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.
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.
The Crab-like Limulus, ([Limulus cancriformis].)
The Limuli are found in deep ditches of fresh water, marshes, &c.; they are frequently met with congregated together in great numbers; their principal food in the Spring appears to be tadpoles.