28 



TEETIAEY VEETEBEATA OE THE FAY^M. 



pair of hypapophysial prominences is present, and the neural spine is represented 

 by a W-shaped thickening. 



In the last cervical (text-fig. 10, E) the slightly biconcave centrum is still short, 

 somewhat more so dorsally than ventrally ; it is oval in outline. The neural 

 spine is represented by a blunt ridge. Behind the pedicle of the neural arch 

 there is a deep groove running down from the neural canal behind the transverse 

 process, which is here imperforate and has a blunt tuberous extremity. On the 



Axi 



Text-fig. 10. 



Cx4 



n.sji 



Dxi 



as/i 



Exi 



n.sp. 



Cervical vertebrae of Arsinoiiherium zitteli : A, third cervical, from front ; B, fifth cervical, from front • 



C, fourth cervical, from front ; D, ditto, from right side ; E, seventh cervical, from front. 



a.z., anterior zygapophyses ; <%>., diapophysial bar ; h^., hypapophyses ; n.sp., neural spine ; pj>; parapo- 



physial bar ; p.z., posterior zygapophyses ; t.jt., transverse processes ; v.c, vertebrarterial canal, i nat. size. 



hinder border of the centrum near its ventral angles is a pair of facets for the 

 heads of the first pair of ribs. These facets are continuous posteriorly with the 

 posterior face of the centrum and look outwards, backwards, and downwards. 



The thoracic series is not completely known. In the anterior region (text-fig. 11) 

 the centrum is wider than high ; its anterior face is flat, while the posterior face is 



