210 



CRUSTACEA. 



are terminated by strong and pointed claws. They walk with the 

 same facility forward or backward, on one side or the other, or in all 

 oblique directions ; they also climb witli great celerity. 



The Edible Crabs (Pagurus), well known at our tables, generally 

 frequent rocky coverts, and hide in the clefts of rock?, where they 

 are sheltered from the waves, and secured from the pursuit of their 

 enemies. When the waters rise, they approach the shore and seize 

 on marine animals incapable of resistance, or devour such as have 

 perished. It is principally during the night that they proceed to 

 plunder. As they do not always regain the sea with sufficient 

 promptness, and they cannot swnu, they are often exposed to be 

 stranded at the retreat of the tide. Under such circumstances, if 

 they do not find a hole to take refuge in, they contract their feet, 

 squat down in some corner, and thus await with patience the return 

 of the water. Crab-fishing is usually conducted by two men, in a 

 boat provided with lines and creels, cruives, or crah-pots, as they are 



Fig. 160.— first stage of siioue-ckac. 



variously called, made of a kind of osier basket-work. These are 

 constructed upon the same principle as a wire mouse-trap, but the 

 aperture instead of being on the side is at the top. The bait, which 

 consists of stale fish, is fastened to the bottom, and the cre^ is then 

 sunk in a favourable situation, by stones of sufficient weight placed 

 within it ; a line is fastened to the creel, to the upper end of which 

 a cork is attached. The bait can readily be seen by the crabs, 

 whicli entering, are caught like-rats in a trap; the difficulty of egress 

 being increased by the aperture being overhead. 



Crabs undergo a remarkable metamorphosis. On leaving the 

 egg, their larvse have a very grotesque appearance. They are fur- 

 nished with a large, helmet-shaped head, ending behind in a long 

 point, and provided in front with two monstrous sessile eyes, like 

 the windows of a lantern. By means of a long, articulated tail, the 

 little creatures continually turn head over heels. Claws are as yet 

 wanting, and the young crab has only four pairs of legs, armed with 

 long bristles, that push food towards the ciliated and ever-active 

 mouth. Immediately after casting its first skin, the body makes an 



