LACERTILIA. 



621 



movable eyelids and external ear-openings. The teeth 

 are fused to the edge or to the ridge of the jaws, never 

 planted in sockets. The tongue, broad and short in some, 

 e.g. Geckos and Iguanas, long and terminally clubbed 

 in Chameleons, is oftenest a narrow bifid organ of touch. 



FIG. 339. Lateral view of brain of Hatteria punctata* 

 After Osawa. 



1-12, Cranial nerves ; p.e., parietal eye ; h.g.^ pineal gland ; 0., optic 

 lobe; c., cerebellum; z>., fourth ventricle; /#., infundibulum 

 and pituitary body. 



The opening of the cloaca is transverse. There is *a urinary 

 bladder , corresponding to that of the frog, and a double penis. 

 Most are oviparous, but in a few the eggs are hatched within 

 the body. They are usually active, agile animals, beautifully 

 and often protec- 

 tively coloured. 

 The tail is readily 

 thrown off by a 

 reflex action ; lost 

 tails and even legs 

 may be regenerated. 

 The food generally 

 consists of insects, 

 worms, and other small animals, but some prey upon larger 

 animals, and others are vegetarian. Most are terrestrial, 

 some arboreal, a few semi-aquatic, and there is one marine 

 form. Lizards are most abundant in the tropics, and are 

 absent from very cold regions. 



FIG. 340. Hatteria or Sphenodon. After 

 Hayek. 



