1912] Miller: Pacific Coast Avian Palacontology 95 
more intimate relationships of the forms are not discussed by 
the authors. 
List OF SPECIES ASSIGNED TO THE SUBORDER FALCONES THAT ARE KNOWN 
ro Occur AS Fossits IN NorrH 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 leueurus (Vieillot), Rancho La Brea. 
Cireus hudsonius (Linnaeus), Rancho La Brea, Fossil Lake. 
**Cireus sp. (smaller than hudsonius), Rancho La Brea. 
Aquila chrysaétos (Linnaeus), Rancho La Brea. 
*Aquila sodalis Shufeldt, Fossil Lake. 
*Aquila pliogryps Shufeldt, Fossil Lake. 
*Aquila dananus Marsh, Loup Fork. 
Haliaétus leueocephalus (Linnaeus), Rancho La Brea. 
**Morphnus woodwardi Miller, Rancho La Brea. 
**Geranoaétus grinnelli Miller, Rancho La Brea. 
**Geranoaétus melanoleucus Auct. (?), Hawver Cave. 
**Geranoaétus 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. 
Faleo peregrinus Tunstall, Raneho La Brea, Potter Creek Cave. 
*Faleo, sp. (smaller than peregrinus), Rancho La Brea. 
Faleo sparverius Linnaeus, Rancho La Brea, Samwel Cave and Potter 
Creek Cave. 
**Polyborus tharus Auet., 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 
