l8 ROCHESTF.R ACADEMY OF SCIENCE. [Oct. 26, 



Anodonta undulata, Say. 



Anodonta rugosus, Swain. 



" Pennsyiva/iica, Lam. 

 Unto undulata, Desh. 

 Strophitus undulaius, Stimp. 



Unto rosaceus is quite local. I have found it only at Long Pond 

 and the margin of Lake Ontario, between Long Pond and Charlotte. 

 De Kay's figures are very characteristic of all I have collected. 



All our local species are found also in the canal and generally in 

 much better condition than elsewhere, owing partly to the fact that 

 the bottom of the canal is covered with a fine sediment of mud and 

 partly to the quiet condition of the water. 



The shells found in the canal only are common in the large lakes 

 and their tributaries west of us, and doubtless reach here in their 

 young state with the influx of the water in spring-time when the Erie 

 canal is replenished. 



Family CYRENIDiE. 



Sphaerium similis, Say. (pi. 8, fig. 4.) Erie canal. 

 Sphaerium partumeium, Say. (pi. 8, fig. 5.) Genesee river. 

 Pisidium variabile, Prime, (pi. 8, fig. 6.) Brighton. 



The paper was illustrated by a collection of the shells of the 

 various species, which collection Mr. Walton presented to the 

 Academy. 



Remarks were made upon the paper by Dr. Anna H. Searing, 

 Mr. J. E. Putnam and the President. 



A vote of thanks was tendered Mr. Walton for his valuable gift 

 of the collection of Monroe County shells to the cabinet of the 

 Academy. 



Mr. J. E. Putnam discussed a recent paper in the Engineering 

 News, on incandescent electric lighting. 



