286 Mr. Montagu's Observations 
species in the Second Supplement to the General Synopsis, under 
the title of Brown Gull, is no other than the Black-headed Gull 
in its adolescent state; and it becomes the more necessary to clear 
up this point, as it is stamped with such high ornithological au- 
thority, which might lay a foundation for more confusion in this 
very intricate class. 
To point out the errors of our friends, for whom we have the 
highest regard, would, indeed, be a task ill suited to our pen, 
were we not, from long habits of intimate friendship with both 
these gentlemen, well aware of the purity of their writings, 
and that nothing would afford them more pleasure than the fur- 
therance of science, by clearing up the doubts existing by well 
grounded facts. 
In the former works of my friend Dr. Latham, he had been in- 
duced to fall into the opinion of other authors, and made some of 
the varieties of the Black-headed Gull distinct species. In his Index 
Ornithologieus, however, he has very judiciously brought the L. ci- 
nerarias and erythrogus of Gmelin, together with the ridibandus, as 
mere varieties; but suffers the Sterna obscura to remain a distinct 
species, although he expresses a doubt whether it may not be a 
young of some one of the Tern or Gull genus. 
Thus the Doctor had cleared away much of the obscurity; and 
it only remains to restore the Brown Gull to its proper place, as 
the young of the Black-headed species, and scarce differing in 
plumage from the state in which it is described as the Brown- 
headed. 
Whether the Brown Tern of the older naturalists is a Tern or a 
Gull is perhaps a doubt; for, as the young of the former do not 
remain with us long after they are capable of flying, we cannot 
ascertain their several changes in plumage; though we ought, 
perhaps, to give them credit, and admit it was a Tern, but not a 
distinct 
