Genus— H lERAAETUS. 
Hieraaetus Kaup, Classif. Saugeth. ii Vogel, p. 120, 
1844 . . . . . . . . . . . . . . Type H. pennatus. 
Also spelt — 
Hiera'etus Kaup, Mus. Senekenb., Vol. III., p. 260, 1845. 
Hieracaetus Agassiz, Index Univers., p. I8l, 1846. 
Jercetus Kaup, Archiv. furNaturg., 1851, p. 89. 
HieroaUus Gray, Cat. Gen. Subgen. Birds, p. 3, 1855. 
leraetw Gray, Handl. Gen. Sp. Birds, Vol. I., p. 12, 1869. 
Eutolmaetus Blyth, Journ. As. Soc. Bengal, Vol. XIV., 
p. 174, 1845 . . . . . . , . . . . , Type H. bonelU. 
Also spelt — 
Tolma'etus Blyth, i6.,Vol. XV., p. 5, 1846. 
Vtolmaetua V^tlock, Emu, Vol. IX., p. 190, 1910. 
Butaetus Blyth, Joum. As. Soc. Bengal, Vol. XIV., p. 174, 
1845 . . . . . . . . . . . . , . Type H. pennatus. 
(Not Butaetes Lesson, Traite d’Orn., 1830, p. 83.) 
Pseudaetus “Hodgs. 1844” Bonaparte, Rev. Mag. Zool. 
1854, p. 531 . . . . . . . . , . . . Type H. honelli. 
Asturaetos Brehni, Naumannia 1855, p. 26 . . . . Type H. honelli. 
Aquilastur Brehm, AUg. Deutsche Nat. Zeit., N.F., 
Vol. II., p. 53, 1856 . . . . . . . . . . Type H. honelli. 
Small Aquiline birds with short bills, long wings, long tail, rather long 
feathered legs and short toes. 
The bill is short with a rather large cere, in which the oval nostrils, 
which show internally a bony process, are perpendicularly obliquely placed ; 
the lower edges of the upper mandible show little sinuation. 
The wing is long with the first primary short, the fourth longest ; the 
second is about equal to the sixth, while the third and fifth are subequal and 
little less than the fourth. 
The long tail is square and more than half the length of the wing. 
The legs are long, the tarsus measures about one-third the length of 
the wing and is feathered right down to the toes. The toes are normal, 
and short in comparison to the length of the tarsus. 
For many years this genus was known under the name of NisaUus, but 
it was shown before I published my “ Handlist ” that that name had been 
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