580 VIPEEIDiB. 



e. c? (Sc. 23 ; V. 167 ; N. America. College of Surgeons, 



0. 24). 



/. (J (Sc. 25 ; V. 173 : N. America. 



C. 28). 



ff. Skull. N. America. 



6. Crotalus tigris. 



Crotalus tigris, Kennicott, B.ep. U.S. Mex. Bound. Surv. ii., Hept, 

 p. 14, pi. iv. (1859) ; Garm. N. Am. Mept. p. 117 (1883) ; Cope, 

 Froc. U.S. Nat. Mus. xiv. 1892, p. 689 ; Stejneger, N. Am. Faun, 

 no. 7, p. 214 (1893), and Rep. U.S. Nat. 'Mus. f. 1893, p. 449 

 (1896). 



Oaudisona enyo, Cope, Proc. Ac. Philad. 1861, p. 293, and 1866, 

 p. 309. 



tigris, Cope, Proc. Ac. PhUad. 1866, p. 309. 



Crotalus enyo. Cope, Chech-list N. Am. Rept. p. 33 (1875), and 

 Proc. U.S. Nat. Mus. xiv. 1892, p. 689. 



oregonus, var. enyo, Oarm. I. o. p. 174. 



Snout with distinct canthus. Eostral broader than deep, in 

 contact with the anterior nasal and a pair of internasals ; a large 

 shield on each side between the internasal and the supraocular; 

 middle of snout covered with small smooth or obtusely keeled scales ; 

 supraoculars narrower than the space between them, which i» 

 occupied by six longitudinal rows of keeled scales ; three series of 

 scales between the eye and the labials; 13 to 15 upper labials. 

 Scales in 23 or 25 rows, dorsals strongly keeled. Ventrals 166- 

 181 ; anal entire ; subcaudals 26-46. Yellowish or pale brown 

 above, with a dorsal series of brown, dark-edged spots, widening t» 

 cross-bands posteriorly ; sides with smaller dark spots ; head with 

 small dark spots and a dark streak from the eye to the angle of the 

 mouth ; yellowish beneath, scantily spotted with brown. 



Total length 380 millim. ; tail 60. ' 



Southern California, Lower California, Nevada, Colorado, Arizona, 

 Northern Mexico. 



a. Yg. (Sc. 25 ; V. 181 ; Ventanas, Durango. Hr. A. Ferrer rC.l, 

 0. 46). 



7. Crotalus mitchelli. 



Caudisona mitchellii, C(^e, Proc. Ac. Philad. 1861, p. 293, and 1866,. 



p. 310. 



pyrrha. Cope, Proc. Ac. Philad. 1866, p. 808. 



Crotalus mitchellii, Cope, Wheeler's Rep. Surv. W. \00th Mer. \, 



p. 635 (1875), and Proc. U.S. Nat. Mus. xiv. 1892, p. 689 ; Van 



Dentmrgh, Proc. Cal. Acad. (2) iv. 1894, p. 460 ; Stejneger, Rep, 



U.S. Nat. Mus.f. 1893, p. 454, pi. xvii. (1895). 

 pyrrhus. Cope, Wheeler's Rep. p. 535, pi. xxii., and Proc. U.S. 



Nat. Mus. xiv. 1892, p. 689 ; Stejneger, W. Amer. Scient. vii. 



1891, p. 165. 



confluentus, var. pynhus, Garm. N. Am. Rept. p. 173 (1883). 



oregonensis, var. mitchellii, Garm. I. c. 



