26 A NATURALIST'S WANDERINGS 



taneous stampede of the dense crowd of the peopled shore into 

 their dwellings, just Avithin the door of which they halt, with 

 the larger of their two pincer-claws, which is of a rich pink 

 colour, effectually barring the entrance except where one 

 watchful stalked eye is thrust out to take an inquiring look 

 if the alarm is real. As one advances the pink areas again 

 change into white, as the Crustaceans withdraw into their sub- 

 terranean fastnesses. On traversing a broad field occupied by 

 these crabs, the constant undulations and change of colours, 

 produce a curious dazzling effect on the eyes. 



The land between tide-marks is occupied by another turret- 

 eyed vigilant pioneer of vegetable occupation against marine 

 possession, which extends its operations further landward than 

 the Gelasimus, and where the ground is more or less wet. This 

 is a species of Macrophthalmus whose Colour protects it from 

 general observation till it starts to run. One-third of its time 

 is spent under water, and two-thirds in energetic mining opera- 

 tions on land. It is to be seen constantly scattering aroundit, 

 with a nervous jerk, the arm-fulls of sand which, held between 

 its body and clawed foot, it has dragged up from below out of 

 the burrows into which it carries all sorts of vegetable debris. 

 On the slightest sound it scampers off to take refuge in the 

 water, and is at once noticeable by its mobile stalked eyes curi- 

 ously pricked up high over its body. These eye-stalks are 

 conical cylinders set round, except on the narrow area along 

 which they are applied to each other in the mid-line of the 

 body, with facets which really form perfect little watch-towers 

 commanding an unobstructed outlook to all points of the 

 compass. 



The area along the dry margin of the land is occupied 

 by a third — a short-eyed — species of crab (Ocypoda), whose 

 labours seem to tell more than those of the otliers. Besides 

 burying smaller particles of vegetable debris, it lowers down 

 large branches of trees, and even cocoa-nuts, by scooping away 

 the soil below them, and carries down also the newly fallen seeds 

 of the iron-wood tree (Cordia). Both these trees, which along 

 with a rough sort of grass {Lepturiis repens) and the hard- 

 wooded Pemphis acidula lead the van of vegetable occupation 

 of lands wrested from the sea, are in this way aided in their 

 forward march. As soon, however,. as its busy labours have 



