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Show I . I 'I 12 REPTILIA. and is devoured in turn by the old ones. It:; flesh is highly esteemed.( 1) ORDER II. SAURIA.(2) The Saurians have a heart like that of the Chelonire, composed of two auricles and a ventricle, sometimes divided by imperfect partitions. . Their ribs are movable, partly connected With the ster-num, and rise and fall in respiration. Their lung extends more or less towards the posterior extremity of the body; it frequently penetrates very far into the lower part of the abdomen, whose transverse muscles pass under the ribs, and even towards the neck, to clasp it. Those in which this organ is very large, possess the singular faculty of changing the colours of their skin according to the excitement produced in them by their wants or passions . Their eggs are enveloped by a covering more or less hard, and the young always retain the form in which they quit them. Their mouth is always armed with teeth, and their toes, with very few exceptions, are furnished with nails; their skin is covered with scales, more or less compact, or at least with scaly granules. They all have a tail more or less long, and generally very thick at base : most of them have four legs, a few only having but two. (1) Add Trionyxjavanicus, Geoff. Ann. du Mus. XIV ;-Tr. carinatus, Id.;-11-· stellatus,Id.;-Tr. eupltraticus, Olivier, Voy. en Turquie, &c. pl. xlii;-Tr. gan· geticus, Duvaucel;-Tr. granosus, Leach, or Test. granosa, Schcepf. xxx, A and B. N.B. The Tortue de Bartram, Voy. Am. Sept. tr. fr. I, pl. 2, appears to me to be the T. ferox, to which, through a mistake, two nails too many have been added to each foot. (2) From (J'r.tvpor, (Lizard) animals analogous to Lizards. SAURIA. 13 Linnreus included them all in two genera, the DRAGONS and the LizARDs: but it has been found necessary to divide the latter into several, which so far differ in the number of feet, &c. the shape of the tongue, tail and scales, that we are even compelled to distribute them in several families. FAMILY I. CROCODILIDA. This family contains the single genus CRoconrLus, Br. Crocodiles are large animals, with a tail flattened on the sides, five toes before and four behind, of which only the three internal ones on each foot are armed with nails, all more or less united by membranes; a single range of pointed teeth in each jaw; the tongue fleshy, flat, and adhering dose to its edges; a circumstance which induced the ancients to believe that they had none;1 the back and tail covered with very stout, large, square scales or plates, relieved by a ridge along their middle; a deeply notched crest on the tail, which is double at its base. The plates on the belly are smooth, thin, and square. Their nostril'S, which open on the end of the muzzle by two 'Small crescent-shaped fissures closed by valves, communicate with the extremity of the hind part of the mouth, by a narrow canal which traverses the palatine and sphenoidal bones. The lower jaw being continued behind the cranium, the upper one appears to be movable, and has been so described by the ancients; it only moves, however, with the entire head. They have the power ()f closing the external ear by means of two fleshy lips, and there are three lids to their eyes. Six small holes, orifices of as many glands, may be observed under the throat, from which issues a kind of musk-scented pomatum. The vertebrre of the neck rest on each other through the medium of small false ribs, which renders all lateral motion difficult, and does not allow tbese animals to deviate suddenly from their course; consequently it is easy to escape from them by pursuing a zig-zag direction, or by running round them. They are the only Saurians that nre destitute of clavicles, but their coracoid apophyses are attached to the sternum, as in all the others. In addition to the common and false ribs, there are others which protect the abdomen, without |
