Miscellanies. 375 



U. spuria and australis do not exist in any cabinets examined 

 by Mr. Lea. 



U. anodontina. The marginalis which is found only in India. 



U. suborbicidata. Tlie rotnndata. 



Hi/ria avicularis. This is the Mya syrmatophora of Gmelin 

 and DiLLEXius : avicularis, should therefore, be given up. 



H. corrugata. A distinct species. 



Anodonta cygnea. The Mytilus cygneus of Linnaus. 



A. anatina. Resemble the cygnea. 



A. sulcata. A variety of cygnea-. 



A. fragilis. A distinct species. 



A. ruhens. Deshayes places it under Iri'dina. ' 



A. aispata. A distinct species. 



A. uniopsis. do. 



A. Pennsylvanica. The imduhta of Say and rugosus of Swain- 

 son. 



A. intermedia. A variety of anc^iina. 



A. trapeziaJis. The gigantcus of Spix. 



A. exotica. A distinct species. 



A. glauca. do. 



A. sinuosa. do. 



A. Patagonica. do, • • 



Iridina exotica. do. 



1. Clappertoni. Is a young nilotica. 



The geographical distribution of the Naiades in the United States 

 has received the attention of Mr. Lea; and he offers some very in- 

 teresting remarks upon this subject. He finds the Alleghanies to 

 be a dividing line of the species so perfectly that " it is matter of 

 doubt if there be more than two or three species of all the genera 

 of this family existing in the eastern waters which have their analo- 

 gues in the Western States." Respecting the extremities of this 

 range, the shells of the River Mohawk and its tributaries, appear to 

 be the same with those of the Delaware, Potomac, he, with the 

 exception of the Symphynota compressa Lea and which is also 

 found in the Ohio. " The tributaries of the lakes Erie, Michigan, 

 Sic, whh few exceptions, produce the western species, and conse- 

 quently the lakes do also." Lake Champlain which empties into 

 the St. Lawrence contains the Symphynota alata, the Unio occidens 

 and the Unio. rectus with other western species. In the southern 

 extremity of the Alleghany ridge, where the sources of the rivers 



