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Scientific Memoirs by

the body—this enormous appendage being used, at least in one species, as a love-
signal, as a war-club, and also as a buckler.

      The Indian species of Gelasimus are ten in number, but the only one that I
have had opportunities of observing in a state of nature is Gelasimus annulipes.
This species, which has an extensive range over the Indo-Pacific region, from the
shores of East Africa to the Sandwich Islands, is to be found in vast warrens, in
which the males far outnumber the females, on the extensive tidal mud-flats of the
Godavari and Kistna deltas. If one lands here in the early months of the year,
one becomes aware of a multitude of bright twinkling objects which, when one
advances to examine them, suddenly disappear: these objects are the brandished
chelipeds of Gelasimus annulipes, and their disappearance is caused by the crabs
retreating in alarm into their burrows.

      If one remains perfectly quiet the crabs in time cautiously come out again and
resume their occupation. The males, being so vastly more numerous than the
females, attract attention first, and their behaviour is something quite grotesque.
They dance round the mouths of their respective burrows, keeping up a continual
beckoning motion with the big chela, which is of a beautiful cherry-red and rose-
pink colour. Here and there a little dingy female may be seen picking at the mud
near her burrow, and at last it becomes evident that the singular demonstrations
of the males are intended for the female in their vicinity; for if the female should
approach one of the males the excitement of that favoured individual becomes
almost frantic. lf, on the other hand, one male should skirmish near another, a
fight takes place, the little creatures making savage backhanded sweeps at one
another. No doubt they claw each other too, for on going over the field of action
dismembered chelipeds are seen lying about.

      There can be little doubt that in Gelasimus annulipes the courtship of the
female by the male and the consequent rivalry between the males, is as sustained
and as complicated a piece of work as it is among many higher animals, and that
to this fact the cheliped of the male probably owes its brilliant colouring (to attract
the female) and its enormous size (for giving and warding-off blows).

      My only opportunities of observing Gelasimus have been at the courting
season, during the cold-weather months; but the ordinary habits of the American
Fiddler-crabs have been graphically described by McNair Wright in the American
Naturalist for May 1887 (Volume XXI, pages 415-418), and by Kingsley in the
same serial for 1888 (Volume XXII, pages 889-893).

4. On the Habits of some Indian species of Ocypode Crabs.

      The crabs of the genus Ocypoda resemble their near relatives of the genus
Gelasimus, both in their suggestive geographical distribution and in their manner
of life.