469 
Mr. R. B. Sharpe’s Catalogue of Accipitres. 
men; in this bird new feathers are appearing on the mantle 
of the dark hue indicative of adult plumage. A third speci¬ 
men shows a similar appearance on the back, and is also 
beginning to assume the rufous tail; in this example the 
tibial feathers are white, much mingled with rufous. The 
two last-named specimens are evidently in a state of change 
from the immature dress to that designated by Mr. Sharpe 
as the plumage of the “ adult male.” 
RuppelFs plate of his “ Buteo hydrophilus” (Neue Wir- 
belthiere, pi. 17) probably represents two immature speci¬ 
mens of P. augur —that marked “ Fig. 2 ” being apparently 
the younger of the two, and perhaps partially melanistic. 
There remains but one other species of the subgenus Ptero - 
lestes requiring consideration, the South-African P. jakal. 
Mr. Sharpe, in his description of the “ adult male,” has the 
following sentence:—Centre of chest whitish or rufous 
white, more or less mottled with black, being the remains of 
immaturity, as also are the white edgings to the feathers of 
the abdomen and thighs, and rufous on the under tail-coverts.” 
Having examined many skins of this Buzzard, and having 
also observed it in confinement, I feel certain that the ap¬ 
pearances indicated in this passage are not “ the remains of 
immaturity,” but are characteristic of the fully adult normal 
plumage of this species. 
Mr. Sharpe alludes, both at page 176 of his Catalogue, 
and at p. 29 of the second edition of Mr. Layard's f Birds of 
South Africa/ to the occasional occurrence of specimens of 
P. jakal in which the underparts are entirely black, as in the 
melanistic form of P. augur . Such specimens must, I appre¬ 
hend, be very rare, as none such have come under my notice, 
and as no mention of this phase of plumage is made by Mr. 
Layard in the first edition of his work, though he found this 
species “ very common throughout the colony ” of the Cape 
of Good Hope. 
I now proceed to the consideration' of the genus Leuco- 
pternis, which has been merged by Mr. Sharpe in that of XJru- 
bitinga ; but I think it more convenient to use both these 
generic names as indicating two distinct groups, which are 
2 k 2 
