MONOGRAPH OF THE FALCONID/E, 
I assign the third rank to the Brachypteri , because among them we 
find very tall forms, imperfect wings unfit for flying, three toes, and 
a large number of ribs. — (Uria.) 
Among the Gallince, I give the third rank to the Crypturidce as 
a family, because they have the nostrils towards the tip of the bill, 
imperfect wings, and little power to fly, the legs and feet more per- 
fect for running, with 3-4 toes, long necks, and but a scanty de- 
velopment of the tail. 
Applying these analogies to the Accipitres , we observe that the 
Gypogeranidce , Bonap., represent obviously the Grallatorial type,* 
by a long heron-like feathered neck, stiff bristling eye-lashes, indif- 
ferent use of the wings, extremely long tarsi, with very short toes, 
and feeding on reptiles. 
Among the Falconidce tve see the Geranopus (F. gracilis, T.), 
analogous to the JBrevipennes and Gypogeranidce, by a meagre tall 
figure, long neck, high scaly tarses, exterior toe very short, by their 
plumage, and probably also by their way of living. 
This genus gives to itself as genus, and to all Accipitrince as sub- 
family, the third rank. Among this subfamily w r e generally find 
very short wings, whereas the legs and feet are more perfect, and 
are sometimes furnished with enormous claws, as, for instance, the 
Spmaeti , and the subgenus Thrasaetur in the genus Asturina. 
The analogies collected or deduced from the Grallatores , Gypo- 
geranidce , and Accipitrince , viz., from the structure of their wings 
and feet, from their mode of living, aptness for running, building 
their nest on the ground, &c., give to the corresponding genera of 
the other subfamilies of Falconidce the third rank. 
Thus Harpagus assumes the third rank among the Falconince, 
from the structure of the wings, tarsi with transverse scales, and 
short toes. In like manner Circus does among the Milvince , from 
the structure of the wing, long tarsi, with transverse scales, short 
toes, partly feeding on reptiles, building their nests on the ground 
or among reeds, and swift running. 
Circaetes represents the third genus among the Aquilmce, on 
account of showing the longest tarsi in proportion to extremely 
short toes, and from running on the ground, feeding on amphibia, and 
* ^ ^is family, in like manner as of the Gypaitidce, I suppose that all mem- 
bers have perished but one. 
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