40 



MAEINE EEPTILES OP THE OXEOED CLAY. 



on the side of the centrum, the ventral face of which is here somewhat flattened. Tlie 

 vertebra in which the union of the two processes takes place is regarded as the first 

 caudal. In the portion of the precaudal region in which the diapophyses are distinct 



Text-fig. 26. 



Dorsal and caudal vertebne o£ OpIitJialmosaurus : A, last dorsal and two anterior caudal vertebroe from the 

 left side ; B, anterior dorsal, posterior face ; C, anterior caudal, posterior face. (Type specimen, 

 E. 2133, f nat. size.) 

 d., diapophysis ; n.c, floor of neural canal ; n.f., facet for neural arch ; p, parapophysis ; f.j}., transverse 

 process (combined diapophysial and parapophysial prominences). 



from the neurapophyses, they are situated a little farther forwards than the para- 

 pophyses, and in the anterior part of this region they are nearer the anterior than the 

 posterior border of the centrum. Throughout this region the anterior and posterior 

 surfaces of the centra are fairly deeply concave, and although the sides of the concavity 



