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-crab,' 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. 



