94 University of California Publications in Geology (V0L-7 
deseribed by Shufeldt as distinct from any of the Rancho La 
Brea forms. 
Aquila dananus Marsh*’ is described as being slightly smaller 
than the existing A. chrysaétos. A single specimen of the species 
was taken in the Loup Fork of Nebraska. It consists of the 
distal part of the tibia only and is not figured by Marsh in the 
original description. The assignment of the specimen to the 
genus Aquila is proper in the absence of any feature to dis- 
tinguish it from that genus. The suggestion of the possible 
identity of one of the Fossil Lake forms, A. sodalis, with Marsh’s 
A. dananus is made in Shufeldt’s paper but that author con- 
siders the case improbable on the score of smaller dimensions in 
the former species. Geranoaétus gracilis Miller from the asphalt 
is the smallest of the fossil eagles from California and, as indi- 
cated above, this species is about the same size as A. sodalis Shu- 
feldt. Marsh himself considered the Loup Fork specimen to be 
‘‘nearly as large as the Golden Eagle,’’ in which case A. dananus 
may be considered as probably intermediate in size between 
Aquila chrysaétos (Linnaeus) and Morphnus woodwardi Miller. 
The only other fossil faleonids from American localities out- 
side of California are Cope’s Palaeoborus umbrosus, which 
Lucas*® very properly ascribes to the Polyborinae, and two species 
from South America recorded by the Argentine palaeontologists, 
Moreno and Merecerat.*t Lagopterus minutus Mor. and Mer. is 
the smaller of these two South American species. It is repre- 
sented by an almost perfect humerus which, according to the 
authors describing it, is intermediate between Buteo and Poly- 
borus, with the preponderance of characters relating it with, 
Polyborus. The other species, Foetopterus ambiguus, Mor. and 
Mer., is considered to be intermediate between Buteo and Cath- 
artes, but is assigned by the authors to the Falconidae. The 
28 Marsh, O. C., Am. Journ. Sci., vol. 2, p. 125, Aug. 1871. 
29 Cope, E. D., U. S. Geol. Surv. W. of 100th Merid., vol. 4, pt. 2, p. 287, 
1876. 
30 Zittel, Textbook of Palaeontology, trans. by Eastman, vol. 2, p. 277, 
1902. 
31 Moreno and Mercerat, Palace. Argentina, An. Mus. La Plata, vol. 1, 
1891. 
