66 PROFESSOR OWEN ON THE GENUS DINORNIS. 



The principal articular cavity is the large and deep one that occupies the major part 

 of the expansion at the articular end of the ramus : the second surface for the tympanic 

 is a very narrow strip along the outer border of the expansion, which slightly overhangs 

 that part of the ramus. The angle of the jaw is obtuse. From the proportions of this 

 lower jaw it appears that the ramus, as restored in vol. iii. fig. 1 . pi. .54, is about half 

 an inch too long, and the whole beak of the Palapteryx thus figured must be shortened 

 to that extent. 



Humerus. — As the number of importations of the remains of the large wingless birds 

 of New Zealand has progressively increased, the argument deduced from the absence 

 of any bones of the anterior extremity in the first large collection transmitted by the 

 Very Rev. Wm. Williams, has been gaining cumulative force, in proof of the extremely 

 insignificant size of those bones. But, in the collection of remains last transmitted to 

 me by Governor Grey, I found a fragment of a long bone, which I believe to be the 

 proximal half of the humerus. It is three inches and a quarter in length, with an en- 

 larged oblong-ovate, convex articular end ; the shaft, at first three-sided, takes an oval 

 transverse section as it recedes, diminishing from the head, and shows a slight ridge on 

 one side, and a rough surface on the opposite for the attachment of small antagonizing 

 muscles. The only other bone in the Dinornis with which it is comparable is the 

 fibula; but, in the present specimen, the head is too convex, and has not the lateral 

 concave articular surface which this fibula shows for the tibia. This small humerus 

 may belong to a large species of Dinornis or Palapteryx ; but to whatever sized species 

 it did belong, it is as devoid of those muscular crests and tuberosities indicative of 

 powers of flight, as the humerus of the Apteryx is. 



A cranium of the Notornis in the collection transmitted by Governor Grey exhibits the 

 frontal portion which was deficient in the specimen described in vol. iii. p. 366, in 

 which that genus and its aflinities were defined. 



The postfrontal processes equally divide the upper region of the skull from the super- 

 occipital ridge to the naso-premaxillary groove : that region is moderately convex : the 

 superorbital ridge is of about the same extent as the temporal ridge ; it is somewhat 

 irregular, is grooved posteriorly, and terminates anteriorly in very short antorbital pro- 

 cesses directed forwards. The coalesced frontals terminate anteriorly in a moderately 

 thick straight transverse border of nine lines' extent, overhanging the flat smooth plat- 

 form formed by the coalesced prefrontals : from the outer border of this platform, a bony 

 plate descends and blends with the interorbital septum, half-way down, leaving an 

 interval between the septum and the upper part of the plate, through which the olfac- 

 tory nerves were continued. The posterior turbinals were attached to the fore-part of 

 these descending plates. The interorbital septum is perforated anterior to the common 

 outlet of the optic nerves, is deeply grooved at its upper part by the olfactory nerves, 

 and is formed below by the presphenoidal prolongation. 



In all other respects in which a comparison can be instituted with the less complete 



