GREAT BLACK-BACKED GULL. 
SADDLE-BACK. COBB. 
Larus marinus. 
Char. Mantle slaty brown ; outer wing-feathers more or less black, 
tipped with white ; rest of plumage white ; bill yellow, red at the angle , 
legs and feet pink. Length about 30 inches. 
The full plumage is not assumed until the fourth year Immature 
birds arc mottled brown and white, very young specimens having the 
upper parts almost entirely brown, and the bill dusky. 
Nest. On an inaccessible cliff by the sea, or upon a rocky island in a 
lake, a mere depression in the turf, lined with grass or sea-weed ; some- 
times a bulky affair made of coarse herbage and lined with grass and a 
few feathers. 
2-3 (usually 3) ; bufiish gray to deep buff, sometimes slightly 
tinged with olive, boldly blotched with brown and gray ; average size 
about 3 00 X z.ro. 
The Saddle-back, or Black-backed Gull, is a general denizen 
of the whole northern hemisphere, and extends its residence in 
