Zoological Society. 131 



skull of Dinornis struthoides and a corresponding portion of the skull 

 of Dinornis dromioides, which in general form more resembled that 

 part of the skull of the Dodo than of any existing bird ; but they are 

 remarkable for the great breadth of a low occipital region, which 

 slopes from below upwards and forwards ; the almost flat parietal 

 region is continued directly forwards into the broad sloping frontal 

 region ; the temporal fossae are remarkably wide and deep ; the orbits 

 small ; the olfactory chamber expanded posteriorly, but not to so 

 great an extent as in the Apteryx ; the plane of the foramen mag- 

 num is vertical. Many other characteristics in the cranial organi- 

 zation of the genus Dinornis were described, and the specific distinc- 

 tion of the two mutilated crania pointed out. 



The tympanic bone of the Dinornis giganteus was described in 

 detail and compared with the same bone in existing birds. 



Different cervical and dorsal vertebrae, referable to the species 

 Din. giganteus, ingens, struthoides and crassus, were described. These 

 vertebrae were remarkably entire, and with some of the best-preserved 

 bones of the extremities, described in a subsequent part of the Me- 

 moir, had been obtained from a turbary formation on the coast of the 

 Middle Island, near Waikawaite. 



One of the most interesting of the novel acquisitions from this 

 locality was an almost entire sternum, referred by Prof. Owen to the 

 Din. giganteus. It is a subquadrate, keel-less, shield-shaped bone, 

 broader than long, with the posterior angles and the xiphoid process 

 prolonged, as in the Apteryx, but without the anterior emargination. 

 The coracoid depressions very small. This bone was minutely de- 

 scribed and compared with the keel-less sternums of the existing 

 Struthious birds ; that of the Apteryx being demonstrated to be most 

 like the sternum of Dinornis. 



The following bones of the extremities, imperfectly or not at all 

 known in 1843, were next described : — 



The entire femur of Dinornis giganteus. Entire tibiae and tarso- 

 metatarsi of Din. giganteus, indicating a robust variety of this stupen- 

 dous bird to have existed in the Middle Island. 



The tarso-metatarsus of Dinornis ingens from the North Island, 

 distinguished by a rough depression indicative of a fourth or back- 

 toe, and consequently a genus {Palapteryx) distinct from Dinornis. 



Femora, tibiae and tarso-metatarsi of a Dinornis of the height of 

 the Din. ingens, but of more robust proportions, from the Middle 

 Island ; with a feeble indication of a surface for a back-toe.' 



The tibiae and tarso-metatarsi of Dinornis {Palapteryx) dromioides 

 from the North Island, confirming by their long and slender propor- 

 tions the conjecture hazarded in the author's former memoir (Zool. 

 Trans, vol. iii. pp. 252, 264). The tarso-metatarsus also shows the 

 rough elliptical surface for the attachment of the back-toe, indicating 

 the Din. dromioides to belong to the same generic or subgeneric sec- 

 tion as Din. ingens from the North Island. 



Femora, tibice and tarso-metatarsi, from the Middle Island, were 

 next exhibited and described, which establish a new species, for 

 which Prof. Owen proposed the name of Din* casuarinus : a small 



