THE ARTHROPODS 



117 



or in the mouths of the burrows which they excavate, and 

 from which they rush upon the small fish, the larvae of 



awn (Heptacarpus bremrostris). 



many animals, and other equally defenseless creatures 

 which constitute their bill of fare. In turn they are 

 eagerly sought by certain birds and four-footed animals, and, 

 especially, in France, 

 are extensively used for 

 food by man. 



Closely related to 

 the crayfishes and dif- 

 fering but little from 

 them structurally are 

 the lobsters. In this 

 country they are con- 

 fined to the rocky coasts 

 from New Jersey to 

 Labrador, living upon 

 fish, fresh or otherwise, 

 various invertebrates, 

 and occasionally sea- 

 weeds. Far more than 

 the crayfish, the lobster 

 is in demand as an arti- 

 cle of food. By the aid 



Of nets Or Various traps FIG. OS. The crayfish (Astacus). 



