The Under-Water World 



The widely distributed, triangular- 

 shaped, small-clawed spider crabs deck 

 themselves with various articles such as 

 seaweed, pebbles and shells, relying for 

 safety upon their powers of camouflage. 

 In some species the shell has a smooth 

 surface that offers good anchorage to 

 such growths as sponges, but more often 

 one beset with hooks and bristles that 

 serve to retain seaweeds. These the 

 crab deliberately plants in position, first 

 chewing the roots to render them frayed 

 and more adhesive. Unlike most crabs 

 the members of the spider family are so 

 jointed that they can reach backwards 

 and so touch any parts of the carapace. 

 The common British species labours un- 

 ceasingly in bedecking itself and if 

 stripped of its covering will at once set 

 about its toilet in order to re-acquire 

 a camouflage suit. The largest spider 

 crab, a native of Japanese seas, covers 

 eighteen square feet of floor space. This 



