424 NEW GENUS AND SOME NEW SPECIES 



U. nana. This species is said to inhabit Franche Comte. 

 I do not know if there be a specimen in this country. 



U. alata is the well known alatus of Say, and is herein 

 made the type of a new genus, Symphynota. 



U. delodonta. Description too short to identify it. Has 

 no habitat. 



U. sulcidens. A variety of complanatus ; and is from the 

 Schuylkill, Pennsylvania. 



U. rostrata. The specimens which I received from Eu- 

 rope with this name are only elongated varieties oi pictorum. 



U. pictorum. This is a well known species, and described 

 by Linnaeus and others as Mya pidorum. 



U. batava. The specimens sent me of this species from 

 Europe appear to be only a variety of the pictorum. It is 

 more obtuse*. 



U. corrugata. This species can not be identified with any 

 of ours. It comes from the coast of Coromandel, and is, 

 doubtless, a distinct and well characterised species. 



U. nodulosa. The habitat of this species is Lake Cham- 

 plain, and although pictured in the Ency. Meth. I cannot 

 identify it, the drawing being evidently incorrect. Although 

 represented with a lamellar tooth, I should not be surprized 

 if it proved to be a young Jilasmodonta unilulata of Say, as 

 it has the strong character on the beaks. 



U. varicosa. I can only assimilate this with the Masmo- 

 donta undulata of Say. Its habitat is the Schuylkill and 

 Lake Champlain. 



U. granosa. This is a beautiful and distinct species. Ha- 

 bitat Guyana. 



U. depressa. Habitat New Holland. The description is 

 very imperfect, but the species nevertheless distinct. It is a 

 very different shell from that called depressa by Rafinesque, 

 who does not seem to have known that the name was preoc- 

 cupied by Lamarck. 



* The U. anas I believe to be a variety of pictorum very similar to this. My 

 specimen is certainly such. The U. tumida, from the north of Europe, appears 

 to me to be only a large and thick pictorum. 



