(C.) 



PARTIAL LIST OF SHELLS FOUND NEAR TROY, 



NEW YORK. 



By Tkxjman H. Aldrich, of the Rensselaer Polytechnic Institute. 



This list is the result of collections made during the summers of 

 1866 and 1867, within a radius of six miles around Troy, and is by 

 no means complete. 



Reference is made, as far as practicable, to De Kay's Report on 

 Mollusca, in the New York State Natural History. 



UNIO, Brugtjiere. 



Unio alatus, Say. De Kay, p. 195. De Kay speaks of Dr. New- 

 comb obtaining it from the Northern canal, near Waterford. In the 

 spring of 1867, the canal was searched for it, both above and below 

 Waterford, for several miles, without success. Mr. H. Rousseau, 

 of this city, found a single valve in the canal at the weigh lock. 



Unio nasutus, Say. De Kay, p. 191. Moderately abundant in the 

 Mohawk basin. Specimens of medium size, and many deformed. 

 Seldom found in the canals or Hudson River. 



Unio complanatus, Solander. De Kay, p. 188. Yery common. 

 Fine varieties, with deep radiating lines outside, and beautiful 

 nacre within are sometimes found. 



Unio cakiosus, Say. De Kay, p. 193. Moderately abundant. Fine 

 specimens found in the Mohawk basin, Erie canal and Hudson 

 River. 



Unio ooheaceus, Say. De Kay, p. 193. Mohawk basin and canals. 

 Not abundant. 



Unio tappanianus, Lea. De Kay, p. 194. Many years ago Dr. New- 

 comb found this shell quite plentiful, but of late years the locality 

 had been lost. In the spring of 1867, Mr. Rousseau and myself 

 found it again. The precise locality only occupies a few rods of 

 the Northern canal, between Cohoes and Waterford, just beyond 

 the first lock, above the canal bridge, across the Mohawk. 



De Kay's description is taken from shells from this locality. 

 [Sen. No. 87.] 3 



