196 REPTILES OF THE WORLD 



a mature specimen of a burrowing snake but five or six 

 inches long and not thicker than a goose quill; or place 

 side by side a squatty, flat-headed viper and an enor- 

 mously elongated tree snake — one secreting itself by 

 shovelling sand over its back, the other darting away 

 with the speed of an arrow! 



In their general occurrence and distribution snakes 

 are considerably more abundant than lizards though not 

 so commonly seen, as the greater number lead a secretive 

 life and the feeding habits of them all induce them to 

 seek seclusion during the progress of the assimilation 

 of food. Snakes also range much farther into the tem- 

 perate regions than lizards; in many latitudes where 

 lizards cease to occur, numerous species of snakes are 

 common. As with the lizards, the number of species 

 is especially high in the tropics, thence decreases north 

 or south of the Equator. Details regarding distribution 

 will be treated under the heads of the respective fam- 

 ilies. A few points, however, should be primarily under- 

 stood : The various species of Rattlesnakes are confined 

 to the New World and the majority of them to the 

 United States and northern Mexico; yet the subfamily 

 to which the rattlesnakes belong — the Crotalince (Pit 

 Vipers) — is represented in both the Eastern and West- 

 ern Hemispheres. The true Vipers — without head pits 

 — are confined to the Old World. The famous Cobras 

 are confined to the Old World and there are ten species; 

 not all of them spread a "hood." The subfamily to 

 which the Cobras belong — the Elapince — is represented 

 in the New World by a single genus, Elaps. The 

 Elapine snakes swarm in Australia, forming the great 

 majority of the serpent life; this is one of the few parts 

 of the world where the poisonous species far exceed 

 the harmless ones in number of species. Madagascar 



