The Rattlesnakes 



Habits. — Seems to be essentially a mountain reptile. All 

 of the Tucson specimens were taken at an elevation, some of 

 them on ledges in company with the black-tailed rattlesnake. 

 Croialus molossus. The typical form of atrox was common in 

 that vicinity, but always in the desert. 



THE RED DIAMOND RATTLESNAKE 

 Croialus atrox, variety ruber, (Gape) 



The Red Diamond Rattlesnake differs from the typical 

 form only in the distinctly reddish hue of the former. 



Colouration. — Ground-colour dull, rusty red; the diamond 

 markings are of a deeper red, narrowly margined with dull white. 



The tail is in marked contrast to the red of the body. It is 

 chalky-white,with vivid, black rings. 



Dimensions. — Much like the typical form. It grows to a 

 considerable size though not equal to the length of the largest 

 Texas specimens of the typical atrox. The writer had a female 

 specimen from San Diego County, California, that was five and 

 a half feet long. Of four other specimens received from the same 

 districts two were under four feet, one measured four feet three 

 inches and the other, four feet eight inches. 



Distribution. — Arid regions of southern California and the 

 peninsula of Lower California generally; southwestern Arizona. 



Habits. — Like the typical form. 



THE PRAIRIE RATTLESNAKE 

 Crotalus confluentus, (Say) 



The average snake of this species is of moderate size, and not 

 so stout of body as most rattlesnakes. Occasional specimens 

 are six feet long. 



Colouration. — Greenish yellow, or olive, with a row of large, 

 round and well separated blotches of brown upon the back. 

 There is usually a smaller and less distinct row of blotches on 

 the side. The blotches of the back have a narrow, dark margin 

 and outside of this is usually a narrow margin of white or yellow. 

 Toward the tail the blotches fade into obscure transverse bands. 



The head markings are important as they may alone be 

 employed in distinguishing the species from the Pacific Rattle- 

 snake, which it closely resembles. 



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