No. 50.] 41 



47 Valvata tkicarinata. Vicinity Mohawk, canal and river. 



48 Amnicola . Erie canal, Mohawk river, Mohawk. 



49 Cyclas truncata, 10 sp. Cambridge, Mass. 



50 PisiDiuM FEKRUGiNEUM. Cambridge, Mass. 



51, 52, 53, 54, 55, 56 Varieties of Physa, referable to different locali- 

 ties, not yet fully examined. 



57 Melania , 11 sp. Erie canal, Mohawk. 



58 Melania , 7 sp. Erie canal, Mohawk. 



CRUSTACEA. 



ORDER PCECILOPODA. 



ZooLOGT — Part VI. 



Polyphemus occidentalis. Horsefoot or King Crab. - - - - p. 55 



Two specimens (small). Presented by William S. Canedt, of 

 East- Albany. 



ECHINODERMS. 



Echinaster sangttinolentis. The Starfish (Agassiz). 



From the coast of New-England. Presented by William S. Oa 

 KEDX, of East-Albany. 



