laUANAS. 117 



the tribe of the Iguanas and their kindred, and that of the Geckos 

 and their kindred. The tribe of 



Stbobilosaura 



Have the scales of the back and sides imbricate, generally rhombic, 

 and those of the lower parts imbricate and of small size. Tail 

 with more or less distinct whorls of scales. The eyes diurnal, 

 with round pupil, and valvular lids. Feet with toes of very 

 unequal length. Many of these reptiles have a row of spines or 

 spine-like scales along the back and tail, which in some are very 

 long, while others have high dorsal and caudal crests, an expansile 

 gular pouch, or other adornments. Like the Varans among the 

 Leptoglossa (p. 114), these Lizards do not renew the tail, or a 

 portion of it, after mutilation. There are two great families of 

 them — one peculiar to the Old World with Australia, the other to 

 the New World ; but as families they do not differ much, and might 

 very well be retained as divisions of the same extensive family. 



In the family of Jguanidm, all of which inhabit America or its 

 islands, the teeth are round at the root, dilated and compressed at 

 the tip, and toothed at the edge; they are placed in a simple 

 series on the inner side of the jaws, just below the edge, and are 

 covered on the inner side by the gums ; as they faU out they are 

 replaced by others, which grow at the base of their predecessors, 

 and gradually cause the absorption of their roots. Probably not 

 fewer than a him.dred and fifty species are now recognised, which 

 are distributed under more than fifty genera. We can only 

 notice a few of the most remarkable of these Lizards, some of the 

 larger of which attain a length of five or six feet, with propor- 

 tionate bulk of body. As a general rule, the larger species are 

 mainly herbivorous, while the smaller are chiefly insectivorous, 

 though many of the latter also devour fruit. As most of them are 

 remarkable for their rapid changes of colouring, the name of 

 Chameleon is often misapplied to them, in the supposition that 

 the Chameleons are the only Lizards in which that curious phe- 

 nomenon is observable. In one remarkable species, the Sph(Srops 

 anamalus, inhabiting Brazil, it is stated that the eye nearly re- 

 sembles that of the true Chameleons, and it is also one of those 

 which are particularly celebrated for its changes of hue.J 



