372 ZOOLOGY 



a pursuing enemy, which seizes the brilliant object, 

 while the lizard escapes, to grow a new tail in due time. 

 Snakes 9. The snakes, called Ophidia, are well known to all 



and easily recognized, unless the comparatively rare 

 legless lizards and amphibians are confused with them. 

 They are highly specialized animals, in which the limbs 

 and limb girdles have disappeared. The eyes are with- 

 out eyelids, which are present in the lizards. Many 

 snakes are poisonous, but more are harmless, and the 

 latter should be protected as useful animals, since they 

 destroy many mice and gophers. The poisonous 

 rattlesnakes, instead of having warning coloration, 

 possess a rattle on the tail, by means of which they are 

 enabled to frighten possible enemies. 



References 



GADOW, H. "Amphibia and Reptiles." Cambridge Natural History. 



STEJNEGER, L. "The Poisonous Snakes of North America." Report of 

 United States National Museum for iSg^. 



MATTHEW, W. D. "Dinosaurs." Handbook of American Museum of Natu- 

 ral History. New York, 1915. 



