1926] Swarth: Birds and Mammals from the Atlin Region 119

at 3500 feet on Otter Creek, July 30, and a male in juvenal plumage
at the base of Monarch Mountain, August 17, the last date of record.

The Wright flycatcher was of decidedly rare occurrence, not more
than six or eight individuals, all told, being seen during the summer.
Breeding birds were taken at a higher altitude than that at which
hammondw. occurs.

Otocoris alpestris arcticola Oberholser. Pallid Horned Lark

Breeds in fair abundance throughout the open country on the
ridges above timber line. On June 19, young out of the nest were
seen. During the last week in July and the first week in August, old
and young were in the midst of the molt; two adult males collected
on August 7 and 8, respectively, have nearly completed the change.
During this season of molt, the horned larks were generally found
either as single birds or two or three together, but before the end of
August they were gathered in flocks of from fifty to one hundred
individuals.

Fourteen specimens were collected (nos. 44769-44782), three in
juvenal plumage, three adults in worn breeding plumage, and one
immature and seven adults in more or less completely acquired winter
plumage. The species was last seen on August 24, though later trips
were made to the high altitudes where it occurs.

Pica pica hudsonia (Sabine). American Magpie

Several pairs were seen near Carcross during the last week in May,
and two nests found, occupied but without eggs. None was seen about
Atlin during the early part of our stay, and we were told that magpies
did not nest in that section but that the birds did appear there at the
very end of the summer. I saw several at Gladys Lake, September 8.
On September 19 one appeared at Atlin, and I saw the species each
day until the 23rd, when I left.

The late summer invasion of the Atlin region by the magpie is
probably related to the migration of this species to the coast of south-
eastern Alaska, as observed by me on the lower Taku River in
September, 1909 (Swarth, 1911, p. 77). The valley of the Taku, lying
southwest of Lake Atlin, is a natural outlet from this region to the
coast, and the magpies I saw there were, together with other species,
migrating down this valley from the interior.