U14 NEW UNIONIDiE OF THE 



Anodonta Kennicottii. PI. 33, fig. 283. 



Testa kevi, elliptica, subinflata, insequilaterali, postice obtuse biangulata, antice rotunda; valvulis 

 subtenuibus ; natibus proniinentibus, acuniinatis, ad apices granulatis ; epiderniide pallido-lutea 

 usque tenebroso-fuscil, eradiata; ruargarita casruleo-alba et iridescente. 



Shell smooth, elliptical, somewhat inflated, inequilateral, obtusely angular behind 

 and round before ; valves rather thin ; beaks somewhat prominent, pointed, granulate 

 at the tips ; epidermis from pale yellow to dark brown, without rays ; nacre bluish 

 white and iridescent. 



Proe. Acad. Nat. Sci., 1861, p. 56. 



Hab. — Great Slave Lake, at Fort Rae, and North End of Lake Winnipeg, Arctic 

 America, R. Kennicott. 



My cabinet and cabinet of Smithsonian Institution. 

 Diam. - 7, Length l - 2, Breadth 1*9 inches. 



Shell smooth, elliptical, somewhat inflated, inequilateral, obtusely angular behind 

 and round before ; substance of the shell rather thin ; beaks prominent, pointed and 

 granular at the tips ; ligament long, thin and dark brown ; epidermis varying from 

 pale yellow to dark brown, without rays, with eight or ten rather close lines of 

 growth ; umbonial slope raised and rounded ; posterior slope rather narrow, 

 elliptical, slightly carinate, with two indistinct lines in each valve from the tips to 

 the margin ; anterior cicatrices confluent and very slightly impressed ; posterior cica- 

 trices confluent, large and scarcely perceptible, dorsal cicatrices placed over the 

 centre of the cavity of the beaks ; cavity of the shell rather deep and wide ; cavity 

 of the beaks shallow and very obtusely angular, nacre bluish white and iridescent. 



Remarks. — Seven specimens were sent recently by Mr. Kennicott, from his pre- 

 sent quarters, in Arctic America, where he is liberally entertained by the Hudson 

 Bay Company's officers, who promote the object of his explorations in Zoology by all 

 the means in their power. All these specimens are more or less imperfect, and 

 probably were all dead specimens when taken. The largest is 1*5 long by 2-2 inches 

 wide. It is a well characterized species, nearly allied to Pepiniana, (nobis,) but is 

 more elliptical and has the beaks rather higher and more recurved. The lines of 

 growth are closer and the umbonial slope is not angular as it is in Pepiniana. 

 It is to be regretted that none of the specimens were perfect in the beaks, but they 

 were enough so to show that they had a double row of granules. The pointed beaks 

 of this species is a remarkable character among the Anodontoe. 



I have great pleasure in dedicating this species to my young friend Mr. Kennicott, 

 who has displayed so much energy in his arduous expedition to the great waters lead- 

 ing to the Arctic seas. 



Accompanying this new species were two well-known ones which inhabit over 

 a vast expanse of territory, — viz. : TJnio luteolus, Lam., in Great Slave Lake, and 



