60S 



ARTICULATA. 



upon the sandy bcftch in search of his prey ; but the moment danger threatens him lie disappears 

 into his cell, the orifice of wliich is then occupied by one of liis claws, wliich is always larger than 

 tiic other. As the crab does not possess the same power of adding to the size of the domicile 

 that was ciijoyctl by tiic original tenant, he is compelled, from time to time, to change his 

 residence for one a little larger, and often appears almost as dillicultto please as a human house- 

 holder ill the same jM-edieameut. Often they may be seen crawling about among the shells 



just thrown upon the beach, trying one 

 after another, until they meet with one 

 uniting all the conditions requisite for crus- 

 tacean comfort; but, until this great ob- 

 ject of their search is attained, always 

 returning to their old house after each un- 

 successful trial. It is said, indeed, that 

 when two of them happen simultaneously to 

 cast a longing eye upon some particularly 

 suitable residence, they often engage in a 

 fierce battle for the possession of the coveted 

 object, which the victor carries off in tri- 

 umph. 



The Purse-Crab, Birr/us latro, is a 

 very curious species found in Amboyna 

 and some of the adjacent islands. They 

 inhabit the fissures of rocks along the sea- 

 shore by day and come forth at night to 

 search for food along the beach. When 

 they meet a person they set up their claws 

 in a threatening manner and snap their 

 pincers and retreat backward. The natives 

 say they climb the cocoanut-trees to get 

 the cocoanuts. 



THE PnRSE-CRAB. 



THE BRACHYUEA. 



This terra is from the Greek brachus, short, and ovra, tail, and includes the Short-tailed Crabs, 



of which the Common Crab may be taken 

 as the type. 



THE MAIAD^. 



This includes the Spider-Crabs or Sca- 

 Spidcrs : in these the legs are long and 

 hairy ; the back is usually covered with 

 spines and hairs. They generally live in 

 deep water, and rarely approach the shore. 

 One species, the Libinia canaliculata, is 

 common along our coast from the Chesa- 

 peake northward. It is said to frequent 

 the oyster-beds, and to devour large quan- 



THE SPINOUS SPIDEE-CRAB— MAIA SQUINADO. titicS. 



THE CANCEKIDiE. 



The genus Cancer of Linnseus included the Crabs generally, many of which, though bearing 

 the general form of the more common species, are still possessed of very peculiar and remarkable 

 features. The Er'q^hia spinifrons, for instance, distributed in nearly all seas, has the front covered 

 with numerous sharp spines ; and the Parthenope horrida, a native of the Atlantic and Indian 



