CRABS. 
2 57 
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 
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 liat. size). 
