842 13. COLUBRID 
hammondii. Intergradation between these two subspecies is 
shown by certain specimens from the San Joaquin Valley, 
but it seems to be individual rather than geographic. It 
doubtless will become more evidently geographic when 
specimens are secured from the proper areas. 
The relationship of T. 0. couchii to T. 0. vagrans is still 
closer than to T. 0. hammondii. This is shown by the 
character of the spotting adjacent to the dorsal line when 
present, the frequent occurrence of more or less dark pig- 
ment on the gastrosteges, and the fact that in many of the 
specimens of 7. 0. couchii some indication of a dorsal line 
is present. 
In typical T. 0. vagrans, as it occurs in Idaho, Utah and 
eastern Nevada, the dorsal line is well marked, the dorsal 
spots are very evident and invade the edges of the dorsal 
line, and the gastrosteges almost always are rather heavily 
pigmented. T. 0. couchii differs from this type of colora- 
tion in the shortness of or indistinctness of its dorsal line, 
which may be only a half-inch in length, in the less frequent 
and less extensive pigmentation of the gastrosteges, and in 
the absence, indefiniteness, or less characteristic arrangement 
of the dorsal spots. Intergradation between T. 0. couchii 
and T .o. vagrans is to be looked for in western Nevada. 
The relationship between T. 0. couchii and T. o. elegans 
also is very close. Typical T. 0. elegans seems to occur 
only at considerable elevations in the Sierra Nevada and in 
the mountains of southern California. T. 0. couchii occupies 
the lower levels, but extends its range up in the Sierra 
Nevada so far, at certain points, that it overlaps that of 
T. o. elegans, just as the range of T. 0. hammondii overlaps 
that of 7. o. elegans in the San Bernardino Mountains of 
southern California. But, while 7. 0. hammondii and T. o. 
elegans seem to remain perfectly distinct and true to charac- 
ter at the places where their ranges meet, specimens showing 
