GECKOS, LIZARDS, AND CHAMELEONS. 95 



amphisbsenas have become still further modified, 

 for the body, in place of a covering of overlap- 

 ping scales, is invested only in a soft skin, form- 

 ing a series of worm-like rings, each of which, 

 however, is cut up into a series of little squares - 

 the vestiges of scales. Burrowing like earth- 

 worms, eyes, even if protected from injury, like 

 those of the glass-snake and "blind- worms," for 

 instance, would be not only useless but a source 

 of danger, and consequently have disappeared. 

 These remarkable creatures exhibit a decided 

 preference for ant-heaps and mounds of decaying 

 vegetable matter. Their method of progression, 

 is peculiar, inasmuch as they are able to move 

 either backwards or forwards with equal ease, 

 Only the lack of scales on the body renders such 

 a form of locomotion possible. The common 

 mole, it will be remembered, has peculiarly 

 nodified hair, which also allows of similar 

 forward or backward movements. The facility 

 with which the amphisbaenas move in either 

 direction, as well as the difficulty of distinguish- 

 ing the head from the tail, has led to the belief 

 in some parts of the world that these creatures 

 possess two heads. They feed on worms and in- 

 sects, and in rare cases, apparently, on snakes. 

 Tropical America,, the southern parts of the 

 United States, and Africa furnish the bulk of the 

 species; four, however, occur in the Mediter- 

 ranean countries. 



Although most lizards are expert swimmers, 

 aquatic forms are rare, and only one species is- 

 entirely marine. This is the remarkable Iguanoid 

 (Amblyrhynchus cristatus) the Galapagos Sea. 



