146 PROFESSOR OWEN ON THE GENUS DINORNIS. 
it, and to Mr. Davies, of the Department of Geology, for first calling my attention to 
the specimen in a collection of Sheppey fossils which Lord Enniskillen had sent (for 
determination) to the British Museum. 
In size this cranium equals that of the Dinornis giganteus; its proportions are also 
dinornithic, exemplified in the great breadth, small height, and forward slope of the occi- 
put, in the flatness of the calvarium—with all the indications, in short, of low cerebral 
development. But there are well-marked differences as compared with Dinornis. The 
occipital condyle (Pl. XVI. fig. 3, 1) exceeds in size by 1 line that of Dinornis robustus 
(Trans. Zool. Soc. vol, vy. pl. 56. figs. 1, 2,1) in both vertical and transverse diameters ; 
its shape is almost the same; and it is similarly impressed along the middle of its upper 
half by a vertical groove deepening, and in the fossil slightly expanding, to the end. 
This latter character is more marked in Dinornis elephantopus than in D. robustus; but 
the groove goes lower, and the hemisphere is more truncate above in D. elephantopus. 
The condyle in the fossil shows, under the pocket-lens, the same fine punctate diploé, 
or cellular structure, as does the condyle in Dinornis, when the thin, smooth outer coat 
has been rubbed off. The foramen magnum (ib. 0) is rather smaller, especially across, 
than in Dinornis giganteus or D. robustus ; it resembles in shape that of the specimen of 
the latter species from the limestone fissure at Timaru, figured in Trans. Zool. Soc. vol. v. 
pl. 53. fig. 2,0. The foramen has been overtopped, not by so sharp or narrow a pent- 
house as in Dinornis robustus (ib.), but by a thicker prominence of the combined ex- 
and super-occipitals, like that in Caswarinus, in Dromaius, and in Dinovnis gravis. The 
abrasion of this part, and of the arc thence curving down to each paroccipital, exposes 
the diploé at many parts; where the outer table remains it shows the arched ridge 
(ib. 3, d@) to be broader and more smoothly rounded than in Dinornis robustus, more 
like that in Dinornis elephantopus; but the descending curve is less, the arch is wider, 
spanning more transversely to the paroccipitals (ib.4): in the degree of transverse and 
vertical concavity of the area below the exoccipital arch (2,2, fig. 3. Pl. XVI.) Dasornis 
resembles Dinornis robustus rather than Dinornis elephantopus, in which the area is 
more depressed. The vagal foramina in this area, of which the right is plainly recog- 
nizable, open rather nearer the condyle than in Dinornis. In a direct upper view (fig. 1) 
the condyle is visible, as in Dinornis struthoides (Trans. Zool. Soc. vol. iii. pl. 38. fig. 3) 
and in D. dromioides (ib. pl. 39. fig. 5). It is plain from what remains of the basi- 
occipital tuberosities (Pl. XVI. fig. 3,1'1') that they were developed from a tract not 
descending below the condyle in a degree beyond that in Dromaius; otherwise they 
resemble those protuberances in Dinornis in size and position. ‘The superoccipital 
surface (ib. 3) inclines from below forward in a degree as great as in D. struthoides and 
D. dromioides (Trans. Zool. Soe. vol. iii. pl. 39. figs. 4 & 5)—consequently more so than 
in the larger Moas, much more so than in any of the existing Struthionide@, or in any 
aquatic or other known living bird. 
Notwithstanding the degree of abrasion of the transverse superoccipital ridge, there 
