839 
(notwithstanding the great improvements 
made in this delightful study), still remain 
in great obscurity ; it is well known that 
some species differ so essentially in their 
plumage, at different ages, and seasons, 
that Naturalists have been, and will conti- 
nue to be, at variance With each other, and 
occasionally with themselves. Dr. Latham 
originally considered the My rota as one 
of the varieties of the Fuligula, but, 
in his latter work he has given it as 3 
distinct species. Other authors have con- 
sidered Mr. Pennant's bird as the female of 
some other species, probably that of the 
Wigeon, which in its autumnal plumage is 
sometimes very rufous ; or it may prove to 
be a young bird of this species, in its first 
plumage. In this state of doubt we have 
added to the Nyroca the synonyma of those 
of Ferrtiginea. 
Montagu says the Castaneous Duck "is 
most certainly the Olive tufted Duck of 
the British Miscellany ; and we think 
there can be no doubt that it is the Nyrom 
of Gmelin." 
Our reasons for considering the African 
