OT THE GENUS MERGUS. 
481 
net in Europe ? I have myself no doubt that they are 
merely different sexes of the same species *. 
Having alluded to the resemblance which existed between 
the plumage of the Dundiver and the female Red-breasted 
Merganser, I shall add, that the latter, notwithstanding its 
being considerably less, is frequently confounded with the 
former, both in foreign and British collections, as well as 
by systematic writers. 
Indeed, I conceive that the only obscure point or desi- 
deratum in the history of this genus, is the establishment 
of a precise and unvarying specific character, by which to 
distinguish the female of the Red-breasted Merganser from 
the Dundiver, or female of the Mergus merganser. This is 
a point which, I do not know for what reason, has never been 
alluded to by any writer on ornithology as a matter of dif- 
ficulty, and yet none of them has given any character by re- 
ference to which such difficulty may, with certainty, be ob- 
viated. Knowing the fact that they were really distinct, they 
have disregarded the circumstance that in many instances 
* Dr Heysham, and otliers, have combated the opinion of the Goos- 
ander and Dundiver being specifically the same, by referring to the pendent 
crest which frequently adorns the nape of the Dundiver, an ornament with 
which the Goosander is more sparingly provided. This mark bein^, in 
other crested species, either peculiar to the males, or, when common to both 
sexes, less elongated in the females, has, therefore, been regarded as a proof 
that the Dundiver could not be considered as the female of the Goosander. 
This objection to the identity of these two birds is, however, done away 
with by the legitimate supposition, that the Dundivers with elongated crests, 
described by various authors, were not Dundivers commonly so called (by 
which, of course, I mean the females of the Goosander), but rather the 
females of the Red-breasted Merganser, the male of which is distinguished 
by a very fine pendent crest. Such specimens of the Dtmdiver as were re- 
markable for their length of crest, when compared with that of the male 
Goosander, I have always found, upon examination, to be either females or 
young males, of the Red-breasted Merganser. 
