406 CONDOR. 
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 subdivi- 
sions, on the different conformation of the nostrils, on the 
tongue, aculeated on its margin in Gyps, and not in Agypius, 
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 Vuléwr 
divided into two very natural subgenera, corresponding to the 
two genera of Vieillot, Vultur (comprising ten species) and 
Neophron (comprising but two), the first being subdivisible 
into the two minor. groups of Savigny. The three might in- 
deed be considered as co-ordinate subgenera. 
As for the genus Cathartes, it is by no means so easy to 
divide, and the two groups or subgenera which we admit are 
perhaps artificial and blended too much together. The first, 
comprising the condor, the Californian condor, and the king 
vulture, that is, the stowt-billed American vultures, may be 
called Sarcoramphus, a name confined by Duméril and Cuvier 
to those that have caruncles or fleshy appendages on the head, 
but to which Vieillot very justly added C. Californiaius, call- 
ing the group Gypagus. 
The second subgenus of Cathartes may be called Catharista, 
Vieillot, or the slender-billed American vultures, analogous 
in a parallel series, where the strength of the bill is considered, 
to the Percnoptert, but having no immediate affinity with 
them. The only known species are the two of Wilson’s work, 
Cathartes aura, and Cathartes iota of my Synopsis, the former 
of which is a link between its own group and the preceding. 
The best discriminating mark between the two principal 
genera of this family, one which is obvious and easily under- 
stood, is the striking character of the perviousness of the 
nostrils in Cathartes, through which light appears broadly 
from one side to the other, while in the vultures they are 
separated by an internal cartilaginous partition, This will 

