on some Species of British Quadrupeds, Birds, and Fislics. 287 
distinct species. So with respect to the Brown Gull, whether it is 
or is not the Brown Tern of older authors is of* no importance, as 
at any rate it is an i unmatured bird, and alike ought to Ik* ex- 
punged from the works on ornithology as a distinct species. 
Since the perusal of Dr. Latham's last valuable work, we sent 
him the bird in question, bearing every mark of that described by 
him as the Brown Cull ; and we believe the Doctor is thoroughly 
satisfied with our observations upon it. 
Jt is indeed remarkable that a bird bearing such strong marks 
as the Black-headed Gull, in all the changes, from the nestling 
to the adult plumage,, should have ever been multiplied into so 
many species ; as it is in its various stages readily ascertained by 
the superior whiteness of many of the first quill feathers, espe- 
cially on the outer webs, and the greater coverts immediately im- 
pending them; which is very conspicuous when the wings are 
extended, and an obvious distinguishing mark from all others, 
even when flying. 
In order to elucidate the subject more clearly, we shall here 
subjoin a description of the several remarkable changes incident 
to the Black-headed Gull, which a long and intimate acquaint- 
ance from daily observation has warranted us to assert, and from 
which it will appear evident, that one of those mutations is the 
identical bird in question, the Brown Gull of the Second Supple- 
ment to the General Synopsis. In making any part of the his- 
tory of this intricate class of birds more clear, by endeavouring 
to bring them into the limits of truly definable distinetion, we do 
not arrogate superior knowledge on the subject, except so far 
as favourable situations, and a strict attention to a favourite pur- 
suit, have conspired to develop truth and undeniable facts. 
AVithout detailing the various synonyms of authors for this bird 
in its several changes of plumage, we shall only have recourse to 
a i 
