59 BULLETIN 98, UNITED STATES NATIONAL MUSEUM. 
Immature female, No. 171041, U.S.N.M.; Pulo Manguan, August 
31,1899. Length, 203 mm. 
All the adult birds are in process of molt, involving chiefly the 
wing and tail feathers, though the type (No. 176954, U.S.N.M.) 
has the feathers of most of the chin and forepart of the head in their 
sheaths, and all the other specimens have some molting feathers on 
the body. 
The adult female differs from the adult male in her shorter tail; 
smaller general size; dull, nonmetallic, bluish slate-colored upper 
parts, throat, and breast, the pileum with a brownish tinge; duller, 
more brownish wings and tail; tawny edgings on some of the upper 
wing-coverts; and lighter shade of the posterior lower parts, the 
thighs and middle of abdomen particularly paler. 
The immature male (No. 171042, U.S.N.M.) obtained by Doctor 
Abbott is in process of molt, and is changing from the juvenal mto 
the completely adult plumage. It differs from the adult male in 
partly brown head and back, the black feathers of the adult plumage 
having only partly replaced those of the juvenal dress; short, more 
brownish tail; much more brownish wings, the remiges edged partly 
on exterior webs with tawny, the greater and median wing-coverts 
broadly tipped with the same (the lesser coverts have assumed the 
black of adult plumage); sides of head and of neck dull dark brown, 
mixed with tawny ochraceous, also with a few black feathers, leaving 
only the center of chin, throat, and jugulum glossy black; posterior 
lower parts of a paler rufous. 
The immature female (No. 171041, U.S.N.M.) is in what appears 
to be juvenal plumage, and differs from the adult female in having 
the upper surface lighter, decidedly more brownish, the pileum, 
back, and scapulars being particularly brown; the rump with an 
anterior band of tawny, and all the white washed with tawny; tail 
more brownish, all the white tips, excepting those of the two outer 
pairs, much mottled with brown; wmgs more brownish; remiges 
broadly edged on outer webs with dull tawny; median wing-coverts 
more conspicuously tipped with tawny ochraceous; lesser wing- 
coverts with a broad white streak along the shaft or on the outer 
web of each feather; forehead, lores, superciliary stripe, orbital 
region, and cheeks, dull white, finely mixed with brownish gray; 
sides of neck slate gray; auriculars slate gray, streaked with whitish; 
chin buffy white; a buffy ochraceous spot on upper throat just back 
of the chin; rest of throat rather light gray, washed and streaked 
broadly with buff; posterior lower parts much paler than in the 
adult. This example shows only slight indications of molt. 
Doctor Abbott reported this species as common on Pulo Siantan 
from August 19 to September 6, 1899; and observed it also on Pulo 
Kelong, September 1, 1899. 
