Zoological Society. 59 



behind, its less depth, its vertical foramen magnum and prominent 

 occipital condyle, the lower position of the basisphenoidal platform, 

 and the marked angle which it forms with the almost vertical basi- 

 occipital, concurs with the beak in establishing the generic distinction 

 of the great bird to which it belonged. As the characters which 

 were adduced in a former memoir (Zool. Trans, iii. p. 327) to sepa- 

 rate those bones of the extremities that by their more slender pro- 

 portions approximated the Struthionidee and, by the indication of a 

 small back-toe, the Apteryx more particularly, from other bones of 

 corresponding size but more robust proportions and devoid of a back- 

 toe, — led to the former being assigned to the genus Palapteryx, and 

 the latter to Dinornis proper ; — so the characters which, in the first 

 of the skulls described in the present memoir, show a departure from 

 the struthious type, and in the second skull an approach thereto, 

 clearly indicate the propriety of assigning the one to the genus 

 Dinornis and the other to the genus Palapteryx. The total length of 

 the skull referred to Palapteryx gerano'ides is 6 inches at least ; the 

 breadth of the cranium 2| inches : the bird probably equalled the 

 Emeu in size. 



The skull which indicates the third genus of apparently extinct 

 bird (Notornis) measures A\ inches in length, and the cranium is 

 1 inch 8 lines in breadth. The bones of the beak closely resemble in 

 form and structure those of the Purple Coot (Porphyrio), but the 

 occiput is relatively broader, and more inclined forwards as it ascends : 

 the plane of the occipital condyle is vertical, and the basioccipital 

 extends further below the occipital condyle, though less so than in 

 Palapteryx. In these characters the Brachypteryx or Short- winged 

 Rail of New Zealand more resembles Notornis. The articular surface 

 of the tympanic is divided, as in Dinornis and Otis, into two subcir- 

 cular cups. The parietal region is singularly flat, the temporal fossae 

 unusually long, well-defined by ridges extending from the paroccipital 

 to the postfrontal. In the comparatively small Porphyrio and Bra- 

 chypteryx, in which, as in all small birds, the cerebral hemispheres, 

 as requiring a certain bulk for their functions, do not decrease in 

 the ratio of the size of the body, the upper surface of the cranium 

 is raised by the hemispheres beneath into a smooth convexity. 



The Notornis is a large modified form of the same natural family 

 of the Grallce as the Porphyrio and Brachypteryx, and from the form 

 of its sternum it must have been, like the latter peculiar bird of New 

 Zealand, deprived of the power of flight. 



The fourth genus of bird indicated by portions of the skull in Mr. 

 Walter Mantell's collection was referable to the family of Parrots 

 (Psittacidce), and amongst these to the genus Nestor. The bony 

 portion of the upper beak — the only part of the skull preserved — by 

 its deep, subcompressed, curved and pointed form, its seeming solidity, 

 pierced by small subcircular nostrils close to its base, attested the 

 family character ; whilst the proportional length as compared with 

 the depth, the narrow upper surface to where it suddenly expands 

 above the nostrils to join the cranium, the absence of the notch on 

 the under border, the very narrow elongated triangular palatal sur- 



