CRUSTACEA. 



capods, we find that the external organs above enumerated, 

 although existing in precisely similar situations, are so far modified 

 in their construction and relative proportions as to become suited 

 to a mode of life widely different from that led by the members 

 of the last division. The Anomoura^ as their name imports, 

 have tails of very unusual conformation : instead of being en- 

 cased in a hard coat of mail as in the Macroura, the hinder part 

 of the body is soft and coriaceous, possessing only a few detached 

 calcareous pieces, analogous it is true to those found in the lobster, 

 but strangely altered in structure. 



These animals (Jig- 153), usually known by the name of 

 Soldier-Crabs or Hermit-Crabs, frequent level and sandy shores, 



Fig. 153. 



and, from their defenceless condition, are obliged to resort to 

 artificial protection. This they do by selecting an empty tur- 

 binated shell of proportionate size, deserted by some gasteropod 

 mollusc, into which they insinuate their tail ; and, retreating 



