260 PKOFESSOE OWEN ON THE GENUS DINGENIS. 



o-roove 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 i) is deeper but shorter 

 than that on the opposite side (PI. LXI. fig. 1). 



The proportion of the toes (ii, in, iv), as to relative length, are closely those of the 

 species of Binornis 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 Binornis didinus are intermediate 

 between those of Binornis rheides and B. dromioides. 



From the osseous structure of the foot, especially the strength and curvature of the 

 ungual phalanges of the digits ii, m, 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 (Pis. LX. & LXI. fig. 2) vary from 2^ 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 Aj)teryx, 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 

 preser\ed small feathers of the foot of Binornis didinus. 



If, as is most probable, a character of the genus may be inferred from parts of the 

 species here described, Binoniis differs from Apteryx, as from all the large existing 

 Struthionidae, in having the metatarse (or ornithological ' tarsus ') feathered down to 

 the toes^ From Apteryx, Binornis (or at least B. 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 robwstus (p. 18S, pi. xlis. fig. 1), Dinornis rheides (p. 105, pi. 1. fig. 1), Dinoniis dromioides 

 (p. 194, pi. U.). ' hoc. cit. p. 103. 



^ Mr. Forbes informs me that feathers have been seen on the metatarse of a young Rhea. 



