TRUE REPTILES. 215 
of motion (Fig. 258). The toes are provided with cling- 
ing ridges of bristles, by which they walk upon the walls 
in search of insects, though in the forest species this ar- 
rangement is sometimes absent, The jaws have small 
teeth, and the tongue is not extensible. 
Fic. 257.—Horned lizard (Pkr cornutum) Fic. eRe, 
Dorsal view and side view of head. 
The Scinks (Scinkide) are spindle-shaped (Fig. 259) 
and covered with smooth scales. The five-lined and red- 
headed scinks are common in the Southern States. The 
Glass Snakes (Chalcide) have no feet, the body being 
serpent-like (Fig. 260). The glass snake 
Fic. 259.—Scink (Sczncus officinalis), showing structure of the feet. 
have also been seen devouring their own cast-off skin and wriggling 
tail. The geckos of the East Indies utter a shrill cry. The leaf-tailed 
gecko is one of the most curious. One species is said to be luminous. 
They are all insect-eaters. Two hundred species are known. 
