298 BULLETIN 50, UNITED STATES NATIONAL MUSEUM. 



V)elow the black crescent produce a clouding or indistinct spotting across the breast. 

 The yellows are much brighter. 



Young of the year are usually more conspicuously sjjotted, washed with buffy across 

 the breast, and browner and darker above, with smaller bills. 



Feviales in breeding plumage. — Smaller than males; black areas more restricted and 

 less clearly defined; streaked continuously above from frontal band to rump-band, 

 lines narrowest on the head and fewest on the nape, sometimes forming a black patch 

 (rarely as distinct as in the most indistinct male) on the fore part of the crown; frontal 

 band often narrow and obscure; shoulders and ear-coverts frequently obscured with 

 dusky; otherwise similar to the male. 



Adult females in autumn plumage. — Plumage softer and colors more suffused than in 

 breeding dress, grayish, brownish, or yellowish tips obscuring the various areas of color. 

 Brownish wash and dusky spotting on the breast more or less distinct. 



Young of the year usually darker and browner above, the breast below the crescent 

 more conspicuously washed with buffy and more heavily spotted with dusky brown. 



Yoking in first plumage. — Above dusky, brownish, or buffy, conspicuously dotted 

 from bill to tail with white; wing-quills and coverts edged with buffy; below white, 

 spotted (more or less) across the breast with dusky, often on a buffy wash. This plum- 

 age is completely moulted in acquiring the autumn dress, which varies but little from 

 that of the adult. The feathers of the back are first replaced, those of the shoulders 

 next, then the wing-quills, beginning with those nearest the body, and when the spot- 

 ted plumage has nearly all disappeared, the head changing last, the black about the 

 head and then that of the jugular crescent begins to show, and the tail feathers appear 

 last of all. Bill and feet pale yellowish. 



KEY TO THE SUBSPECIES OF OTOCORIS ALPESTRIS.a 



a. Upper parts not speckled. (Adults.) 



' 6. A sharply defined patch of black covering fore part of crown and posterior part 

 of forehead, continued laterally to and involving the horn-like occipital tufts; 

 black area on side of head and black patch across chest larger, deeper black. 

 (Adult males) 

 C. Color of back more grayish, more strongly contrasted with pinkish color of 

 hindneck and occiput, more heavily or darkly streaked. 

 d. Occiput, hindneck, and lesser wing-coverts paler and more vinaceous (between 

 vinaceous-buff and buff-pink). 

 e. Larger (wing averaging more than 111 mm.''). 

 /. Throat always white ; general color above paler and grayer, with hind- 

 neck, etc., more lilaceous. (Breeding in Alaska, except coast district 

 east and south of Alaska peninsula; migrating south to Oregon, Utah, 

 Montana, etc.) Otocoris alpestris arcticola (p. 307) 



a The characters of the various subspecies, consisting almost entirely of differences 

 in measurements and relative grayness 'or redness of upper parts, depth and extent 

 of yellow of head (if present) and thus of a purely comparative nature, the construction 

 of a really useful "Key" is necessarily a matter of very great difficulty. In fact, one 

 that would be entirely satisfactory is, from the nature of the case, probably impossible, 

 and I can only hope that the one here presented may be of some assistance in the 

 proper identification of specimens. In the case of adult birds in winter, and especially 

 young birds in their first winter, identification is still more difficult, since the distinctive 

 color-characters are in these far less pronounced than in spring or summer, while on 

 account of their extensive migrations the locality often does not provide any clue. 



6 All the measurements of Otocoris in this volume, except those of total length, are 

 taken from Mr. Oberholser's paper (Proc. U. S. Nat. Mus., xxiv, 1902, 801-884). 



