1912] Miller: Pacific Coast Avian Palaeontology 87 
Other members of the group range as follows: The Andean 
condor (Sarcorhamphus) oceurs along the Cordillera from 
equatorial Peru to the extremity of Patagonia and from  sea- 
level to the highest summits of the Andes; Catharista wrubu 
inhabits the whole of tropical America, southward to Argentina 
and northward as a straggler to the Canadian border; the two 
remaining genera, Gyparchus and Gymnogyps, occupy succes- 
sively more cireumseribed areas. Not, however, till the latter 
was so nearly exterminated by human ageney, was either form 
of restricted range. Gymnogyps is confined entirely to the 
Nearctic realm, Sarcorhamphus is entirely Neogaeic, but the three 
remaining forms are distributed without regard to realm and 
all are independent of the generally recognized life-zones. — That 
a group thus distributed, many of whose members are so in- 
dependent of climatie and of minor geographic barriers, should 
be limited to the western hemisphere seems indeed strange. 
The influence of a virile and aggressive species is not infre- 
quently effective as a barrier to the distribution of a less active 
one and it may be urged that the slightly more rapacious vul- 
turines of the Old World have served as a check upon any ten- 
deney of the eathartids to diffuse into Eurasia. Such a view is 
controverted by the fact that the latter birds prove themselves 
perfectly able to maintain their existence in competition with 
the polyborine scavengers which, in a way, represent the Old 
World vultures in their habits. 
With the geographical limitations of the group before us, the 
question of aneestry and the geological record assume a very 
important aspect. 
Concerning the antiquity of the group there is unfortunately 
but little known. Previous to the opening up of the Rancho La 
Brea deposits in California, fossil cathartids of unquestionable 
identity were unknown to North America. Cope’s Palaeoborus 
umbrosus* from the Pliocene of New Mexico, which he orig- 
inally placed in the genus Cathartes, he later transfers to the 
genus Vultur. The new genus Palaeoborus was established by 
“ec 
Coues for its reception since . . . the deseription and figures 
21 Cope, E. D., U. S. G. Surv. W. of 100th Merid., vol. 4, pt. 2, p. 287, 
1876. 
