IVORY GULL 453 
DESCRIPTIVE CHARACTERS. 
PLUMAGE. Adult male nuptial. — ecmplencly white, 
tinged in life with a rosy hue. 
“Adult female nuptial.—Similar to the male plumage. 
Adult winter, male and female.—Apparently similar to 
the nuptial plumage. 
Immature, male and female. — Cheeks and_ throat, 
greyish ; back, wing-coverts, and tail-coverts, spotted with 
vrey and black; tips of primaries, blackish; tail, with a 
subterminal band of black ; rest of plumage, white. 
Nestling.—Greyish. 
Brak. Lead-colour, tipped with reddish-yellow. 
Fret. Black; hind-toe fully developed. 
IrnrpDES. Blackish-brown ; margin of eyelids, brick-red 
(Feilden). 
AVERAGE MEASUREMENTS. 
TOTAL LENGTH .. 18 in. Female smaller. 
WING .... ai cate ten a oe 
BEAK oe omen 
TARSO-METATARSUS ... 1.95) oS 
UP SS JET tha) 
Eae 
