146 APT ERA. 



8. Thorax oblong, and the hand without 

 . fingers. 



8 . longer than the shell, which it 



does not cover completely. 



This genus, which includes the Lobsters, 

 Shrimps, and Prawns, has lately been expelled 

 from the class of Insects, and very properly ar- 

 ranged in a separate department, by the name 

 of Crustacea. 



Crabs, having neither fins nor tail adapted 

 for swimming, are obliged to confine them- 

 selves to the bottom of the sea, or to the sand 

 upon its shore. They run sideways with great 

 agility, but if a wave leaves them dry upon the 

 shore, they immediately draw in their legs and 

 remain immoveable. Once a year they cast 

 their shells. This happens in the spring, and 

 after the operation they remain for some time 

 concealed in the sand till their new coat is suf- 

 ficiently strong to guard them from the common 

 accidents of their situation. There is one spe^ 

 cies in particular, to which Nature has not only 

 denied any covering, but has left it conscious of 



