108 
ON THE CLASSIFICATION OF BIRDS. 
these horny points will enter into crevices and inequali- 
ties of the bark, which the more thickened tips of 
the woodpecker’s quills would glide over. A third 
modification is seen in the tail of our common creeper 
{Certhiafaniiliaris), where the form of the feathers is 
unequally lanceolate (fig. 55. c) ; that is to say, they gra- 
dually taper to a point ; but the inner web is near four 
times the breadth of the outer, the webs themselves 
being continued to the very tip of each feather : the 
shaft also is neither enlarged, or is it near so rigid, as in 
the preceding group. The next variation of the scan- 
sorial structure is peculiar to the Brazilian genus Selerurus 
(fig. 56. d) and the Australian genus Orthonix (c); two 
lorms,iuhabiting different regions, but which are unques- 
tionably united by the closest affinity : both have the 
shaft of each tail feather nearly as rigid as that of the 
Vendrocolnpti, but the webs are particularly broad and 
soft : and although, from being worn away towards the 
tips, the shaft appears to be naked at that part, it is not 
so in reality, since vestiges of die webs may be traced 
on both sides, nearly to the extreme point. Now this 
remarkable breadth and softness of the webs, leaves us in 
no doubt that each of these genera are the Rasorial types 
of their own proper circles, the one entering into that 
of the Certhiance, the other into the Suphagince. Lastly, 
we have the genus Lochmia*, where the scansorial tail’ 
• The only species yet known is the Lochmia 
the Birdi of Br axil ^ pi 33. 
squamulataf figured in 
