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PHYLUM CHORDATA : CLASS REPTILIA 



Some Families of Lacertilia 



In the Geckos (Geckonidte) the vertebra) are biconcave or amphi- 

 coelous, the tongue is short and fleshy, the eyehds are rudimentary, the 

 teeth are pleurodont, the toes bear numerous plaits, by means of which 

 they adhere to smooth surfaces, e.g. Platydactylus. 



The Agamas (Agamidae) are acrodont lizards common in the Eastern 

 hemisphere. Examples. — Agama ; Draco, with the skin extended on 

 long prolongations of five or six posterior ribs ; Chlamydosaurus, an 



Fig. 412. — The slow-worm {Anguis fragilis), a limbless lizard. 



— From a Specimen. 



There is a specially pigmented dorso-median line. Unlike a snake, the 

 slow-worm has a relatively long tail. There are no specially 

 broad scales extending across the ventral surface, yet these 

 are also absent in the burrowing snakes. Unlike a limbless 

 Amphibian (blindworm), the slow-worm is covered with epidermic 

 scales ; and its cloaca is far in front of the end of the body, whereas 

 it is terminal in the blindworm. 



Australian lizard, with a large scaled frill around the neck ; Moloch, 

 another Australian form bristling with sharp spikes. 



Iguanas (Iguanidae) are pleurodont lizards, represented in the 

 warmer parts of the New World. Examples. — Iguana, an arboreal 

 lizard, with a large distensible dewlap ; A mblyrhynchus or Oreocephalus 

 cristatus, a marine lizard confined to the Galapagos Islands ; Anolis, 

 the American chamaeleon, with powers of rapid colour-change ; 

 Phrynosoma, the American " horned toad," with numerous horny 

 scales, and a collar of sharp spines suggesting in miniature that of 

 some of the extinct Reptiles. 



The slow-worms (Anguidae) are limbless lizards, with serpentine 

 body, long tail, rudimentary girdles and sternum. The British Anguis 



