68 



PITUOPHIS. 



above is yellowisli brown, with small black spots on the vertex and 

 occiput. Frontal black bar distinct in small individuals, obsolete 

 in large ones ; postorbital vitta narrow ; suborbital spot small. In- 

 ferior surface of the head and abdomen light straw-color, with an ex- 

 ternal series of distant black spots on each side, confluent under the 

 tail, and constituting a medial band. 



Betw. San Antonio ) 

 & El Paso. j 

 Rio Grande. 231. 53. 33 



F't Webster, Santa 

 Rita del Cohre 



" 225. 63. 31. 39. 5i 



Sonora, Mex. 222. 60. 29-31. 23|. 4^ 



California. 226. 58. 31 



228. 44. 33. 61|. 5f . 

 611. 5f. 

 ^^""I 225. 63. 31-33. 44i. 6J. 



3. ) 



45f, 



5|. 



Col. J. D. Graham. 



Gen. S. Churchill. 



Col. J. D. Graham. 



a 

 Dr. W. Gambel. 



3. Pitssopliis McClellanii, B. & G. — Head subelliptical. Rostral 

 plate very narrow. Anteorbitals 2 ; postorbitals 4. Dorsal 33-35 rows ; 

 the 7 outer rows smooth. Tail forming ^ or J^ of total length. Postocular 

 vitta brown, and rather broad. Suborbital black patch conspicuous ; com- 

 missure of labials black. Color of body reddish yellow, with a series of 53 

 blotches from head to origin of tail. Blotches of adjoining series, on either 

 side, confluent across the light spaces between medial blotches. Flanks 

 covered with small blotches, forming 3 or 4 indistinct series. Twelve trans- 

 verse jet black bars across the tail. Abdomen yellowish, thickly maculated 

 with black patches. 



Head proportionally large, ovoid, detached from the body. Snout 

 pointed. Occipital plates small. Vertical broad, subpentagonal, 

 slightly concave on the sides. Superciliaries large. Internal postfront- 

 als rather narrow, elongated, external postfrontals quadrilateral, a lit- 

 tle broader forwards. Prefrontals irregularly quadrangular. Rostral 

 very narrow, extending halfway between the prefrontals, convex 

 and raised above the surface of the snout. Nostrils in the middle 

 line between the nasals, the posterior of which is a little the smaller. 

 Loral trapezoidal, proportionally large. Inferior anteorbital very 

 small, resting upon the fourth upper labial. Postorbitals varying 

 in comparative size. Temporal shields small, resembling scales. 

 Upper labials 8, 6th and 7th the larger. Lower labials 12, 6th and 

 7th largest. Posterior mental shields very small, extending to op- 

 posiie the junction of the 7th and 8th lower labials. Scales propor- 



