FALCOJXIDiE — THE FALCONS. 



321 



and rounded underneath almost as much as in Pandion ; but the other spe- 

 cies are less so, eacli diflering in this respect, so that I consider this as only 

 indicating the greatest perfection in the specialization of the piscatorial type 

 of modiiied structure. In the jiossession of fourteen tail-fcatliers, its very 

 large bill, naked lores, and general aspect, the H. j^elaijkus shows an ap- 

 proach to the Old World Vultures. 



About nine species are known, of which only two belong to North Amer- 

 ica, one of them [H. Icucocrphalus) being peculiar to that continent. Tropical 



525U9 : 9128. Haliaetus leucocephalus. 



28100. H. jitlagicus. 



America is without a single representation of the genus. The majority of 

 the species belong to the Indian region, only the IT. alhicilla and H. pelagicus 

 belonging to the Palajarctic Realm, the former representing the western, and 

 the latter peculiar to the eastern, district of that zocigeographical division ; it 

 is the former whicli straggles into the N"earctic fauna. The habits of the 

 Sea Eagles differ considerably from those of the true Eagles {Aquila) in very 

 important respects ; they frequent the shores of the sea, lakes, or large rivers, 

 instead of mountainous portions, and feed chiefly — some of the species 

 entirely — on fisli. Tliuse of the subgenus Polioaetus are almost precisely 

 like Pandion in their habits. 



VOT,. III. 41 



