252 ANOMOUROUS DECAPODS; HERMIT-CRABS. 



appendages, or false legs, which it bears at its hinder portion. 

 When they are feeding or walking, the head and thorax project 

 beyond the mouth of the shell ; but when they 

 .are alarmed they draw themselves in, closing 

 the mouth with one of the claws, which is 

 much larger than the other, and holding to the 

 interior so firmly, that they will rather be torn 

 asunder than quit their attachment. As they 

 increase in size, they are obliged to change 

 their habitation for a more commodious one; 

 and the way in which they accomplish this is 

 very amusing. They may be not unfrequently 

 observed crawling slowly along the line of 

 empty shells, &c., left by the last wave; and 

 as if unwillin g to P art witn their old domicile 

 till a new one has been obtained, they slip their 

 tails out of the old house into the new one, again betaking 

 themselves to the former, if the latter is not found suitable. In 

 this manner they not unfrequently try a large number of shells, 

 before they find one to their liking. There are several species 

 of various sizes, which are inhabitants of our own shores ; they 

 feed for the most part upon dead fish, and all kinds of garbage 

 thrown upon the shore. The Birgus, an allied genus of tropical 

 regions, has the tail somewhat more protected, but still soft ; 

 this does not lodge in shells, but retires to rocks, or hides itself 

 in burrows in the earth. The best-known species, Birgus latro, 

 inhabits the Isle of France, and lives upon cocoa-nuts ; it bur- 

 rows at the roots of the trees, and feeds upon the fruit which 

 falls from them ; and it is even said to climb the trunk, to obtain 

 a further supply. In the curious genus Hypoconcha, belong- 

 ing to the family DROMIID^;, which of all the families of Ano- 

 moura makes the nearest approach to the preceding sub-order, 

 the dorsal surface of the body is soft, and the animal protects it- 

 self by attaching to this part one valve of a bivalve shell, which 

 serves it as a sort of convex shield. The only known species, 

 Hypoconcha sabulosa, has been found on the coasts of Cam- 

 peachy, Cuba, and St. Domingo. 



