FORMIDABLE ROBBER-CRABS 105 



are two huge iron tanks filled with rainwater, 

 which is stored, as our host informed us, in case of 

 a ship being wrecked there. 



The most interesting event of our excursion 

 was the discovery of several robber-crabs {Birgus 

 latro), a highly specialized form of hermit-crab 

 of huge proportions. It is a most formidable- 

 looking creature, and, unlike the hermit-crab, 

 carries no shell, but has the tail covered with a 

 jointed " armour," like that of the lobster. The 

 robber-crab is of a reddish colour, though in some 

 specimens there is a tinge of blue both on the head 

 and on part of the upper surface of the body. 

 Its food is said to consist chiefly of cocoanuts, 

 but as there are none of these nuts on He de Lise 

 it feeds on maize, of which it devours enormous 

 quantities. Curiously enough, although plentifiil 

 on He de Lise, this crab is not found on Glorioso 

 Island, and our host was fearfvd lest it should by 

 some means get across to his cocoanut plantations. 

 I examined several heads of maize, from which 

 the seed had been shorn off by the claws of this 

 crab ; each head of corn had the appearance of 

 having been shaved with a sharp knife. The 

 robber-crab is nocturnal here, and during the day 

 hides in hoUows up in the trees. We found several, 

 but they were so securely ensconced that we had 

 to hew part of the tree-trunks with an axe before 

 we could get at them. Their strength is terrific. 

 When held by the claws they twine their legs 



