CONDOR. 
7 
to what we consider the principles of Illiger, as they certainly 
are the dictates of reason, it so happens that this genus Cathartes, 
as is often the case, is found to correspond to a geographical 
division, being exclusively American, whilst that of Vultur is in 
like manner confined to the old continent. The other genera 
which have been proposed among the Vulturidas may be considered 
as groups of secondary importance. 
Thus the three European species* belong, according to Savigny, 
to as many separate genera, namely. Gyps , JEgypius, and Neophron. 
The last, restricted to its proper limits, is a very well marked 
subgenus, which we adopt under the name of Percnopterus, Cuvier. 
It contains to my knowledge but two well ascertained species, 
which are the Slender-billed Vultures of the old continent. 
The other European Vultures, with stout bills, are comprised 
in my subgenus Vultur , composed of ten well known species. But 
we must confess that the Vultur cinereus and Vultur fulvus differ 
materially, and that even their skeletons present differences that 
in other cases might be considered as even more than generic, 
while one uniform osseous structure is found to prevail throughout 
the numerous species of Falcons. This observation I believe has 
never before been made. Savigny founded his groups, which are 
excellent as subdivisions, on the different conformation of the 
nostrils, on the tongue, aculeated on its margin in Gyps, and not 
in jEgypius, and on the number of tail-feathers, which is twelve 
in the latter, as in the American genus, and fourteen in his genus 
Gyps , as well as in Neophron. 
Thus are the twelve species constituting my genus Vultur 
divided into two very natural subgenera, corresponding to the two 
genera of Viellot, Vultur (comprising ten species,) and Neophron , 
(comprising but two,) the first being subdivisible into the two 
* Ruppel reckons four. He makes two of V. fulvus, considering the Chassefimte of 
Le Yaillant a distinct species. 
