64 PITUOPHIS. 



Genus PITUOPHIS, Holbr. 



Gen. Char. Body subcylindrical, deeper than wide, attaining 

 often a considerable size. Head elongated, ovoid, in some instances 

 narrow anteriorly. Vertical plate elongated, sometimes as broad 

 anteriorly as long. Superciliaries large, subtriangular. Posterior 

 frontals two pairs, an internal and external, both elongated. Pre- 

 frontals subquadrate. A small loral. Postorbitals three or four; 

 anteorbitals generally two, occasionally only one. Temporal shields 

 very small, resembling the scales. Cleft of mouth curved. Dorsal 

 rows of scales 29-35, variable in some species ; those on the back 

 carinated, on the sides smooth. Abdominal scutellae 209-243; 

 posterior large and entire. Subcaudal scutellae all bifid. 



Ground-color whitish or reddish yellow ; a triple series of dorsal 

 black blotches, those of the medial series the largest; several 

 series of smaller blotches on the flanks. Abdomen unicolor or ma- 

 culated, with an outer row of blotches. Head of the same color as 

 the body, maculated with black spots. A narrow band of black 

 across the upper surface between the eyes, and a postocular vitta on 

 each side, extending obliquely from the eye down to the angle of the 

 mouth. A black vertical patch is often seen beneath the eye. 



Syn. PihwpMs, Holbr. N. Amer. Herp. IV, 1842, 7. 

 Fityophis, HALLOiV. Proc. Acad. Nat. Sc. Philad. VI, 1852, 181. 

 ChurcMllia* Baird & Girard, Reptiles in Stanshury^s Expl. of 

 the valley of the Great Salt Lake, 1852, 350. 



■-•■■ The species upon which the genus ChurchilUa was established, exhibits in the 

 structure of the cephalic plates the remarkable character of having a small mediau 

 plate in advance of the vertical, limited on each side by the external, and in front 

 by the internal postfrontals. This character, together with the presence of two 

 anteorbitals and four postorbitals, one more on either side than in Pituophis me- 

 lanoleiicua, the only species then known, appeared a sufficient generic character. 

 Since the discovery of several other species, in which there are two anteorbitals 

 and four postorbitals, with the structure of the cephalic plates similar to what they 



