140 



ZOOLOGY 



so-called palm-crab, feeds upon cocoanuts, which it opens by 

 inserting its claws into the eyes and then breaking the shell 

 upon the rocks. 



The mole-crabs (Hippidfe ^) include certain oval animals 

 that burrow in sand}' beaches, head first like a mole. The 

 abdomen is partly turned under the body in a position some- 



FiG. 134. — Eupagnrus longirarpiis TQraovQd Fig. 135. — Hippn falpoirks, 

 from .shell. y IJ. Photo, by W. H. C. P. Nat. sizr. Photo. by 



W. H. C. P. 



thing like that of the crabs. Therefore these animals make an 

 interesting link between the long-tailed (INIacrura) and short- 

 tailed (Brachyura) crustaceans (Fig. 135). 



The crabs (Brachyura) are represented on our ■chores liy 

 three principal families, which may be designated as triangular 

 crabs, arched crabs, and sciuare crabs. 



The spider-crabs, or sea-spiders, as they are sometimes 

 called, belong to the triangular crabs. As their name implies, 



' From hippos, horse ; used by Aristotle as the name of a kind of 

 crab, 



