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.) 



b l . 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. Eggs .78 X -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 2 . "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. 



c 1 . Hind-neck, back, scapulars, and rump always gray ; adult with inner 

 webs of quills chiefly dusky gray; length about 6.75-7.50, wing 

 3.50-3.60, 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 SWINH. Swinhoe's Wagtail. 



c 2 . 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 M. ocularis ; larger than M. 

 ocularis; length about 7.00-7.75, wing 3.50-3.95, tail 3.70-4.20, ex- 

 posed culmen .50-.55. Hab, Kamtschatka, Amurland, Kurils, and 



