19 



[Vol. xxxi. 



It had hitherto been considered a matter of great difficulty 

 to distinguish immature males of the two species, but 

 Mr. Ogilvie-Grant said that he had been fortunate in finding 

 a character by which they might always be recognized at a 

 comparatively early period. The black and white inner 

 scapular feathers which formed such a conspicuous feature 

 in the adult bird began to make their appearance in young 

 males killed towards the end of November. These white and 

 black feathers, though much alike in general appearance, 

 were structurally quite different in the two species. In 

 Barrow's Golden-eye the black lateral portion was produced 

 into a long process extending much beyond the white por- 

 tion, while in the Common Golden-eye the white feather 

 was of the usual shape, margined on the side with black. 

 Moreover, the young of C. islandica had the general colour 

 of the head much darker and of a blackish-brown, while in 

 C. glaucion it was rufous- brown, much like that of the 

 female. 



Clangida islandica. Clangula glaucion. 



Mr. Ogilvie, writing of the doubtful specimen killed by 

 him on the Aide River, stated that he too had arrived 

 at the conclusion that it was a Common Golden-eye. He 

 remarked : "I also know of a character which appears to me 

 to be a good one for separating C. islandica from C. glaucion 

 at any age. There is a ' boss' on the frontal bone imme- 



