SALVADOR A. 105 



labials 9 ; lib. largest, the 4 anterior ones comparatively small. 

 Lower labials not conspicuous, 10 in number, 5tli largest, the three 

 posterior ones scarcely to be distinguished from the scales. Posterior 

 pair of mental scutellse much smaller than the anterior, extending to 

 the middle of the fifth inferior labial. 



Body subcylindrical, elongated, tail subconical, tapering, forming 

 about the i of the total length. Scales elliptical, disposed in 17 

 rows ; outer row somewhat broader, the rest slightly diminishing to- 

 wards the dorsal region. 



Surface of head brown. An ochraceous vitta extends from the 

 occiput to near the end of the tail, embracing anteriorly three rows 

 of scales, and posteriorly one row, and two adjoining halves to oppo- 

 site the anus; on the tail it covers two half scales. On each side of 

 this a black vitta runs parallel, and covers the same number of scales 

 anteriorly and posteriorly, except on the tail, where it is narrower, 

 and embraces only half a scale. The antero-inferior margin of the 

 scales in the black vitta is yellowish green. The remaining portion 

 of the flanks, embracing four rows of scales, and the extremities of 

 the scutellse, is uniform yellowish green, with the bases of the scales 

 blackish, as is also the skin. The abdomen is uniform dull yellow. 



Sonora,Mex. 180+1.97.17. 28 J. 7 J. Col. J. D. Graham. 



