GOLDEN-EYE DUCK. 107 



the forehead, that in another it is all purple, and in a third green on 

 the cheeks and purple on the top. Therefore it is obvious that the 

 colour of that part cannot be taken as an unvarying specific distinc- 

 tion. 



The authors of the Fauna Boreali- Americana consider the Golden- 

 eye when it has a semilunar patch before the eye, and a black band 

 separating the white patch on the wing, as a distinct species, differing 

 from the Golden-eye when it has a roundish patch before the eye, and 

 no perceptible black band on the wing ; and call the bird in its former 

 state " Clangula Barromi^' characterizing it as follows : — " Head and 

 upper parts of the neck pansy-purple, with a large crescentic mark be- 

 fore each eye; white speculum separated from the band on the coverts by 

 a black stripe." Now this character, in so far as regards the " pansy pm-- 

 ple," supposing it to be universal in all crescent-spotted individuals, is not 

 at all distinctive, because there are roimd-spotted individuals that have 

 the whole head of precisely the same tint, which, however, in neither the 

 one nor the other is " pansy " or violet purple. As to the white patch 

 before the eye, I find it varying greatly in form and extent, being, for 

 example, in one individual,, roundish and entirely placed below the 

 level of the eye ; in another nearly rhomboidal, in a third oblong, be- 

 ing, as it were the original round spot elongated above and below, in 

 a fourth, ovate, elongated backwards, but not upwards, in a fifth cres- 

 centic, and in younger birds scarcely perceptible, as is the case in the 

 Bufifel-headed Duck Clangula Albeola at various stages of its life. 



In the length of the tarsus and toes there are no remarkable dif- 

 ferences, and the scutella of both alleged species are the same in num- 

 ber and form. It is stated that in " Clangula vulgaris,'''' the " bill is high 

 at the base, narrower towards the point," and in " Clangula Barromi^'' 

 that it is " shorter and narrower towards the point," while the feathers 

 of the fore head, instead of rising to a point on the ridge of the bill, 

 as in the Golden-eye, terminate with a semicircular outline. I find 

 no difference in the latter respect, ,and as to the former, I observe 

 great differences in the breadth of the upper mandible in undoubted 

 specimens of Clangula vulgaris, apparently dependent upon the degree 

 in which the edges of the upper mandible have expanded or contracted 

 in drying. In the measurements of the two supposed species, as given 

 by the writers alluded to, there are no other differences than such as 

 we find in different individuals of almost any species. Although they 



