasauga Creek, Monroe Co., East Tennessee, Miss Law. 

 My cabinet and cabinets of Dr. Lewis and C. M. Wheatley. 

 Diam. -6, Length 1-3, Breadth 1-9 inch. 



/ Shell smooth, subtriangular, somewhat compressed, flattened at the sides, ine- 

 quilateral, obtusely biangular behind, rounded before; substance of the shell some- 

 what thick, thicker before; beaks somewhat prominent; ligament rather short, 



