RAPTORES — BIRDS OF PREY. 3 



than 450, are valid species, the others ranking as geographical races, or are 

 synonymous with others ; of this number about 350 nominal species are 

 accredited to the Old World. America, however, possesses the greatest 

 variety of forms, and the great bulk of the Old World llaptorial fauua is 

 made up chiefly by a large array of species of a few genera which are repre- 

 sented in America by but one or two, or at most half a dozen, species. The 

 genera Aquila, Spizcctus, Accipitcr, Halimtus, Falco, Circus, Athene, Strix, and 

 Butco, are striking examples. As regards tlie number of peculiar forms, 

 America is considerably ahead. 



