﻿EXTERNAL ANATOMY. SCANSORIAL FEET. 143 



hatches, of equal length to the middle one ; yet it is 

 even of greater power than in these latter birds, for 

 towards the end of the claw there is a small notch, 

 apparently intended to give an additional supporting 

 power to the hallux, this notch being constructed for the 

 purpose of resting upon the bark, in like manner as the 

 point itself: there is a very slight tendency to this 

 structure, almost imperceptible, in our common nut- 

 hatch ; but it has never been noticed, and probably 

 would not have been now observed, had not our atten- 

 tion been drawn to it by finding it so conspicuous in 

 the Brazilian bird. Having now described the foot of 

 Sclerurus, the rasorial genus of the circle of Certhiance, 

 the ornithologist will be better prepared to understand 

 the next modification, as seen in 

 the Australian genus Orthonyx 

 {fig- 77.)- Let him imagine, 

 therefore, a bird rather larger 

 than a sparrow, but with the 

 general form and proportions 

 of the Menura, except in the 

 tail, which is that of Scleru- 

 rus. Like Menura, the bill (a , a) 

 is short, arched, and rasorial, 

 the wings rounded, and the feet 

 enormously large and strong. The relative length of the 

 toes (6) is altogether peculiar ; the outer one is actually 

 longer (in a slight degree) than the middle, while the 

 two outer claws (unusually slight in their curvature) 

 are one-third as long as the toes ; the hallux is as long- 

 as the middle toe, but one-half its length is occupied by 

 the claw. Now we think it quite obvious that claws, 

 so constructed, were never intended to be used for 

 ascending trees, and yet the rigidity of the tail would 

 imply that this most singular bird feeds in a semi- 

 perpendicular attitude, for if otherwise, such a tail 

 could be of no use. Our specimen confirms this sup- 

 position, for the ends of the feathers, or rather the 

 Webs, are much worn away. We hazard the conjecture, 



