BIRDS OF NORTH AND MIDDLE AMERICA. 679 



GEOTHLYPIS BELDINGI Ridgway. 

 BELDING'S YELLOW-THROAT. 



Much larger than any of the forms of G. trtch.n>< (tarsus 22. 9-2-1:. 6, 

 exposed eulmen 12.9-14), the adult male with the black mask l)ordered 

 continuously behind by bright yellow. 



Adult male. — Forehead, with loral, orbital, auricular, and malar 

 regions uniform black, forming a conspicuous black "mask;" space 

 immediately behind this black area clear yellow (intermediate between 

 canary and naples yellow, brightening into lemon yellow on sides of 

 neck); occiput and hindneck olive or olive-brown superficially, the 

 feathers olive-yellow or j^ellowish olive-green beneath the surface, 

 grav'ish dusky at base; rest of upper parts plain olive-green; under 

 parts rich lemon or gamboge yellow, passing into paler yellow on 

 lower abdomen and anal region and into light brownish or bufl'y olive- 

 green on sides and flanks; bill black, with paler tomia, in summer, 

 browner, with mandible paler basally, in winter; iris brown; legs and 

 feet light brownish (in dried skins); length (skins), 135.1-110.5 (138.3); 

 wing, 61.2-61.3 (62.S); tail. 61.5-65.8 (63); exposed eulmen, 13.2-14 

 (13.6); tarsus, 22.9-24.6 (23.5); middle toe, 15-16.8 (15.6).^ 



Adult female. — Above dull yellowish olive-green, brighter on wings 

 and tail, paler on forehead, the anterior portion of crown tinged with 

 or inclining to russet-brown; an indistinct narrow superciliar}^ stripe 

 of olive-yellowish; lores and suborbital and auricular regions olive- 

 dusky; malar region, chin, throat, chest, breast, and upper abdomen 

 lemon or gamboge yellow, deeper on chest; lower abdomen dull buiiy 

 whitish; under tail-coverts yellow, paler than that on throat, etc.; 

 sides and flanks light butf}^ olive; maxilla dark brown with paler 

 tomia; mandible horn brownish, darker terminally, paler basally; iris 

 and feet as in adult male; length (skins), 131.6-135.9 (133.4); wing, 

 58.T-59.9 (59.2); tail, 57.9-61 (59.8); exposed eulmen, 12.9-13.7 (13.4); 

 tarsus, 22.9-23.1 (23); middle toe, 15.2-15.5 (15.3).' 



[In wintei" both sexes have the feathers of back, etc., indistinctly 

 tijjped with grayish, and color of sides and flanks rather j^aler and 

 more butfy, but otherwise similar to the spring plumage.] 



Young., jit'Ht plumage. — ''Above uniform dark olive-brown; below, 

 sides, and under wing-coverts light yellowish buff. Faint indications 

 of light superciliary stripe. Wings above dark olive-green, w^ith dis- 

 tinct greenish edging to outer web of each feather except the lirst, 

 which has a whitish edging the same as adults. Greater wing-coverts 

 rust}^ on edges. Tail olive-green above, lighter below." ^ 



^ Eight specimens. 

 ^ Three specimens. 

 ^Bryant (W. E.), Bull. Calif. Ac. Sci., 2d ser., ii, 1889, 20. 



