

271 
produced, with a narrower base, in D. robustus (Pl. LXIII. fie. 2 k). Vhe pterygoid 
and pterapophysial ( pt) articular surfaces are well marked. uf he 
The mandible (Pl. LAXVT. fig. 1, 29, 52, and figs. 7, 8, 9), nearly 5 inches in leneth 
has a more irregular upper border than in most Moas, owing to the deeper ee 
tion between the coronoid process of the surangular (20') and the alyeolar border of the 
dentary (#2'). The posterior triangular fossa is deeper and better-defined than in Dinornis 
elephantopus; its upper and outer angle is more produced; the expanded articular part 
is longer in proportion to its breadth. But the chief and most recognizable modifica- 
tion is at the rostral or symphysial end (figs. 8,9), which is more expanded, more 
obtuse, and shallower above (fig. 9) than in D. elephantopus—conforming in shape to 
that of the premaxillary. 
Skull of Dinornis rheides, Ow. (Plate LXXV.) 
With the sternum and limb-bones of Dinornis rheides, in the collection of H. Sumpter, 
Fisq., of which the former bone is described, pp. 255-258, there was a cranium and 
mandible proportionate in size. In the collection of Moa-remains brought by Mr, 
Walter Mantell from Ruamoa there were, with limb-bone evidences of Dinornis rheides, 
two skulls, more or less entire, which so clearly agree with that above-mentioned that 
I refer them to the same species; and this species I believe, on this evidence, to be 
D. rheides. 
The cranium is narrower in proportion to its length than in D. crassus. ‘The super- 
occipital so projects at its midpart as to conceal the condyle from view, looking 
directly upon the calvarium; comp. Pl. LXXV. fig. 8, with PL LXU. fig. 1, D. robustus. 
From this structure the plane of the occipital foramen (Pl. LXXY. fig. 2,m) is less 
vertical, inclining from above downward and a little forward to the condyle. From the 
prominent upper border of the foramen the superoccipital plane inclines from below, 
upward and forward, at an angle of 60° with the basi-presphenoidal axis. If the 
occipital plane be understood as the hind wall or face of the skull from the basioccipital 
mammillee (ib. 1’) to the superoccipital crest (ib. 3), such plane lies nearly at a right angle 
with the basi-presphenoidal axis. But in the present and some other dinornithine 
skulls it describes a convex curve vertically, of which the upper border of the foramen 
magnum is the most prominent part (ib. fig. 1,437). The basicranial axis is usually 
understood to traverse the lower border of the occipital foramen, and it would then be 
out of the parallel of that of the basi-presphenoidal tract or axis. 
The occipital condyle forms rather more than half a hemisphere, truncate above, from 
the mid part of which a slight depression or dimple extends toward the middle of the 
condyle. The crenate ridge (3) and the more advanced upper transverse superoccipital 
both the mid vertical and transverse ridges of the 
d than in D. crassus, D. elephantopus, and 1). ro- 
262 
ridge (fig. 8, 7) are approximate ; 
superoccipital are less strongly marke 

