1916] 



Miller: Vulturid Raptors from Rancho La Brea 



109 



period of years. During this time the problem has been taken up, 

 worked out, and then laid aside many times. During each interval, 

 many specimens of the tarsometatarsus of Pleistocene eagles have been 

 examined, amounting in all to some thousands. In each case the same 

 conclusion has been reached, i.e., that the tarsometatarsus of Neogyps, 

 instantly recognizable among many specimens of varied species, pre- 

 sents a markedly vulturid aspect. Only after such mature considera- 

 tion, strengthened by the occurrence of another vulturid, Neophron- 

 tops, in the same horizon, is the final and constant conclusion 

 announced. Neogyps is either a true vulturid or else an approximation 

 to that group due to convergent modification. 



The general impression made by the tarsometatarsus is of a stockily 

 built bird with a general resemblance to Gypaetus, though less in size 

 than Gypaetus barbatus. With the exception of the immediate region 

 of the anterior openings of the proximal foramina, the contours of 

 the bone are less rugged than in Gypaetus ; the antero-external angle 

 of the shaft is less sharp ; the trochleae are less distinctly set off from 

 the shaft and are less profoundly grooved ; the outer hypotarsal ridge 

 is less developed. All these are characters which, in general, dis- 

 tinguish the vulturids from the more predaceous raptores, evidences 

 of degeneracy wherein Neogyps seems to have exceeded Gypaetus 

 barbatus. 



Table of Measurements op a Series op Fourteen Specimens op the 

 Tarsometatarsus of Neogyps errans 





Type 



Average 



Length, intercotylar tuberosity to extreme convexity of 







middle trochlea 



88.0 mm. 



87.8 



Transverse diameter of head 



19.6 



19.6 



Transverse diameter through trochleae 



22.6 



22.4 



Intercotylar tuberosity to center of papilla of tibialis anticus 



20. 



20.1 



Ratio of power arm to resistance arm 



22.6% 



22.8% 



Transmitted August 15, 1915. 



