OUR CARCINOLOGICAL FRIENDS. 87 
so that it may acquire a new one conformable to 
its progressive stature. This process of sloughing 
the shell appears to take place annually; the length 
of time required for its full accomplishment—i.e., 
from the moment of the throwing off of the old 
shell to the proper cementing of the new—being 
in the neighborhood of forty-eight hours. In this 
interval the crab is known as a ‘soft-shell’ or 
‘shedder,’ in which condition it is by many highly 
prized as an article of food. 
The common edible crab or ‘ blue crab’ delights 
in the sheltered muddy shores of coves and bays, 
and in the brackish waters of estuaries, where it 
can be frequently seen in numbers swimming up 
and down with the advancing and retreating waters. 
The young, more particularly, frequent the tangle of 
shore-line grass and weed, whence in case of alarm 
they swim out to deep water. The food of this spe- 
cies consists largely of fishes, certain forms of which, 
in turn, destroy great quantities of the crabs. 
Two interesting hole-inhabiting crabs somewhat 
related to the fiddlers, but with nearly equally de- 
veloped claws, are Sesarme reticulata and Ocypoda 
arenaria. The latter, which is also sometimes 
known as the ‘sand-ecrab,’ is interesting from the 
close approximation of its coloring to that of the 
sand in which it dwells—an instance of true pro- 
tective resemblance. It is carnivorous in habit, 
and is said to spring upon the beach-fleas much 
as a cat springs upon mice. 
There are two species of so-called ‘ oyster crab’ 
on our coast, which possess widely different habits. 
