1912] Miller: Pacific Coast Avian Palaeontology 95 



more intimate relationships of the forms are not discussed by 

 the authors. 



LIST OF SPECIES ASSIGNED TO THE SUBORDER FALCONES THAT ARE KNOWN 



TO OCCUR AS FOSSILS IN NORTH AMERICA 



Species marked with the asterisk are extinct or are no longer repre- 

 sented in the region. Species marked with the double asterisk are con- 

 sidered to show their closest relationship to forms at present more southern 

 in their distribution. 



Elanus leucurus (Vieillot), Eancho La Brea. 

 Circus hudsonius (Linnaeus), Eancho La Brea, Fossil Lake. 

 **Circus sp. (smaller than hudsonius), Rancho La Brea. 



Aquila chrysaetos (Linnaeus), Rancho La Brea. 

 *Aquila sodalis Shufeldt, Fossil Lake. 

 *Aquila pliogryps Shufeldt, Fossil Lake. 

 *Aquila dananus Marsh, Loup Fork. 



Haliaetus leucocephalus (Linnaeus), Rancho La Brea. 

 **Morphnus woodwardi Miller, Rancho La Brea. 

 **Geranoaetus grinnelli Miller, Rancho La Brea. 

 **Geranoaetus melanoleucus Auct. (?), Hawver Cave. 

 **Geranoaetus fragilis Miller, Rancho La Brea. 



Buteo borealis (Gmelin), Rancho La Brea, Potter Creek Cave. 

 Buteo swainsoni (?) Bonaparte, Samwel Cave. 

 *Buteo, sp. (larger than Archibuteo), Rancho La Brea. 

 Archibuteo ferrugineus (Lichtenstein), Hawver Cave. 

 Falco peregrinus Tunstall, Rancho La Brea, Potter Creek Cave. 

 * Falco, sp. (smaller than peregrinus), Rancho La Brea. 

 Falco sparverius Linnaeus, Rancho La Brea, Samwel Cave and Potter 



Creek Cave. 



**Polyborus tharus Auct., Rancho La Brea. 

 *Palaeoborus umbrosus (Cope), Loup Fork of New Mexico. 

 Accipiter velox (Wilson), Samwel Cave. 



The species of Circus remaining undetermined is a form 

 smaller than the North American C. hudsonius. It is not named 

 in this paper since no opportunity has been presented to com- 

 pare it with the South American species Circus cinereus and 

 C. maculosa. The last two species, it seems, are smaller than 

 C. hudsonius and possibly the asphalt specimens referred to the 

 indeterminate species are of a form identical with the one or 

 the other. 



The material from Rancho La Brea representing Polyborus 

 is abundant and embraces most parts of the appendicular skele- 

 ton and the beak, including the characteristic nareal region. 

 All this material was compared very carefully with the Recent 



