48 



REPTILES AND BIRDS. 



of the eye is round or vertical. Most of the species of this family 

 belong to the fauna of tropical Africa, which also produces a slender 

 form (Psammophis elegans). The other species are of a stouter 

 habit, frequenting plains, or at all events living on the ground. Ot 

 the Indian Psammophis condanarus, Dr. Jerdon procured one which 

 had killed and was swallowing a small viper (Echis carinata), this 

 being one of the few instances in which a non-venomous Snake has 

 been known to overpower a poisonous one.* We have heard the 



Fig. 12.— Viperine Snake. 



same of a small boa-like Serpent ( Chilabothms ?) in the West Indies, 

 which is said to prey upon the formidable Crotalidce. The Psammo- 

 dytiastes pulverulentus has a wide geographical range over south- 

 eastern Asia and its islands. Although innocuous, it has the aspect 

 of a venomous species. 



In a kindred African family, the RachiodontidcB, the species of 

 Dasypeltis have the maxillary teeth minute and few in number (four 

 to seven) ; but they have also some remarkable gular teeth, which 

 are formed by the elongated inferior spinous processes of the hinder 



* The Black Snake of North America undoubtedly preys upon the formidable 

 Rattlesnake. — Ed. 



