BIRDS OF PREY. FALCONS. 289 
and many others of lesser note, deterred us, some years 
ago, from attempting any classification of the Falconidce, 
when treating of the North American species discovered 
on the Arctic expeditions ; rather choosing to prosecute 
further inquiries, and collect additional materials by slow 
degrees, than to adopt a circular arrangement of the 
family; which arrangement, although we may know it to 
be erroneous, we may be unable to rectify in a satisfactory 
manner. With this decision, which was then thought 
to be somewhat fastidious, we have now reason to be 
satisfied. In the following distribution of the family, 
we trust to have placed the primary types upon that 
sure basis which reposes both upon affinity and analogy ; 
so that some advance, at least, will he made towards a 
more natural disposition of the family, and, by indi- 
cating what appears to us the true station of some of the 
minor groups, a clue will be furnished by which the 
validity of the genera and subgenera not here adopted 
may be more correctly ascertained. 
(239.) The three primary divisions of the Fal- 
coNiDAi are characterised by the following peculiarities. 
The first contains the true falcons, having a deep and 
sharply angulated tooth (which is often divided into 
two) near the tip of the upper mandible : these compose 
the restricted genus Fako. The second is composed 
of the hawks, wherein the tooth just mentioned is not 
apparent, or rather it assumes a form of a rounded 
projecting lobe, or festoon, towards the middle of the 
margin : the shape of the bill, however, in other re- 
spects, is the same ; that is to say, it is short, high, and 
eurved from the base : the wings are also more rounded 
than those of the true falcons, but both groups agree in 
having the tarsus fully developed. To these birds we 
retain the generic name of Accipiter, originally given 
exclusively to them by our great countryman, Wil- 
lughby. The third, which is tire aberrant division, is 
characterised, as a whole, rather by negative than positive 
characters. The bill is weaker, less curved, and more 
straight at its base ; it is never toothed, and seldom 
V 
