242 POPULAR HISTORY OF THE AQUARIUM. 



blish it, and in the meantime we must be content to take 

 the obvious facts as we find them. 



The front, or exposed part, then, of the common Soldier 

 resembles that of other Crabs in some degree. The two 

 first claws are pincers, always unequal in size ; the next two 

 pairs are long, arched, and pointed, very well adapted for 

 ambulatory purposes. The front part of the thorax, or 

 body, only, is covered by the shield or carapace, which in 

 other Crabs covers the whole body. Then comes the hinder 

 part of the thorax, which is soft, and two pairs of legs, which 

 are small, irregular, and very feebly developed. The abdo- 

 men is a membranous sac of irregular form, with very ru- 

 dimentary plates, and terminating in a crustaceous tail of 

 three joints, the second with appendages or flappers. Trom 

 the unprotected condition of the hinder part of this animal, 

 it will be easily understood that it requires constant shelter. 



AYhen two ^' Soldiers" meet in an Aquarium, there is 

 generally a passage-of-arms between them, being very pug- 

 nacious animals, each one trying to seize the other with his 

 strong claws, the object being to wrench the enemy out of 

 his tenement and feed upon the unprotected part of his 

 body : and this atrocious design is sometimes carried out. 

 But in other cases the fight is not for the possession of the 



