32 A NATURAL HISTORY OF THE SEAS 



bends over towards the centre of operation and take its full 

 share of the feast. 



Recent observations have shown that sometimes the 

 crab's lodgers become so large and numerous as to con- 

 stitute an embarrassment and force him to seek another 

 home. The Velvet Cloak Anemone (Adamsia palliatd) 

 is likewise parasitic, living on a small hermit crab. The 

 polyp in time dissolves the shell and the crab is thus 

 comfortably ensconced in an elastic tenement permitting 

 his ample expansion and no longer necessitating as he grows 

 in size that constant search for more spacious accommoda- 

 tion which occupies so much of the average hermit crab's 

 career. 



The Velvet Cloak Anemone is found only in association 

 with the smooth-clawed hermit crab, and invariably tucks 

 itself just underneath the shell so that its eager tentacles 

 are always within easy reach of the crab's mouth and any 

 food the latter may be negociating. 



Still more remarkable is the partnership between a small 

 Indo-Pacific crab and certain anemones. The crab de- 

 taches the anemones from the rocks and carries them in 

 its claw, employing them as knuckle-dusters to ward off 

 foes. 



A giant anemone of the Barrier Reef may reach 2 ft. 

 in diameter, and is the chosen host of certain brilliant 

 little Coral Fishes of a kind often exhibited in the Zoo 

 Aquarium. These fishes and also a species of prawn 

 closely approximate to the anemone's colouring and habitu- 

 ally shelter in the polyp's gastric cavity, always hurrying 

 to this strange shelter on the slightest hint of danger. 



