129 
that in the smaller species, with the modifications of the ornithic type presented by most 
Gralle and Galline (ib. fig.4, Ciconia Argala), but differs considerably from the cor- 
responding part in the Ostrich (ib. fig. 2). In this largest of existing Struthionide the 
epicnemial process (0) does not rise above the level of the proximal surface of the tibia, 
but extends directly forwards, sends out a compressed and prominent procnemial 
ridge (p) and a short thick obtuse process (k) from its outer side in place of the ecto- 
cnemial ridge. In the Dinornis the posterior articular tuberosity (fig. 1, £) is divided, 
by a wider and deeper depression than in the Ostrich, from a smaller anterior prominence 
to which a fibular ligament is attached (fig. 4, 1) : this depression in the Dinornis receives 
the inner prominent division of the outer condyle of the femur ; the posterior tibial tube- 
rosity rising into the space between that and the inner condyle, whilst the fore-part of 
the outer condyle rests upon the inner side of the ascending tibial ridge: this occasions 
a closer interlocking of the tibia and femur than in the Ostrich. The only difference in 
the dimensions of the tibiz of the Dinornis giganteus from the North and Middle Islands 
is a slight increase of the breadth of the distal end of the more recent and better-preserved 
bones from the latter locality (see the ‘ Table of Admeasurements, p.137.’), I subjoin 
to the figure of the well-preserved proximal end of one of these tibize from the Middle 
Island, figures of the same parts of the tibia in the Ostrich (fig. 2), Emeu (fig. 3), and 
Gigantic Crane (fig. 4), all of the natural size. 
The tarso-metatarsal bones of the Dinornis giganteus from the Middle Island are more 
generally and sensibly stronger in proportion to their length than the femora or tibie, 
compared with those from the North Island; but I cannot venture to infer from this 
evidence alone more than a stronger variety of the species: the degree of difference 1s 
accurately given in the ‘ Table of Admeasurements, p. 137,’ 
A new species might with more reason be founded on the bones of the hind extremity 
from the Middle Island, which agree in length with those of the Dinornis ingens, since 
they surpass in thickness in a somewhat greater degree their homologues from the North 
Island. This difference I have not only been able to appreciate with regard to the 
femur and tibia on which the species D. ingens was founded*, but also with regard to 
the tarso-metatarsal bones, having received one speciinen from the North Island, trans- 
mitted by Mr. Colenso, which presents intermediate dimensions between the tarso- 
metatarsal bones referred to Dinornis giganteus and Dinornis struthoides, and having 
compared it with three tarso-metatarsals of similar length in the collection of Mr. Perey 
Earl. These differences will be appreciated by the ‘ Table of Comparative Dimensions ’; 
but I shall here notice these stronger bones from the Middle Island as belonging to 
Dinornis ingens, var. robustus, until other parts of the skeleton, especially the skull, may 
arrive, although the following differences of form are observable in the homologous 
bones of the extremities from the two localities. 
* Loc. cit. pp. 86, 88. 
