18 



Genus HETERODON, Pal. be BEAtrv. 



Gen. Char. Body short, stout : tail short. Head, neck, and "body capable 

 of excessive dilatation. Posterior palatine teeth longer. Head broad, 

 short. Outline of mouth very convex, on a single curve. Orbit enclosed 

 by a continuous chain of small plates ; the circle completed above by 

 the superciliaries. Rostral prominent : its anterior face very broad, and 

 turned up ; its ridge above sharp. Behind it a median plate, either in 

 contact with the frontals or separated by small plates. Frontals in two 

 pairs : nasals two ; loral one or two. Dorsal rows of scales 23 - 27, 

 carinated. Abdominal scutellae 125 - 150 ; posterior bifid. Subcaudal 

 scutellse all bifid. 



Colors light, with dorsal and lateral darker blotches ; or else brown, with 

 dorsal transverse light bars : sometimes entirely black. 



Stn. Heterodon, Pal. de BEAtrv. in Latr. Hist. Nat. des Rept. IV. 

 1799. 



8. Heterodon platyrhinos, Latr. — Blowing Viper. 



Spec. Ceak. Occipitals and verticala longer than troad, about equal in length. 

 Centre of eye anterior. Dorsal rows 25, all carinated; the outer sometimes 

 smooth. Keels of the scales extending to their tips. Scales on the back quite 

 linear anteriorly; posteriorly they are muqh broader. Color yellowish gray or 

 brown, with about 28 dark dorsal blotches from head to anus, and 15 half-rings 

 on the tail. One or two lateral rows. Beneath yellowish. A dark band across the 

 forehead in front of the vertical, continued through the eye to the angle of the 

 mouth. 129+1, 53, 25, 28, 6 (Penn.). 



STNONYUS. 



Coluber heterodon, Daud. Hist. Nat. Eept. VII. 1799, 153, pi. Ix. f. 28.— Sat, 

 Amer. Journ. of Sc. I. 1818, 261.— Habi. Journ. Acad. Nat. Sc. Philad. V. 

 1827, 357; and Med. & Phys. Res. 1835, 120. 



Heterodon platyrhinos, Late. Hist. Nat. Rept. IV. 1799, 82, f . 1 - 3. — Holbk. 

 N. Amer. Herp. II. 1828, 97, pi. xxi. ; and 2d ed. IV. 1842, 67, pi. xvii.— 

 Dekay, N.Y. Fauna, III. 1842, 51, pi. xiii. f. 28.— B. & G. 1. c. (1863), 51. 



This curiously formed snake, known as Hognose, Blowing Viper, Spreading 

 and Checkered Adder, etc., although supposed to be venomous, is perfectly 



