﻿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 

 ( Certhia familiaris), where the form of the feathers is 

 unequally lanceolate (fig. 55. e) ; 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 Sclerurus 

 (fig. 56. d) and the Australian genus Orthonix (c); two 

 forms, inhabiting 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 

 Dendrocolapti, 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 the 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 CerthiancB, the other into the Buphagince. Lastly, 

 we have the genus Lochmia*, where the scansorial tail 



* The only species yet known is the Lochmia squamulata, figured in 

 the Birds of Brazil, pi. 33. 



