450 Mr. N. A. Vicons on the Natural Affinities 
the deficiency, accompanied by a corresponding weakness of 
the whole member, is real, and of sufficient consequence to de- 
prive the bird of the means of using its legs and feet to advan- 
tage. The force and powers of these parts are in fact trans- 
ferred to the wings, which are thus endowed with a more than 
usual share of strength, in order to afford the bird a more than 
usual assistance in the aerial mode of seeking its food which it 
is assigned by Nature. In the Buceros, on the other hand, the 
gressorial feet are accompanied by a superior robustness, which 
counterbalances their inferiority in form. And hence the family 
may consistently maintain its station in the vicinity of the more 
perfectly formed and typical groups of the Insessores, which 
are now before us. ‘The tendency, already observed, which 
opposite points of the circle in which a series of affinities is 
united have to approach each other, accounts for the resem- 
blance here pointed out between these otherwise discordant 
groups, and serves to explain the reason why the analogous 
relation between them has been mistaken for a relation of affi- 
nity by systematic writers, so far as to induce them to arrange 
all the gressorial birds in one connected group. Besides the 
genus Buceros, Linn., the protuberance on the bill of which 
varies in almost every possible shape in which fancy can embody 
it, the present family includes the Momotus of M. Brisson, 
which accords with the entire of that genus in its gressorial feet, 
and with several species of it, as the genus now stands, in its 
curved but somewhat shorter and more attenuated bill. 
The family of Loziade, the extreme of the tribe of Conirostres, 
exhibits a conformity to the groups we have just quitted, in the 
strength and grossness of their bill. Inferior to them chiefly 
in size, some species of the family may be observed to equal 
cven the Hornbills, allowance being made for their relative pro- 
portions, in the extreme enlargement of this member. ‘The 
curved and serrated bill of the latter family, perceptibly shorten- 
ing 
