S92 ON THE TOXGUE ETC. OF THE AMERICAN VULTURES. [DeC. 1. 



edge of the iipper lamella, which forms the joint, is neatly rounded 

 off instead of i^rojecting irregularly as in Gypagus. These 

 points will be better understood after an inspection of the accom- 

 panying drawings (text-figs. 46-48). It will be seen that my 

 reading of the facts differs slightly from that of Mr. Pycraft. 

 Articular perfection appears to me to have been arrived at both 

 in Cathartes and Sarcorhamphus from a lower stage such as 

 persists in Gypagus. 



On the ventral surface of the skull a very conspicuous difference 

 defines Cathartes on the one hand from Sarcorhamphus and 

 Gypagus on the other. In the two latter birds the basitemporal 

 region is deeply excavated, and the sides are prolonged into very 

 marked exoccipital processes. In Cathartes, on the contrary, 

 this region of the skull is much flatter and there are no such 

 conspicuous lateral processes. The inner lamina of the palatines 

 is hooked and overhanging posteriorly in Sarcorhamphus and 

 Gypagus ; in Cathartes this region of the bone does not over- 

 hang posteriorly and is merely triangular in form. Moreover, in 

 Cathartes the anterior half of the palatine has its broad surface in 

 a plane horizontal, in the other genera it is rotated upwards and 

 is at an angle to the horizontal plane. A final point to which I 

 desire to direct atteiition is illustrated in the accompanying- 

 drawings (text-figs. 46-48). These sketches represent the man- 

 dibles of the three genera under consideration viewed from behind. 

 The relatively, as well as actually, much greater thickness of the 

 internal angle in Sarcorhamphxis and Gypagus will be apj)arent. 



The foregoing account does not at all pretend to be a detailed 

 review of the structure of the skull in the American Vultures. I 

 have economised space by simply dealing with those facts which 

 appear to me to throw light upon the neutral relationships of the 

 genera Sarcorhamphus, Carthartes, and Gypagus. Other facts which , 

 in my opinion, do not bear upon this svibject have been ignored. 

 The result is, I think, to show that the Condor and the King 

 Vulture are comparatively slight variations of the same type, 

 while Cathartes stands equally apart from both, a conclusion which 

 is quite in accord with current ornithological opinion. I think it 

 is going rather too far, as has been done*, to include both the 

 former Vultures in one genus ; but it is, in my opinion, manifestly 

 absurd to combine Cathartes and Gypagus, and to write of 

 Cathartes j^apa, as has also been done t. 



* 'Standard Natural Historj%' Boston, 1885, p. 268. 

 t Tasclienberg, ' Bibliotlieca Zoologica,' v. 1899, p. 3966. 



