310 



NATURAL HISTORY. 



tus, there being three pairs of jaws. I have already said 

 enough of the Lobsters and Crabs. The Shrimps and 

 Prawns are quite small animals, regarded as great deli- 

 cacies. In Fig. 241 the Shrimp is above and the Prawn 

 below. 



Fig. 241. Shrimp and Prawn. 



530. The Hermit Crabs, Fig. 242, are very peculiar 

 both in their conformation and their habits. The crus- 



taceous covering in the 

 case of these animals is 

 confined to the upper part 

 of the body. The lower 

 part of the body, being 

 uncovered, needs protec- 

 tion, and the animal se- 

 cures this by inserting its 

 tail into some empty shell 

 which it finds. This it 

 drags about with it as it 

 wanders in search of its 

 food. When it is alarmed, 

 it withdraws itself wholly 

 into its portable house, closing the mouth of the shell 

 with one of its claws. As it grows it is obliged to seek 



Fig. 242. Hermit Crab. 



