CHAPTER XXXIII: THE BULL SNAKES 



Genus Pituophis 



Large Constricting Snakes that are Closely Allied to the Rat Snakes. 

 Descriptions of the Three North American Species. Their Habits 



Closely related to the fine reptiles of the preceding genus, 

 are the Bull Snakes — Genus Pituophis, which, possessing sharply 

 pointed snouts, differ in this conformation from the square, flat 

 heads of the colubers. The scales of the back are moderately 

 keeled, while those of the sides are smooth and polished. 



The species of this genus probably attain the greatest size 

 of any of the North American harmless snakes. Their large size, 

 pointed head, and colouration — yellow or white, with dark, 

 square blotches upon the back, render them readily distinguish- 

 able. 



Three species inhabit the United States and northern Mexico. 

 These may be classed among the most useful reptiles, as they 

 feed upon small mammals that are injurious to man, in the latter's 

 agricultural pursuits. 



Owing to one character the Bull Snakes are quite unique 

 among the North American snakes. This is the presence of a 

 peculiar filament of cartilaginous fiesh in the mouth, situated 

 immediately in front of the breathing passage. When the snake 

 is angry, the mouth is partially opened, the filament is raised 

 and the breath expelled violently against it. A very loud, 

 hissing sound is thus produced. 



A key is given to aid in the identification of the species: 



I. Ground-colour whitish. 



White, with large black or rusty-brown blotches, some 

 distance apart. pine snake, P. melanoleucus. 



Habitat. — Eastern States. 



II. Ground-colour yellow. 



Yellow, with reddish-brown or black blotches, at a mod- 

 erate distance apart. bull snake, P. sayi. 

 Habitat. — Central and Western States. 

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