128 BULLETIN 50, UNITED STATES NATIONAL MUSEUM 



tail coverts, and central pair of rectrices black to dark fuscous-black 

 coarsely vermiculated, barred, and irregularly mottled with cream buff, 

 dull grayish buff and whitish (the white largely restricted to the narrow 

 tips of the feathers), the buffy tones richest and darkest on the lower 

 back, rump, and upper tail coverts; remiges and all but the inner upper 

 wing coverts white; all but the median pair of rectrices white; entire 

 underparts whiter than the dorsum; the feathers of the throat and sides 

 of head, the breast, upper abdomen, sides, flanks, and under tail coverts 

 pale cream buff to cream buff heavily barred with dark fuscous-black and 

 tipped with white; center of abdomen, thighs, and a varying amount of 

 the flanks unbarred white; under wing coverts white; feathers of tarsi 

 and toes white more or less tinged with pale buffy ; iris dark brown ; bill 

 black ; supraorbital "comb" vermilion ; toes and claws brownish gray. 



Adult female, suuimer plmiiage. — Similar to that of the male but with, 

 on the average, a richer, more ochraceous-buffy tone in the buffy areas. 



Adult male, autumn plumage. — Remiges, all but the innermost upper 

 v;ing coverts, the under wing coverts, all but the median pair of rectrices, 

 abdomen (except for narrow sides and to some extent flanks) and under 

 tail coverts pure white ; head, nape, interscapulars, scapulars, and inner- 

 most upper wing coverts, back, rump, and upper tail coverts with a 

 ground color of pale tawny to fulvous-buff (in one very dark specimen, 

 Dresden brown) mixed with grayish, finely vermiculated and freckled 

 with fuscous-black, these dark markings heavier and forming more 

 regular bars on the head and nape, and becoming smaller and scarcer 

 (i.e., leaving more of the tawny fulvous-buff exposed) on the scapulars, 

 rump, and upper tail coverts; sides of head, chin, and throat white nar- 

 rowly barred with dull sepia to clove brown ; breast similar but with the 

 brown areas broader ; sides and upper flanks tawny-buff coarsely mottled 

 and speckled with dull sepia; feathers of tarsi and toes white more or 

 less tinged with buffy. 



Adidt female, autumn or tutelar pluuiage. — Similar to that of the male, 

 but upperparts and throat and breast much more ochraceous— the gen- 

 eral appearance being isabelline to cinnamon-buff only sparingly mixed 

 with gray, and with the blackish vermiculations somewhat heavier and 

 more widely spaced than in the males ; some of the remiges occasionally 

 with dusky shafts. 



Adidt male, zvinter plumage. — Entirely white, the feathering of the 

 tarsi and toes much longer and denser than in the summer or autumn 

 plumages ; supraorbital "comb" reduced or absent. 



Adtdt female, zvinter plumage. — Similar to the male. 



First autumn plumage (sexes alike). — Similar to the adult female in 

 autumn plumage, but slightly less isabelline, more grayish ; the tail and 

 wings very dift'erent ; in the tail the median two pairs being isabelline 

 narrowly barred Vv^ith dark clove brown, the next pair with the inner 



