FRESH WATER AND LAND SHELLS. 09 



I'.MO DTRICULUS. PI. I. Fig. 3. 



Testa Istvi, ellipticd, in/Iatd; valvulis subcrassis; natibus subprominentibus ,• epidermide tenebroso-fuacd ; 

 dtntibus cardinalibus parvis ; lateralibus longis reclisque; mar gar it & ulbu et valde iridescente. 



Shell smooth, elliptical, inflated; valves ralher thick; beaks rather prominent; epidermis dark-brown; cardinal 

 h small; lateral teeth long and straight; nacre white and very iridescent. 



Hub. North Carolina. 15. W. Budd, M. D. 



Mv cabinet and cabinet of Dr. Budd. 

 Diam. .8, Length 1.1, Breadth 1.7 inches. 



Shell smooth, regularly elliptical, inflated, very inequilateral, obscurely angular on the 

 umbonial slope; substance of the shell thick before and thin behind; beaks rather promi- 

 nent: ligamenl short and thin; epidermis very dark-brown, without rays, and with regular, 

 nearly equidistant lines of growth ; cardinal teeth very small, erect, and sharp; lateral 

 teeth long and straight; anterior cicatrices distinct; posterior cicatrices distinct; dorsal 

 cicatrices placed on the under side of the cardinal tooth; cavity of the shell rather deep 

 and rounded; cavity of the beaks shallow and rounded; nacre very white and beautifully 

 iridescent. 



Remarks. — Two specimens of this species were received by Dr. Budd. They came 

 with the others from North Carolina, and no doubt from one of the tributaries of the 

 Tennessee river. This species has some resemblance to U. Vanuxemensis, (Nobis,) and 

 U. glans, (Nobis,) but need not be confounded with either of them. It is less flat than 

 the former, and not so much inflated as the latter, and is dissimilar to each in having a 

 white nacre. 



UNIO HYALINU9. PI. II. Fig. 4. 



Tenia few", obovatd, subinflatA, diaphand; valuulis pertenuibus ; natibus prominulis, ad apices undtdatit; 

 midt tenebroso-fuscd ; denlibus cardinalibus parvis, compressis; lateralibus longis reclisque} margaritd 

 cseruleo-albd et iridescente. 



Shell smooth, obovate, Mibinflated, transparent; valves very thin; beaks slightly prominent, undulated at the 

 beaks; epidermis dark-brown; cardinal teeth small and compressed; lateral tcclh long and straight; nacre bluish- 

 white and iridescent. 



Hali. Richmond, Virginia. Major Le Contc. 



Cabinet of Major Le Contc. 

 Diam. .5, Length .9, Breadth 1.4 inches. 



Shell smooth, obovate, rather inflated, transparent; carinate on the posterior slope; 

 substance of the -in II very thin; beaks slightly prominent, minutely undulated at the tips; 

 ligament vev horl and thin; epidermis dark-brown and obscurely rayed; cardinal teeth 

 rle in the right valve and slightly cleft in the lefl valve; lateral teeth single in both 

 valves, long and compressed; anterior cicatrices distinct; posterior cicatrices confluent; 

 dorsal cicatrices placed immediately on the centre of the cavity of the beaks; cavity of 

 shell rather shallow; cavity of the I >< .- 1 1 . - very shallow and angular; nacre bluish-white 

 and iridesi ent. 



Remarks. — Major LeConte placed in my hands a Bingle specimen of tin- Bpecii b, which 

 he proem-, d from Richmond. It is a distinct and peculiar species which cannot be easily 

 vol. x. — 18 



