GREAT BLACK-BACKED GULL. 
161 
aries, and tertials are white ; the spurious wing white; the 
quills black, the first two quills have a triangular white 
spot on the tip; the second has a black spot in the white 
tip, all the other quill-feathers are tipped with white, and 
their inner webs lead grey. The beak is wine yellow, with 
a red spot on the under mandible ; the eyes pale yellow; 
the eyelids bright red ; the legs and feet flesh-colour. 
In winter the head and neck are streaked with umber 
brown, like other gulls, with a dark luark before the eye, 
and the nail on the upper mandible dusky. 
The eggs of this species are three or four in number, 
and are in appearance as represented in plate 310. 
