Ill 
Mr. Say on the genus Ocythoe. 
not seem to be corroborated by the probable habits of the 
animal. All those hitherto discovered of that group, are 
known to swim at the surface of the ocean, and not being 
furnished with other organs of locomotion than fins, they 
cannot glide upon the bottom ; we must therefore (analogi- 
cally) suppose this to have been the habit of the animal ; and 
yet it is hardly admissible that it should, in that case, have 
eluded the observation of voyagers, since the shell has not un- 
frequently been found in a state of occupancy by the parasite. 
