60 



PROFESSOR OWEN ON THE GENUS DINORNIS. 



Breadth of the cranium across the mastoids (s, s) 



Length of the cranium to the anterior border of the coalesced 1 



frontals (ii) J 



Breadth across the postorbital angles 



Breadth across the temporal fossEe 



Vertical diameter from supraoecipital ridge to basisphenoid. . . . 



Transverse diameter of occipital foramen 



Breadth across the paroecipitals (4, 4) 



Total length of skull, in a straight line 



Total length of premaxillary 



Breadth of the middle of the upper beak 



From the anterior border of the intercommunicating aperture 1 



between the nostrils to the end of the premaxillary J 



From the fore- part of the bony palatal opening of the nostrils 1 



to the end of the premaxillary j 



Length of the olfactory fossa in the frontal bone 



Breadth of the same fossEe 



Pal. ingens (?). 



inches, lines. 



3 8 



11 



8 



8 0(?) 

 4 0(?) 

 2 



Struthio. 



inches, lines. 



3 



1 

 1 

 9 



fii 

 9 

 

 10 



8 



10 



10 



The occipital region of this cranium corresponds very closely with that of the cra- 

 nium referred to Dinornis struthio'ides, in vol. iii. p. 308. pi. 38. of the ' Zoological 

 Transactions,' and with that subsequently conjectured to show the characters of 

 Palapteryx gerano'ides (?) in the same volume, p. 361, pi. 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 (PI. 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. iii. pi. 38. The temporal fossae are separated from each other by a similar tract 

 upon the parietals (PI. 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 

 fossae 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, s), 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 {ib. tr). An arterial canal is continued upwards from the 

 posterior aperture of the carotid canal, and grooves or notches the lower border of the 



