POISONOUS SNAKES OF NORTH AMERICA. 449 



and upwards, and in the southern portion of these States this Eattle- 

 snake almost certainly does not descend below 5,000 feet. Dr. Mer- 

 riam's various parties, which in 1891 were scouring the mountain ranges 

 and deserts of Nevada and Utah south of the thirty-eighth parallel, 

 failed to find a single specimen, so that it seems almost certain that it 

 does not occur there. The records of this species from Arizona are 

 very dubious, as the specimens so recorded which I have had an oppor- 

 tunity to examine have either been misidentitied, or else the locality 

 was very doubtful. 



Habits. — The Pacific Rattlesnake undoubtedly in a general way shares 

 in the habits of its congeners, but is perhaps even less offensive than 

 most of them in spite of the fact that it often reaches dimensions which 

 might make it dangerous enough. It seems to prefer rocky places, 

 whether timbered or not, but it does not invade the desert proper. 



The Tiger Rattlesxake. 



Crotahis ticjris,^ Kenn. 



Plate 14. 



1859. — Crotahis tigris, Kennicott, U. S. and Mex. Bound. Surv., ir, Rept., p. 14. — 

 Baird, Pac. R. R. Rep., x, Reptiles, p. 16 (1859).— Cope, Proc. Phila. 

 Acad., 1859, p. 338.— Cope, iu Wheeler's Surv. W. 100 Mer., v, p. 534 

 (1875).— Cope, Bull. U. S. Nat. Mus., No. 1, Check-list, pp. 33, 90 (1875).— 

 Cope, Proc. U. S. Nat. Mus., xiv, 1891, No. 882, p. 693 (1892).— Cooper, in 

 Crouise, Nat. Wealth Calif., p. 483 (1868).-— Cooper, Proc. Calif. Acad. 

 Nat. Sc, IV, p. 66 (1870). — Garmax, Rept. Batr. N. Am., i, Ophid., pp. 

 117, 175 (1883).— Garmax, List Rept. Batr. N. Am., p. 35 (1884).— Yarrow, 

 Bull. U. S. Nat. Mus., No. 24, Check-list, pp. 12,74 (1883).— Yarrow, in 

 Buck's Ref. Handb. Med. Sc, vi, p. 166 (1888).— Stejneger, N. Am. 

 Fauna, No. 7, Death Vail. Exp., p. 214 (1893).— Merriam, N. Am. Fauna, 

 No. 7, p. 215 (1893). — Caiidisona tigris, Cope, iu Mitchell's Res. Van. 

 Rattlesu., p. 122(1861).— Cope, Proc. Phila. Acad., 1866, p. 309.— CoUES, in 

 Wheeler's Surv. W. 100 Mer., v, p. 608 (1875). 



Figures. — Baird, Mex. Bound. Surv., ii, Rept., pi. iv (1859). — Baird, Pac. R. R. 

 Rep., X, Rept., pi. xxx, fig. 1 (1859). 



Description. \ — Body slender; head small, very much depressed, nar- 

 row behind; nose remarkably broad and obtuse; whole outline of head 

 nearly quadrangular. Superciliaries (supraorbitals) and frontals smooth ; 

 space between superciliaries very wide; 4 frontal plates (internasals), 

 C post-frontals (prefrontals). Two rows of scales between suborbital 

 chain (which is complete) and labials. Labials 14 above, 13 to 14 below. 

 Dorsal rows 21 to 23; very slightly carinated. Dorsal scales broad, 

 rounded behind. Color, yellowish ash above, with rather small, indis- 

 tinct dorsal brown blotches anteriorly ; 2 posterior thirds of body banded 

 with brown . 



* From the Latin tigris, a tiger, with reference to its yellowish color and tiger-like 

 cross streaks. 



t Original description by R. Kennicott in Mex. Bound. Surv., ii, Ropt., p. 14, from 

 type specimen, U. S. Nat. Mus., No. 471. 

 H. Mis. 184, pt. 2 29 



