A'GAMA, in Zoology, a genus of reptiles belonging to the order Saurians, and family Iguanians, of Baron Cuvicr.
In the form of their heads and teeth the species of Agama resemble the common lizards, but differ is the imbricated scales which cover their tails. These animals have the body thick, and shorter in pro portion than the generality of the saurian family ; the skin is lax, and capable of being distended or puffed out with air at the will of the reptile ; the whole body, as well as the head, neck, and feet, is covered with minute rhomboidal or hexagonal scales, often prolonged in the form of little spines, and bristling when the body is inflated with air. The head is short, broad, and fiat, particularly towards the occiput ; the neck also is short, and the tail seldom longer than the body. These proportions give the Agamas much of the hideous and disgusting appearance of toads. In many parts of South America they are called Chameleons, from their power of dilating the skin with air, and imitating, to a certain extent, those animals in the various hues which they are capable of assuming. In other respects the various species of Agamas differ so considerably from one another, as to have induced Baron Cuvier to arrange them in separate sub genera, distinguished by the form of their scales and the presence or absence of pores in the thighs. Generally speaking, the Agamas have no thigh pores ; some however are provided, as is the case with many other saurian reptiles, with a row of these pores along the inner surface of each thigh ; some species have the toes so short and rigid as to compel them to live entirely on the surface of the earth, where they reside among rocks and heaps of stone, and conceal themselves is the crevices; others again, which have long and flexible toes, ascend trees with great facility, and sport among their branches with the utmost security. All are of a diminutive size, and, like most other reptiles, feed upon insects and other small animals : one or two species however are reported to he herbivorous. Their geogra phical distribution is very extensive, and embraces all the hot and most of the temperate parts of the known world Asia, Africa, Australia, and South America have each their appropriate species, which often differ from one another very slightly.
The most remarkable species are, of those without pores on the interior face of the thighs :—The Muricated Agama (Agama muricata, Cuvier), first described by the celebrated John Hunter in the zoological part of White's Voyage to New South Wales.' It is
one of the moat common lizards of that colony ; measures upwards of a foot in length, comprehending the tail, which is twice as long as the body, and, from the great length and perfect division of its toes, readily ascends trees, and lives entirely iu the woods, where it hunte about for insects and caterpillars. Its general colour is a brownish gray, marked with dusky bars, which run in a longitudinal direction on the body, but transversely on the legs and tail. The scales which cover the upper and outer parts of the trunk and extremities are rhomboidal and carinated, or elevated into sharp-pointed ridges, forming parallel lines or rows of spines upon the back and sides, from the shoulders to the very point of the tail. The head is covered similar scales, all directed backwards and prolonged upon the occiput into a crest of weak spines. The toes of all the feet are well separated, and furnished underneath with small pointed scales ; the two middle toes of the hind feet are nearly twice the length of the others.
The Agama barbata of Cuvier is another species from the same locality. It is rather larger than the Muricated Agama, but preserves the same relative dimensions, and lives in the forests in the same manner. This species is figured and described in White's 'Voyage,' p. 255, but was considered by Mr. Hunter as a mere variety of the former.
Other species of this division, having pores on the inner surfaeo of the thighs, are the Leiolepis (A. guttata of M. Cuvicr) of Cochin China, with white rays and spots on a bright blue ground ; the Tropidolepis (A. undulata), of a uniform dark blue colour with a parts of South America ; the Brackdophes (A. which seems to form the connecting link between this genus and the guanas, from which latter it is distinguished only by the absence of teeth in the palate ; it is found in India, and has light blue bands upon a dark blue ground : and lastly the Physivuttlies (A. cocincinus), from the Malayan Peninsula, remarkable for its large size, uniform blue colour, but more particularly from being one of the very few species of saurian reptiles which feed upon vegetable substances. Baron Cuvier assures us that it lives entirely upon fruits and nuts.