270 BULLETIN UNITED STATES GEOLOGICAL SURVEY. 



Family COLUBRID^. 



Genus HETER'J:)0X. Beauv. 



Hetekodon simus nasicus. {B. & G.) Cope. 



Hog-nosed Snake; Sand Viper; Puffing Viper; Blowing Adder. 



Heierodon nasicus, Baird & Girard, Stansbury's Exp. Great Salt Lake, 1852, 

 352.— Baird & GiR. Cat. N. A. Reptiles, 1853, 61, 157.— Hallow. Sitgr. Rep. 

 ExpL Zuui and Colorado R. 1853, 147.— Bd. P. R. R. Rep. 4, 1859, Whipple's 

 Route, Reptiles, 41. — Bd. P. R. R. Rep. x. 1859, Beckwith's Route, Rep- 

 tiles, 19.— Bd. U. S. Mex. B. Survey, ii. pt. ii. 1859, 18, pi. 11, f. 1.— Hayd. 

 Trans, Amer. Phil. Soc. xii. 1832, 177. — Cope, Proc. Acad. Nat. Sci. Phila. 

 1866, 307.— Allen, Proc. Bosfc. Soc. Nat. Hist. xvii. 1874, 69. 



Heterodon simus subsp. nasicus, Cope, Check List Bat. and Rep. N. A. 1875, 43. 



Specimen. 

 No. 1101. Big Muddy River, Montana. June 25, 1874. 



The serpents of the genus Heterodon are medium-sized or rather 

 small species, thick-set in form and sluggish, of repulsive aspect, not 

 distantly resembling some of the venomous species, especially the Cop- 

 perhead {Ancistrodon contortrix). The similarity to poisonous species is 

 heightened by the flat, broad, triangular shape of the head and the 

 habit of hissing when irritated. They are commonly called "Adders " 

 and "Yipers", and are reputed venomous; nevertheless, they are per- 

 fectly harmless. They cannot be provoked to bite. The belief in the 

 poisonous qualities is further heightened by the presence of two toler- 

 ably large teeth in each upper jaw, resembling fangs, these teeth l>eing 

 the ninth (?) of the series in some individuals, their bases being below 

 the fifth upper labial. There is no groove present, nor is the tooth mov- 

 able. We do not know that this fact has ever been before mentioned, 

 although the post-palatine teeth are spoken of as being larger than 

 others. These large teeth have, however, a sort of sheath over them, 

 similar to the fang-sheath of Crotalus. There is an interval between 

 the small anterior teeth, and these are not contained in the same sheath 

 as the fang-like tooth, which in some cases is found to have in its sheath 

 one or more smaller fang-like teeth. They may be distinguished from 

 any other serpents of this country by the sharp-pointed and elevated 

 end of the muzzle, the rostral plate being prolonged into a spur. 



The present species finds its nearest ally in the Heterodon simus of the 

 Southern States, sharing with this species the separation of the median 

 plate behind the rostral from the frontals by the interposition of several 

 small plates. From H. simus it is distinguished by the slaty-black, 

 which occupies all or most of the under surface. The color above is an 

 obscure grayish-brown, with very numerous darker blotches along the 



