86 University of California Publications in Zoology [Vou. 30

Lagopus lagopus albus (Gmelin). Southern Willow Ptarmigan

Specimens of willow ptarmigan collected by myself in the Atlin
region include three adult males and one adult female in summer
plumage, two in natal down, two in juvenal plumage, twelve adult
males and five adult females in ‘‘winter plumage, preliminary”’ or
partly in that plumage, five immature males and two immature females,
mostly in first ‘‘winter plumage, preliminary,’’ a total of thirty-two
skins (nos. 44680-44711). Additional specimens collected by Brooks
near Atlin and near Log Cabin were also at my disposal.

In previous papers I have used the name alexandrae for the willow
ptarmigan of British Columbia, but this additional mainland material,
together with a large series of alexandrae from the Alexander Archi-
pelago, southeastern Alaska (in the collection of George Willett), now
available, demonstrates differences that exist between the two.

Riley (1911, p. 233) divided the willow ptarmigan of the North
American mainland into two subspecies, Lagopus lagopus ungavus
from the region east of Hudson Bay, and L. l. albus from the region
to the westward. Ungavus he describes as having a heavier bill than
albus. The range of albus is given as ‘‘from the west side of Hudson
Bay, west through northern Alaska to eastern Siberia.’’

Clark (1910, p. 52), on the other hand, had previously said of the
mainland birds (to which he gives the name Lagopus lagopus albus)
that ‘‘all those from Labrador and central arctic America, with others
from Point Barrow, Kotzebue Sound, Cape Lisbourne, Kowak River,
Yukon River, and near St. Michaels, belong to a well-differentiated
race, with the beak very large, high, and stout, the culmen strongly
arched, and usually with a prominent ridge from the inferior corner
of the maxilla to in front of the nostril. They are identical among
themselves, it being impossible to tell from the examination of any one
specimen whether it was taken in Alaska or in Labrador.’’

Thayer and Bangs (1914, p. 4) described Lagopus lagopus koreni
from eastern Siberia, as differing from the willow ptarmigan of north-
ern Alaska in its still heavier bill.

Differences which I had previously noted between British Columbia
ptarmigan and those from northern Alaska were not to be reconciled
by either Clark’s or Riley’s treatments of the races, and compelled
further comparisons. Through the courtesy of Dr. Alexander Wetmore,
Assistant Seeretary of the Smithsonian Institution, I was enabled to
borrow from the United States National Museum three specimens of