HALF AN HOUR WITH CRUSTACEA. 239 



Singularly enough, the male seeks the female when 

 she is moulting ; and when a female crab retires to 

 some quiet and safe corner for the purpose of 

 throwing off her shell, she is always attended by a 

 male ! When crabs moult they differ somewhat 

 from their relations the lobsters in their way of 

 effecting it. The latter draw out the body, just 

 above the abdominal ring ; but in the crabs the 

 shell parts asunder by a suture which opens in a 

 curved direction around the under side of the shell. 



Another abundant species along our British shores 

 is the common "Shore-crab" (Carcinus mtenas). 

 The wonderful manner with which this creature can 

 walk and burrow, and partly swim, distinguishes it 

 from its fellows. Its carapace, or shell, is covered 

 with little tubercles, and the whole is a blackish- 

 green colour. In the young, however, it is mottled 

 with white. This crab may be found everywhere at 

 low water, crouching under stones, and, when dis- 

 turbed, either trying to make its way to the water, 

 or else to suddenly bury itself in the yielding sands. 

 It is so formed that it can live out of water longer 

 than any other British crab, and, at the same time, 

 it can live wholly immersed in water for days to- 

 gether. This crab is often sold for the last 

 mentioned, and is much eaten in our large towns. 

 ( It may always be identified by its toothed margin ; 

 that of the great, or edible crab, being frilled. As 

 food, its flavour is good, and its flesh sweet and 

 wholesome. It lives on the fry of fish and other 



