REPTILES OF THE PACIFIC COAST. 161 



the half of the frontal plate, its external margin with 

 the upper margin of the f renal; the frontal plate is about 

 as broad as long, narrower posteriorly; supraoculars 

 broader posteriorly; occipitals of moderate size, pen- 

 tangular; nostril large, deeply excavated, in nearly the 

 center of a large and conspicuous nasal plate, somewhat 

 pyriform; a long and very narrow f renal, lying between 

 the second and third supralabials, and the prefrontal; 

 but one preocular, which is quadrangular, resting on the 

 third supralabial; two postoculars, the upper much larger 

 than the lower; there are seven supralabials, the three 

 anterior smaller considerably than those which follow; 

 the eye in contact inferiorly with the third and fourth; 

 body long and slender, depressed; scales, of which there 

 are fifteen rows, quadrangular, smooth and shining, 

 their posterior margins rounded, the three inferior rows 

 larger than the others; gastrostiga appearing to a slight 

 extent upon the flanks; tail short, with a somewhat 

 blunt extremity." Gastrosteges 147-158. Urosteges 

 34-44. 



"Milk white above, with thirty-four transverse black 

 bands, including one upon the posterior part of the 

 head; six complete rings of black upon the tail, and one 

 incomplete just behind the anus; jaws, chin, throat and 

 abdomen white; interspaces between rings upon under 

 part of tail white." 



Length to aiius 229 



Length of tail 56 



Distribution. Mojave and Colorado Deserts. 

 Genus 26. CONTIA. 



Contia, B. & G., Cat.N.A. Kept., I, Serp., 1853, p. 110(type mitis); 

 Lodia, B. & G., 1. c., p. 116 (type tenuis); ? Sonora, B. & G., 

 1. c., p. 117 (type semiannulata); " Eirenis, JAN, Eleuco Sist. 

 d.Ofidi, 1863, p. 48." 



