THE ARTHROPOD A OF THE DEEP SEA 139 



' in which the dorsal face appears like a bit of 

 muddy area covered by corals, with a huge white arm 

 resembling a fragment of an Isis-like gorgonian.' 

 It is evident that this is a case in which the animal 

 in protected by its resemblance to the surround- 

 ings. 



The hermit crabs of the abyss, too, are not usually 

 characterised by any very great development of 

 spines. They find their protection in the shells they 

 inhabit. Some of the deep-sea hermit crabs carry 

 about with them on their shells a sea anemone, as we 

 find to be frequently the case among the shallow-water 

 species. Pagurus aby'ssorum, from a depth of 3,000 

 fathoms, is an example of this. 



In cases where there is a scarcity of gasteropod 

 shells the hermit crabs are obliged to find some 

 other form of protection for their bodies. The ' Blake ' 

 found in the West Indies a hermit crab that had 

 formed for itself a case of tightly compressed sand, 

 and another curious form, named Xylopagurus rectus, 

 makes its home in pieces of bamboo or in the holes 

 in lumps of water-logged wood. 



The last group of the Arthropoda we need refer 

 to is that of the Pycnogonida, those curious creatures 

 seemingly made up entirely of legs, and by some 



