SPIDER CRABS. 



177 



front If they will live, they are useful creatures 

 in an aquarium ; for they are good scavengers 

 themselves, and, in addition, often carry on their 

 shells a whole army of zoophytes. Two of these 

 creatures, which inhabited a large aquarium be- 

 longing to a friend, were perfect treasures to the 

 microscopist ; for when a specimen of a living 

 zoophyte was wanted, one of the spider crabs 

 was hunted up, and the requisite portion re- 

 moved. They were both rather sluggish animals, 

 and generally resided in two dark holes, in 

 different parts of the aquarium, where a practised 

 eye was needed to discover them. 



The species represented is Maia squinado; but 

 there are several other spider crabs to be found 

 on the shores, some of whom possess limbs so 

 wonderfully elongated, that they seem to have 

 been subjected to the process of wire-drawing. 

 These may be captured at spring- tides, when the 

 water has sunk much below its usual level, and 

 left the unsuspecting crabs on dry land. Various 

 curious fish, and other creatures, may also be 

 taken at the same time. 



We now come to a very curious race of creatures, 

 the Soft-tailed Crabs. Those already mentioned 

 are entirely covered with a strong shelly mail; 

 but there are others whose tails are left bare and 



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