GECKOS, LIZARDS, AND CHAMELEONS. 83- 



feature of the body, is large, of a bright golden 

 colour, relieved by curious crescentic lines of 

 bright chestnut, ranged on either side of the 

 pupil, which is vertical possibly in accordance 

 with nocturnal habits. The horns of the crescents 

 are directed inwards, and the crescents them- 

 selves are three or four in number, one lying 

 within the other, by fine semilunar bars of red. 

 It is known to the natives by a name which 

 signifies "the beast that leaps at the chest," 

 and they believe that if any one approaches the 

 tree on which one of these curious creatures is 

 lying it will leap out on to his chest, and cling 

 there so firmly that it can only be removed by 

 shaving away the skin ! 



In these two species we have the highest point 

 of specialisation for an arboreal life which has 

 been attained in the group. 



Let us now turn to the modifications which 

 have taken place through adaptation to a 

 desert-dwelling habitat. The best instance is 

 that furnished by the Persian Seratosdncus 

 scincus, a denizen of the desert. The digits, 

 in place of the adhesive lamella, have their 

 under surface granular, and fringed with 

 lamellae, resembling those which form the ad- 

 hesive disc of climbing species. In this desert 

 form the lamellae serve for running over loose 

 sand. Furthermore, the body differs from 

 that of climbing species in that it is clothed 

 with scales. On the upper surface of the tail 

 these scales give place to large nail-like plates. 

 Their use is remarkable, inasmuch as they can be 

 rubbed one upon another to produce a shrill 



