72 DESCRIPTION OF NEW 



Shell very nodulous, rounded, rather compressed; valves thick; beaks elevated; epidermis yellowish-brown; 

 cardinal teeth large; lateral teeth short, thick and nearly straight; nacre white. 



Hab. North Carolina. 13. W. Buck!, 3VI. D. 



My cabinet and cabinet of Dr. Budd. 

 Diain. 1.4, Length 2.2, Breadth 2.4 inches. 



Shell tubcrcnlate nearly all over, rounded, rather compressed on the sides and towards 

 the margin; substance of the shell thick, thinner behind; beaks elevated; ligament rather 

 short and thick; epidermis yellowish-brown, striate, and crimpled; posterior slope im- 

 pressed and thickly tuberculatc; anterior slope nearly free from tubercles; cardinal teeth 

 large, wide, and double in both valves; lateral teeth short, thick, and nearly straight; 

 anterior cicatrices distinct; posterior cicatrices distinct; dorsal cicatrices placed on the 

 under side of the cardinal tooth; cavity of the shell shallow; cavity of the beaks rather 

 deep and angular; nacre white. 



Remarks. — Three specimens of this species were sent to me by Dr. Budd, labelled 

 " North Carolina." They are evidently from that portion of the state which is drained 

 by the tributaries of the river Tennessee, and were accompanied by species common to 

 the Holston, &c. In this we have another species which must be placed in the group 

 which Mr. Barnes' verrucosus must be considered to form the type. It certainly is more 

 nearly allied to that species than any other. It differs, however, from it in having a white 

 nacre, instead of a chocolate-coloured one — in having smaller and more frequent tuber- 

 cles, and in being more rounded in the outline. It differs from Cooperianus, (Nobis,) in 

 the tubercles being smaller, more frequent, and in being more compressed. In the three 

 specimens before me there is no indication of flesh colour, which usually is found in the 

 Cooperianus. There is no indication of any rays on these specimens, and the beaks of 

 all of them being eroded, they do not present the opportunity of observing their normal 

 undulations. 



Unio flavescens. PI. III. Fig. 9. 



Tcatn hrvi, ellipticd, svbinflata; valvulis subtenuibus; nalibxts subprominentibus ; epidermide. lutco-cornia, 

 striata; denlibus cardinalibus parvis ; luteralibus sitblongis, subrectisque ; margarita alba el iridescente. 



Shell smooth, elliptical, somewhat inflated; valves ralhcr thin; beaks somewhat prominent; epidermis yellow- 

 ish horn colour, striate ; cardinal teeth small ; lateral teeth rather long and nearly straight ; nacre white and iridescent. 



Hab. Black Warrior river, Alabama. B. W. Budd, M. D. 



My cabinet and cabinet of Dr. Budd. 

 Diam. .7, Length 1.1, Breadth 1.7 inches. 



Shell smooth, elliptical, somewhat inflated, inequilateral, obscurely angular on the 

 umbonial slope, and flattened on the side; substance of the shell rather thick, thinner 

 behind; beaks rather prominent; ligament rather short and thin; epidermis yellowish horn 

 colour, striate, shilling, and without rays; cardinal teeth very small, single in the right 

 and double in the left valve; lateral teeth rather long and nearly straight, thickened at the 

 posterior end; anterior cicatrices distinct; posterior cicatrices distinct; dorsal cicatrices 

 placed nearly in the centre of the cavity of the beaks; cavity of the shell rather shallow 

 and rounded; cavity of the beaks shallow and rounded; nacre white and iridescent. 



