28. COLUBER 



united. Postocukrs two, upper a little larger, very rarely 

 united. Temporals normally two followed by two, but 

 rarely 2+1, 1+2, 2+3, or 1 + 1. Eight or nine (rarely 

 seven or 10, superior and 10 or 1 1, or rarely eight or nine, 

 inferior labials, seventh or eighth upper and fifth lower 

 largest, fourth and fifth or fifth and sixth superior reaching 

 eye, first pair of inferior meeting on median line. Genials in 

 two pairs, posterior pair a little larger. Scales on body smooth, 

 in 1 7 rows. Anal plate almost always divided, rarely entire. 

 Gastrosteges varying in number from 188 to 213. Uros- 

 teges in two series of from 99 to 128. Third, fourth and 

 fifth urosteges of one specimen not divided. 



The general color is whitish, grayish, ochraceous, brown- 

 ish, straw yellow, or black, usually lightest at the edges of 

 the scales, often spotted with brown or black at their tips 

 or bases. Across the nape are several (3 to 7) brownish or 

 blackish bands, often more or less blended. Faint indica- 

 tions of longitudinal lines may sometimes be seen along the 

 sides. The lower surfaces are pale yellow or white more or 

 less spotted anteriorly with black, gray, brown, or yellow. 

 These spots usually form one row along each side of the 

 anterior gastrosteges. 



Young are more or less distinctly cross-barred above 

 with gray, brown or black, and show a light line or blotch 

 along the side of the face. The latter mark is often re- 

 tained by adults. 



Ruthven describes the color of a specimen from Tucson, 

 Arizona, as follows: 



"Above, except for a short distance anteriorly, the color 

 is yellowish brown, relieved by small, mostly concealed bars 

 of whitish that margin each scale on either side of the base. 

 On the anterior half of the body, the base of nearly every 

 scale is black, although the light lines are still present, occa- 

 sionally being of a pinkish tint. On the neck the light marks 



