Apo (Celestino); Basilan (McGregor); Cagayancillo (McGregor); Cebu (McGregor); Luzon (Celestino); Mindanao (Celestino); Palawan (Everett). Mongolia, Japan, Kamtchatka, and the Kurile Islands; in winter to southern China and Borneo.

“Spring plumage.—General color of the upper parts olive, slightly yellower on the rump; eye-stripe well defined, narrow, yellowish white, extending to the nape; lores and the feathers behind the eye to the nape dark olive; wing-coverts olive, the median wing-coverts with narrow, and the greater wing-coverts with broad yellowish white tips, forming an obscure upper wing-bar and a conspicuous lower wing-bar; quills brown, narrowly tipped with grayish white, the outside web edged with green and emarginated as in the preceding species; tail-feathers brown, the outside web margined with green, and the inside web with a narrow well defined grayish white margin; general color of the under parts greenish yellow, grayer on the breast and flanks; axillars, under wing-coverts, and thighs pale yellow; inner margin of quills grayish white. Bill acrocephaline; upper mandible dark brown, under mandible pale; legs, feet, and claws brown; third and fourth primaries longest; second primary usually intermediate in length between the sixth and fifth, sometimes slightly shorter than the sixth; bastard [first] primary measuring 12.7 to 15.2 mm. Length of wing, male, 72.1 to 68.5; female, 68.5 to 66; tail, male, 53.3 to 49.5; female, 49.5 to 45.7; culmen, 12.9 to 13.9; tarsus, 20.3.

“The changes of plumage in this species are similar to those of the preceding species, but at all seasons of the year the general color of the under parts is much paler in color in P. borealis (Blasius). The smaller size and smaller first primary of the latter species serve, however, to distinguish even birds of the year from the present species, though they approach each other very closely.” (Swinhoe.)

The yellow willow warbler is undoubtedly much rarer in the Philippines than the next preceding species, but upon a careful examination of available material I find it necessary to refer to this species a number of specimens which were previously recorded as A. borealis. These changes will be found in the list of localities under each species.

570. ACANTHOPNEUSTE LUGUBRIS (Blyth).
MOURNING WILLOW WARBLER.

Basilan (Steere Exp.); Mindanao (Steere); Samar (Steere Exp.). Western China to Chuan-che, eastern Himalayas; in winter to eastern Bengal and Burmese provinces.

“Coloration.—Very similar to A. magnirostris, but rather darker and smaller, and differing also in the proportions of the primaries. Upper mandible dark brown, lower one yellowish, somewhat dusky on the terminal half; iris brown; mouth yellow; legs brown; claws horn-color. Length, 127; tail, 53; wing, 66; tarsus, 19; bill from gape, 15.7; the second primary is intermediate in length between the ninth and tenth, and sometimes equals the tenth; the first primary is very long, being sometimes 20.3 mm. in length.” (Oates.)