POISONOUS SNAKES OF NORTH AMERICA. 451 



Cooper, Proc. Calif. Acad. Nat. Hist., iv, p. 67 (1874).— Yarrow, Bull, 



U. S. Nat. Mils., No. 24, Check-list, pp. 12, 73 (1883).— Yarrow, iu Buck's 



Ref. Haudb. Med. Sc, vi, p. 166 (1888).— Carman, Rept. Batr. N. Am., 



I, Opliid., pp. 116, 175 (1883).— Garman, List N. Am. Rept. Batr., p. 35 



(1884).— Stejneger, N. Am. Fauua, No. 7, Death Vail. Exp., p. 216 



(1893). — Merriam, N. Am. Fauna, No. 7, p. 217 (1893). — Caiidisonn cerastes 



Cope, in Mitchell's Res. Veu. Rattlesu., p. 124 (1861).— Cope, Proc. 



Phila. Acad., 1866, p. 309. -Cope, Proc. Phila. Acad., 1867, p. 85.— 



Jliclimophrjis cerantcs CouES, in Wheeler's Surv. W. 100 Mer., v, p. 609 



(1875). 



Fitjures: Hallowell, Pac. R. R. Rep., x, Williamson's Route, pi., iv, fig. 1 



(1859).— Baird, Pac. R. R. Rep., x. Reptiles, pi. xxxv, fig-. 4 (1859).— Baird, 



U. S. Mex. Bound. Surv., ii, Rept., pi. iii (1859). — Jan, Icon. Ophid., livr. 



46, pi. Ill, fig. 5 (1874). 



Description.* — Head small, augles roaiided; nose, obtuse, mncli 



depressed; rostral as broad as high; nostril in the middle of a single 



large plate (tigs. 0(), G7). Lateral edge of superciliary plate (supraocular) 



elongated iuto a horn-like process directed upward over the eye. Two 



Fig. 66. Fig. 67. 



HEAD OF CROTALUS CERASTES, TOP VIEW. HEAD OF CROTALUS CERASTES, SIDE VIEW. 



Oat. No. 4S2. U. S. N. M Cat. No. 432. V. S. N. M. 



rows of scales between the suborbital series (which is complete of large 

 scales) and the labials. Upper labials 11 to 13, lower 12 to 13. Dorsal 

 rows of scales 21, slightly carinated; each scale along the middle of the 

 baek with a tubercular swelling toward the center. Crown tubercular. 

 Entire head and upper parts of a slight yellowish, with a dorsal series 

 of small, indistinct blotches, below which are several irregular rows of 

 isolated brown dots. A narroAv, brown stripe extends from the orbit 

 back over the angle of the mouth. 



Geofjraphical distribution. — In a general way the horned rattlesnake 

 inhabits the same region as C. tigris, viz, southern Arizona, California, 

 and Nevada, but while the latter inhabits the mountain ranges of this 

 area the former is more confined to the desert plains and valleys. 



The type locality is Mojave Desert, whence Dr. Merriam, in 1801, 

 rediscovered it and secured specimens. His Death Valley expedition 

 brought home numerous specimens from nearly all the suitable locali- 

 ties visited, and he found it to be " the characteristic snake of the 

 Lower Sonoran deserts of the Great Basin, from southern California 

 easterly across southern Nevada to Arizona and southwestern Utah." 

 We have received specimens from Mr. E. C. Orcutt, who obtained them 



* Description by R. Kennicott, in Mex. Bound, Surv., ii, Rejit., p. 14, from speci- 

 men in U. S. Nat. Mus., No. 482. 



