138 CUAYFISII, LOBSTERS, Sl'IDEKS, AND INSECTS 



Fig. 76. — Crab, from above. 



or a craj'fish very little. The 

 covered by the carapace, is very 

 length (Fig. 76). The 

 abdomen, instead of 

 being long and large, 

 is short, and is per- 

 manently curled be- 

 neath the head and 

 thorax. In this posi- 

 tion it is invisible fron i 

 above (Fig. 77). Both 

 pairs of antenniP are 

 very small. The first 

 pair of legs beai's 

 the great claws for 

 grasping. 



The life historv of ,. ,_ 

 this ci'ab is j-ather coni- 



abdomen are very 

 rudimentary except 

 the sixth pair. This 

 pail' serves to hold 

 the body firmly in 

 the shell. One of the 

 pincers is larger than 

 the other and both 

 are used to close the 

 mouth of the shell to 

 keep out intruders. 



Rock crab. — At 



first sight this crab 



resembles a lobster 



cephalothorax, which is 



broad in proportion to its 



-Crab, from the under .?ide. Note 

 the abdomen. 



