DRACO VOLANS; STELLIS. FAMILY AGAMID^E. 561 



496. Besides the foregoing, some other genera, having the 

 teeth arranged on the upper edge of the jaw, belong to this 

 family ; and these are for the most part inhabitants of the Old 

 World. Here we place the curious little Draco volans (Fig. 

 306), whose structure and habits have been already described 

 ( 468) ; this interesting animal is a native of the Asiatic 

 Archipelago. To this group also belongs the Stellio, the dif- 

 ferent species of which are the most common Lizards of the 

 Levant, tenanting old walls, piles of stones, crevices of rocks, 

 &c., and feeding upon insects. 



497. The AGAMID.E, or Agamas, are in general short, thick- 

 bodied lizards, covered with a lax skin, which is capable of being 



inflated with air at the 

 will of the animals ; they 

 are frequently beset with 

 spines, which are raised 

 up when the skin is in- 

 FIO. m-AGAMA. fl ate( j 5 presenting a formi- 



dable array. In many of them, the general form and aspect are 

 so Toad-like, that, were it not for the presence of a tail, they 

 might be mistaken for that Reptile on a first glance. These lurk 

 among rocks, heaps of stones, and mouldering ruins ; where 

 their dull and sombre colours protect them from observation. 

 Others, however, have a more slender contour, longer limbs, 

 and more flexible toes ; and ascend trees with facility. Many 

 of them are capable of changing the colours of the skin. A 

 very remarkable species of this group, found in Australia, is 

 distinguished by the presence of a sort of frill or ruff attached 

 to the neck ; this lies back in plaits, when the animal is undis- 

 turbed ; but is raised, to the extent of five inches on either side, 

 when the animal is alarmed. This Frilled Lizard has received 

 the scientific name of Chlamydosaurus. 



498. The family VARANIDJE, or Varans, includes the largest 

 of the Saurian Reptiles, with the exception of the Crocodiles. 

 It is chiefly characterised by the form of the tongue, which is 

 fleshy and very extensible, and forked at the tip like that of Ser- 

 pents ; and by the peculiar mode in which the skin is covered 



