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BACKBONED ANIMALS. 



Order II. Lizards (Lacertilid). General Character- 

 istics. The lizards (Fig. 253) are scaly reptiles with cy- 



FlG. 253. Skeleton of a lizard, sp, spinous processes, which in the tortoise 

 are flattened into plates ; r, ribs ; s, shoulder-bone ; # , upper arm ; e, 

 elbow ; /a, forearm ; h, hip-bone ; ///, thigh-bone ; k, knee ; /, bones of 

 the leg ; q>, quadrate bone between upper and lower jaw. 



lindrical bodies, long, slender tails, and have usually two 

 pairs of feet. The jaws are not extensible, as in the snakes, 

 and are armed with sharp, conical teeth. The tongue is 

 free, long, and sometimes forked. All lizards are ovipa- 

 rous. Their eggs are deposited either in the ground or in 

 hollow trees. About seventeen hundred living species are 

 known ; eighty-two species are found in North America, 

 north of Mexico. 



Chameleons (Chamaleonidce). These strange lizards 



(Fig. 254) are 

 found in Africa 

 and Asia, thirty 

 species being 

 known. The 

 body is com- 

 pressed, the 

 skin rough, the 

 tail round and 

 prehensile ; the 

 tongue is cylin- 

 FlG. 254. The chameleon, showing tongue. drical, and ca- 



