THE CRUSTACEANS 99 



forward and downAvard between the eyes, another rises from the 

 centre of the hack, 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 wegalops stage, in 

 Avhich it resembles a little crab excepting that the abdomen is 

 stretched straight out, and not bent forward under the body as in 

 full grown crabs. 



The Blue or Edible Crab, fCallinectes mpidus, Fig. 67 J, 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 



