Why the singular creature here represented should have the name
Polyphemus given to it, is hard to guess. Polyphemus, as every
schoolboy knows, was the fabled giant overcome by Ulysses, who is
represented as having one eye in the centre of his forehead; whereas,
this creature has two eyes and one horn. It is interesting from its
being so nearly allied to many very minute species.
The Polyphemus sometimes reaches the length of two feet; there are but
two species, which only differ from each other in the shape of their
buckler. That we have represented is found in the Indian Ocean, and has
been called the Molucca Crab.
The tail, or rather the horn, of the Polyphemus, is greatly dreaded by
the fishermen, from the idea that its wound is venomous. The natives
employ it to point their arrows, and as they are in the habit of
poisoning the points of these weapons, it is most likely from this
circumstance that the idea we have noticed originated, for there is no
other ground for the belief.
[Illustration: _Polyphemus gigas._]
During the night-time they lie half out of the water, and are then very
easily taken, as they appear to take but little notice of anything
until their danger becomes imminent.
It is but a small portion of their flesh that is considered good for
food, but the eggs, which are very numerous, are reckoned a delicacy.
These Crabs are in the habit of leaving the water and walking to a
considerable distance over the wet sands,—but if incommoded by the
sun, they hurry back as fast as they are able to their native element.
When walking, none of their legs are visible. Most authors say that, if
this Crab is laid on its back, it must inevitably perish, unless the
waters return in time, but one observer asserts that it has the power
of righting itself with the assistance of its tail.