DIVISIONS OF EEPTILIA. 



271 



This same brittleness exists in the Glass-snake {Ophisaurus ventralis) 

 of the Southern United states, in which also there are no limbs. In 

 other allied genera, there may be fore-feet alone, or hind-feet may 

 be present, or all four limbs exist in a more or less rudimentary 

 condition. In the true Lizards {Lacerta), all four limbs are present 

 in a well-developed form ; as is seen in the common Green Lizard 

 {L. viridis) of Europe. The genus Lacerta is represented in America 

 by the Ameivce, of which the Striped Lizard (Ameiva sex-lineata) of 

 the Southern States may be taken as a good example. Of all living 

 Lizards the largest are the Monitors ( Varanidce), which are exclu- 

 sively confined to the Old World, and attain sometimes a length of 

 from six to eight feet. Very large, too, are some of the Iguanas 



Fig. 196.— Head of Gecko stcntar. (After GUnther.) 



(fig. 194), which occur in warm regions in various parts of the world, 

 but especially in South America, where they are often eaten. Belated 

 to the Iguanas are the singular Lizards known as the Flying 

 Dragons {Draco), various species of which inhabit the Indian Archi- 

 pelago and the East Indies. They are all of small size, living in 

 trees and feeding on insects ; and their great peculiarity consists in 

 the fact that certain of the ribs are straightened out and support a 

 wing-like fold of the skin on each side of the body, by means of 

 which the animal can take very extensive leaps from tree to tree. 



The Scincoid Lizards form a very large family, represented by 

 numerous species in all parts of the world. One species is a common 

 form in Egypt and Arabia, and was formerly used as a remedy in 



