26 



GUIDE TO REPTILES AND AMPHIBIANS. 



the margin of the jaws. In the skeleton the bodies of the vertebrae 

 are cupped at both ends (amphiccelous) ; the clavicles (collar-bones) 

 are dilated and perforated near their junction with the breast- bone ; 

 and the parietal bones of the skull are separate. In the second 

 family the vertebrse articulate by ball-and-socket joints, the eyes 

 have movable eyelids, and the parietals are united. The members 

 of the third family show no expansion of the clavicles. 



Fiff. 25. 



A, Turkish Gecko (Hemidactylits tiirciciis), and B, Common Gecko [Tarentola 



mcmritanica) . 



The tail varies, being in some cases of ordinary form, and in 

 others trowel-shaped. Many species have the toes expanded and 

 furnished with adhesive structures, by means of which they are able 

 to climb window-panes and adhere to ceilings (fig. 24). The eggs, 

 which are nearly spherical and usually two in number, have hard 

 shells. Geckos feed on animal matter, chiefly insects, and are quite 

 harmless, and for the most part nocturnal. In a limited degree they 

 have the power of changing colour according to the nature of their 

 surroundings. 



