302 Illinois State Laboratory of Natural History. 



Variety arnyi. 



Seventeen rows of dorsal scales. Yellow beneath, thickly 

 spotted with black. Occipital band from one to one and a half 

 scales wide. Ventrals KH). Subcaudal.-s r)0 pairs. 



A specimen of this species in the Laboratory collection 

 from Warsaw, Hancock county, has the lower part of the ros- 

 tral and, excepting a narrow superior border, all the supralabial 

 plates but the last yellow. In some respects it resembles the 

 form described by Prof. E. D. Cope as var. stictogenys. 



Heterodon, Beau v. 



Beauv., Latreille, Hist. Nat. Kept., 1799. 



Bd. and Gir., Cat. X. A. Kept., Pt. I., 1853, p. 51. 



Dorsal scales carinated, in twenty-three to twenty-seven 

 rows. Anal plate divided. Rostral plate plow-shaped, with a 

 a keel above. Two internasals, with a small azygos plate be- 

 tween them or separated by numerous small plates. Two pre- 

 frontals, in contact or separated by small plates. One or two 

 loreals. Short and stout, with large, wide head and short tail. 

 The species possess the power of expanding the body. 



Internasals and prefrontals in contact with the azygos. 



H. PLATYRHINUS. 



Internasals and prefrontals separated from the azygos by small 

 plates H. siMus. 



Heterodon platyrhinus, Latreille. Spreading Adder, Hog- 

 nose Snake, Blowing Viper. 



Var. platyrhinus. 



Heterodon phifyrhinus, Latr., Hist. Nat. Rept., 1802, p. 32, pi. 

 28, fig. 1-3.— Holbr., N. A. Herp., 1842, IV., p. 67, pi. 17.— De 

 Kay, Nat. Hist. N. Y., I., Zool. III., Rept. and Ampli., 1842, 

 p. 51, pi. 13, flg. 28.— Bd. and Gir., Cat. N. A. Rept., Pt. I., 

 1853, p. 51.— Kenn., Trans. 111. State Agr. Soc, 1853-54, 1., p. 

 592.— Dum. et Bibr., Erp. G6n., VII., 1854, p. 766.— Davis 

 and Rice, Bull. 111. State Lab. Nat. Hist., I., No. 5, 1883, p. 

 43; Bull. Chicago Acad. Sci., 1883.— S. Garman, Mem. Mus. 

 Comp. Zuf)]., 1883, pp. 75, 159, pi. 6, fig. 5. 



