The Rattlesnakes 



Bands angular in the rear — sometimes brf^l<en into three 

 blotches — the central the larger. 



BANDED RATTLESNAKE, C. horriduS. 



Distribution. — Eastern United States, Vermont u 

 Florida; westward to the Plains, 

 b. Bands roen. 



Yellowish or gray; three series of blotches on anterioi 

 portion of body- Ring-like bands — close together — 

 on latter two-thirds of body. 



TIGER RAITLESNAKE, C. tigris. 



Distribution. — Desert mountains of Southern Cali- 

 fornia, Arizona and Nevada. 

 **Size small. 



Greenish; narrow and regular black bands at a consid- 

 erable distance apart. 



GREEN RATTLESNAKE, C. IcpiduS. 



Distribution. — Region of the Mexican boundary — 

 western Texas to western Arizona. 



Following are detailed descriptions of these serpents: 



THE BLACK-TAILED RATTLESNAKE 

 Croialus molossiis, (B. & G.) 



By the uniform jet-black of the tail, this fine Rattlesnake 

 is readily distinguished from the other species occurring in the 

 Southwest. It attains a fair length — from three and a half to 

 five feet, and is proportionately stout of body. The head is 

 large, and quite blunt at the snout. On the upper portion of 

 the snout are three pairs of enlarged scales or shields. 



Colouration. — The ground-colour above is rich sulphur- 

 yellow, yellowish-brown, or olive. Down the back is a series of 

 brown rhombs, with a narrow, yellow border, and open at the 

 sides, whence they extend to the abdomen as narrow bands. Each 

 of the rhombs usually contains two yellowish blotches. Toward 

 the tail the markings become obscure. The tail is unijorm black. * 



With the exception of a brown blotch or band on each side 

 of the head, behind the eye, there are no head markings. 



Dimensions. — The largest specimen examined b)' the writer 

 was forty-nine inches long. It was fully adult, with a rattle 

 consisting of nine, perfectly equal segments, and was captured 

 in the mountains near Tucson, Arizona. 



* Occasional specimens are said to have the tail alternately barred 

 with the ground-colour and black, 



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