CAKCINUS. 
41 
as an oar, with that peculiar action which is known to boat- 
men as sculling. . . . “None of our native Crabs are f at 
the top of the tree' in the swimming profession. Their 
efforts, even those of the best of them, are awkward bun- 
glings, when compared with the freedom and fleetness of 
those I have seen in the Caribbean Sea, and among the gulf- 
weed in the tropical Atlantic, which shoot through the 
water almost like a fish, with the feet on the side that hap- 
pens to be the front all tucked close up, and those on the 
opposite side stretched away behind, so as to ‘ hold no 
water/ as a seaman would say, and thus offer no impedi- 
ment to the way. Our species are obliged to keep their 
pair of sculls continually working while they swim ; a series 
of laborious efforts just sufficient to counteract the force of 
gravity ; and the seesaw motion of the bent and flattened 
joints of the oar-feet is so much like that of a fiddler's 
elbow, as to have given rise to a very widely-adopted appel- 
lation of these Crabs, among our marine populace."* 
Gen. 12. CARC1NUS,+ Leach. 
Carapace nearly as long as wide, the front projecting; 
* Gosse, Aquarium, p. 195. 
f K aptcivos, a Crab. Mr. Dana places the genera Carcinus, Portumnus, and 
