160 DECAPODS. 



and Barbary, run so quickly that a man on horseback is said not to be able 

 to overtake them. The West Indian species dig holes three or four feet deep, 

 immediately above high-water-mark, and only leave them after dusk. 



The Beckoning Crabs (Gelasimus)* have one of the claws, sometimes 

 the right, sometimes the left, much larger than the other, and the pincers of 

 the smaller forceps shaped like a spoon. These creatures live in burrows, 

 which they excavate upon the sea-shore, and close the entrance by means of 

 their large claw, the disproportionate size of which is thus found to be a won- 

 derful and beautiful adaptation to their habits. Their burrows are cylindrical, 

 and carried obliquely into the ground to a very considerable depth : they are 

 met with in great numbers, placed close together, but are usually inhabited 

 each by a single individual. From these crabs having the habit of flourishing 

 their large claw as if they were beckoning to some one at a distance, they have 

 received the name of " Calling Crabs " (Cancer vocans}. They pass the winter 

 in their burrows, without stirring abroad, and only visit the sea to lay their 

 eggs. 



Dr. Gardner, in his " Travels in Brazil," says that while he was near Rio 

 San Francisco, he amused himself with watching the operations of a small 

 species belonging to the genus Gelasimus, that was either making or enlarging 

 its burrow in the sand. About once in every two minutes it came up to the 

 surface with a quantity of sand enclosed in its left claw, which, by a sudden 

 jerk, it ejected to a distance of about six inches, always taking care to vary 

 the direction in which it was thrown, so as to prevent its accumulation in one 

 place. 



Another species, which inhabits India, is thus noticed by Bishop Heber in 

 his journal : " All the grass through the Deccari generally swarms with a small 

 land-crab, which burrows in the ground, and runs with considerable swiftness, 

 even when encumbered with a bundle of food as big as itself; this food is 

 grass or the green stalks of rice ; and it is amusing to see the crabs, sitting, 

 as it were, upright, cut their hay with their sharp pincers, and then waddling 

 off with their sheaf to their holes as quickly as their sidelong pace will carry 

 them. They have been found on the table-lands, at an elevation of nearly 

 4,000 feet; but it is believed that they do not perform an annual pilgrimage 

 to the sea, for the purpose of depositing their eggs." 



Most probably they prefer fresh water. 



The Cocoa-nut Crab (Birgus) is said to climb the cocoa-nut palms for 

 the sake of procuring their fruit ; but Mr. Darwin says that it merely lives upon 

 those that have fallen upon the ground. Its front pair of legs is terminated 

 by very strong and heavy pincers, the last pair by forceps, which are narrow 

 and of a weaker structure. After having selected a nut fit for its dinner, the 

 crab begins its operations by tearing off the husk, fibre by fibre, from that end 

 where the three holes are situated ; it then hammers upon one of them with its 

 heavy claws until an opening is made, through which, by means of its hinder 

 pincers, it extracts the white albuminous substance of the nut. It inhabits 

 deep burrows, where it accumulates surprising quantities of picked cocoa-nut 

 husks, on which it rests as on abed. Its habits are diurnal, but every night 

 it is said to pay a visit to the sea for the purpose of moistening its branchiae. 

 It is Very good to eat, and the fat accumulated under the tail of the larger 

 ones sometimes yields a quart of oil. 



The Land-Crabs (Gecarcimis}^ inhabit the West Indies and other warm 



* 7eXdw, gelao, to laugh at or ridicule, f 777, ge, the earth ; KO-PKIVOS, carcinos, a crab. 



