162 



MAEINE EEPTILES OF THE OXEOED CLAY. 



In the postaxial cervicals the articular ends of the centra are moderately deeply 

 concave, and in uncrushed specimens their vertical diameter is a little greater than the 

 transverse; beneath the neural canal the upper border is flattened. The sides of the 

 centrum are concave both from before backwards and from above downwards ; the 

 anterior and posterior borders are usually raised into a series of fine rugosities. The 

 ventral face is concave longitudinally and between the bases of the parapophyses from 

 side to side also, but behind these it is convex. The parapophyses, except in the last, 

 are situated near the front of the centrum and very low down, so that a line joining 

 the lower borders of the opposite parapophyses will pass beneath the centrum. The 

 parapophyses are very short — shorter, indeed, than in Steneosaurus — and at their outer 



Dorsal vertebra of HetriorhjncJius moreli : A, from front ; B, from below ; 

 C, from left side. (E. 2054, | nat. size.) 



a.z., anterior 7ygapopbysis ; d.p., diapophysial process ; n.sp., neural spine ; p.p., parapophysial 



process ; p.z., posterior zygapophysis. 



end they bear an articular surface, elongated in a horizontal direction. In the last 

 cervical the parapophysis passes up on to the side of the centrum, forming a strong 

 prominence immediately beneath the neuro-central suture. In the next vertebra, here 

 spoken of as the first dorsal, the parapophysis passes wholly or partly on to the neural 

 arch, but still arises quite separately from the diapophysis. 



The pedicles of the neural arch in the cervical vertebrae unite with the whole length 

 of the centrum. Just above the neuro-central suture and about midway between the 

 anterior and posterior ends they bear the prominent diapophyses, which increase in 



