Vol. XXIX1 



1912 



J Phillips, The American Black Ducks. 303 



No. 113448 was taken to be a female (absence of sex feathers 

 noted above) although the specimen is without doubt a male, as 

 evidenced by the characteristic breast pattern, large size, and dark 

 chin. The smaller upper wing-coverts are broadly margined with 

 cinnamon in this specimen, a character also seen especially well in 

 No. 131718 and in the type of A. aherti. This certainly looks, 

 as Stejneger himself suggests, like a youthful t} pe of plumage for 

 the males of more advanced plumage show the small wing-coverts 

 plain drab, slightly edged with white. 



Of the other two specimens described as females. No. 21319 is a 

 typical male, and this leads to a misunderstanding. The only 

 female then, which Dr. Stejneger had was No. 113450. He 

 mentions among true individual differences, the curious white 

 ring around the eye in one specimen, the transposition of the white 

 anterior wing-bar, the coloring of the lining of the wing, etc. These 

 will be referred to again. 



Salvadori, 1895, confesses that he does not understand the 

 species. He thinks that domesticated mallards might have 

 become feral and influenced A. wyvilliana. This seems to me to be 

 not at all probable because of the small size of the species and its 

 perfect uniformity as to measurements. Salvadori calls attention 

 to the characters that distinguish the adult males and shows that 

 young birds resemble adult females. 



Rothschild, 1900, in two fine plates shows well the Mallard affini- 

 ties of the species. His series is a large one and especially inter- 

 esting are the few white flank feathers finely undulated with 

 blackish brown which, together with the faint cross-barring on the 

 abdomen occur only in his oldest males. 



This series shows nothing of this sort and it is therefore probable, 

 as suggested by Rothschild, that final male plumage is not obtained 

 for several years. He picks out his younger males by the presence 

 of spotted abdomen and absence of curled retrices, but this diagno- 

 sis would not hold in the series at hand, as will be seen in the above 

 description of the males. 



Rothschild calls attention to variability, which he considers 

 greater in the female. In some of his female specimens white tips 

 were present on the coverts which form the anterior edge of the 

 speculum. The different appearance of the under wing-coverts 



