Mr. R. B. Sharpe's Catalogue of Accipitres. 235 
Mr. Sharpe does not mention in his account of Buteo 
swainsoni the difference in coloration which exists between 
the adult male and female in their normal state of plumage. 
This difference is thus summarized by Mr. Ridgway, in his 
paper on the Subgenus Craxirex, to which I have already 
referred :— 
“ S • Breast-patch rufous, with darker shaft-streaks ; 
$ . Breast-patch dark greyish-umber or blackish-brown 
(like the back) ” 
According to the measurements of this species given by 
Mr. Ridgway, a very remarkable disparity exists in the 
dimensions of different individuals of the same sex, especially 
in the length of the wing from the carpal joint to the tip of 
the primaries. In twenty-two adult males whose dimensions 
are given by Mr. Ridgway, the length of this measurement 
of the wing varies from 12 inches to 16, and in thirty adult 
females from 14*75 to 17*25. Having regard to these differ¬ 
ences, it seems to me probable that the investigations of Ame¬ 
rican ornithologists will ultimately result in the discrimi¬ 
nation of two distinct races, a larger and a smaller, both at 
present referred to Buteo swainsoni , but not in reality iden¬ 
tical, in which case the smaller race will, I think, be entitled 
to the name of Buteo fuliginosus , Sclater. 
I may here mention that I have recently remeasured the 
type specimen of Buteo fuliginosus in the Norwich Museum, 
and make the wing 12*6, and the tarsus 2*05, both these 
measurements being slightly different from those given in the 
original description of this specimen (P. Z. S. 1858, p. 356). 
Mr. Sharpe speaks of the melanistic phase of Buteo swain¬ 
soni as being fully adultbut if this means that every 
individual which lives to be “ fully adult ” attains this state 
of plumage, it is a statement in which I cannot concur. It 
may possibly be correct as regards the smaller race, which I 
am disposed to look upon as separable under the title of B. 
fuliginosus; but in the larger and commoner form, to which 
I would restrict the name of B. swainsoni , melanistic speci¬ 
mens are comparatively so rare that in my opinion they can 
only be looked upon as accidental. 
r 2 
