27. HETERODON 655 
the labials. Temporals numerous. The scales are keeled, 
with two apical pits. The anal plate is divided. The 
urosteges are in two series. The eye is of moderate size, with 
round pupil. The dentition is dicranterian. There are four 
North American species, of which one occurs in Arizona. 
143. Heterodon nasicus Baird & Girard 
WEsTERN Hoc-NosE SNAKE 
Plate 62 
Heterodon nasicus Bairpv & Girarp, Stansbury’s Exp. Surv. Great Salt 
Lake, 1852, p. 352 (type locality, Texas); Barrp & Grrarp, Cat. N. 
Amer. Rept., Pt. 1, Serp., 1853, p. 63 (type from Rio Grande); 
HacioweE.t, Sitgreaves’ Exped. Zufii and Colorado Riv., 1853, 
p- 147; Barrp & Girarp, Marcy’s Exp. Red River, 1854, p. 193, pl. 4, 
Ha iowELt, Proc. Acad. Nat. Sci. Phila., 1856, p. 249; Bairp, Rep. 
Pacific R. R. Surv., Vol. X, 1859, p. 19, 41; Barrp, U. S. Mexican 
Bound. Surv., Vol. II, Rept., 1859, p. 18, pl. XI, fig. 1; Haypen, 
Trans. Am. Philos. Soc., 1862, p. 177; JAN, Elenco Syst. degli Ofidi., 
1863, p. 46; Jan & Sorpe wu, Iconogr. Génér. Ophid., toe livr., 
1865, Pl. V, fig. 1; Cope, Proc. Acad. Nat. Sci. Phila., 1866, p. 307; 
ALLEN, Proc. Boston Soc. Nat. Hist., 1874, p. 69; Cope, Proc. U. S. 
Nat. Mus., Vol. XIV, 1892, p. 644; BouLencer, Cat. Snakes Brit. 
Mus., Vol. Il, 1894, p. 156; Cocxereiti, Amer. Nat., Vol. 
XXX, 1896, p. 326; Brown, Proc. Acad. Nat. Sci. Phila., 
1901, p. 90; Brown, Proc. Acad. Nat. Sci. Phila., 1903, p. 5513 
Branson, Kansas Univ. Sci. Bull., Vol. I, No. 13, 1904, p. 376, 
fig. 10; Battey, N. Amer. Fauna, No. 25, 1905, pp. 28, 35, 453 
Moztey, Trans. Kansas Acad. Sci., Vol. VI, reprint, 1906, p. 343 
Dirmars, Reptile Book, 1907, p. 384, pl. CXV; Extis & HENDER- 
son, Univ. Colorado Studies, Vol. X, No. 2, 1913, p. 95, pl. VI; Van 
DensurcH & Stevin, Proc. Cal. Acad. Sci., Ser. 4, Vol. 3, 1913, 
P- 393; STRECKER, Baylor Bulletin, Vol. XVIII, No. 4, 1915, p. 41; 
STEJNEGER & Barsour, Check List N. Amer. Amph. Rept., 1917, 
p- 77; RutHven, Occas. Papers Mus. Zool. Univ. Michigan, No. 
66, 1919, p. 2. 
Heterodon kennerlyi Kennicort, Proc. Acad. Nat. Sci. Phila., 1860, p. 
336 (type locality, Rio Grande & Sonora); Jan & SorveELLI, 
Iconogr. Génér. Ophid., roe livr., Pl. V, fig. 2. 
Heterodon simus nasicus Cope, Bull. U. S. Nat. Mus., No. 1, 1875, p- 433 
Yarrow, Surv. W. tooth Meridian, Vol. V, 1875, p. 555; Cougs, 
