349 
enemius externus are less longitudinally extended, less ridge-like, and are more concen- 
trated, broader, and better marked than in Apteryx australis’. 
The entogastrocnemial surface (Pl. XLII, a, 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 (ib. fig. 2, 2) 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 semioval 
form, 1 inch 9 lines in length, 7 lines in extreme breadth, and is divided from the 
back part of the articular surface of the outer trochlea (1v) by a smooth tract about 
4 lines in breadth. A narrow, oblong, rough tract at the proximal part of the shaft 
behind the ectometatarsal ridge (ib. fig. 2, 4) may serve also for gastrocnemial insertion ; 
but it is divided from the lower ectogastrocnemial tract by a smooth surface of the mid 
part of the metatarsal, about an inch and a half in extent in one instance, and two 
inches in the specimen figured in Pl, XLII.a@, The narrow tract from the entogastro- 
cnemial tuberosity (7) is more feebly marked, if it be discernible, in Dinornis crassus. 
The ectogastrocnemial surface is also less defined, and is continued upwards as a more 
or less conspicuous ridge to within a few lines of the ectometatarsal rough surface in 
Dinornis crassus. 
The fore part of the entotrochlea (fig. 1, 11) is broader relatively to the hind part in 
Dinornis gravis than it is in Dinornis crassus. The outer side of the fore part of the 
ectotrochlea (Iv) is more convex or tuberous, and is less defined from the ectotrochlear 
fossa than in Dinornis crassus. 
The interspaces of the trochlew are narrower in Dinornis gravis ; and this character 
is the more easily seized, inasmuch as the breadth of the three trochlew is almost 
the same in the two species, notwithstanding the difference in the length of the 
metatarsi. 
Dinornis gravis had a stronger and stouter foot, relatively, than Dinornis crassus; 
and the muscular force working it was more powerful, as is indicated by the insertional 
ridges and tracts (9, y, 2). 
In a metatarsus of Dinornis crassus 8 inches 6 lines in length the greatest breadth of 
the mid trochlea is 1 inch 8 lines; in a metatarsus of Dinornis gravis 7 inches 9 lines 
in length the greatest breadth of the mid trochlea is 1 inch 10 lines, 
The general characters of the bone, with the disposition and aspects of the distal 
1 Pla, X. & XL. x. 
312 
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