188 
GAMMARIDiE. 
It may be that they are synonymous, but the very im- 
perfect manner in which Say’s genus is described, arising 
from the want of fixed homological names for the several 
parts of the animal, precludes us from expressing more 
than a supposition of their identity. 
The habits of the only species of Sulcator appear to 
differ from those of the only species of Lepidactylis de- 
scribed, inasmuch as the former is very sluggish, and a 
burrower, whereas the latter is stated by Say to be very 
active, much resembling in its movements the water- 
beetles of the genus Dytiscus. 
The accompanying vignette represents one of our fa- 
vourite hunting-grounds, the Tor Rock in Oxwich Bay, 
near which our specimens of this genus were taken. 
