94 
in the Bustard. The body of the third sacral vertebra is carinate below in the Bustard, 
and none of the vertebra abut by their transverse processes against the anterior part of 
the acetabulum. 
The smaller pelvis of the Dinornis, p 4, when compared with the portions of the 
larger pelves, p 1, p 2, presents so many differences besides those of size as to leave no 
doubt about the specific distinction of the birds to which they belonged. 
The first sacral vertebra in the smaller pelvis (Pl, XX. fig. 2.) has a narrower and 
deeper body, and there is not the deep excavation on the anterior part of the upper trans- 
verse process : I do not lay much stress on the fact that the lower transverse processes 
of the first two sacral vertebre retain the condition of ribs articulated to depressions at 
the upper part of the intervertebral spaces (ib. a) ; but every other part of the present 
pelvis manifests the characters of maturity. These ribs, as well as their anchylosed ana- 
logues, the transverse processes which succeed them, come off higher up than in the 
large pelvis. The lower border of the ilium is thin, and does not form a broad convex 
surface, increasing the width of the pelvis anterior to the acetabulum, as in the large 
Dinornis: the four inter-acetabular vertebre without inferior transverse processes (¢b. 6) 
are carinate along their under surface, not flattened as in the great Dinornis. The upper 
facet of the posterior part of the ilium is more horizontal, and forms a right angle with 
the vertical facet (Pl. XX. fig. 2. ¢): this is also divided from the anterior concave wall 
of the ilium, as in the Ostrich, by an angle formed by an obsolete ridge: the articular 
prominence behind the acetabulum is relatively longer in the axis of the pelvis, but less 
deep in the smaller species. The root of the ischium where it forms the upper part of 
the obturator notch is concave, and an angular process descends towards the pubis, 
forming a well-marked posterior boundary to the notch. In this character the smaller 
pelvis more resembles the pelvis of the Emeu than does that of the larger one; but the 
ischial process does not quite reach, as in the Emeu, the pubic bone. The ischium re- 
sembles, in its gradual expansion and straight direction, that of the larger species, and 
the more perfect condition of the smaller pelvis proves that the extremity of this bone 
(1b. e) projects freely backwards, as in the Apteryx and Emeu. 
The portion of a somewhat smaller pelvis, p 5 (Pl. XIX. fig. 3, Pl. XX. fig. 4.), than 
the preceding is less complete, but manifests characters which prove it to belong to a 
distinct species of Dinornis, and apparently to an older bird, since the second sacral rib 
on the left side'is anchylosed to the vertebral interspace. This anchylosis sufficiently 
demonstrates that the smaller pelvis is not of a younger bird than the larger one; and, 
besides the difference of size, there are the following differences of configuration :—In 
the smaller pelvis the second and third sacral ribs arise nearer the lower surface of the 
bodies of the vertebra, a character by which the smallest pelvis approximates the largest 
one, from which it differs, in having the bodies of these vertebrae relatively less broad 
and flat. The extent occupied by the four posterior orifices forming the interspaces of 
the lower transverse processes of the third to the seventh sacral vertebrze inclusive, is 
three lines greater in the smallest pelvis, p 5, than in the one next in the order of size, 
