COMMON HERMIT CRAB. 1 73 



This species is extremely common, inhabiting, in the 

 course of its growth, almost every species of turbinated 

 shell existing on our coasts ; but in its adult state requiring 

 a habitation not smaller than the full-sized whelk, (Bucci- 

 natum undatum,) in which it is constantly found. Occu- 

 pying, in the early stages of its growth, the small species 

 of Litorina, of Natica, of Buccinum, of Murex, &c. When 

 it becomes too large for its existing dwelling, it leaves it, 

 and seeks for one not merely large enough for its present 

 occupation, but sufficiently so to admit of a certain degree 

 of further increase. Hence we often find individuals in 

 shells considerably larger than would be sufficient to pro- 

 tect them. 



It is a question of some interest whether the Hermit 

 Crab always chooses for its habitation a shell already 

 empty, or whether it actually kills and devours the inha- 

 bitant of one that suits its size, and then takes possession of 

 its violated home. The latter I believe to be true, in 

 many if not in most cases ; certainly, however, not in all, 

 as we often find the Hermit occupying an old and long- 

 abandoned shell. But so much more generally is it found 

 in fresh shells, that it can scarcely be doubted, even on this 

 ground alone, that it often obtains its habitation by 

 violence. The fishermen on the coast are fully persuaded 

 of this ; and an intelligent person of this class at Bognor 

 assured me that the fact has often been observed by him- 

 self and others. He stated that the aggressor seizes its 

 victim the whelk, for instance, immediately behind the 

 head, and thus kills or disables it, then eats it, and finally 

 creeps into and appropriates its vacant shell. It holds on 

 with great force and tenacity by means of the terminal 

 appendages ; and if taken hold of when running about, 

 which it does with great rapidity with its usurped shell 



