In spite of the repulsive appearance of the creature, the negroes occasionally eat it.
Tortoises.
Tortoises (Testudinata, or Chelonians) belong to a very numerous order of reptiles, the usual form of which is too well known to require description. They are shut up, as it were, in a box and breast-plate: the carapace and plastron, in reality, are external developments of certain parts of the skeleton.
The land tortoises have the strongest plastrons. In some species it is slightly movable, but generally fixed by a uniting suture. In one—the pyxis—the plastron is furnished with a transverse hinge, so that the animal can retract its head and fore-limbs within the carapace, and close the plastron upon it, first shutting them in. In another—the kinixis—the carapace has the posterior portion distinct from the anterior, and movable, so as to shield the hind-limbs and tail.
In water tortoises, or turtles, as they are generally called, the plastron is united to the edges of the carapace by intervening cartilage, and not by suture. The jaws of tortoises are not furnished with teeth, but are cased in horny coverings, resembling somewhat the sharp hooked beak of a parrot; which enable them either to crop and mince the vegetable aliment on which most of them live, or to masticate the small, living animals, such as birds and reptiles, of which the food of others consists. Round the outside of this beak are thick fleshy lips.
In the curious matamata, the jaws of which open very wide, these parts, instead of being armed by a strong beak, are protected by a sheath of horn.
In the land tortoises, the feet are stump-like, the toes being enveloped in the skin, so that they can move but slowly. The marsh and lake tortoises have their feet palmated, to enable them to move either on the water or on land. In the turtles, these limbs appear in the form of broad, flat, undivided paddles, well-adapted for moving in the water, but awkward as instruments of locomotion, even on the level, sandy shores to which they resort at the breeding season.
The tortoise has a fleshy tongue like that of a parrot. The brain is but slightly developed, scarcely filling the cavity of the skull in the marine species. At the same time, the animal possesses great muscular irritability, and extreme tenacity of life. All are oviparous, and bury their eggs, which are hatched by the warmth of the sun. The water tortoises, when seen below the surface, move like birds in the air, the paddles flapping like wings.
The order is divided into four groups: first, Chersians, or the land tortoises; second, the Elodians, or marsh tortoises; third, the Potamians, or river tortoises; fourth, the Thalassians, or sea tortoises, generally called turtles. These groups are again variously subdivided.
The waters of Tropical America abound with the second and third families. The Elodians, found in the shallow pools of the Amazonian Valley, swim with facility, and move quickly over the ground. They feed not only on vegetables, but prey on living animals—river molluscs, and other water creatures.