THE CRUSTACEANS 99 
forward and downward between the eyes, another rises from the 
centre of the back, and two others from the side near the middle of 

Fig. 67; BLUE OR EDIBLE CRAB. Long Island Sound. 
the body. The abdomen is long, and is not folded back under the 
body but projects freely. The little creature has a pair of stalked 
eyes and swims rapidly near the surface. It then moults a number 
of times and changes into what is called the megalops stage, in 
which it resembles a little crab excepting that the abdomen 1s 
stretched straight out, and not bent forward under the body as in 
full grown crabs. 
The Blue or Edible Crab, (Callinectes sapidus, Fig. 67 ), is the 
common crab of the markets, and it ranges from the Gulf of Mexico 
to Cape Cod. Very closely allied species are also found in the 
West Indies, on the African coast, and in the Pacific. Our crab 
fishery is worth more than $320,000 per year to the fishermen 
themselves. While we are sufficiently familiar with the general 
appearance of the blue crab, an account of its habits may be inter- 
esting. It delights in shallow bays and estuaries where the bot- 
tom is muddy and covered with eel-grass, and the water may be 
brackish. Here the crabs live during the summer, but in winter 
they retire to deeper places. They feed upon dead or live fishes 
