314 PROFESSOR OWEN ON THE GENUS DINORNIS. 



In the length of the posterior zygapophyses or articular processes (PI. XL. s') and 

 the depth of the triangular depression between them, the present vertebra bears more 

 resemblance to the cervical vertebrae of the Emeu than to any in the neck of the Ostrich , 

 the Rhea, or the Apteryx : but the pleurapophysis or process representing the cervical 

 rib [ib. pi) is not so pointed or prolonged as in the Emeu ; it more resembles that in the 

 Apteryx : the breadth or depth of this process, the large relative size of the canal which 

 it overarches and completes, and the ridges and furrows on the outer surface, bespeak 

 the strong development of the cervical muscles and the great strength of the neck. 



The characteristic conformation of the cervical vertebrae in the class of Birds is well- 

 displayed in the present specimen, and the particular modifications characteristic of the 

 Dinornis are better elucidated by the figures than by verbal description. 



The next cervical vertebra (PI. XL. figg. 4 & .5), like the foregoing, is from the part 

 of the neck where the neural spinous process ceases to be developed, there being in its 

 place a flat surface (s) behind a rough shallow depression for the attachment of the 

 strong, short, elastic ligament : the difference of size and conformation of the present, 

 as compared with the foregoing vertebra, is obviously not such as depends on mere 

 difference of position in the same neck, or in the neck of the same species, but clearly 

 indicates a difference of species in the birds to which they have respectively belonged. 

 The present vertebra may well, from its size, have come from the anterior third part of 

 the cervical series in the Dinornis giganteus ; the preceding from the corresponding part 

 of Dinornis ingens. In assigning the vertebra (Zool. Trans, vol. iii. PI. XVIII. figg. 1 — 3, 

 p. 271) to the largest species oi Dinornis, I was influenced by the ordinary proportions 

 of those bones in other birds : the present specimens prove that the strength of the 

 neck was greater and the cervical vertebrae relatively larger in the genus Dinornis, and 

 the above-cited vertebra must be assigned to Diri. ingens rather than to Din. gigas. 



The costal process (PI. XL. pi) here presents a similar breadth and depth and external 

 sculpturing : the upper and posterior margin is produced into a short obtuse point. 

 From the base of this part a ridge extends obliquely upwards and backwards to that of 

 the posterior zygapophysis or oblique process (ib. s'), parallel with the shorter and 

 stronger ridge from the anterior oblique process {ib. z) to the base of the spine : between 

 these ridges there is a deep depression opening at the bottom into the cancellous struc- 

 ture of the bone. This foramen pneumaiicum is not present in the smaller cervical ver- 

 tebra [ib. figg. 1 — 3). The rudimental spinous process {ib. fig. 5, s) forms a transverse 

 barrier across the front of the depression between the posterior oblique processes, which 

 depression is broader and more rounded at the bottom than in the preceding vertebra, 

 and is quadrate, not triangular, in the present vertebra. 



The largest vertebra in Dr. Mackellar's collection is an inferior cervical one, corre- 

 sponding with that of the smaller species of Dinornis figured in Zool. Trans, vol. iii. 

 PI. XVIII. figg. 7, 8 & 9, in the presence, as in the Apteryx, of a compressed haemal or 

 inferior spinous process. In this character both species of Dinornis more resemble the 



