CRUSTACEA. 
453 
its shell ; it is about four inches in length, and has no 
shell on the hinder part, but is covered down to the tail 
with a rough skin ; it is also armed with strong hard 
nippers. This Crab has not been provided by nature with 
a shell, and is obliged to seek for one which can fit him, 
and has been deserted by its legitimate tenant ; but as 
this covering does not proceed from himself, and does not 
grow of course proportionally with him, he is forced out 
of it by his increasing size, and finds himself under the 
necessity of looking out for a new one : it is curious to 
see him when in want of a new house, how he crawls 
from one empty shell to another, examining and trying 
his new habitation ; and sometimes, when two com- 
petitors happen to eye the same premises, a great contest 
arises, and of course the strongest gets the manor. These 
Crabs live on sea- weed, and the smaller insects which tliey 
find in the puddles which the tide leaves behind. 
1. THE SHRIMP. (Crangon vulgaris.) 
THIS Shrimp is a well-known small crustaceous animal. It 
has long slender feelers, between which are two projecting 
laminae. It has three pair of legs and five fins, but no 
claws. All the sandy shores of Great Britain breed this 
animal : it is frequently found in harbours, and even in 
