45 



anteriorly than posteriorly. The post-zygapophyses pro- 

 ject slightly backwards as distinct processes. 



Seventh Yertebra. — One strengthening ridge on each 

 side, but slightly cleft into two. Nenral spine more com- 

 pact and solid. Posterior zygapophyses are now distinct 

 tubercles projecting backwards from about the middle of 

 the neural arch. The anterior zygapophyses are, as 

 hitherto, except in the first -3 or 4 vertebrae, triangular 

 processes projecting forwards from the hase of the neural 

 arch. 



Eighth Yertebra (fig. 11). — Two moderate and one 

 weak strengthening ridge on the eyeless side and three of 

 about the same character on ocular side. Posterior 

 zygapophyses as in 7. Anterior zygapophyses much 

 stronger on eyeless side. Neural spine for the most part 

 consists of two hollow tubes placed side by side and con- 

 nected by a narroAv bridge of bone. 



Ninth Yertebra. — Two well marked strengthening 

 ridges and rudiment of another on eyeless side and two on 

 ocular side. Zygapophyses getting weaker. Neural arch 

 slightly, and neural spine markedly, asymmetrical, but 

 the centrum is almost symmetrical with the notochordal 

 canal in the centre. 



Tenth Yertebra (fig. 18, F.IO). — Two strengthening 

 ridges on eyeless side and three on ocular. Zygapophyses 

 somewhat reduced, and not much difference between those 

 of the two sides. Centrum slightly asj^mmetrical and 

 neural and transverse processes still obviously so, but the 

 tendency is now on the wane. The accessory and true 

 ribs of this vertebra are the longest of any. Behind both 

 decline in length. 



Eleventh Yertebra (fig. 18). — Three strengthening 

 ridges on eyeless and two on ocular side. Asymmetry 

 slightly less marked than in preceding vertebra. Zygapo- 



