se of the lower series. The dorsal stripe is
yellow with a faint dusky suffusion; it involves all of the middorsal
scale row and approximately the adjacent half of the row on either
side. The lateral stripe is faint, yellowish gray, chiefly on the
upper half of the second scale row, lower half of third, and the
intervening skin, and is often invaded or suffused by the red marks
of the dorsolateral area. The first scale row, adjacent corners of
the ventrals, and lower half of the second scale row are suffused
with dark pigment and appear dusky, but this area is often marked with
black, setting off the paler area of the lateral stripe. The ventrals
are dull, whitish, faintly suffused with yellowish, greenish or
bluish, each ventral having a black dot usually of semicircular shape
on its anterior margin near the anterolateral corner.

COMPARISON OF _T. S. PARIETALIS_ AND _T. S. FITCHI_

Like most widely ranging subspecies, _parietalis_ and _fitchi_ vary
geographically and local populations often are noticeably different
from typical material. It is possible that future revisors will
recognize additional subspecies, but in the variant populations
known to us the degree of differentiation is slight as compared,
for instance, with that in the subspecies of _Thamnophis elegans_.
Scalation is remarkably uniform in all the subspecies of _sirtalis_,
but coastal and northern populations tend to have fewer ventrals
and subcaudals than do their counterparts farther inland and farther
south. In their geographic variation the ventrals and subcaudals
follow clines, and do not in themselves warrant subspecific divisions.
Variation occurs chiefly in the color and pattern including the
intensity of dark pigmentation of the dorsolateral area, head, ventral
surface and lower edge of the lateral stripe; in extent, position and
shade of red or pale colored markings on the dorsolateral area; in
presence and extent of reddish suffusion on the head, in the region
of the lateral stripe, and on the ventral surface of the tail. Most
of these same characters vary within the subspecies _fitchi_, but the
range of variation is relatively minor. Fitch (_op. cit._:582-584)
described typical populations and also described briefly several small
series from British Columbia, Idaho, Oregon, and California which were
not entirely typical. Most frequent variation was in heavy reddish
suffusion on the sides of the head not found in typical _fitchi_. In
each