THE CRAYFISH 



143 



however, eaten in various localities and by various peoples. 

 For example, our little oyster-crab (Fig. 140), found in the 



Fig. 139. — Platyonichus oceHaius, lady-crab, 

 by W. H. C. P. 



Reduced to one-third. Photo. 



mantle chamber of the oyster, is eaten by us together with the 

 oyster or separately. 



The fiddler-crabs are representative of the square crabs. 

 These are the familiar animals which crowd salt-marshes and 

 run sideways to and from their 

 burrows (Fig. 141). One claw 

 is much larger than the other. 

 When the crab is disturbed, the 

 large claw is brandished in a 

 manner which has been likened 

 to the movements of a fiddle 

 as one plaj^s upon it. Gelasi'rnus pug'nax is the most abundant 

 species, and ranges from Cape Cod to the Gulf of Mexico. 

 Together with Cambarus it does much damage by burrowing 

 in the levees of the Mississippi River (Fig. 142). 



Fig 



140. — Pinnotlieres osireum. 

 From Rathbun. 



X4. 



