CLASS EEPTILIA: ORDER OPHIDIA. 



175 



Fig. 296. 



eyes. In cold climates, snakes hibernate, gathering often in 



their holes in large 



masses.* 



Crotalidae. Rattle- 

 snakes have on the end 

 of the tail a series of 

 horny enlargements, 

 loosely attached to each 

 other, which, when 

 shaken, make a rattling 

 noise. Each slough 

 leaves a new button, 

 while the end ones are dropping off from wear ; hence the 

 number is no indication of age. The Copper-head, Mocca- 

 sin, etc., are venomous snakes belonging to this family. 



Skull of Rattlesnake, thawing fangs. 



Fig. 207. 



Fig. 298. 



Rattlesnake's tail. 



Crotalus durissus. Rattlesnake. 



* Naturalists are divided as to whether snakes have the power of " charming " 

 birds and animals. The general belief is that it is only a paralysis caused by fear on 

 *ho part of its victim. 



