764 13. COLUBRID 
tals. Anterior and posterior nasals distinct. Loreal a little 
longer than high. One preocular. Two postoculars. Tem- 
porals normally two followed by three. Seven or rarely 
eight superior and nine, or sometimes 10 or 11, inferior 
labials; fourth, fifth and sixth superior, and fourth and fifth 
inferior largest; third and fourth superior reaching eye. 
Genials in two pairs, anterior much larger than posterior. 
Scales smooth, thin, imbricate, in 23 or sometimes 25 rows. 
Anal plate not divided. Gastrosteges varying in number 
from 207 to 225. Urosteges in two series of from 43 to 56. 
The general color is black or blackish brown and yellow- 
ish white, so arranged that most of the lateral scales are 
black, each with a sharply defined white or yellow elongate 
central spot. Some of the dorsal scales are similarly marked, 
but often these are so grouped as to leave a series of solidly 
black dorsal blotches some 41 to 85 in number on body and 
tail. The lower surfaces are whitish, marbled with black. 
Sometimes lateral dark blotches alternating with the dorsal 
ones are more or less evident. The top of the head is black 
with white markings on the rostral, internasal, and prefrontal 
plates. Similar spots appear on the nasals, loreal, and ocu- 
lars. The labials are light with dark edges. 
Distribution —This subspecies is said to range from 
Texas west into Arizona and south into Mexico (Sonora). 
Arizona specimens have been recorded as taken in Pima 
(Tucson, Fort Lowell), Santa Cruz (Fort Buchanan), and 
Cochise (Fort Huachuca, Babacomari Creek), counties. 
Habits—One specimen, shot near Fort Lowell, was 
found in a tree in the river bottom. It probably was look- 
ing for birds’ nests. 
