284 ON THE CLASSIFICATION OF BIRDS. 
and it must be confessed that if clear conceptions of 
the difference between analogy and affinity are not en- 
tertainedj such a classification has some plausible rea- 
sons to recommend it. The feet, in fact, of the two 
birds, are formed nearly on the same principle ; but, 
then, so are those of OrtlMnyx, a little scansorial bird 
not much bigger than a robin. All three genera, in 
•short, are remarkable for their large disproportionate feet, 
long and slightly curved claws, and the equality of 
length, or nearly so, of the outer and the middle toe. 
It is by instances such as these that we perceive the 
full extent of tho.se unnatural combinations which result 
from founding our notions of classification from one set 
of characters, and forgetting to look at the full conse- 
quences of carrying those notions into extended oper- 
ation. Nor is this the only peculiarity of the New 
Holland vulture ; for, unlike all others of its family, it 
possesses eighteen feathers in its tail. An examin- 
ation of the bill {fiy. 92.), 
which is decidedly rap- 
torial, joined with many 
other considerations, shows 
that aU these are but ana- 
logical relations to the 
Rasores, while the real 
affinities of the bird are 
in the circle of the Ful. 
turid(B, of which it forms the rasorial type. A per. 
feet specimen of this very rare vulture, now before us 
(procured by Mr. Allan Cunningham in the forests ad- 
joining Van Diemen’s Land), enables us to speak of its 
structure from personal examination. 
(235.) The fissirostral type is no less strongly marked 
than is the rasorial. This is exhibited in the bearded 
vulture of the Alps, forming the genus GrypeEtus of 
Storr, the only example yet discovered of this particular 
form. It has the lengthened bill of the vulture, but 
the boldness and rapacity of the falcon family. The 
fissirostral type or form is clearly manifested in its 
