MOTACILLA. 533 
black, with a strongly convex posterior outline; forehead, superciliary re- 
gion, and sides of head pure white, some species having a black streak 
through eye; crown and occiput, sometimes hind-neck also, and in one 
species the entire back, deep black; bill entirely deep black. Adults in 
winter: Differing from summer plumage in having at least the upper por- 
tion, sometimes all, of throat white; in gray-backed species the gray some- 
what tinged with brownish, in black-backed species the black of back re- 
placed by ash-gray. Young in first winter: Much duller in color than adults, 
with gray of a browner tint, black on top of head wanting or merely indi- 
cated, black below confined to a narrow crescent on chest, with sometimes 
a cluster or series of black spots extending upward from each extremity 
of the crescent along sides of lower throat; white of head more or less 
tinged with yellow. Young: Above dull brownish gray, including whole 
top of head, the latter usually with a blackish or dusky suffusion along 
each side of crown; white of wings much reduced in extent, much less 
pure, or sometimes even replaced by light brownish gray; chin and throat 
dull grayish white bordered posteriorly by a rather poorly defined dusky 
crescent across chest; sides of breast dull brownish gray; remaining lower 
parts dull white, purer posteriorly.) 
&. Without a black or dusky streak through eye; adults with wing-coverts 
tipped with grayish white, forming two bands across wing. 
Back, scapulars, and rump always gray; length about 6.50-7.30, wing 
3.25-3.55, tail 3.50-3.80; bill very slender. ggs .78 xX .60, white or 
grayish white, thickly speckled with grayish brown or dark brown. 
Hab. Europe and northern Asia, wintering in northeastern Africa 
and southern Asia; accidental in Greenland. 
694. M. alba (Linn.). White Wagtail. 
b?. With a distinct black or dusky streak through eye (except in first plumage) ; 
adults with exposed surface of middle and greater wing-coverts entirely 
white, forming a large patch on wing. 
¢. Hind-neck, back, scapulars, and rump always gray; adult with inner 
webs of quills chiefly dusky gray; length about 6.75-7.50, wing 
8.50-3.60, tail 3.50-4.00, exposed culmen .45-.50. Hab. Northeastern 
Siberia in summer; south, in winter, through Transbaikal and China 
to Burmah; occasional in Kamtschatka; accidental in Lower Cali- 
fornia (and Aleutian Islands ?). 
695. M. ocularis Swing. Swinhoe’s Wagtail. 
ce. Hind-neck always black in adults, the entire back, scapulars, lesser 
wing-coverts, and rump deep black in fully adult male; adult female 
and winter male with back ash-gray (more bluish than in M. ocularis), 
or gray clouded with black ; adults with inner webs of quills pure 
white except at tips, and white on outer surface of wings much 
more extensive and continuous than in Mf. ocularis; larger than J, 
ocularis ; length about 7.00-7.75, wing 3.50-3.95, tail 3.70-4.20, ex- 
posed culmen .50-.55. Had. Kamtschatka, Amurland, Kurils, and 
