224

194

scratching up the soil is exercised to such a degree that it excavates a burrow for its
safe habitation : in the larger allied extinct species the rasorial actions would doubtless
be restricted to the acquisition of food : and the ascertained structure of the foot thus
accords with and bears out the conclusions deduced from the structure of the bones of
the neck and head 1.

Bones of the Foot of Palapteryx dromioides.

Amongst the toe-bones of smaller dimensions, which from time to time were trans-
mitted to me, I soon found homologous ones presenting different proportions ; and,
finally , by means of the rich accession of specimens due to the obliging exertions of
Col. Wakefield, I have been enabled to recompose the entire feet of two species cha-
racterized by those different proportions of the phalanges. One of these feet is repre-
sented in Pl. L. , the other in Pl. LI.

As the coalesced metatarsals might be expected to manifest the same general propor-
tions as the toes they sustained, I have referred the more slender phalanges to the Pal-
apteryx dromioides, and the more robust ones to the Dinornis rheides, the articular
condyles of the metatarsi of these species bearing the closest correspondence with the
joints of the proximal phalanges to which they have been respectively adjusted in the
specimens represented of the natural size in Plates L. & LI.

The metatarse of the Palapteryx dromioides shows the articular depression for the
small back-toe : but the bones of this toe have not yet reached me.

The proximal phalanx of the inner or second toe, Pl. LI. II. 1, has the contour of the
proximal articulation cordiform, the apex being superior, the notched base below : it is
more concave than in the Palapteryx robustus, and the inner and lower angle is as much
produced as the outer one. A well-marked rough surface extends from each of these
angles forwards upon the under and outer surfaces of the bone. The vertical channel di-
viding the distal trochlea is deeper than in the Palapteryx robustus, especially at its upper
part: the more gradual slope from the upper to the inner side of the bone, as contrasted
with the more vertical outer side, is better marked than in the Palapteryx robustus. The
inner depression at the distal end for the lateral ligament is deeper than the outer one.
The second phalanx is characterized by the deep lateral cavities and the prominent
median vertical ridge forming the proximal articulation, which is also more nearly sym-
metrical than in the Palapteryx robustus ; the inner division is, nevertheless, the broadest.
The distal articular surface extends further back upon both the upper and under sur-
faces of the bone. The ungual phalanx (II 3.) shows the same unsymmetrical character,
produces by the more sloping inner side and the more vertical outer side, as the proximal
phalanx (II. 1) does : the inner side terminates below in a ridge ; the outer one is rounded off
into the under surface : this is protuberant near the lateral vasculr grooves, which are well-
marked. The length and slenderness of the ungual phalanx contrast better with the pro-
portions of the same bone in Palpteryx robustus, than do those of the preceding phalanges.

1. pp. 107, 180.