xii ANELYTROPIDAE AMPHISBAENIDAE 565 



tail with a narrow, brown, median line. Total length, 7 to 

 8 inches. 



Fam. 17. Amphisbaenidae. Worm-shaped lizards with the 

 soft skin forming numerous rings, each of which is divided into 

 many little squares, the vestiges of scales which are otherwise 

 restricted to the head. The eyes and ears are concealed. Limbs 

 are absent except in Chirotes, which has short four-clawed fore- 

 limbs. The pectoral arch, and still more so the pelvic arch, are 

 reduced to minute vestiges. The tail is very short. The skull 

 is small, compact, and strongly ossified, in adaptation to the 

 burrowing life, and is devoid of postorbital and postfronto- 

 squamosal arches and of columellae. The teeth are either acrodont 



AMPHISBAENIDAE. 



FIG. 147. Map showing the distribution of Anipliisbaenidae. 



or pleurodont. The tongue is slightly elongated, covered with 

 scale-like papillae, and bifurcates into two long and narrow 

 smooth points. 



The Amphisbaenas lead an entirely subterranean, burrowing 

 life, like earth-worms. They are frequently found in ants' nests 

 or in manure-heaps. Their progression is very worm-like, their 

 annulated soft skin enabling them to make almost peristaltic 

 motions and to move backwards as well as forwards. They 

 crawl in a straight line, with slight vertical waves, not, like other 

 limbless lizards or snakes, by lateral undulations. The food 

 consists of worms and small insects. About one dozen genera 

 with more than sixty species are known, most of which inhabit 

 the warmer parts of America, the West Indies, and Africa. Four 

 inhabit Mediterranean countries. 



