150 



PEOFESSOE OWEN ON THE GENUS DINOENIS. 



atlas, and equals about 2| inches. The preaxial surface of the centrum (fig. 5, ex) is 

 twice as broad as high, and is concave transversely, but less deeply than it is neuro- 

 hagmally. It is not prolonged neurally, as in the Ostrich, " on to each side of the 



AXIS, or SECOND, VEETEBEA (natural size). 

 Fig. 4. Fig. .5. 



Pig. 6. 



Aspects. 

 Fig. 4, lateral ; -3, prea.xial ; (i, postaxial ; 7, haemal (or ventral). 



base of the odontoid process" i; a slight non-articular concavity separates it on each side 

 from the convex articular surface on the under part of the odontoid (figs, i and 7, 

 ca, 6). This surface is convex, narrower, and more produced than iu the Ostrich -. 



' Mivart, loc. cit. p. 391. 



- Ibid. fig. 12, 0. 



