GENUS SCI^NA. 251 



been sufficient to induce the author to believe that this 

 mineral was not Gahnite, but a substance, whose 

 primitive form was an octahedron, with angles ap- 

 proaching those of the regular octahedron of geome- 

 try. 



Description of three new Species of the Genus Sci~ 

 cena. By C. A. Lesueuh. Read July 26, 1822. 



In the month of July, 1816, we observed a great 

 number of fish, abandoned by the fishermen, on the 

 shores of Lake Erie. They were very well preserved 

 in their exterior form ; the viscera being destroyed 

 by iusects, and the remainder dried in the sun: but 

 as they had been rolled on the beach by the waves, 

 their fins broken and in part destroyed, we could only 

 decide upon their belonging to the genus Scisena, a 

 decision which was confirmed a few days afterwards, 

 by the examination of many living individuals that 

 had been taken in the lake. There, as well as at 

 Pittsburg, they are known by the name of sheeps- 

 head ; and although the individuals takeu at Lake 

 Erie, were closely related to those of the Ohio which 

 we observed on our journey to Pittsburg, yet I have 

 observed such differences between them, as have in- 

 duced me to offer a particular description of each ; 

 they may, however, be only varieties. 



Those of the lake are not esteemed as food, if we 

 may judge by their being rejected by the fishermen; 

 this circumstance, however, may only prove the fish 

 to have been then out of season. 



