154 PROFESSOR OWEN ON THE GENUS DINORNIS. 
comparison of the metatarse of Dinornis elephantopus with that of its nearest congener 
the Dinornis crassus, the following differences present themselves. The entocondyloid 
depression (fig. 2, e) is deeper, its fore-and-aft diameter is greater, and its transverse 
diameter less, than in the ectocondyloid one, ¢; but the breadth of the entocondyloid 
depression is relatively greater and its depth somewhat less in Dinornis elephantopus 
than in Dinornis crassus. 
The transverse convexity dividing the two condyloid depressions is relatively broader 
in Dinornis elephantopus ; and the rough surface external to the anterior intercondyloid 
prominence is more strongly marked. 
The two calcaneal ridges present an equal prominence in Dinornis elephantopus: the 
ectocalcaneal one, ce, is the most prominent in Dinornis crassus. 
The anterior surface of the metatarsus differs chiefly in the proportions indicated in 
the ‘‘ Table of admeasurements,” p. 153, from that in Dinornis crassus: like most of 
the metatarsi of that species, one or more vascular foramina occur above the subcir- 
cular rough surface of insertion of the flexor pedis, which occupies the lower part of 
the shallow depression on the upper and fore part of the shaft. 
Along the lower half of the shaft the median longitudinal and progressively widening 
prominence, due to the middle of the coalesced metatarsal bones, is rather more marked 
than in Dinornis crassus. 
The inner side of the shaft is marked at its upper half by the oblique rough tract 
indicative of the insertion of the powerful aponeurosis of the gastrocnemic muscles. 
At the back surface the upper part of the mesometatarse is relatively less prominent 
than in Dinornis crassus. 
The two vascular foramina occupy corresponding relative positions. All other 
notable differences are those of size and proportion. 
From the metatarsus of Dinornis robustus that of the Dinornis elephantopus differs, 
most strikingly, in its proportions of length to breadth, being little more than half the 
length, but of nearly equal breadth ; the distal trochlez, however, being relatively less 
expanded than in Dinornis robustus. 
The antericr vascular perforation is less than in Dinornis robustus: the inser- 
tional roughness for the ézbialis anticus below the foramen is of equal size. The upper 
half of the fore part of the metatarsus is longitudinally channeled in Din. robustus, 
not in Din. elephantopus. The corresponding part of the back part of the shaft is 
much more prominent in Dinornis robustus. The characteristics of the metatarsus 
of Dinornis elephantopus are more strongly manifested in the comparison with that of 
Dinornis giganteus', of which bone it has only half the length, other dimensions being 
equal or even greater in Din. elephantopus. 
Of the depression,— which is very faint in Dinornis robustus,—for the ligamentous 
‘ Trans. Zool. Soc. vol. ili. pl. 27. fig. 1. 
