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NEW YORK STATE MUSEUM 



description will apply very closely for these platelets among others 

 of the Cathartidae. 



In contradistinction to the Falconidae and the Old World vul- 

 tures, the members of this family are armed with much more power- 

 ful mandibles, the increased strength lying principally in the greater 

 depth of their rami and consequent breadth of the symphysis, as 

 well as the ponderous articular extremities, that these jaws possess. 



The vacuity, forming such a characteristic feature on the sides 

 of the mandible in so many of the class, is here rarely or never 

 present. In Gymnogyps its location is merely indicated by a 

 shallow slit, that does not penetrate to the bone below, though in 

 G y p a r c h u s papa it does for a limited distance along the base 

 of a similar slit, but in our specimen of Sarcorhamphus 

 g r y p h u s every trace of the locality of the foramen has been 

 obliterated ; again in Cathartes and Catharista narrow and faint 

 groovelets are the sole indicators of its position, or the margins of 

 the elements that originally bounded it. 



Deep pits are found in the centers of the upper surfaces of the 

 articular ends ; these are bounded externally by narrow, longitudinal 

 facets, as do the inturned conical processes support more irregular 

 ones. In the Californian condor there is a predisposition to develop 

 from these articular ends quadrate apophyses behind, but this does 

 not seem to be so much the case in the others. The under surface 

 of either articular end is divided into two by a longitudinal ridge, 

 continuous with the lower ramal border; of these two surfaces, the 

 lesser and outer faces outward and downward, while the inner 

 and larger downward and toward the median plane. 



Almost an unbroken smoothness characterizes the internal and 

 external surfaces of the sides of the jaw ; this is extended to the 

 entire dentary region beyond. Even the ramal borders bounding 

 these surfaces above and below are evenly rounded off, there being 

 scarcely any evidences of the coronoidal projections to interrupt this 

 general smoothness ; it is only in the superior one, for its anterior 

 third on either side, and as it sweeps around the curve of the 

 symphysis, that it becomes sharp, to correspond with the tomial 

 edges of the mandible above. 



The depth of the symphysis in Gymnogyps is about 2 centi- 

 meters, and the deepest part of the jaw, the ramus just beyond the 

 articular ends, is V/2 centimeters ; for Cathartes a . s e p t e n - 

 t r i o n a 1 i s and Catharista U r u b u the measurements are 

 equal. The curve that is continuous with the lower ramal borders, 



