Genus— E RYTHROTRIORCHIS. 
Erythrotrioechis Sharpe, Proc. Zool. Soc. (Lend.) 1875 
(Aug.), p. 337 . . . . . . . . _ _ Type E, radiatus. 
Small Aquiline birds with short bills, long wings, long tail, short stout legs 
and strong feet. 
The heavy build of this bird has caused trouble with regard to its 
systematic location, and until careful anatomical examination is made it will 
remain a puzzle. 
It was referred to Astur, but Sharpe in 1874 referred it to the Buteoninas 
under the name, used generically, of Urospizias. 
Sharpe’s definition of his subfamily ButeoninaB (Cat. Birds Brit. Mus., 
Vol. I., p. 158, 1874) reads : “ Outer toe only connected to middle toe by 
interdigital membrane ; tibia much longer than tarsus, exceeding it by more 
than the length of hind-claw. 
“I have done my utmost to secure the exact relative dimensions of 
these two bones, but the scantiness of osteological material renders positive 
identification in many cases impossible. At any rate, the probability that 
some genera placed by me among the Buteoninae may some day be found 
to belong to the Accipitrinae only proves the truth of Professor SundevaU’s 
remark that the two subfamilies are hardly separable (Av. Tent., p. 107).” 
Sharpe’s definition of his subfamily AccipitrinaB may be here given as 
a contrast (p. 46). 
“ Outer toe connected to middle toe by an interdigital membrane ; 
tibia and tarsus to all intents equal in length, the difference between them 
not so great as the length of hind claw.’’ 
Such a distinguishing character would never have occurred to me, as it 
must be so obviously artificial. I would have ignored even the criticism of 
such a valueless feature, but as the refutation of the diagnosis as applicable 
to the present species has been published, I here quote it. 
Austr. Mus. Cat, no. 4, gives the following data : 
p. 19. Adult male. Tibia 3.94, tarsus 3, hind claw along the curve 
1.35j across the curve 1.15 inch. 
p. 20. Adult female. Tibia 4.34, tarsus 3.3, hind claw along the curve 
1.8, across the curve 1.4. 
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