Crustaceans 87 



have the limbs attenuated as to resemble 

 weeds, others have them developed into 

 flattened paddles with which they take 

 swallow-like flights through the water. 

 The circular, bashful crab of our coasts 

 has the limbs so flattened that the 

 animal, when they are tightly folded 

 under the body, resembles a smooth 

 boulder and can submit to being rolled 

 about by the waves on a rough bottom 

 without sustaining injury. Although 

 chiefly inhabitants of salt water, 

 crabs are nevertheless occasionally found 

 high up in mountain streams, and in 

 the tropics are often abundant inland, 

 where they may do serious injury to the 

 crops. One form from the Barrier Reef 

 measures just over a foot across the shell. 

 It has a claw six times as large as that 

 of the biggest lobster, and such monsters 

 may be responsible for the ghastly stories 

 told of shipwrecked mariners being eaten 

 alive on Crab Island in the Pacific. 



