THE BIRDS OF NORTH AMERICA 
EAST OF THE NINETIETH MERIDIAN 
KEY TO ORDERS AND FAMILIES 
1, THE WATER BIRDS 
Fia. 22. 
Order I. Pygopodes.—Gresns, Loons, and AvKs. 
Ducklike birds, but with the bill usually pointed, never feathered and 
wider than high; never with flutings, ‘gutters,’ or serrations on its 
sides; wings short, never with a bright-colored patch or speculum; 
tail insignificant; feet placed far back (most specics, when standing, 
usually rest on their entire length, thus including the tarsus); tarsus 
flattened to present least resistance when swimming; toes webbed or 
lobed. Color, usually blackish above, white below, the throat often dark. 
Grebes and Loons, when pursued, usually dive; Auks generally fly. 
A. Toes four, nail flat or rounded, : 
a. Toes with lobate webs; tail absent. (Fig. 22, a.) 
. .. Family Colymbide: Greses, p. 138. 
b. Toes webbed, tail present. (Fig. 22, b.) 
a: an Pa Se tol mt Uae a aa Family Gaviidae: Loons, p. 142. 
B. Toes three, webbed, nails sharply pointed; tail present. 
(Fig. 22,c). ... Family Alctde: Auxs, MuRREs, 
and Purrins, p. 145. 
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Order II. Longipennes.—Jazcnrs, GuLis, 
and THRNS. 
Birds generally seen on the wing, usually 
over or near water. Bill strong, thick; 
hooked in the Gulls and Jaegers, sharply 
pointed in the Terns; bladelike in the Skim- 
mers; often in part yellow or red; wings 
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