AN ATHXffi. CXXXVI. 229 



ff. Tail feathers with their bases scarcely concealed by the short 

 coverts; tail more than half length of wing, much graduated, 

 the feathers with narrow webs and very stiff shafts. 



TO. Nail of bill very sniall, bent backward beneath 

 tip of upper mandible; outer toe longer than 



middle ERISMATURA, 363. 



mm. Nail of bill normal, not very narrow; outer 

 toe shorter than middle toe. 



NOMONYX, 364. 



bb. Tarsus reticulate all around, the plates rather larger in front; tarsus 

 not shorter than middle toe without claw. Sexes similar. Geese. 

 (Anserince.) 



q. SerraB on tomium of upper mandible visible from outside for most 

 of its length; tomium decidedly sinuate or concave; (bill and feet 

 pale). 

 r. Bill very stout, its depth at base more than half its length above. 



(Color largely white.) CHEN, 365. 



rr. Bill smaller and more depressed, its depth at base not half its 



length. (Color not white.) ANSER, 366. 



qq. Serrae on upper tomium scarcely visible except near angle of mouth, 

 the tomium scarcely sinuate; nostril near middle of nasal fossa; 



(head, bill and feet mostly black) BRANTA, 367. 



aa. Neck not shorter than body; lores partly naked. Color white. Swans. 

 (Cygnince.) 



s. Bill not tuberculate; tail rounded; outer primaries with sinuate 

 webs OLOR, 368. 



349. MERGANSER Brisson. (Lat., mergus, diver ; anser, 

 goose.) 



a. Nostril nearer middle of bill than base. 



685. M. americanus (Cassin). MERGANSER. GOOSANDER. 

 FISH DUCK. black and white above, lower parts creamy 

 white ; a black bar across white of wing coverts ; head glossy 

 green, scarcely crested ; 9 smaller, ashy gray ; head brownish. 

 L. 24. W. 11. B. 2. T. 5. N. Am., common. 



aa. Nostrils near base of bill. 



686. M. senator (L.). RED-BREASTED MERGANSER. Similar ; 

 head crested ; $ with breast reddish brown, black-streaked ; wing 

 with two black bars, instead of one as in preceding. L. 24. W. 9. 

 T. 4. B. 2\. N. Am., abundant. (Eu.} (Lat., one who saws.) 



350. LOPHODYTES Eeichenbach. (Xo$os, crest ; dvrrjs, diver.) 



687. L. cucullatus (L.). HOODED MERGANSER. SHELDRAKE. 

 Black and white ; speculum white with 2 dark bars ; sides chestnut 

 in $ ; 9 duller and grayish ; "crest high and compressed ; nostrils 

 sub-basal. L. 19. W. 8. T. 4. B. \\. N. Am., common. (Eu.} 

 (Lat., hooded.) 



