IVOKY GULL 453 



DESCRIPTIVE CHARACTERS. 



PLUMAGE. Adult male nuptial. Completely 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 

 grey and black ; tips of primaries, blackish ; tail, with a 

 subterminal band of black ; rest of plumage, white. 



Nestling. Greyish. 



BEAK. Lead-colour, tipped with reddish-yellow. 



FEET. Black ; hind-toe fully developed. 



TRIDES. Blackish-brown ; margin of eyelids, brick-red 

 (Feilden). 



AVERAGE MEASUREMENTS. 



TOTAL LENGTH ... 18 in. Female smaller. 



WING 13 



BEAK 1-75,, 



TARSO-METATARSUS ... T5 ,, 



EGG ... 2-5 X 1'7 in. 



