THE WOOLLY CRAB. 



597 



The antennae are apt to become clogged with mud, and the crab is therefore gifted with 

 an apparatus whereby they can be perfectly cleansed. In order to effect this object, the 

 crab bends each antenna sideways, until it rests on the hairy base of its companion ; 

 it then draws it completely through the stiff bristly hairs, until every particle of extra- 

 neous matter is brushed away. Sometimes the Mask-crab buries itself so deeply, that 

 it only leaves the tip of the antenna? above the sand. The name of Mask-crab is given 

 to this crustacean, because the carapace is so formed that its two waved grooves mould 

 the surface into an obscure likeness of the human face. This resemblance may be 

 seen by reference to the left-hand figure. 



The smaller figure on the right hand is the POLISHED CRAB, so called from the 

 smooth shining surface of the carapace. In this genus the carapace is somewhat heart- 

 shaped, and very narrow behind ; the claw-feet are small and short. Although this is 

 one of the British species, it is not very commonly found, probably on account of its 

 habit of burying itself rather deeply in the sand, so that the eye cannot perceive it, 



MASK-CRAB. Corystes Cassivelaunus. 



POLISHED CRAB.-rh/a pollta. 



and the dredge passes over its sunken body without sweeping it into the net. It is 

 rather a pretty little crab, though unfortunately its beauty is only skin-deep, and 

 perishes after death. When living and in good health, the carapace is of a soft rose 

 color, and has a very pleasing appearance ; but when the shell is emptied of its contents, 

 or even after the death of the inhabitant, the pink hue rapidly fades into the dull grays 

 so prevalent among dead crustaceans. In the Mediterranean the Polished Crab is 

 very plentiful, and it is possible that if the British coasts were thoroughly searched, 

 the Polished Crab would be found in tolerable plenty. 



WE now come to another family, of which the WOOLLY CRAB is an excellent type. 



This creature derives its name from the coating of thick short hair with which its 

 body is covered. All the species of this genus possess several peculiarities ; at each 

 side of the shell, and just at the base of the claw-legs, is an aperture that looks as if it 

 had been cut for a button-hole, and partly closed with a membrane. These apertures 

 are in fact the openings through which the water passes for the purpose of supplying 

 the gills with the needful moisture, and allowing it to escape when it has performed 

 that office. 



