RATTLESNAKE HISTORY. 293 



small species in hot weather and with a large store of venom 

 may be more noxious than the largest in a half-torpid state 

 and with a small supply of venom. 



There is one known as the ' Prairie rattlesnake ; ' another 

 frequents the marshy districts of Ohio ; another, the swamps 

 of the Southern States along the coast ; a fourth is known as 

 the ' Western rattlesnake ; ' some of the 20 species described 

 in the United States being more abundant in the 

 mountainous regions, others near the rivers. 



In the wilder regions of Central and South America they 

 also abound ; but less is known of them where there are no 

 United States Exploring Expeditions to record them. 



