54 Philippine Journal of Science " 19 



portions of which are upon the usual ornithic plan of the aqui- 

 ime pes, with the osteological characters I have often described 

 before, of existing forms as well as of fossil eagles. 



CONCLUSIONS 



Coming to the relationships of Pithecophaga jefferyi, with 

 respect to other representatives of the same group and in the 

 light of the osteological material above described and compared 

 with its skeleton, I am of the opinion that its nearest ally, in 

 so far as we are at present acquainted with the morphology ■ 

 of other eagles, is the harpy eagle (Thrasaetos harpy ja) . 



Sharpe 2 makes a very different disposition of this species ; 

 he places it between Circaetus and Spilornis, of the Aquilinse 

 (Subfamily V) ; while the harpy eagle we find arrayed with 

 the Buteoninae (Subfamily III), following Harpy opsis, the next 

 following Subfamily (IV) being the Gypaetinae (Gypaetus bar- 

 batus) . The osteology of Pithecophaga surely does not support 

 this arrangement. 



PREVIOUS PAPERS BY THE AUTHOR ON THE OSTEOLOGY OF THE 



EAGLES AND THEIR ALLIES 



[Papers on the owls and the vultures are not Included-] 



1. On the ossicle of the antibrachium as found in some of the North 



American Falconidae. Bull. Nutt. Orn. Club 6 (1881) 197-203. 



2. On the free post-pubis in certain of the Falconidae. Auk 3 (1886) 133, 



134. 1 text figure. 



3. Osteology of Circus hudsonius. Journ. Comp. Med. and Surg. 10 (1889) 



126-159. 17 text figures. 



4. A peculiar character referable to the base of the skull in Pandion. 



Auk 8 (1891) 236, 237. 



5. Some comparative osteological notes on the American kites. Ibis VI 



3 (1891) 228-232. 



6. On a collection of fossil birds from the Equus beds of Oregon. Am. 



Nat. 25 (1896) 303-306. Plates. 



7. Fossil birds from the Equus beds of Oregon. Am. Nat. 25 (1891) 



818-821. 



8. Tertiary fossils of North American birds. Auk 8 (1891) 365-368. 



9. A study of the fossil avifauna of the Equus beds of the Oregon Desert. 



Journ. Acad. Nat. Sri. Philadelphia 9 (1892) 389-425, pis. 15-17. 



10. On cases of complete fibular in existing birds. Ibis VI 6 (1894) 361-366, 



figs. 1, 2. 



11. Some of the "outliers" among birds. Pop. Sci. Monthly 44 (1895) 



760-780. 10 text figures (not osteological). 



12. On the affinities of Harpagornis. Trans. New Zealand Inst. 28: 665. 



13. Observations on the classification of birds. Proc. Acad. Nat. Sci. 



Philadelphia (1898) 489-499. Illustrated. (Osteology largely used.) 



1 A Hand-list of the Genera and Species of Birds. London 1 (1899) 265. 



