60 PROFESSOR OWEN ON THE GENUS DINORNIS. 
Pal. ingens (?). Struthio. 
inches. lines, inches. lines, 
Breadth of the cranium across the mastoids (s, s) . . G4 
Length of the cranium to the anterior border of the ‘coalesced | 
frontals (11) : eater 
Breadth across the postorbital ‘angles . 
Breadth across the temporal fosse . 
Vertical diameter from supraoccipital ridge to basisphenoid. . 
Transverse diameter of occipital MCE 
Breadth across the paroccipitals (4,4).-..................-. 
Total length of skull, in a straight line ................0... 
Total length of premaxillary .... [aC naee Ooo 
Breadth of the middle of the upper beak 
From the anterior border of the intercommunicating aperture 
between the nostrils to the end of the premaxillary 
From the fore-part of the bony palatal opening of the nostrils 
to the end of the premaxillary 
Length of the olfactory fossz in the frontal bone........... 
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The occipital region of this cranium corresponds very closeiy with that of the cra- 
nium referred to Dinornis struthiotdes, in vol. ili. p. 308. pl. 38. of the ‘ Zoological 
Transactions,’ and with that subsequently conjectured to show the characters of 
Palapteryx geranotdes (?) in the same volume, p. 361, pl. 52, repeating the distinctive 
characters there pointed out, by which the large wingless birds of New Zealand differ 
from the Ostrich, Emeu, Cassowary, and Rhea of the existing class. 
The pedunculate occipital condyle (Pl. XXIII. fig. 1,1), the descending basioccipital, 
the square basisphenoidal platform with its two posterior tuberous angles (ib. fig. 2, 1"), 
the extremely broad, low superoccipital region (ib. fig. 1,3), with its inclination from 
below upwards and forwards, and its subdivision into four depressions, are all well- 
marked characters in the present skull. The border of the vertical occipital foramen 
is rounded off, not sharply defined or grooved, as in the crania above-cited. The outer 
superoccipital depression is separated from the temporal fossa by a smooth non-mus- 
cular tract above the mastoid, of four lines in breadth, as in the cranium figured in 
vol. iil. pl. 388. The temporal fossee are separated from each other by a similar tract 
upon the parietals (Pl. XXIII. fig. 1,7) of one inch eight lines in breadth: this tract is 
almost flat : two very shallow channels, four lines broad, diverge from the flat parietal 
surface along the upper part of the skull close to the anterior border of the temporal 
fosse and terminate at the upper part of the much-developed and deflected postfrontal 
(ib.12). Between these shallow impressions the frontal region is slightly convex, but 
it becomes a little concave at its anterior half, the middle of the fore-part of which is 
impressed by a sharply-defined shallow channel for the reception of the cranial and 
of the median branch of the coalesced premaxillaries. The large tympanic fossa, over- 
arched by the mastoid (ib. fig. 2,8), shows the single oblong deep cavity for the upper 
condyle of the tympanic bone, with the pneumatic, jugular, and auditory foramina, and 
the adjacent trigeminal one (7b. ¢r). An arterial canal is continued upwards from the 
posterior aperture of the carotid canal, and grooves or notches the lower border of the 
