PROFESSOR OWEN ON THE GENUS DINORNIS. 3 
I have applied to the principal elements the names of ‘ entometatarse ’ (11), ‘ mesometa- 
tarse ’ (111), and ‘ ectometatarse’ (1v) respectively, for the convenience of description. 
The shaft in Palapteryx robustus is subtriedral in its upper two-thirds, subcompressed 
from before backwards in its lower third, of equal breadth in its middle fourth, and 
thence expands to both extremities, but more to the inner than the outer side, and in 
a greater degree at the lower end; so that the inner margin is more concave than the 
outer one. This difference is not so great in the Dinornis giganteus, in which, also, 
the shaft continues gradually to diminish in breadth towards its lower third. 
The proximal articular surface of the metatarse of the Palapteryx robustus is divided, 
as usual, into two concavities, that for the inner condyle of the tibia being the largest 
and deepest: it is of a triangular form bounded internally by a well-defined edge which 
extends in a nearly straight line from the anterior internal angle to the posterior angle 
of the concavity: the anterior external angle is formed by the prominent fore part of 
the intercondyloid protuberance. The more shallow concavity for the outer condyle is 
subcircular, its outer boundary being convex and most raised at its middle part ; pos- 
teriorly the border subsides and the concavity passes into a convexity at that part. The 
non-articular surface of the proximal end is chiefly behind the concavities and extends 
upon the upper part of the calcaneal processes: these are, as usual, three in number, 
the internal and middle ones being most prominent: they are obtusely rounded, and 
separated by the deep and wide groove for the flexor tendons of the toes: the lon- 
gitudinal extent of the inner process (the entocalcaneal one, fig. 2, ce) measures one 
inch and a half: its obtuse and thick upper end commences behind and half an inch 
below the posterior border of the entocondyloid cavity: the process gradually contracts 
to a point at its lower end, which overhangs the smooth groove continued obliquely 
downwards and outwards to the foramen formed by the persistent remnant of the inter- 
osseous space between the inner (11) and middle (111) metatarsal elements of the com- 
pound metatarse. 
The mesocalcaneal process (fig. 2, cm) is the largest of the three: it is broad and 
rounded about, slightly grooved down its posterior surface, and supported by the rough 
posteriorly projecting buttress-like part of the mesometatarse, of which it seems to form 
the obtuse summit. 
The ectocalcaneal process is the smallest: it is separated by a shallow open groove 
from the mesocalcaneal process: it begins to project half an inch below the posterior 
convexity of the ectocondyloid surface: its lower part subsides before it reaches the 
foramen between the ecto- and meso-metatarse. The interval between the two inter- 
osseous foramina, which gives the breadth of the mesometatarse at that point, is greater 
in the Palapteryx robustus than in the Dinornis giganteus, notwithstanding the greater 
length of the bone in the latter species. 
The anterior intercondyloid protuberance sends a short obtuse ridge downwards and 
slightly outwards upon the fore part of the upper end of the tarso-metatarse. A large 
B2 
