AMPULLARIA. 



a passage to the Physadse. In the shell there 

 is some affinity with Natica, especially with 

 those species which have not a callus upon the 

 labium, as in N. heros, Say, (Gould Invert, of 

 Mass., fig. 163,) which, without the opercle, 

 might deceive a practised conchologist. 



For my ability to give the history of this 

 genus I am indebted to the kindness of J. 

 Hamilton Couper, Esq,, who has sent me an 

 extensive series of specimens, including several 

 living ones, with notes on their habits. He in- 

 forms me that the species is most active in 

 May. 



