948 16. CROTALIDZ 
Rept., 1917, p- 110; Voruies, Univ. Ariz. Agric. Exper. Station 
Bull. No. 83, p. 360; Van Densurcu & Stevin, Proc. Cal. Acad. 
Sci., Ser. 4, Vol. XI, 1921, p. 29. 
Caudisona tigris Cope, in Mitchell’s Res. Venom Rattlesn., 1861, p. 122; 
Cope, Proc. Acad. Nat. Sci. Phila., 1866, p. 309; Coves, Surv. 
W. rooth Merid., Vol. V, 1875, p. 608. 
Description.—Of moderate size. Head rather small, 
flat-topped varying in outline according to position of fangs, 
etc. Rostral wider than high, in contact with anterior nasal. 
Two nasals. Usually two preoculars and four internasals. 
Supraocular large but not raised into a horn-like process; 
separated from its fellow by five to seven irregular rows of 
scales. About 14 to 16 superior and 13 to 16 inferior labials; 
first pair of latter meeting in front of single pair of genials. 
Three rows of scales between labials and eye. Scales in 21 
to 25 rows, dorsals strongly keeled. Gastrosteges varying 
at least from 165 to 183. Urosteges 18 to 26. 
The ground color is yellowish ash, varying from whitish 
to tawny, marked along the back with a series of rather small 
and indistinct brown blotches which become cross-bars or 
stripes posteriorly, and number about 31 to 37 on the body 
and three to six on the tail. These blotches are paler centrally 
than about their edges, and sometimes are nearly obsolete. 
Smaller alternating blotches are present on the sides. The 
head markings are rather indistinct, especially the postocular 
stripe, which is often lost in the dense sprinkling of minute 
black dots covering the sides of the head. The lower sur- 
faces are yellow or white, sometimes faintly clouded with 
brown, 
Rength towanuse = 515 582 625 688 708 750 
Length of tail to rattle... 35 43 46 48 56 58 
Distribution—The Tiger Rattlesnake “was formerly 
