Stercorarius pomarinus. 
Char. Light phase ; Top of head and upper parts sooty brown or 
dusky; neck and under parts white, the neck tinged with yellow. Dark 
phase : Entirely dark sooty brown or slaty black ; the two middle tail- 
feathers project beyond the other and are twisted. Bill dark gray, 
tipped with black ; legs and feet black. Length about 21 inches. 
Some naturalists think the dark phase assumed by this genus is merely 
melanistic; but numerous examples are met with that combine variations 
of the two, these “ pied ” forms being in the majority rather than excep- 
tional. Young birds are more or less mottled with buff. 
Nest. On a dry knoll of a moorland marsh or tundra, sometimes on 
a rock, — a mere hollow stamped in the moss. 
E.itgs. 2; pale to dark olive, tinged with russet and boldly marked 
with brown; average size 2.35 X 165. 
VOL. II. — 17 
POMARINE JAEGER. 
