1908-1909.] Glimpses of Marine Life on the Forth. 123 



burrows, which it hollows out beneath the roots of trees, and 

 carpets with fibres stripped from cocoa-nuts. Periodically, 

 however, it is compelled to visit the sea to moisten its gills 

 and to lay its eggs. It lives principally upon cocoa-nuts, but 

 it does not climb trees after the fruit. To get at the contents 

 of the nut, the crab first tears away the fibre overlying the 

 three eyes, and then hammers away at the latter until a hole 

 is made, when it extracts the kernel by means of its smaller 

 pincers. Some observers state that, after drilling through the 

 perforated eye, the crab grasps the nut in its claws and breaks 

 it against a stone. 



The Spider Crabs. 



A peculiarity of this group is their extreme untidiness, 

 owing to the quantities of sea- weeds, zoophytes, and other 

 marine objects affixed to the carapace and limbs ; and it 

 has been ascertained that the presence of these extraneous 

 bodies is not the result of chance, but that they are placed 

 there presumably for the purpose of concealment by the crabs 

 themselves. This feat they are enabled to perform owing to 

 the flexibility of their pincers, and to the hooked hairs and 

 spines with which the carapace is studded. Some examples 

 of Hyas, deprived of their covering of foreign bodies, were 

 placed under observation in an aquarium, of which the 

 bottom was covered with a layer of sponges. Contrary to 

 their habitual sluggishness of manner, the crabs appeared 

 much perturbed, running first to one side and then to the 

 other in the aquarium. Soon, however, by means of their 

 pincers, they tore off small fragments of the sponges, and, after 

 first putting them to their mouths, placed them finally upon 

 the dorsal surface of the carapace or limbs, sticking them 

 there with a rubbing movement. Sometimes, after several 

 vain efforts, the crab brought the fragment afresh to its 

 maxillipedes and then repeated its efforts to make it adhere. 

 The animal persevered in these manoeuvres until the piece 

 of sponge remained fixed in the spot where it wished to place 

 it. By continuing to act in this fashion the crab succeeded 

 in completely changing its appearance, and in rendering itself 

 indistinguishable amongst the objects which surrounded it. 



