rious specimens from the drainage basin of the Snake River
in Idaho are predominantly _fitchi_ in the sum of their characters,
although they differ from that subspecies in its most typical form and
resemble _parietalis_ in some respects. KU 23133 from two miles east
of Notus, Canyon County, Idaho, has the red crescents on the lower
part of the sides (between scale rows six and seven) consistently
developed on the anterior half of the body. KU 21873, a large female
from Bannock County, Idaho, is exceptional in having small lateral
black spots on the ventrals, resembling _parietalis_ most closely in
this respect. Also, it has the red lateral crescents unusually well
developed; the first three series are conspicuous, those of the fourth
series are consistently developed, and those of the fifth series show
occasionally.

Forty-five specimens in the University of Colorado Museum from
northwestern Colorado were subjected to pattern analysis. In three
specimens the dorsolateral black area between the dorsal stripe and
the lateral stripe on each side has no markings, and in eight others
there is only an occasional fleck or crescent on the skin between the
sixth and seventh scale rows. All others have the normal complement of
dorsolateral crescents or flecks between the scales of rows three and
four, four and five, and five and six. But, these specimens vary
in extent of development of the crescents in the upper half of the
dorsolateral area on each side--between scale rows six and seven,
seven and eight, and eight and nine. Only six snakes show traces of
the crescents of the uppermost series (between scale rows eight and
nine). Development of these crescents is variable but in all the
specimens the crescents are confined to the anterior half of the body.
The crescents between rows six and seven and between seven and eight
are present in 20 specimens and in ten of these the crescents are
conspicuous and regularly arranged, often meeting and consequently
form H-shaped markings. In most of the snakes the crescents are best
developed in the second fifth of the body and disappear posteriorly.
In five of the twenty, crescents between rows six and seven are fairly
regular, but those between rows seven and eight are few and appear
only sporadically. In eight specimens there are no crescents between
either rows seven and eight or eight and nine. In eight others the
crescents between rows six and seven are likewise absent, and only the