(4). Underparts white; wings highly varied by white; a 

 rounded white spot on side of head near bill. 



(5). As in foregoing, but spot on side of head open-wing- 

 shaped. 



(6). Smallest; white still more extended; collar and occiput 

 from eye to eye white. 



b. Color pattern of head and neck (or head, neck and fore- 



breast) more or less setoff from that of remaining plum- 

 age. 

 (1). Distinction less sharply defined; black of head and 

 neck separated from that of back by obscure chest- 

 nut collar. 

 (2). Head, neck and breast black contrasting with varie- 

 gated character of remaining plumage, 

 (a). Larger, length over 17.50 inches, 

 (b). Smaller, length under 17.00. 

 (3). Head and neck chiefly rufous or brown. 



(a). Head and neck bright chestnut; bill forming dis- 

 tinct angle with forehead, 

 (b). Head and neck rufous and black; slope of bill con- 

 tinuous with that of forehead, 

 (c). Head and neck snuff-brown, contrasting with gray- 

 ish dusky and white of body plumage. 



(d). Head and neck snuff-brown; fore-neck and breast 

 dark brown; sides vermiculated grayish brown on 

 white; region about base of bill (at least chin) 

 white. 



(e). Head and neck mouse-brown; a dull white patch 

 below and behind eye. 



c. Color pattern variously distinctive. 



(1). Rich dark brown, ashy gray and white; tail feathers 

 of male greatly elongated. 



(2). Plumbeous slate slashed with white; female obscurely 

 brown and whitish. 



(3). Head highly variegated, black, white, blue and green; 

 bill greatly swollen at base (gibbous). 



(4). Crown and nape black; cheeks and chin white; remain- 

 ing plumage chiefly rich chestnut; female obscurely 

 dusky, but sides of head and neck whitish; quills of 

 rectrices more or less denuded. 



C. Bill heightened at base, not or not conspicuously flattened at 



tip; tarsi and feet relatively small. Sexes alike {Anserina — 

 Geese). 



1. Plumage chiefly white or bluish gray; bill not longer than 



head, sharply tapering, its lamellae much exposed. 



a. Plumage white. 



(1). Larger; bill about 2 inches long. 



(2). Smaller; bill about an inch and a half long. 



b. Plumage chiefly bluish gray. 



2. Plumage chiefly gray, the underparts extensively black in 



shingled or blotchy scaled pattern. 



3. Of dark coloration; head and neck black with touches of 



white; bill and feet black. 



a. Body plumage lighter; cheeks and upper throat white. 



b. More extensively black, and general tone of body plumage 



darker. No white on upper throat or cheeks, touches 

 on sides of neck instead. 



4. Entire body plumage handsomely scaled; head and hind neck 



white tinged with rusty yellow; throat blackish. 



D. Bill intermediate in character; tarsi and legs relatively much 



larger. (Dendrocygnintz — Tree Ducks). 



1. A large white patch on wing; plumage extensively blackish 



2. No white on wing; plumage chiefly yellowish brown. 



II. Lores chiefly bare; neck greatly lengthened; plumage (of Ameri- 

 can species) pure white. (CygnincB — Swans). 



A. Smaller; tail-feathers normally 20; usually a yellow spot in 



front of eye. 



B. Larger; tail-feathers normally 24; no yellow spot on lores. 



361. American Golden-eye fmale . 



362. Barrow's Golden-eye. 



363. BufHehead fmalei. 



360. Ring-necked Duck. 



358. Greater Scaup Duck. 



359. Lesser Scaup Duck. 



356. Redhead. 



357. Canvasback. 



361 and 362. American and Barrow's 

 Golden-eyes (females). 



358 and 359. The Scaups (females). 



363. BufHehead (female). 



364. Old-Squaw. 



365. Harlequin Duck. 



366. King Eider. 



370. Ruddy Duck. 



371. Lesser Snow Goose. 



373. Ross's Snow Goose. 



372. Blue Goose. 



374. White-fronted Goose. 



375. Canada Goose. 



376. Brant. 



377. Emperor Goose. 



378. Black-bellied Tree Duck. 



379. Fulvous Tree Duck. 



380. Whistling Swan. 



381. Trumpeter Swan. 



2093 



