ON FALCO BABYLONICUS AND FALCO BARBARUS. 481k 
which I have examined of F. barbarus, exhibit, in most instances, 
a somewhat paler grey on the lower part of the back, upper 
tail-coverts, and basal portion of the tail; that most of 
them have a larger extent, and sometimes a brighter tint, of 
rufous on the nape and sides of the neck, and also more 
decidedly rufous foreheads. 
Generally speaking, the adult females of F. babylonicus 
exhibit a slightly darker tint of grey on the upper surface 
than the males, and some adult females are more rufous on 
the under surface than any of the males that I have examined. 
Such a female is well represented in the plate of this Falcon 
given in Gould’s “ Birds of Asia.” The adult females of this 
species are also more cross-barred with dark lines on the under 
tail-coverts than is the case with the adult males. 
The less rufous adult females of F. babylonicus greatly 
resemble in coloring the most rufous adult females of 
F. punicus, but the males of these two species resemble each 
other much less closely than do the females.* 
I may here remark that, when F. babylonicus first assumes 
the adult plumage, the interscapular feathers, especially in 
the males, are edged with a rather dull rufous brown, which 
disappears as the bird advances in age; also that the trans- 
verse bars on the basal portion of the tail, which are usually 
somewhat strongly marked when the bird first attains the 
adult dress, gradually become obsolete and disappear more or 
less completely in the course of subsequent years. 
In the P. ZS. for 1876, pl. xxiii, a figure is given of a male 
Falcon which was shot in the Etawah district of Northern 
India by the late Mr. Andrew Anderson, who referred it to 
F. babylonicus, with which identification I concurred; but 
Mr. Hume, in “Stray Feathers” for 1877, p. 140, expressed 
his opinion that the bird was too small for F. babylonicus, 
and that it should have been referred to F. barbarus. In 
deference to this opinion, and considering that Mr. Hume 
had enjoyed superior opportunities to either of ourselves for 
examining specimens of F. babylonicus, we acceded to his 
view, and expressed our concurrence with it in the P. Z.S., 
1878, p. 2; but after examining with some care the series 
of these Falcons now preserved in the British Museum, I 
have reverted to my original opinion, and believe that Mr. 
Anderson’s Falcon, now in the Norwich Museum, and several 
other Indian Falcons which Mr. Hume referred to F. barbarus 
(in which I followed him in “ The Ibis,” 1882, pp. 311, 312) 
are, in fact, males of F. babylonicus, my present impression 
* For a detailed description of several adult males and females of Falco 
punicus, see “ The Ibis” for 1882, pp. 313 to 321, 
