DECAPODA. 215 



that of a whelk, of proportionate size, into which 

 they insinuate their tail, and retreating within the 

 recesses of their adopted abode, obtain a secure 

 retreat, which they drag after them wherever they 

 go, until by growing larger, they are compelled to 

 leave it, in search of a more capacious lodging. The 

 wonderful adaptation of all the limbs to a residence 

 in such a dwelling, cannot fail to strike the most 

 incurious observer. The chelce, or large claws, differ 

 remarkably in size, so that when the Hermit Crab 

 retires into its concealment, the smaller one may be 

 entirely withdrawn, while the larger closes and 

 guards the entrance. The two succeeding pairs of 

 legs, unlike those of the lobster, are of great size 

 and strength ; and instead of being terminated by 

 pincers, end in strong pointed levers, whereby the 

 animal can not only crawl, but drag after it its heavy 



FlG. 164. SOLDIER CRAB REMOVED FROM ITS SHELL. 



habitation. Behind these locomotive legs are two 

 feeble pairs, barely strong enough to enable the 

 Soldier Crab to shift its position in the shell it has 

 chosen, and the false feet attached to the abdomen 



