306 DwiGHT, Plumages of the Scoters. [j^y 



feathers coming in, while elsewhere black are replacing black and 

 are not obvious unless studied in the fresh bird. A similar specimen 

 was taken May 20 (J. D., Jr., No. 8242) and I have seen several 

 others. Still another (J. D., Jr., No. 29981) of June 26 shows 

 much wear and fading especially on the wing-quills where the 

 pattern of each overlapping primary is impressed on the protected 

 feather beneath. As this bird was perhaps crippled and certainly 

 w^as one that had not gone north in migration, the late date of 

 feather growth may thus be explained. 



3d Winter Plumage (and all later winter plumages) (Plate XXX, 

 Fig. 4, cf, Fig. 5, 9) acquired by a complete second postnuptial 

 moult. Birds are now fully adult. 



Males with a knob on their bills are probably a year and a half old 

 at least and those with the biggest knobs two years old or more. 



The variation in size and in color is very considerable, part of it 

 being due to age and part of it being individual. The depth of 

 color in the plumage, the size of the eye-crescent and of the white 

 area on the wings is also variable. 



Adult females are quite sooty and in fresh plumage are devoid 

 of white about the head but as the feather-tips wear away, exposing 

 the white basal portions of the feathers more or less distinct white 

 patches appear on the sides of the head, especially over the site of 

 the posterior juvenal spot. The wear is most marked in breeding 

 specimens. Females do not assume bills with knobs, nor are the 

 bills colored except a band near the nail. 



Oidemia carbo. 



The plumages and moults of this species seem to correspond to 

 those of 0. deglandi which it most resembles, but I have seen only 

 eight specimens all told. It differs from deglandi in a bill with a 

 concave knob that suggests a battle-ship so marked is the over- 

 hanging protuberance, the loral feathering extending farther for- 

 ward than the frontal, and the latter rounded or flattened instead 

 of extending into an angle. Besides this it is very large and the 

 adult male has black flanks and sides, instead of brown as in deg- 

 landi, a character which it shares with fusca. The feathering of 

 the bill seems to be diagnostic (Plate XXIV, Fig. 6), and its color 

 seems to be richer than in deglandi. 



