322 CONDOR. 



as many separate genera, namely Gyps, ^gypius, 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 contain? 

 to my knowledge but two well ascertained species, which are the Slen- 

 der-hilled 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 Vxiltur 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 osse- 

 ous structure is found to prevail throughout the numerous species of 

 Falcons. This observation I believe has never before been made. Sa- 

 vigny 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 u^gypius, 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 

 Vieillot, Vultur (comprising ten species), and Neop)hron (comprising but 

 two), the first being subdivisible into the two minor groups of Savigny. 

 The three might indeed 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 Cali- 

 fornian Condor, and the King Vulture, that is, the Stout-billed Ameri- 

 can Vultures, may be called Sarcoramphus, a name confined by Dum^ril 

 and Cuvier to those that have caruncles or fleshy appendages on the 

 head, but to which Vieillot very justly added C. ealifornianus, calling 

 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 Percnopteri, 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 understood, 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 make 

 it at once evident that it was for want of proper exatnination that the 

 Percnopterus, merely on account of its slender bill, was ever considered 



