88 University of California Publications in Zoology [Vou. 80

Alexandrae and albus are alike in possessing a small, slender bill,
as contrasted with the heavy, more stubby bill of alascensis, and in
color and markings they are closely similar in some plumages. Adult
males in breeding plumage are essentially alike. The adult female of
albus in breeding plumage (this and further allusions to albus refer
to the British Columbia series) differs from the female alascensis in
that stage, being much darker and less ruddy. The breeding female
of alexzandrae (one specimen from Porcher Island, British Columbia)
is also a dark-colored bird but with a maximum of brown coloration in
the plumage. The dark-colored female of albus has extensive blackish
areas on the feathers, which are edged with dull brown or with grayish.
In the dark-colored female of alexandrae there is an extension of rich
brown markings on all parts of the bird.

Differences between albus and alexandrae are readily apparent in
the ‘‘winter plumage, preliminary,’’ that is, in the brown, late summer
garb (the plumage stage inserted between breeding plumage or juvenal
plumage, and the white winter plumage) in which both sexes and old
and young become essentially alike—or would do so if this plumage
were ever acquired in its entirety.

Alexandrae in this plumage is well represented in a series of
specimens at hand collected by George Willett, mostly from Prince of
Wales and Dall islands. In an adult male (Willett coll., Dall Id.,
September 3, 1919), head, neck, and body (except for a limited white
area on the abdomen) are almost solidly dark brown, ranging from
‘*brick red’’ to ‘‘Hessian brown’’ (Ridgway, 1912), with hardly a
trace of vermiculation or mottling on the breast, and relatively little
on the upper parts. In color tone and in markings on individual
feathers there is extraordinarily close resemblance to winter specimens
of the Scotch red grouse (Lagopus scoticus).

In albus in the same plumage, the browns are paler, there is much
black or dusky barring and vermiculation, and dorsally the feathers
are extensively black centered, and are gray tipped to such a degree
as to affect the color tone of the whole upper surface. In alascensis
the browns are still paler, and the black centers and gray tips of the
dorsal feathers are almost or entirely lacking.

Conditions in these western races of willow ptarmigan parallel to
some extent those found in the rock ptarmigan. In each species the
northern Alaskan subspecies is an extremely ruddy-colored bird com-
pared with the others, and in each the British Columbia subspecies
seems to reach an extreme of grayness. In each species, too, the