PROFESSOR OWEN ON THE GENUS DINORNIS. 363 
A comparison of these dimensions with those of the two species of Dinornis to which 
the present comes nearest, in the Table of Admeasurements, p. 371, will exemplify the 
chief metatarsal characteristics of Dinornis gravis. 
In general configuration, as in robustness of proportion, though exceeding in the 
latter respect, the present metatarsus most resembles that of Dinornis crassus. I note 
the following differences, which are repeated in specimens of the metatarsus from two 
individuals of Din. gravis from remote localities in the South Island of New Zealand. 
The intercondylar rising (Pl. LVIII. figs. 1, 3, ¢) is but slightly developed anteriorly 
in any Dinornis, but it has more claims to be considered a “ process” in Din. gravis 
than in Din. crassus; the entometatarsal tuberosity (ib. figs. 1 & 3,¢) is more pro- 
minent, and is longer. 
In the antinterosseal depression (ib. fig. 1, 7) the upper common anterior orifice (ib. 7) 
of the interosseal canals is less speedily divided into the entinterosseal (ib. fig. 2, 7) and 
ectinterosseal (ib. m) canals than in Dinornis crassus; the rough depression below for 
the tibialis anticus (ib. fig. 1, 0) is deeper and better-defined for its size in Dinornis 
gravis. 
The calcaneal groove (ib. figs. 2, 3, w) is narrower and deeper in Din. gravis; and the 
entocalcaneal process (ib. ib. 7) is rather less prominent. The outer depression on the 
ectocalcaneal process (ib. s) is better marked, and in one metatarsal specimen of Din. 
gravis appears as a shallow longitudinal groove. 
The posterior orifice of the entinterosseal canal (7) does not open into a depression of 
the bone; that into which the ectinterosseal canal (m) opens, is wide and shallow. 
The interval between these two orifices in one of the specimens is greater in Din. 
gravis than in the longer metatarsus of Dinornis crassus; in the other it is as great. 
As in Dinornis crassus, the places of insertion of the strong ligamentous aponeurosis 
formed by the confluence of the tendons of the gastrocnemius internus and gastro- 
cnemius externus are less longitudinally extended, less ridge-like, and are more concen- 
trated, broader, and better marked than in Apteryx australis’. 
The entogastrocnemial surface (P]. LVIII. fig. 2, 7) begins behind the entometatarsal 
tuberosity, and runs downward and backward to near the mid length of the bone; it 
becomes more defined as it descends, retaining a breadth of about 3 lines, before it 
suddenly expands into a rough tract of a semioval shape, about 2 inches long by 6 or 7 
lines in extreme breadth. This surface terminates about an inch and a half above the 
hind end of the articular surface of the inner condyle (11), The lower part of this 
surface indicates the position (ib. fig. 2,1) of the ligaments which would attach the 
metatarsal rudiment of a back toe to the main bone, if such toe existed in Dinornis 
gravis. 
The ectogastrocnemial tract (Pl. LVIII. fig. 2, x) is at the outer part of the hind 
surface, and on the lower or distal half of the shaft, of the metatarsal. It is of a semi- 
’ Trans, Zool. Soc. vol. iii. p. 277, plates 31 & 32, R. 
3F2 
