144 ON THE CLASSIFICATION OP BIROS. 
in the absence of all information upon the subject, that 
the habits of Orthonyx are terrestrial, that it is, essen- 
tially, a walking bird, but that it seeks its food not so 
much upon the barks of trees, as upon steep earthy 
banks, into which its unusually straight claws could 
penetrate, and against which the bird may be supported 
by its tail ; it is also highly probable that these strong 
claws are used for scratching the ground, after the 
manner of most rasorial birds. At all events the dis- 
covery of Sclerurus establishes that link between Den- 
droeokiptes and the bird we have been describing, 
without which we could hardly have guessed on the 
situation of either. Both, however, are thus seen to be 
types of the Jt/inoms, one in the circle of the Certhiance, 
the other in that of BuphngiruB. 
(12.5.) The genus Buphaga, known by the common 
name of beef-eaters, has been by all naturalists placed 
with the starlings, merely, as it would seem, because 
like them they are often seen on the backs of the 
African cattle, clearing them of Acari and other trou- 
blesome insects. This error of arrangement has entirely 
arisen from ignorance 
of the different forms 
which belong to the 
scansorial structure of 
foot. We may admit 
this fact in its econo- 
my, and yet deny that 
Buphaga { fig. 78.) is 
any other than a scan- 
sorial genus. This is evident from its remarkably broad 
and unusually curved claws, more resembling hooks than 
those of any bird out of the raptorial circle. Now it is 
very remarkable that in all the specimens we have seen 
of this bird, however old, not one has occured in which 
the points, which are remarkably fine ami sharp, have 
been at all worn : we hence infer that they are not 
used upon any substance hard enough to blunt their 
acuteness ; the hard bark of trees would unquestionably 
