310 NATURAL HISTORY. 
tus, there being three pairs of jaws. Ihave already said 
enough of the Lobsters and Crabs. The Shrimps and 
Prawns are quite small animals, regarded as great deli- 
eacies. 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 coverig 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. Whenit 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. 
