SNAKES. 369 



HETERODON Platyrhinos. This is the snake commonly 

 called "blowing viper." When approached it makes a 

 hissing sound, swells its head, and flattens out its body, and 

 assumes altogether a threatening aspect, but is harmless. 

 Length, two feet. 



HETERODON Niger, (Troost.) This is the "black viper," 

 a snake frequently found on the mountain. It has the same 

 habit of spreading and swelling when approached or at- 

 tacked, as the blowing viper, making up what it wants in 

 venom by threatening attitudes and ugliness of expression. 

 General length, from two feet to thirty inches. Major Le 

 Conte thinks this a variety of platyrhinos, having seen speci- 

 mens showing the transition to the black color. It seems to 

 attain to greater dimensions than the light-colored viper 

 assumes. 



SCOTOPHIS Alleghaniensis, (B. and Gr.) COLUBER Alle- 

 ghaniensis, (Holbr.) This is the common " big black snake" 

 of the mountain, the slim Bascaaion being called "racer." 

 On the subject of its common name, Dekay remarks : "It 

 is manifestly the snake which has been frequently described 

 to me of great length and prodigious velocity, and to which 

 they gave the name of ' Racer,' or ' Pilot.' As these names 

 are frequently applied to the black snake, I had supposed 

 that species to have been intended by their description."* 

 In Pennsylvania it does not receive this name, both species 

 being abundant, and generally recognized as different ; the 

 Bascanion, from its greater thinness and delicacy of style 

 and more marked celerity of action, being exclusively styled 

 the "Racer." 



The "big black snake" grows to a great size, as its com- 

 mon name indicates ; sometimes attaining to the length of 

 eight feet, and is strong, quick, and violent in its motions, 

 frequently presenting a truly formidable appearance. It is 

 said to be tamable, and to become familiar and friendly. 



OPHIBOLUS Eximius, (B. and G.) COLUBER Eximius, 



* Fauna of New York. 



