PEOFESSOR OWEX ON THE GENUS DINOENIS. 155 



'J'he parial hypapophyses (' catapophyses,' Mivart) commence at the fifth cel•^•ical as 

 low tubercular ridges. They come nearest to each other at the fourteenth, but do not, 

 in Binornis, circumscribe a haemal canal in any vertebra '. In the fifteenth cerncal the 

 parials combine to form a single medial hypapophysis near the middle of the length of 

 the under surface. 



In one skeleton of JD. elephantoims this coalescence takes place at a sixteenth cervical, 

 the antecedent series having one more vertebra than in the skeleton of D. mcLvimus 

 here described. 



The pleurajjophysial plate is sculptured outwardly by longitudinal ridges and 

 channels ; the riblet loses relative length after the sixth or seventh cervical. The pre- 

 and post-axial articular surfaces retain their essential character throughout, being con- 

 cavo-convex in opposite directions ; the fore surface is always superior in breadth, and 

 this dimension, though less in the hind surface, is greater than the vertical diameter. 

 A larger proportion of the neural surface of the fore end of the centrum is uncovered 

 by the neural arch after the third and fourth cervicals. 



From the neck series are selected vertebra; for views corresponding to some of those 

 given by Mivart of the Ostrich, which best illustrate the modifications of such vertebrse 

 in the larger flightless bird. 



SIXTH VERTEBEA (i nat. size). 

 Fig. U. 



Eig. 14, tamal (ventraJ) aspect. 



The hypapophyses in the sixth cervical (fig. 14, %) are oblong, smoothly obtuse 

 tuberosities. The exterior of the parapophysial part (p) of the pleurapophysial plate 



' Comp. with this modification the cerrical vertebra in the Flamingo (' Anat. of Vertehrates,' vol. i. p. 29, 

 tig. 20, h). 



VOL. X. — PART III. No. 4. — October 1st, 1877. z 



