346 Dr. P. L. Sclater on Hypotriorchis castanonotus. 
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XXXVII.— Note on the Hypotriorchis castanonotus of 
Dr. Heuglin. By P. L. Sclater. 
(Plate XII.) 
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The series of Abyssinian birds collected by Sir William Harris 
during his residence at Schoa, which was formerly in the Museum 
of the East India Company in Leadenhall Street, having been 
transferred to the British Museum, I have been enabled, through 
Mr. George Gray's kindness, to compare the specimen entered 
in Horsfield and Moore's Catalogue of the East India Company's 
Museum as “ Polihierax semitorquatus " with typical examples of 
the true Falco semitorquatus , Smith, collected in South Africa by 
the describer of the species. In the first place I should mention 
that the Abyssinian specimen of Sir W. Harris has not the 
red back, which is stated by Dr. Heuglin to be found in both 
sexes of his H. castanonotus. This point of difference, therefore, 
which seems to be the chief ground on which Dr. Heuglin has 
maintained the specific distinction between his bird and the 
southern Falco semitorquatus , seems to fail entirely; and we must 
suppose that Dr. Heuglin is in error in stating that the male of 
the Abyssinian bird, when adult, resembles the female in having 
a red back, although this may be the case in young males. On 
comparing the Abyssinian bird with the South African specimen 
in corresponding plumage, the differences which present them¬ 
selves are but slight. The head and neck are of rather a darker 
slaty-grey, the wings rather longer, and the legs generally rather 
stronger and stouter in the Abyssinian specimen; but the two 
birds are otherwise so much alike, that I should much hesitate 
in considering them as specifically distinct. The white external 
marginations of the ends of the rectrices appear to be of about 
the same extent in both specimens. 
The figure (PI. XII.) is an exact copy of Dr. Heuglin's original 
figure of Hypotriorchis castanonotus , which accompanied his de¬ 
scription of the bird as already given in ‘ The Ibis' (1860, p. 407). / 
It represents, according to him, an adult male, two-thirds of the 
natural size. Dr. Smith, in his f Illustrations of the Zoology of 
South Africa,' has figured the female of Polihierax semitorquatus; 
but this is, I believe, the first published representation of the 
