2G0 DESCRIPTION OF NEW 



greenish, with obscure rays, and the undulations of the beaks are less pronounced than 

 those of the complanatus. It is somewhat like U.folliculatus, (Nobis,) but is a thinner and 

 less transverse species. The older specimens are very much compressed in the middle, 

 near to the basal margin. 



Uniomerus. PI. XV. Fig. 10. 



Testa Isevi, elliptica, subinjlata; valvidis crassis; nalibus subprominentibus, ad apices undulatis; epider- 

 mide luted, radiatd, nilidd; dentibus cardinalibus tnagnis, cremdatis; lateralibus longis, rectis,a cardinalibus 

 separatis; margaritd alba el iridescente. 



Shell smooth, elliptical, somewhat inflated; valves thick; beaks somewhat prominent, undulated at the beaks; 

 epidermis yellow, radiated, shining; cardinal teeth large, .crenulate; lateral teeth long, straight and separated from 

 the cardinal tooth; nacre white and iridescent. 



Hab. Abbeville District, S. C. J. P. Barratt, M. D. 

 My cabinet and cabinet of Dr. Barratt. 

 Diam. .G, Length 1, Breadth 1.5 inches. 



Shell smooth, elliptical, rather inflated, somewhat striate, rounded before and angular 

 behind; substance of the shell thick, thinner behind; beaks somewhat prominent, rather 

 coarsely undulated at the tip; ligament short and rather thick; epidermis yellow, obscurely 

 radiated, shining; umbonial slope subangular; marks of growth distant and distinct; car- 

 dinal teeth large, compressed, crenulate, pointed, single in the right and double in the left 

 valve; lateral teeth long, straight, lamellar, separated from the cardinal tooth; anterior 

 cicatrices approximate; posterior cicatrices confluent; dorsal cicatrices situated on the 

 under side of the cardinal tooth; cavity of the shell shallow; cavity of the beaks small and 

 angular; nacre white and iridescent. 



Remarks. — In its general character, this species resembles U. Congarseus, (Nobis.) It 

 is not, however, so much compressed, and the angle of the umbonial slope is much less 

 expressed. Of the six specimens before me, five have white nacre. The sixth and largest 

 is slightly tinted with salmon colour. 



Unio concavus. PI. XV. Fig. 11. 



Testa Isevi, elliptica, inflatd; valvidis sabtcnidbtis ; natibus prominulis ; epidermide pallido-luteold, virido- 

 striatd; dentibus cardinalibus parvis, compressis; lateralibus longis reelisrjue; margaritd alba et iridescente. 



Shell smooth, elliptical, inflated; valves rather thin ; beaks slightly prominent ; epidermis pale-yellow, with 

 green rays; cardinal teeth small and compressed; lateral teeth long and straight; nacre white and iridescent. 



I lab. Abbeville District, S. C. J. P. Barratt, M. D. 

 My cabinet. 

 Diam. .8, Length 1.2, Breadth 2.2 inches. 



Shell smooth, elliptical, inflated, rounded before and subangular behind; substance of 

 the shell rather thin, slightly thickened before; beaks slightly prominent, nearly medial; 

 ligament rather long and thin; epidermis pale-yellow, with numerous green rays reaching 

 to the margin, smooth and polished, scarcely showing the lines of growth; cardinal teeth 

 compressed, single in both valves, and abruptly terminated; lateral teeth long, straight, 



