Poisonous Animals oi^ the; Desert 359 



in length, and its range extends into southern Arizona from the 

 eastward to about the central part of the State. 

 Our larger rattlesnake species are as follows : 

 The Western Diamond Rattlesnake (Crotaliis atrox), next lo 

 the largest of all, attams to a length of seven feet, and is common 

 in at least the southern half of Arizona. Distinguished by the white 

 tail, banded zcith jet black. A variety of this, known as the Mountain 

 Diamond Rattlesnake, is found at higher elevations, the typical 

 form being found in the desert valleys. For the first of these 

 the common name of Desert Diamond Rattlesnake has also been 

 proposed, and the latter seems slightly more appropriate, since it is 

 the common form in the desert valleys. 



The Black-Tailed Rattlesnake (Crotaliis molossus), may attain 

 to as much as four or five feet in length. It is reported common in 

 northern Mexico and extreme southern Arizona, though two were 

 once taken on San Francisco Mountain, near Flagstaff. It is found 

 in the mountains rather than in the desert, the largest examined by 

 Ditmars having come from "the mountains near Tucson, Arizona," 

 and was reported by the late Mr. Herbert Brown to be "fairly 

 common in the Santa Catalina and Pincon Mountains." 



The White Rattlesnake {Crotaliis mitcheUii), as its name indi- 

 cates, is very light in color, even so white as to have suggested to 

 one collector when coiled the appearance of bunches of cotton. 

 About three and one-half feet seems to be the maximum length. 

 This is probably restricted in Arizona to the southwestern portion 

 and records do not indicate that it is very common anywhere. The 

 tail being white with black rings might lead to the assumption of 

 its being a very light variant of the Diamond Rattlesnake. Two 

 bright red specimens have been reported from Cave Creek, Mari- 

 copa County. 



Price's Rattlesnake {Crotaliis pricei), is next to the smallest 

 of the Crotaliis kinds, an adult measuring a little less than two feet 

 in length. It is rare, at least in the United States, Ditmars report- 

 ing that "barely a dozen specimens have been taken" in this coun- 

 try. It was discovered in the Huachuca Mountains in 1895. It 

 ranges probably only in the most southern portion of Arizona, at 

 considerable elevations in the mountains. 



The Green Rattlesnake (Crotaliis lc[^idus), is the smallest of 

 the Crotaliis species, less than two feet in length, slender, with 

 broad head. Color "greenish-gray, or rich dark green above, 

 crossed at intervals with narrow, jet-black bands. The bands are 



