164 



and indeed very often of opportunity for close in- 

 vestigation, has given rise to several errors among 

 writers on Ornithology, and has caused great con- 

 fusion, and a consequent incorrect multiplication, 

 of species. The gradual increase of knowledge, 

 in this, as well as other branches of Zoology, and 

 the labour of several recent Naturalists (among 

 whom stand prominent the names of Temminck 

 and Montagu), have, however, essentially contri- 

 buted to the development of these singular and 

 unexpected changes of plumage, and cleared up 

 many of the doubts and difficulties, in which the 

 history of several species had been so long in- 

 volved. By many modern Ornithologists, five 

 subordinate divisions or subfamilies, have been 

 recognised in the Falconidce ; viz. AquilincB, Ac- 

 cipitrinw, Falconina, Bute'oninw, and MilvitKE, 

 which again are divisible into groups of still less 

 amount, constituting the genera of the present 

 work, and all forming a circular series of affinities 

 within themselves. Of these Subfamilies, the 

 Accipitrince and Falconinae, are the typical forms, 

 possessing peculiarities of structure, habits, &c, 

 which either do not exist, or become modified in 

 the others. 



" Subfam. I, AQUILINJE. 



" The distinguishing characters of this Subfami- 

 ly, consist in superiority of size, in having the bill 

 longer and straighter at the base than in the typi- 

 cal Falcons, in which respects they approach nearer 

 to the Yulturine Family ; the feathers of the crown 

 of the head and neck are narrow and sharp-pointed, 

 and in some subjects the head and throat are found 

 partially naked. Their limbs are generally short 

 and muscular, and their talons very strong and 



