BIRDS OF PREY. CVMINDIS. 
309 
{quelque analogie) with those birds on account of the 
nakedness of its face and throat ; thus investing analogy 
with the same meaning as affinity. . Its whole struc- 
ture, indeed, shows that it has very few of the raptorial 
characters ; and we accordingly find, by the relation of 
travellers, that it feeds as much upon fruits and seeds, 
as upon insects and small reptiles. 
(250.) The types we have now retained in the Aqui- 
hne circle are four ; viz. Pandion, Harpyia, Aquila, and 
Ibycter. Of these we consider the first to represent 
the aquatic, or fissirostral, type ; the second and third 
are the typical and sub-typical ; while every ornitholo- 
gist must perceive in the relation we have just given of 
Ibycter, that it is the representative of the gallinaceous 
order, — in other words, the rasorial type ; while Astu- 
rina, as before hinted, may possibly occupy the tenui- 
rostral station. 
(2.51.) We enter the genus Cymmdis, or the mil- 
vine division, by means of Polyborus, a South Ame- 
rican group, so closely allied to Ibycter that, until we 
had personally examined and studied both, we were 
ted to believe they were only modifications of the 
same subgenus.* There is a remarkable part of the 
structure in Ibycter, which neither M. Vieillot, who 
first proposed the genus, nor those w'ho have followed 
him, have taken any notice of. In all the preceding 
types of this family we have examined, the hinder 
toe (with its claw) is equal in length to that which is 
the interior, or the difference is so very slight as scarcely 
to deserve mention ; but in Ibycter this structure is 
not seen : the hallux, or hind 
toe {fig.lOZ. a), is consider, 
ably shorter than the other 
(i) — a further proof of 
this genus being the rasorial 
type of the aquiline circle ; 
for every ornithologist knows that this disproportion is 
eminently conspicuous throughout the whole of the gal. 
• Zoological Illustrations, ii. pi. L 
X 2 
