144 



LIZARDS. 



with bone : while they are further characterised by a fold covered with small 

 scales running along the sides of the body and marking off the upper from the 

 under-parts. The tongue is simple, with its anterior moiety not extensile, and its 

 tip either rounded, or but slightly notched ; while there are well-developed eyelids, 

 and the drum of the ear is exposed. The back is either clothed with large shield- 

 like, and mostly keeled scales, arranged in well-marked transverse zones, or, more 

 rarely, with granules ; the head having large, regular shields. As regards their 

 teeth, these lizards conform to the pleurodont type, each tooth having its base 

 widely open. Resembling in many respects the Iguanoids, from which they are 

 distinguished by the ossifications in the skull, these lizards also approach the 

 members of the next family, from which they differ by their simple tongues, the 



CAPE GIRDLE-TAILED LIZARD 111 at. Size 



hollow bases of the teeth, and the structure of the bony plates underlying the 

 scales, when such are present. In the South African snake-like genus (Chamce- 

 saurci), the fore-limbs are wanting, and the hind-pair rudimental, while the tail is 

 of extraordinary length. All the members of the family appear to be carnivorous. 

 Girdle-Tailed We take as our special example of this small family one of the 



Lizard. members of the South African girdle-tailed lizards (Zonurus), a 

 genus represented by seven species. These lizards differ from the other three 

 genera in having the scales of the back underlain by bony plates of simple 

 structure ; and, resembling in appearance the rough-tailed lizard among the 

 agamoids, they have a flattened triangular head, and a tail of moderate 

 length. On the upper surface the neck and back are covered with large quad- 

 rangular shield-like scales, while beneath there are large flat shields ; the limbs 

 bearing keeled overlapping shields, and the tail being protected with whorls of 



