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