AYTHYA. 103 



(.95), least width .70-.85 (.78). Hab. Northern portions of 

 Old World, from western Europe to Kamtschatka. 



A. marila (LINN.). Scaup Duck. 1 



e*. Six inner quills without distinct white spaces on inner webs ; 

 otherwise not appreciably diiferent from A. marila length 

 18.00-20.00, wing 8.25-9.00 (8.63), culmen 1.85-2.20 (2.03), 

 greatest width of bill .85-1.05 (.97), least width .70-.90 

 (.79). Eggs 2.54 X 1-71, pale buffy olive-gray. Hab. North 

 America in general, breeding far northward; south, in 

 winter, to Guatemala. 



148. A. marila nearctica STEJN. American Scaup Duck. 

 d 1 . Flanks vermiculated or zigzagged with blackish. 



e l . Similar to A. marila nearctica (including absence of distinct 

 white spaces on six inner quills), but black of head in male 

 glossed with purplish instead of green ; length 15.00-16.50, 

 wing 7.50-8.25 (7.81), culmen 1.58-1.90 (1.75), greatest 

 width of bill .80-.95 (.89), least width .60-.78 (.69). Eggs 

 2.25 X 1-58, same color as in F. marila nearctica. Hab. 

 North America in general, breeding northward ; south, in 

 winter, to Guatemala and West Indies. 



149. A. affinis (EYT.). lesser Scaup Duck. 



e j . Similar to A. affinis, but six inner quills with a distinct white 

 space on inner webs, as in A. marila. Hab. Eastern Asia 

 (Japan and southward). 



A. affinis mariloides (Via.). Chinese Scaup Duck." 



c 1 . Back and scapulars, in adult male, black, sometimes minutely sprinkled 

 with whitish ; a long, pendent occipital crest. 



Otherwise, in color, much like A. marila; wing 7.60-8.10, culmen 

 1.85-1.90, greatest width of bill .75-.S5. Hab. Northern parts 

 of Old World, from western Europe to Kamtschatka. 



A. fuligula (LINN.). Crested Scaup Duck. 3 

 6*. Speculum bluish gray. 



Adult male : Head, neck, chest, under tail-coverts, and upper parts black, the 

 head with a violet-purple gloss, and middle of neck with a more or less 

 distinct collar of chestnut ; chin with a triangular white spot ; bill trans- 

 versely banded with black, grayish white, and plumbeous. Adult female :* 



1 Anas marila LINN., Faun. Suec. 2d ed. 1761, 39. Aythya marila Eons, Isis, 1822, 564. 



2 Fuligula mariloides Via., Zool. Blossom, 1839, 31 (in text). Aythya affinis mariloides STEJN., Orn. Expl. 

 Kamts. 1885, 161. 



8 Anas fuligula LINN., S. N. ed. 10, i. 1758, 128. Aythya fuligula STEJN., Bull. U. S. Nat. Mus. No. 29, 

 1885, 160. 



*The female of this species resembles very closely in coloration that of the Red-head (A. americana), but 

 may be readily distinguished by the very different proportions, the average measurements of the two being 

 about as follows : 



A. americana. Wing 8.50, culmen 1.90, greatest width of bill .85, least width .75, tarsus 1.60, middle toe 

 2.30. 



A. collaris. Wing 7.50, culmen 1.80, greatest width of bill .85, least width .65, tarsus 1.35, middle toe 2.00. 



