DECAPODA. 



211 



approach to its future permanent form, the eyes become raised on 

 stalks, the claws and feet begin to make their appearance, but the 

 tail still remains like that of a lobster, and is used by the young 

 crab to swim about merrily in the water. It is not until the next 



FlG. 161. SECOND STAGE OF SHORE-CRAB. 



moult, when the little creature measures about one-eighth of an inch 

 in diameter, that the mature form is completely developed. The 

 facility with which these crustaceans cast off their legs, and even 

 their heavy claws, when they have been wounded, is a most remark- 

 able feature in their economy. Without the least appearance of 

 pain, they continue to run about upon their remaining legs, and, won- 

 derful to relate, after some time a new limb grows out of the old 

 stump, ,and takes the place of the original member. When the old 

 claw is separated, a scar forms, and remains until the animal casts 

 its shell. After the shell is thus cast, a protuberance in the centre 

 of the scar suddenly enlarges, and under it may be seen a small 

 claw, doubled on itself beneath the membrane of the stump. This 

 remains in a soft state until the crab again casts its shell, when the 

 new claw is set at liberty, straightened out, and becomes hard and 

 calcareous, like other parts of the body. 



The Eider or Eacer Crabs (Ocypoda)* found on the coasts of Syria 

 and Barbary, run so quickly that a man on horseback is said not to 

 be able to overtake them. The West Indian species dig holes three 

 or four feet deep, immediately above high-water mark, and only 

 leave them after dusk. 



* w/cus, okys, swift ; irdvs, 7ro86s, pous, podos, a foot. 



