142 PROFESSOR OWEN ON THE GENUS DINORNIS. 
posterior diameter; an extent of 1 inch 9 lines intervenes at the upper part of the 
cranium between these fossie (fig. 3). The postorbital process is triangular, more rapidly 
decreasing in breadth as it descends, and its outer plane is directed more backward, less 
outward, than usual. The presphenoidal rostrum, 2 inches 8 lines in length, is com- 
pressed at its middle part below, expanded and convex before and behind this ridge, 
pointed anteriorly and confluent throughout its upper extent with the prefrontals and 
orbito-sphenoids. The “shelf” (Pl. XIV. fig. 4, 9") extends further outward than in 
Dinornis crassus or D. rheides. A broad vertical lamina, continued from the lachrymal 
and the olfactory girdle, descends external to the posterior olfactory orifice almost to 
the level of the presphenoid, forming the anterior wall of the orbit. The fronto-nasal 
articular tract for the median process of the premaxillary is 1 inch 7 lines in length and 
6 lines in breadth (fig. 3); there is no distinct orbital process of the nasal. 
The mandible of D. gravis, 4 inches 4 lines in length, is 2 inches 9 lines across the 
condyles, 1 inch 3 lines in breadth opposite the back part of the symphysis, which is 
only 7 lines in length (fig. 6). ‘The splenial bends inward anteriorly toward the sym- 
physis, its pointed end terminating in the groove at the back part of the symphysis : 
it has coalesced throughout its length with the other elements of the lower jaw. The 
form of the symphysial or rostral part of this lower jaw (Pl. XIV. fig. 6) indicates a 
corresponding breadth and obtuse termination of the short rostral part of the pre- 
maxillary. The type of beak of D. crassus is that which is exemplified in D, gravis. 
In size of head D. gravis most resembled D. rheides; but the degree in which specific 
characters are exemplified may be satisfactorily appreciated by contrasting their respec- 
tive mandibles in the figures 5 and 6 of Pl. XIV. 
Skull of Dinornis ingens, Ow. (Plate XV.) 
To pl. 23, vol. iv. of the Transactions of the Zoological Society, representing the 
most perfect skull of a Dinornis which had come to my hands at the date of my fifth 
Memoir (Noy. 12, 1850, p. 59), I added a note of interrogation to the name of the 
species to which such skull was, with that expression of doubt, referred. 
This skull and many other bones, including limb-bones of Dinornis ingens, were dis- 
covered in 1849 in a cave in the district which lies between the river Waikata and 
Mount Tongariro, in the North Island of New Zealand; they were obtained and 
liberally transmitted to me by Governor Sir Grorgr Grey in 1850. 
Successive receptions of Moa-remains, especially those with which the British 
Museum has been enriched by the laborious collectings of Mr. Walter Mantell, have 
added evidence of the general fixity of the characters of the above-described skull as 
belonging to an adult individual of a large and well-defined species; and the recent 
additional confirmation of its appertaining to the Dinornis ingens, published in the 
Paleontological part of the Circumnayigatory Expedition of the ‘Novara,’ induces me 
no longer to defer the publication of the description and figures of the more perfect 
