260 PROFESSOR OWEN ON THE GENUS DINORNIS. 
groove being bounded by raised margins, sharpest at the outer (fibular) side of the 
groove; these margins, losing sharpness, are continued along the borders of the claw’s 
concavity to near its base. Each claw phalanx shows the lateral vascular grooves. 
That on the inner (tibial) side of the phalanx (Pl. LX. fig. 1 1) is deeper but shorter 
than that on the opposite side (Pl. LXI. fig. 1). 
The proportion of the toes (II, 11, IV), as to relative length, are closely those of the 
species of Dinornis of which the toe-bones are described and figured in the fourth 
volume of the Zoological Society’s ‘Transactions’' (1851). In robustness, or the 
proportion of thickness to length, the toe-bones of Dinornis didinus are intermediate 
between those of Dinornis rheides and D. dromioides. 
From the osseous structure of the foot, especially the strength and curvature of the 
ungual phalanges of the digits 11, 11, Iv, it was inferred’ that the hind limbs of the 
Moas might have been put to the work of uprooting the ferns which, from the unusual 
proportion of nutritious matter their roots contain, are peculiar to New Zealand, and 
still afford the material of a favourite bread of the Maoris. This deduction receives 
support from the additional knowledge of the foot of a Dinornis now acquired. 
The dried remains of the sole-pad show the thick and smooth integument; and this 
smoothness is continued to near the proximal end of the metatarse. ‘The lateral and 
dorsal, or anterior, parts of the metatarsal integument show numerous pits for insertion 
of feathers, of which some of those attached to the proximal and also near to the distal 
ends of the metatarsal segment are preserved. 
These feathers (Pls. LX. & LXI. fig. 2) vary from 24 inches to 1 inch in length; the 
barbs are loose, filamentary, directed at an angle with the shaft, which gives a breadth 
of half an inch at the proximal third of the feather, where the barbs are about a quarter 
of an inch in length; beyond the basal third the barbs incline more to the tip, and the 
feather becomes narrower. The colour of the basal part is lighter than that of the 
apical two thirds of the feather, deepening from a greyish to a reddish brown colour, 
which latter, as in the larger kinds of Apterya, may probably be the prevailing hue of 
the entire Moa. There is no trace of an accessory plume, or of any basal down, in the 
preserved small feathers of the foot of Dinornis didinus. 
If, as is most probable, a character of the genus may be inferred from parts of the 
species here described, Dinornis differs from Apteryx, as from all the large existing 
Struthionide, in having the metatarse (or ornithological ‘ tarsus’) feathered down to 
the toes*®. From Apteryx, Dinornis (or at least D. didinus) also differs in the greater 
relative size of the hind toe. Indeed, a foot of the proportions above described must 
have possessed a certain grasping-power ; and this may have been exercised in pulling 
their fern food up by the roots, after these had been exposed and loosened by the strong 
' Dinornis vobustus (p. 188, pl. xlix. fig. 1), Dinornis rheides (p. 195, pl. 1. fig. 1), Dinornis dromioides 
(p. 194, pl. li.). ? Loc. cit. p. 103. 
* Mr. Forbes informs me that feathers have been seen on the metatarse of a young Rhea. 
