246 
This ridge begins, as in the tibize of other species of Dinornis, be- 
low the expanded end of the tibia near the middle of its back part, 
inclining to its outer side. 
In its slender proportions, and the relative positions of the proene- 
mial and ectocnemial ridges, the tibia of the Dinornis struthioides 
agrees with that of the D. dromioides. 
Description of the Bones of the Leg of the Dinornis gracilis. 
The advantage of additional specimens, as confirming, by the repe- 
tition of the same characters, a species previously defined, is still 
greater in respect of the ground which they afford for the discrimi- 
nation of a distinct but nearly allied species. Notwithstanding the 
well-marked differences observable between the femur of the Dinornis 
struthioides and the Dinornis gracilis, 1 might have deemed them 
due to differences of sex or individuals, had I not had evidence of the 
fixity of the specific characters of the Dinornis struthioides by the 
successive arrivals of additional specimens of its bones. Attending 
the hoped-for confirmation from such arrivals, it appeared to be 
most prudent to refrain from announcing a new species of the rapidly 
increasing family of the great wingless birds of New Zealand until 
further confirmation might be obtained by corresponding differences 
in the tibize and metatarsi of the two species. 
Having had the good fortune at length to obtain these additional 
illustrations of the Din. gracilis, I no longer delay communicating 
descriptions and figures of them to the learned Society, in whose 
Transactions my former Memoirs have appeared and have been so 
liberally illustrated. 
Femur. 
The following are the chief dimensions of this bone :— 
in. lin. 
SN a Ie ona i Be ae ke a 1 i ieee 4 
Breadth of proximal end in the axis of the neck . 3 10 
Breadth transverse of distalend.............. 4 0 
Circumference of middle of shaft ............ 4 8 
A small portion of the upper ridge of the great trochanter has 
been broken off: when entire, the femur of the Din. gracilis presents 
the average length of that of the Din. struthioides, but it is more 
slender in proportion, the head is smaller, and is supported by a 
better-marked constriction or neck, especially at its under part. The 
upper platform of the trochanter is narrower, the anterior border of 
the trochanter not being extended so far forwards and outwards. 
The angle between the upper and fore surfaces of the trochanter is 
a right one, and they meet at a sharp ridge. The rough oval surface 
between the head of the femur and the base of the trochanter is 
smaller than that of the Din. struthioides. The outer irregular sur- 
face of the trochanter is of much less breadth in the Din. gracilis. 
The muscular impressions at the sides of the shaft meet and form a 
longitudinal ridge along the back part of the middle third of the 
