42 , RAPTORIAL BIRDS 
Several species of these three genera which we 
possess are birds of considerable rarity, amongst which 
we may particularly mention the type specimens of 
Buteo fuliginosus, figured iv the transactions of the 
Zoological Society, and the type specimen of Zachy- 
triorchis zonocercus, which has been also figured there, 
as well as subsequently in Mr. D. G. Elliot’s recent 
folio work on the Birds of North America. 
Another species which our Museum possesses, and 
which, like Buteo fuliginosus. and Tachytriorchis zono- 
cercus, is a native of the most southerly countries of 
North America, may also be mentioned as being, not 
only very rare, but also very conspicuous for the 
beauty of its snow-white plumage. This handsome 
Buzzard bears the name of Leucopternis ghiesbreghtiz, 
given to it in honour of its discoverer Auguste Ghies- 
breght, a Belgian naturalist, who first obtained this 
species in Southern Mexico, not far from Vera 
Cruz. | 
Leaving the Buzzards, we now arrive at two genera 
composed of birds which appear to form a link be- 
tween the Buzzards and the Hawks, and which there- 
fore may with propriety be termed Buzzard-Hawks. 
The first of these genera, Poliornis, is limited to 
Eastern and South-eastern Asia, and the neighbouring 
islands, with the exception of one species, which is a 
native of Abyssinia, and the adjacent countries of 
Africa. 
The second genus, Asturina, is composed of various 
