176 REPTILES OF THE WORLD 



chin are covered with shields. It is by means of the 

 segments (divided into numerous minute squares) that 

 the members of this family are able to crawl. The seg- 

 ments are movable, carrying the lizard backward or 

 forward with equal speed; they are employed in wave- 

 like, peristaltic fashion, the body assuming slight, ver- 

 tical undulations. Like the members of the preceding 

 family, the present lizards are persistent burrowers. 

 They are commonly found in ant-hills. 



Over ten genera are recognized, these embracing about 

 sixty species. AmpMshcEna is the largest genus, with 

 about thirty species, the members inhabiting tropical 

 America and tropical Africa. 



The White-Bellied Worm Lizard, AvipMsbcena 

 alba, found in tropical South America and in Trinidad, 

 is tj^pical of its genus. A large specimen is two feet 

 long, slightly over an inch in diameter and perfectly 

 cylindrical for almost the entire length. The tail is just 

 as thick and stumpy as the head; unless one examines 

 the animal closely the two extremities cannot be told 

 apart. Thus the reason for a popular name in some 

 part of South America — Two-Headed Blind "Snake." 

 If a specimen is carefully inspected, the eyes may be seen 

 as two mere bluish spots sunk under the translucent skin. 

 But we cannot say these queer lizards are absolutely 

 blind. All of the writer's si^ecimens showed a marked 

 distaste for a strong light. They would display an im- 

 mediate nervous movement if a match was struck in 

 front of their cage at night. They were peculiarly 

 sensitive to vibrations, moving uneasily if one stepped 

 heavily across the room and twitching every time a finger 

 was tapped on the glass of the cage. When a specimen 

 was annoyed it would elevate the stubby tail in a fashion 

 that caused the organ to look like a head reared in 



