362 A FIRST LIST OF THE BIRDS 
p- 180), records three Indian examples of this species, from Nipal, 
Etawah, and Madras. 
Possibly Mr. Sharpe not having a sufficient series before 
him, may have relied too implicitly on the extent of the 
feathering of the tarsus, which, as I have shown, is a worth- 
less character, as regards individual specimens, although it may 
be good specifically. It may be quite true that desertorum, 
as a species, has the tarsus less feathered than plumipes, but 
it is impossible to take a particular specimen, and because it 
has 1°5,1°6, or 1:7 of its tarsus bare, thereupon to pronounce 
that itis necessarily not plumipes, because we have essentially 
typical plumipes, with 1°5 and 1°6 of the tarsus bare. 
Or again he may bave relied, similarly in the absence of 
a good series, on the more rufous character of the plumage 
and specially of the thighs, which is said to be a diagnosis of 
desertorum. But plumage in the case of these Buzzards is, 
J am convinced, a delusion and a snare; not only ferow (and ? 
desortorum), but equally plumipes and Archibuteo strophiatus 
exhibit similar variations of plumage from the pale, through the 
rufous and brown to the blackish brown, and though one type 
of plumage is more common in one species and another in 
another, specimens of each may, I believe, be met with in each. 
So in plumipes we have a specimen from Native Sikhim, a 
typical specimen wing, 15:9, and barely 1:1 of the front of the 
tarsus bare (the feathers running a good deal further down on the 
interior of the tarsus), which is as red as ¢ any Buzzard can be. 
It is, however, possible that while the South African deserto- 
yum with a wing never, as far as I can make out, exceeding 
153 inches, may, the sexes being known, be clearly separable at 
all times from even rufous and slightly tarsi-plumed plumzpes ; 
gradations between the two may occur in intermediate coun- 
tries, a consideration of which would as completely justify 
Mr. Sharpe in uniting his Indian specimens with desertorum, 
as a careful examination of my series (unfortunately but few 
of them reliably sexed) justifies mein assigning all mine to 
plumipes. 
Turning now to ferov and being desirous of contributing 
my quota 1 to the discussion which has been going on as to the 
changes of plumage of feror, I propose “to give alist of 94 
specimens in my museum which I have recently examined, 
and arranged according to types of plumage in the order in 
which, from a consideration of my large series, these appear, 
if sequent and not alternative, to falter each other, together 
with the dimensions of the wing in each specimen. 
There appear to me to be “five fairly well-marked types, 
with of course numbers of intermediate forms, showing how 
