CHIEFLY OF THE UNITED STATES. 57 



with rather distant' marks of growth and with rather indistinct and irregular 

 furrows ; umbonial slope inflated and obtusely angular ; posterior slope rather broad 

 and scarcely carinate ; cardinal teeth sniall, acuminate, rather compressed, double in 

 both valves; lateral teeth rather small, lamellar and slightly curved ; anterior 

 cicatrices distinct, rather large and well impressed ; posterior cicatrices distinct, 

 moderately well impressed and rather large ; dorsal cicatrices placed on the upper 

 part of the cavity of the beaks ; cavity of the shell rather deep ; cavity of the 

 beaks rather deep and angular ; nacre white before and slightly tinted with salmon 

 color behind. 



Remarks. — A single specimen only of this little species was sent to me by Mr. 

 Wheatley. It has all the appearance of being adult. It is so much eroded that 

 the character of the beaks and the posterior slope cannot be perfectly ascertained. 

 It is unlike all other species I have seen from Asia Minor. In outline it is some- 

 what like a stunted variety of Batavus. There is no appearance of rays in this 

 specimen, but perfect specimens may perhaps present them. The furrows are 

 stronger over the posterior half, but are irregular and imperfect. 



Unio tripartitus. pi. 19, fig. 55. 



Testa sulcata, subelliptica, subinflata, subffiquilaterali ; valvulis crassis, antice crassioribus ; natibus 

 prominentibus, solidis, parum undulatis ; epidermide viridi-lutea, obsolete radiata, mieante ; dentibus 

 cardinalibus crassis, valde corrugatis, in utroque valvule duplicibus ; lateralibus curvatis, percrassis, 

 valde corrugatis et in valvule sinistro tripartitibus ; margarita dilute salmonia at elegantissinie irides- 

 cente. 



Shell sulcate, subelliptical, somewhat inflated, subequilateral ; valves thick, 

 thicker before; beaks prominent, solid, somewhat undulate; epidermis greenish 

 yellow, obscurely radiate, shining; cardinal teeth thick, corrugate and double in 

 both valves ; lateral teeth curved, corrugate, very thick and in the left valve tri- 

 partite ; nacre slightly salmon and richly iridescent. 

 Proc. Acad. Nat. Sci., 1863, p. 190. 



Hah. — Jillingee River, India, M. Burrough, M. D. 



My cabinet. 

 Diam. I'l, Length 1-5, Breadth 2-4 inches. 



Shell sulcate, subelliptical, somewhat inflated, subequilateral ; substance of the 

 shell thick, thicker before ; beaks prominent, solid and somewhat undulate at the 

 tips ; ligament rather thick, short and light brown ; epidermis greenish yellow, 

 obscurely radiate and shining, and with two or three distant marks of growth ; 

 umbonial slope raised and I'ounded ; posterior slope rather wide, greenish, with 

 three rays from the beaks to the posterior margin on each valve ; cardinal teeth 

 thick, corrugate, double in both valves; lateral teeth curved, corru<i;ate, very thick, 



15 



