957 
Subfamily. StTERNINAE. Terns. 
All of the Terns treated here have forked tails. They usually carry the head at a sharp angle to 
the line of the body, thus having something of the appearance of a huge mosquito. All are beneficial. 
I. Length about 21 inches. H. 44. Caspian Tern. 
Il. Length about 1o inches. 303. Black Tern. 
IIJ. Length about 15 inches. 
A.- Tail forked for only 1.5 inches. H. 43. Gull-billed Tern. 
B. Tail forked for more than 3 inches. 
1. Entire bill coral red. 302. Arctic Tern. 
2. Bill blackish at tip. 
a. Inner web of outer tail feather dusky. 300. Forster’s Tern. 
b. Outer web of outer tail feather dusky. 301. Common Tern. 
OrpvEerR 12. ANSERES. Ducks, Geese, Swans. 
There is but a single family within this order, the ANATIDAE, but the group is divided into five sub- 
families, as follows: 
Subfamily 1. Merrcinar. Mergansers, Fish Ducks, 
These are known by the slender cylindrical bill. The two larger species eat fish almost wholly and 
so are not good to eat. The Hooded eats a good deal of other food, and its flesh is more savory. 
I. Length under 18 inches; a conspicuous hood. 306. Hooded Merganser. 
II. Length over 21 inches. 
A. Head and throat black. 
1. Underparts white, tinged with salmon. 304. American Merganser. 
2. Breast brownish, heavily streaked with black. 305. Red-breasted Merganser. 
B. Head and sides of neck rufous-brown. 304. American Merganser. 
C. Head and sides of neck grayish brown. 305. Red-breasted Merganser. 
Subfamily 2. ANATINAE. River and Pond Ducks, 
_ These birds are popularly known as “tip-ups,” from their habit of feeding in shallow water and 
tipping the head down beneath the water while the tail sticks straight up in the air. Their food is 
largely vegetation, and their flesh therefore savory. 
I. Length under 17 inches. 
A. Lesser wing coverts green. 310. Green-winged Teal. 
B. Lesser wing coverts blue. 
1. Prevailing color reddish brown. 312. Cinnamon Teal. 
2. Prevailing color pattern mottled. 
a. A white crescent in front of the eye. 311. Blue=-winged Teal. 
b. Underparts suffused with rusty brown. 312. Cinnamon Teal. 
c. Underparts suffused with rusty gray. 311. Blue=-winged Teal. 
II. Length over 18 inches. 
A. Belly not conspicuously streaked or spotted. 
1. Head shining green. 307. Mallard. 
2. Center of crown white or whitish. 
a. Side of head and neck reddish brown. B.C. & H. 23. European Widgeon. 
b. Side of head and neck light, mottled. 309. American Widgeon. 
3. Crown greenish, throat white. 315. Wood Duck. 
4. Crown dark olive brown. 314. Pintail. 
5. Crown finely streaked with black. 
a. Wing coverts with chestnut. 308. Gadwall. 
b. Wing coverts without chestnut. 
(1). Sides barred with black. 314. Pintail. 
(2). Sides plain brown. 309. American Widgeon. 
(3). Sides spotted with black. : 308. Gadwall. 
B. Belly conspicuously marked or chestnut. 
1. Underparts chestnut. 313. Shoveller. 
2. Underparts not chestnut. 
a. Lesser wing coverts bluish. 313. Shoveller. 
b. Lesser wing coverts brownish gray. 
(1). Speculum purple. 307. Mallard. 
(2). Speculum gray and white. 308. Gadwall. 
