THE BROAD-CLAW PORCELAIN-CRAB. 46] 
can endure a long absence from water, and is fitted with a peculiar addition to the breathing 
apparatus. There are twenty-eight gills, fourteen at 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 foliowing 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 repeatedly 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 accomplished, 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. 
‘*T 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 branchize. 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 antennze are very sensitive, 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 claw 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 inter- 
mediate 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 inter- 
cepted 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. The specimen shown in the engraving is of natural size. 
Several of these crabs are natives of the European seas, among which we may mention two 
species. The first of these is the common Broap-cLaw PoRCELAIN-CRAB, So called from the 
