Page:Natural History, Reptiles.djvu/31

Rh Soft Tortoises devour greedily in the African and Indian rivers. In seizing their food, or defending themselves, they dart out their long neck with the sudden rapidity of an arrow. The grasp of their powerful and trenchant beak is sharp and deadly, nor is it relaxed until the piece is taken clean out; and as they are bold and ferocious, they are much dreaded even by those who fish for them.

Like the Emydes, the Soft Tortoises love to repose on the islets and points of rock, on the fallen trees at the rivers' margins, or on floating logs of timber, whence they drop into the water on the slightest alarm. They swim with ease and swiftness, both on and beneath the surface.

No species of this Family is found in any of the rivers of Europe. The Nile, the Niger, and the Senegal, the Euphrates, and the Ganges, the Mississippi, the Ohio, and their tributaries, and the great lakes of the St. Lawrence, are the localities known to be inhabited by various species of Trionychidæ.

The species belonging to this genus, which includes the majority of those known, are distinguished by the following characters. The carapace is surrounded by a cartilaginous circumference, very wide, floating behind, and deprived of bone externally. The hinder part of the plastron is too narrow to hide the posterior limbs completely, when the animal draws them up under the carapace.

The common Soft Tortoise of North America