CRABS. 257 



the South European Thelphusa fluviatilis, which swarms on the muddy banks 

 of the Lake of Albano, and is also abundant in the neighbourhood of Rome, where 

 it is captured for sale. Another well-known form is the Indian land -crab (T. 

 indica), to which the species here figured is nearly allied. 



The second tribe (Catometopa) is characterised by the broad and squared 

 frontal region of the carapace being bent downwards. It is typically represented 

 by the family Gecarcinidce, including most of the true land-crabs. A large number 

 of these belong to the genus Gecarcinus, which has representatives in both the 

 Eastern and Western Hemispheres. Two inhabit the West Indian Islands, and of 

 one of these (G. ruricola) from Jamaica a full account has been given by 

 Mr. Browne. 



These crabs are generally found at a distance of from two to three miles from 



INDIAN LAND-CRAB (f Hat. size). 



the sea, where they spend the day under stones, or in other sheltered situations. 

 Pairing takes place in the spring; and shortly afterwards the whole population 

 makes a move for the sea, in which the females lay their eggs. When seized with 

 this migratory instinct, nothing can turn them from their course. Issuing from 

 hollow trees, from under rocks, and out of innumerable holes, they muster in a host 

 so fast that they thickly cover an area more than a mile long, and upwards of 

 forty yards wide. The males lead the way, and the band proceeds in a straight 

 line to its destination, climbing over everything that comes in its road, be it 

 hedges, houses, churches, hills, or cliffs, and rather clamber up at the peril of their 

 lives than make a circuit. Having reached the sea, the females lay their eggs, and 

 the young hatch out as miniature copies of their parents. At the time of moulting, 

 which takes place late in the summer, the crabs retire to their burrows, close up 

 the apertures, and remain there out of harm's way until the old shell is cast and 

 the new integument hardened. It is while still in the soft state that these crabs, 

 which are eaten by the natives, are considered most palatable. 



VOL. VI. 17 



