The Bull Snakes 



hen in size. They are yellowish-white, with a tough, leathery 

 shell. 



THE ARIZONA BULL SNAKE 

 Pituopbis sayi, variety bellona, (Baird and Girard) 



This variety of the preceding reptile is not strongly defined 

 in pattern or colours. The pattern appeals strongly to the 

 typical form, although occasional specimens exhibit markings 

 that tend to place them as intermediate between the Bull Snake 

 of the Central and Western States and the species inhabiting the 

 Pacific Coast region, on which the blotches are smaller and very 

 numerous. This condition tends to render the latter species 

 P. catenifer rather doubtful, and points to the advisability of 

 considering it but another variation of P. sayi. 



The principal difference between the present variety (bellona) 

 and the typical form consists in the formation of the rostral 

 (nose) plate. With the latter reptile this plate extends upward 

 and is very narrow above; with the former snake (variety bellona), 

 it is more bluntly triangular, and lower on the snout. 



Dimensions. The measurements given are of a specimen from 

 Beaver County, Utah: 



Total Length 4 ft. 9 inches. 



Length of Tail 7* " 



Diameter of Body if 



WidthofHead i| " 



Length of Head if 



Distribution. Southern Oregon, Idaho, Colorado, Nevada, 

 Utah, Arizona, New Mexico and western Texas. It also extends 

 southward into Mexico. The Western border of its distribution 

 is the Sierra Nevada range of mountains, west of which boundary 

 occurs the Pacific Coast species, P. catenifer. 



THE PACIFIC BULL SNAKE, "YELLOW GOPHER 



SNAKE" 



Pituophis catenifer, (Blainville) 



Moderately large in size and stout of form, but with pro- 

 portionately smaller head than the preceding. 



Colouration. Dull yellowish-brown, with small and square 

 reddish-brown (or black) blotches on the back. These blotches 



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