108 



University of California Publications in Geology 



[Vol. 9 



Tibiotarsus, cotype no. 22403, Univ. Calif. Col. Vert. Palae.— The 

 tibiotarsus of the asphalt species is almost absolutely identical with 

 that of Neophron except that the shaft is slightly more slender and 

 the cnemial crest more prominent. The tunnel under the osseous 

 supratendinal bridge is similarly small and quite in keeping with the 

 weakness of the flexor tendons. The furrow leading to this tunnel 

 is almost obsolete, more so even than in the American Cathartes. The 

 intercotylar depression is practically identical with that of Neophron. 

 On the inner face of the inner condyle occurs a rugosity marking the 

 attachment of articular ligaments. This rugosity is raised to a tubercle 

 in the active raptors, is less in Neophron and is least in Neophrontops. 

 Seen from the proximal end the two bones show an identical pattern. 

 From the rear the same holds true. 



Humerus. — This bone in the fossil species is practically identical 

 with that of the Recent Neophron. Size, curvature, condyles, muscle 

 scars are almost as nearly alike in the two bones as though they had 

 been taken from the same individual. Certainly no tangible difference 

 is noticeable to the writer. 



Judging from the remains thus far identified, Neophrontops 

 americanus must have been a vulture of about the same size and build 

 as Neophron ginginianus. The habits in feeding must also have been 

 fully as far removed from the truly rapacious as in the case of the 

 living bird. 



The factor of error in referring the several segments here discussed 

 to the same species is reduced to a minimum by the close resemblance 

 of all the segments respectively to the corresponding parts of the 

 skeleton of Neophron and by the repeated occurrence of the various 

 segments together in the same section of the asphalt excavation. 



NEOGYPS ERR AN S, n. gen. and sp. 

 Type specimen no. 22401, Univ. oalif. Col. Vert. Palae. From the asphalt beds 

 of Rancho La Brea 



Tarsometatarsus. — Slightly smaller than the minimum of Aquila 

 chrysaetos, but general proportions much the same as in that species. 

 The contours much less rugged; papilla of the tibialis anticus more 

 rounded and knob-like and placed higher on the shaft ; distal trochleae 

 and outer ridge of the hyptotarsus weaker than in Aquila. 



Assignment of the genus Neogyps to the family Vulturidae is a 

 step which has been taken only after deliberation extending over a 



