PROTECTIVE PEEIL 117 



of the chelipeds are almost the only smooth part about it. 

 It is said by Stalio to be sensitive to changes of tempera- 

 ture, and at any increase of cold to crouch closely in the 

 crevices of the rocks, but as he also says that its habitat 

 is at a depth of thirty to forty fathoms, it is not easy to 

 understand how this valetudinarian shrinking has been 

 ascertained. The crab is only about two inches long, and 

 according to Herbst is commonly covered with worm-tubes, 

 corals, algas, and mud, to such an extent that it is scarcely 

 to be recognised or to be taken for a living creature. 



Ghionoecetes, Kroyer, 1838, is a northern genus, with 

 a name meaning ' the snow-dweller,' founded for the 

 Greenland species Chionoecetes opilio, which, according to 

 Professor S. I. Smith, is taken rarely in the deep water 

 off the New England coast. ' It is,' he says, ' one of the 

 largest arctic crabs, and occasionally attains gigantic pro- 

 portions.' In the largest specimen that he examined the 

 span of the walking-legs was two feet eight inches. The 

 specimen figured by Kroyer in Gaimard's voyages was, he 

 says, even somewhat larger, but though the figure occupies 

 the whole extent of the folio plate, I do not find that even 

 with the second pair of legs which are the longest or with 

 the third pair which are inserted at the broadest part of 

 the carapace could it span more than twenty-eight inches. 



Antiiibinia Smithii, M'Leay, is a South African species 

 which Krauss observed in its native haunts on the per- 

 pendicular wave-lashed cliffs of the headland at Natal. 

 Its legs are powerful and have the terminal joint bent into 

 a strong hook by which the crab can fasten on to the pores 

 of the rock. Its body is rounded off and has a very hard 

 horny shell well adapted to resist the continual beating 

 upon it of the surf. Among the bright and dark green 

 algae, and coloured like them, it sits almost completely 

 motionless and lets its food be floated to it by the ever- 

 moving sea. When Krauss wished to take some speci- 

 mens away from their dangerous position, they clung so 

 tight that he had to use considerable force to disengage 

 them, and was in consequence several times overtaken by 

 the returning waves before he could effect his purpose. It 



