72 THE STORY OF REPTILE LIFE. 



his eye. The lad showed us the marks of the 

 alligator's teeth in his thigh." 



CHAPTEE IV 



GECKOS, LIZARDS, AND CHAMELEONS 



THE creatures which form the subject of the 

 present chapter are those which, with the Snakes 

 to be considered presently, make up the sub- 

 class Squamata. This sub-class is divided into 

 two orders Lacertilia or Lizards in a wide 

 sense, and Ophidia, or Snakes. The Lacertilia 

 are again divided into three sub-orders Geckos, 

 Lizards proper, and Chamseleons. The total 

 number of species comprising these sub-orders 

 amounts to more than 1800. 



The exact origin of the forms which belong 

 to this sub-class is unknown, but they are pro- 

 bably descendants of the ancient group to which we 

 have already referred, and of which the remark- 

 able Tuatera Lizard is the sole representative. No 

 fossils are known which carry us beyond the 

 Juranic. Attaining their greatest develop- 

 ment within the Tertiary period, they appear, 

 says Dr Gadow, " to have a future before them, 

 being apparently still on the increase in number 

 and species, but certainly not in size." 



Their manifold variety in shape, size, and 

 structure give them a quite peculiar interest, 

 inasmuch as their several variations are generally 

 directly traceable to adaptation to their environ- 



