126 CRUSTACEA AND M0LLU6CA FOB 



hours from tho time of getting rid of the old shell 

 until the new one is firmly consolidated. During this 

 interval, they arc known under the name of soft-shdl 

 crabs, or shedders, and are sought after with great 

 avidity. They are considered a great luxury when fried 

 and are often sold with us at the rate of two dollars 

 the dozen. The Lupa is fond of burying himself in the 

 saud, and we shall be able to observe this habit whenever 

 we use silver-sand as part of the bottom of our tank. 

 The mode of sinking himself In the sand is curious and 

 the observing of it never fails to make me smile. It is 

 as follows : the hind part is thrust a little way into 

 the sand, and then the fore part brought down to its 

 level ; and, again, the hind part is sunk, the fore part 

 after, and so on until the whole of the creature is 

 beneath the level, when he blows the sand away from 

 his mouth and eyes, which remain exposed; but, usually, 

 the eyes and antouna) are all that are to be seen, mov- 

 ing around continually on all sides, as if watching for 

 prey. From his having this strange habit, we shall not 

 be able at all times to find our friend, unless we look 

 sharp or have the bottom of our tank formed entirely 

 of pebbles and empty shells, but even then he will 

 attempt to hide himself under them. The burying is done 

 in an instant, and very often the Lupa will also kick 

 the sand over himself with his hind legs, thus securely 

 hiding himself from enemies. 



The Sea-spider, or Spider Crab (Libinica caniadata — Plate 

 VIII., Fig. 4), I understand has been domesticated, but I 

 have never tried it. It is a curiously shaped animal, and is 



