40. THAMNOPHIS 819 
or yellowish white. The belly is yellow or olive, sometimes 
dusky or washed with brick red. The dorsal line is never 
bluish. There are four distinct types of coloration, each of 
which might be considered a distinct species if compared 
with typical specimens of the others, but all of which pass 
into one another almost imperceptibly when large series are 
examined, These types are: 
(a) The ground color brown with three light lines, 
a pair of dark nuchal blotches and numerous black or dark 
brown spots along the sides. This style of coloration is seen 
in young only, but many of the smallest specimens are un- 
spotted. 
(b) Brown above with three longitudinal lines; the 
dorsal line yellow; the lateral lines and more or less of the 
belly bright brick red. 
(c) There are three lines, the dorso-lateral region is 
largely red with dark spots, and the belly often is more or 
less suffused with bright brick red. 
(d) Dark olive above with no lateral lines; the dorsal 
line yellow and very wide, the throat bright yellow, the 
belly deep olive or slate, with or without a yellow streak 
along its middle. This is Cope’s E. infernalis vidua. 
None of these forms occurs alone in any one place, and 
the series of intergradations is complete, so that these cannot 
be recognized as geographical races. Nevertheless, the form 
“qd” without lateral lines seems to occur nowhere else than 
on the San Francisco peninsula, and the style “c” is most 
abundant in Marin and San Francisco counties. 
Length to anus -.__..__175 450 475 510 540 560 
engthsors tail) 58 155 130 178 163 pees 
Variation—Three hundred and sixty-three specimens 
show variation as follows: 
The loreal is 1—1 in all specimens. Preoculars are 1—1 
