302 
FAI.CONID.ffi. 
into the broad sternum and its deep keel. The 
clavicles are also strong, and the os furcatorius, 
which is circular, broad and strong, affords a firm 
support to the shoulders.* The bill, having a 
strong tooth in the species most truly rapacious, 
is really a tearing instrument, as much so as 
the powerful canines of the Felidae. The legs 
and feet possess immense muscular power, and 
the claws, remarkably sharp, are also retractile, 
(though by a different process,) as among their 
feline representatives. The intestinal canal and 
digestive organs present gradations between the 
membranous pouch of the true birds of prey, to 
the muscular gizzard of other orders, according 
to the food they particularly select, f and the 
former is comparatively short and wide, or narrow 
and very lengthened ; the latter modification is 
seen in those which prey on fish, and thus, to a 
certain extent, those species agree in proportions 
with the digestive canal of the Ichthyophagous 
Feraa.J 
In the language of the natural system, the 
Falconid® are separated into Typical, Subtypical, 
and Aberrant groups, all of which are so far 
represented by the birds in our own country ; 
* See some interesting remarks on the anatomy of 
birds of prey by Mr Yarrell, Zool. Journal, No. X. 
p. 151. 
t Yarrell, 1. c. 
t See paper by Mr Macgillivray “ On digestive organs 
of birds,” in Mag. of Zool. and Bot. vol. i. a. 125. 
