BIRDS OF NORTH AND MIDDLE AMERICA. 679 



GEOTHLYPIS BELDINGI Ridgway. 

 BELDQfG'S YELLOW-THROAT. 



Much larger than any of the forms of G. triclim (tarsus 22.9-24.6, 

 exposed culmen 12.9-14), the adult male with the black mask bordered 

 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 yellowish olive-green beneath the surface, 

 grayish 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 buffy 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), 135.1-140.5 (138.3); 

 wing, 61.2-64.3 (62.8); tail, 61.5-65.8 (63); exposed culmen, 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 Things 

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

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

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

 dusk}^; malar region, chin, throat, chest, breast, and upper abdomen 

 lemon or gamboge yellow, deeper on chest; lower abdomen dull bufi'y 

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

 sides and flanks light buff)'^ olive; maxilla dark brown with paler 

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

 and feet as in adult male; length (skins), 131.6-136.9 (133.4); wing, 

 58.7-59.9 (59.2); tail, 57:9-61 (59.8); exposed culmen, 12.9-13.7 (13.4); 

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



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

 tipped with grayish, and color of sides and flanks rather paler and 

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



Yaung., first 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, with dis- 

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

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

 rusty on edges. Tail olive-green above, lighter below." ' 



' Eight specimens. 

 ^ Three specimens. 

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



