CHIEFLY OF THE UNITED STATES. 251 



mens before me almost white, some of them quite so. The anterior porfion of the 

 valves are quite sulcate in some specimens, but it does not pervade enough to put 

 this species in the sulcate division. 



Unio Kullethensis. pi. 29, fig. 65. 



Testa Irevi, oblonga, valde infequilaterali, ad latere planulata, antice subtruncata, postice obtuse angu- 

 lata; valvulis crassis, antice crassioribus ; natibus prominulis ; epidermide luteola, postice radiata 

 et tenebroso-viridi ; dentibus cardinalibus parvis, acurainatis crenulatisque ; lateralibus longis 

 subreetisque ; margarita vel alba vel aurea et valde iridesceute. 



Shell smooth, oblong, A'ery inequilateral, flattened at the sides, subtruncate before 

 and obtusely angular behind; valves thick, thicker before; beaks slightly prominent; 

 epidermis yellowish, radiate and dark green behind ; cardinal teeth small, pointed 

 and crenulate; lateral teeth long and nearly straight ; nacre white or golden and 

 very iridescent. 



Proc. Acad. Nat. Sci. 1864, p. 285. 



Edb. — Near Mardin, in a stream from Kulleth falling into the Tigris River, Asia. 

 C. M. Wheatley. 



My cabinet and cabinet of Mr. Wheatley. 

 Diam. -8, Length 1-2, Breadth 2-1 inches. 



Shell smooth, oblong, very inequilateral, flattened at the sides, subtruncate before 

 and obtusely angular behind ; substance of the shell thick, thicker before ; beaks 

 slightly prominent; ligament rather short and light brown; epidermis yellowish, 

 radiate and dark green behind, with rather approximate lines of growth; umbonial 

 slope rounded ; posterior slope rather depressed and covered with green rays ; car- 

 dinal teeth small, pointed, double in the left and treble in the right valve; lateral 

 teeth long, nearly straight and rather thick ; anterior cicatrices distinct and deeply 

 impressed ; posterior cicatrices distinct and slightly impressed ; dorsal cicatrices 

 placed over the centre of the cavity of the beaks ; cavity of the shell rather deep and 

 wide; cavity of the beaks subangular; nacre white or golden and very iridescent. 



Eemarks. — I am indebted to Mr. Wheatley for several specimens of this species, 



with other very interesting ones from the fresh waters of Asia Minor, which seem 



to have escaped the attention of Naturalists who have travelled through this part of 



Asia. Kullethensis is nearly allied to Mardinensis, herein described, but it is a thicker 



shell and is more inequivalve. In outline it is nearest, of the American species, to 



Wliitelanus, (nobis) but in most of its characters very different. The beaks of all the 



specimens before me are eroded so much as to prevent the character of them being 



well ascertained, but an appearance of undulation remains sufficiently to designate 



that they possessed such corrugated wrinkles as most of the species of Western 



Asia. 



64 



