THE BROAD-CLAW PORCELAIN-CRAB. 607 



each side of the body, and enclosed in a large hollow, which they do not nearly fill. 

 Even when the footstalks are considered, on which the gills rest, they hardly occupy 

 the tenth part of the hollow. 



The Robber-crab is found in several parts of the Indian Ocean, is very common in 

 Amboyna, and has been taken off the Mauritius. Mr. Darwin gives the following 

 interesting account of this crab : " It would at first be thought impossible for a crab to 

 open a strong cocoa-nut covered with the husk, but Mr. Liesk assures me he has repeat- 

 edly seen the operation effected. The crab begins by tearing the husk, fibre by fibre, and 

 always at that end under which the three eye-holes are situated. When this is accom- 

 plished, the animal commences hammering with its heavy claws on one of these holes till 

 an opening is made ; then, turning round its body, by the aid of its posterior and narrow 

 pair of pincers, it extracts the white albuminous substance of the nut. 



I think this is as curious a case of instinct as ever was heard of, and likewise of 

 adaptation of structure between objects apparently so remote from each other in the 

 scheme of nature as a crab and a cocoa-nut tree. This crab is diurnal in its habits, but 

 every night it is said to pay a visit to the sea, no doubt for the purpose of moistening its 

 branchiae. The young are likewise hatched and live for some time on the coast. These 

 crabs inhabit deep burrows, which they excavate beneath the roots of trees, and here 

 they accumulate surprising quantities of the picked fibres of the cocoa-nut husk, on 

 which they rest as on a bed. The Malays sometimes take advantage of their labor by 

 collecting the coarse fibrous substance, and using it as junk." 



In the missionary voyage of Messrs. Tyerman and Bennett, a very spirited account 

 is given of these crabs, and one or two interesting details are mentioned. For example, 

 when the crab walks it raises itself well off the ground, standing nearly a foot in height, 

 and gets along quickly, though with a clumsy and stiff gait. The antennae are very sen- 

 sitive, and it is said that if they are touched with oil, the creature immediately dies. 

 Another mode of opening the shell is employed by these crabs besides that which is 

 mentioned by Mr. Darwin, for, according to Messrs. Tyerman and Bennett, the crab after 

 tearing off the husk, insinuates the smaller joint of the ckiw into one of the holes 

 at the end of the nut, and then beats the fruit against a stone, until the shell is 

 broken. 



This Crab is by no means handsome, but is a very large and remarkably shaped 

 creature. A fine specimen, when stretched out at length, will measure between two and 

 three feet in length, and as it is stout in proportion to its length, it may rank with some 

 of the largest of the crustaceans. The abdomen is of a curious form, and is evidently one 

 of the structures intermediate between the crabs and the lobsters. Its general color is 

 pale yellowish brown, and its limbs are covered with little projections of a nearly 

 black hue. 



During the day the Robber-crab mostly hides in the fissures of rocks, or in holes at 

 the foot of the trees, and in the evening issues from its concealment to prey upon the 

 cocoa-nut. Its wonderful skill and power in opening this huge fruit have already been 

 mentioned, but some writers give it credit for more extensive qualities, and say that it is 

 in the habit of climbing up the palm trees for the purpose of obtaining the fruit. The 

 particular palm which it is said to climb is the Pandanus odoratissimus . 



It appears to be fierce in proportion to its strength, and Mr. Cuming found that if 

 intercepted in its passage, it at first tried to intimidate its disturber by holding up the 

 claws and clattering them loudly ; and that even when it found itself obliged to give 

 ground, it retreated with its face to the enemy, still maintaining a threatening attitude. 

 The eyes of the Robber-crab stand on rather long but stout footstalks. 



WE now come to the Porcelain-crabs, so called because their shells are smooth and 

 polished as if made of porcelain, and have much of the peculiar semi-transparent gloss 

 of that manufacture. 



Several of these crabs are natives of the British seas, among which we may mention 

 two species. The first of these is the common BROAD-CLAW PORCELAIN-CRAB, so called 

 from the singular width and flatness of the claws, each of which is nearly as large as the 

 whole body. Altogether this is a flat crab, and, like all flattened beings, is formed for a 



