KEY TO FAMILIES 119 
very long and pointed, the outer feathers being much the longest; 
toes webbed. Adult Gulls and Terns are usually pearl-gray above, 
white below; Jaegers and most young Gulls are dark. 
A. Bill hooked and hawklike. F 
a. Bill with a naillike hook, its base with a scaly shield; plumage 
dark; central tail-feathers longest. (Fig. 23,a).... Family 
Stercorariide: Sxuas and JaEGERs, p. 150. 
6, Hook continuous with bill, no scaly shield, tail-feathers usually 
of about equal length (Fig. 23,6)... . Subfamily Larine: 
GuLis, p. 152, 
* Fra. 24, Fia. 25. 
B. Bill not hooked. P 
a. Bill straight, usually slender and sharply pointed; tail usually 
‘more or less forked. . . . Subfamily Sternine: Terns (Fig. 24), 
p. 162. ; 
6. Bill thin and bladelike, the lower mandible longer than the 
upper (Fig. 25)... . Family Rynchopide: Sximmers, p. 172. 
Fia. 26. 
Order III. Tubinares.—A.patrosses, Petrers, and FULMARS. 
Gray, sooty, or black and white sea-birds; living, except when nesting, 
well off shore; flying low, often skimming the waves. Nostril-openings 
tubelike; bill hawklike, its ‘hook’ often prominent; front-toes webbed, 
hind-toe small or absent; wings long and pointed; tail short. 
A. Size very large, nostril-tubes separated, on sides of bill (Fig. 26, a). 
4 Family Diomedeide: ALBATROSSES, p. 172. 
B. Size smaller, nostril-tubes joined on top of bill (Fig. 26,6)... . 
Family Procellartide: Perre.s, FULMARS, SHEARWATERS, p. 173. 
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