56 PROCEEDINGS OF THE ACADEMY OP 



Descriptions of two new species of ANODONTJE, from Arctic America. 

 BY ISAAC LEA. 



Axodonta Kenmcottii. Testa laevi, elliptica subinflata, insequilaterali, pos- 

 tice obtuse biangulata, antice rotunda ; valvulis subtenuibus ; natibus promi- 

 nentibus, acuminatis, ad apices granulatis ; epidermide pallido-lutea usque 

 tenebroso-fusca, eradiata; ruargarita saeruleo-alba et iridescente. 



Hub. Great Slave Lake at Fort Rae, aud north end of Lake "Winnipeg, 

 Arctic America. R. Kennicott. 



Anodonta Simpsoniana. Testa, lam, elliptic^, subeompressa, elongato-len- 

 ticulari, postice obtuse angulata., antice rotunda ; valvulis tenuibus ; natibus 

 prominulis, ad apices undulatis ; epidermide tenebroso-fusca, eradiata; marga- 

 rita camileo-alba et iridescente. 



Hab. Fort Rae, Great Slave Lake, Arctic America. R. Kennicott. 



March 5 th. 

 Mr. Lea, President, in the Chair. 



Forty-three members present. 



The following papers were presented for publication : 



" Descriptions of twelve new species of Uniones from Alabama, by 

 Isaac Lea." 



" Remarks on a species of Osmerus, taken in the Schuylkill, below 

 Fairmouut dam, by Thaddeus Norris." 



And were referred to Committees. 



Mr. Lea read extracts from a letter from T)r. Showalter, TTniontown, 

 Alabama, in which he expresses a belief that the genus Schizostoma is 

 found only in the Coosa River. 



The deaths of Dr. Samuel Moore, a member, at Philadelphia, on the 

 18th of February, and of Prof. F. Tiedemann, of Heidelberg, a corres- 

 pondent of the Academy, were announced. 



March 12th. 

 Mr. Lea, President, in the Chair. 



Forty-seven members present. 

 A paper was presented for publication entitled 



" Notes on new and rarer species of Diatomacete of the United States, 

 by Francis W. Lewis, M. D.," and was referred to a Committee. 



Dr. Stewardson read extracts from a letter from Prof. Wyman, of Cam- 

 bridge, dated Feb. 24, 1861, in relation to the habits of Anableps, which, 

 swimming as it usually does upon the surface of the water, and sometimes 

 leaving that element entirely, is enabled, by the peculiar structure of its eyes, 

 to see as well in air as water, the upper half of the eye being especially adap- 

 ted to receive the rays of light from the atmosphere, the lower half, from the 

 water. 



March 19th. 



Mr. Lea, President, in the Chair. 



Forty-five members present. 



Copies of the Proceedings for January and February were laid on 

 the table. 



[March, 



