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III. On Divornis (Part XIV.): containing Contributions to the Craniology of the Genus, 
with a Description of the Fossil Cranium of Dasornis londinensis, Ow., from the 
London Clay of Sheppey. By Protessor Owen, F.R.S., F.Z.S., &e. 
Read January 28th, 1869. 
[Puates X. to XVI.] 
IN the Memoir on the skeleton of Dinornis elephantopus, the skull is briefly noticed’. 
Subsequent acquisitions of specimens of that part, in some respects more complete, 
enable me to better appreciate its specific characters and to bring them out by com- 
parisons with those of the skull of Dinornis robustus, described in Memoir, Part [X.? 
T also avail myself of these grounds to determine and elucidate the cranial characters 
of some other species of Dinornis, as well as those of a seemingly dinornithoid gigantic 
bird which, like Gastornis parisiensis, existed in our own part of Europe at a remote 
tertiary period. 
Skull of Dinornis elephantopus. (Plate X.) 
The cranium of Dinornis elephantopus equals in length that of D. robustus*, but is 
inferior in breadth and more convex both longitudinally and transversely, especially the 
latter, at the interorbital region (fig. 1,11). The entire skull of D. elephantopus is 
shorter than that of D. robustus, by reason of the relatively shorter premaxillary and 
mandibular bones. 
The occipital condyle (Pl. X. figs. 2, 4,1) is a hemispheroid with a small proportion 
truncate above, from the middle of which surface a groove extends to the centre; its 
breadth is 44 lines, its vertical diameter 4 lines. 
The occipital foramen is in one skull subcircular, in others shield-shaped, as in the 
second specimen of D. robustus (tom. cit. pl. 56. fig. 2). The lower transverse superoc- 
cipital ridge (Pl. X. fig. 2,2), which overhangs the foramen, subsides upon the exoccipi- 
tals sooner than in J. robustus. The basioccipital descends proportionally lower to its 
bimammillate union (ib. figs. 2, 4, 1’) with the basisphenoid. There is one small precon- 
dyloid foramen on each side the base of the peduncle of the condyle. The vagal (ib. v), 
carotid (ib. ¢), and sympathetic canals have the same relative position as in D. robustus. 
The superoccipital is much less broad and is more arched than in D. robustus; its 
median vertical ridge (ib. fig. 2, 3) is less prominent in the present specimen, subsiding 
* (Part VIII.) Trans. Zool. Soe. vol. iv. (1856) pp. 161, 163. * Trans. Zool. Soc. yol. v. p. 337. 
* Measured from the superoccipital protuberance to the premaxillary depression on the nasals; comp. Pl. X. 
fig. 3 with pl. 53. fig. 1, vol. v. Trans. Zool. Soe, 
VOL. VII.—PaRT 1. Jan. 1870. 8 
