138 University of California Publications in Zoology [Vow 50

at intervals during the summer. After the middle of August they
were more frequently encountered, migrating through the poplar
woods in company with other warblers. Last definitely recognized on
August 28, though others may have been included with ‘‘orange-
crowned warblers’’ seen on August 31.

Nine specimens were collected (nos. 44904-44912), five breeding
adults, three in juvenal plumage, wholly or partly, and one immature
female in first winter plumage, taken August 28. <A young bird
collected August 21 is still mostly in juvenal plomage.

In my opinion orestera is a valid subspecies, and on the basis of
the characters ascribed to it by Oberholser (1905, p. 243). It is
slightly duller colored than lutescens, much brighter yellow than celata,
and of greater sizé than cither. The juvenal plumage of orestera, as
shown by young birds from the Atlin region, is gray ; juvenal lutescens
is yellow.

It will be of interest to ascertain the dividing line between the
breeding ranges of celata and orestera in the north. This is some-
thing that is as yet but imperfectly understood, and it will be a difficult
line to draw. Atlin specimens of orestera are not typical of that sub-
species in that they are smaller (or at least shorter winged) than those
from more southern points. This may, perhaps, be evidence of inter-
gradation toward celata,

Vermivora peregrina (Wilson). Tennessee Warbler

Breeds in small numbers in the lowlands of the Atlin region.
Three specimens were collected (nos. 44913-44915), an adult male on
June 29 and two females on July 14, all in poplar woods. The species
was not otherwise positively identified.

Dendroica aestiva aestiva (Gmelin). Eastern Yellow Warbler

Common in the lowlands of the Atlin region, and here, as in most
places, showing a predilection for willow copses, First arrival noted
May 31, last seen August 26. «

Eleven specimens were collected (nos, 44916-44926), three adult
males, two adult females, three males and one female in juvenal
plumage, male and female in first winter plumage. I refer these birds
to the eastern subspecies, Dendroica aestiva aestiva, as the form they
most nearly resemble. Such variation as is exhibited from the average
of aestiva is shown in a slight darkening of the dorsum, in which