REPTILES 209 



D. corais con peri (Holbrook). Indigo snake; gopher snake. Length 

 2,300 mm.; tail 330 mm.; scales in 17 rows: Gulf States; northward 

 into South Carolina; westward to Texas; the largest American snake; 

 often round barns and houses, looking for rats and mice. 



14. Pituophis Holbrook. Bull-snakes. Large, non-poisonous, con- 

 strictor snakes with a long pointed head; scales in 25 to 35 rows; dorsal 

 scales keeled, lateral scales smooth; ventrals about 215; upper labials 



Fig. 120. — Pituophis sayi: i, sheath of tongue; 2, epiglottis; 3, glottis {from Cope). 



8 or 9; a peculiar epiglottis-like membrane (Fig. 120) in front of the 

 glottis vibrates when the animal is alarmed, producing a loud hiss: 

 4 species, all American; the largest American, harmless snakes; terres- 

 trial and arboreal, feeding on small mammals, birds and eggs, and 

 living usually in dry woods. 



Key to the Species of Pituophis 



ai In the eastern forested region P. melanoleiicus. 



a2 In the prairie States and Great Plains P. sayi. 



as On the Pacific slope and in the Great Basin P. catenifer. 



P. melanoleiicus (Daudin). Pine snake. Length 1,500 mm.; 

 tail 220 mm.; greatest length 2,400 mm.; color whitish, with a series 

 of from 27 to 33 large, black or brown, irregular dorsal blotches and 

 2 series of smaller lateral blotches on each side; belly white: southern 

 New York to Florida and Louisiana; often abundant in pine woods. 



P. sayi (Schlegel) (Fig. 120). Length 1,550 mm.; tail 200 mm.; 

 greatest length 2,600 mm.; color reddish yellow, with a series of large, 

 square brown or black dorsal blotches, and a series of smaller blotches 

 on each side; abdomen yellow, with a row of black spots on each side: 

 western Indiana and Alberta, Canada, to Arizona and Texas and the 



