166 



MAEINE EEPTILES OF THE OXFOED CLAY. 



The centra of the anterior caudals (test-fig. 65, A) have gently concave articular 

 ends, which are nearly circular in outline; they are considerably constricted in the 

 middle, and the first thirteen or fourteen, at least, bear caudal ribs, which are strongly 

 compressed from above downwards and diminish in size when followed backwards 

 in the series. The centrum of the first caudal is considerably shorter than that of 

 the second, behind which there is a gradual diminution in length to the end of the tail. 

 In the first two or three caudals no chevrons are present and the ventral faces of the 



az 



Caudal vertebra? of Metriorhynchus tee : A, anterior caudal from left side ; B, posterior caudal from front ; 

 C, ditto from left side ; D, vertebrae at bend of tail from left side ; E, first vertebra in deflected part 

 of tail from front. (E. 3014, | nat. size.) 



fl.p., anterior process of neural spine ; a.z., anterior zygapopbysis ; c.f., elievron-facets 

 i).sj>., neural spine ; p.:., posterior zygapopbysis. 



centra are evenly convex from side to side ; but further back, where the chevrons are 

 present, the ventral face is somewhat flattened, the borders of the flattened area forming 

 a pair of ridges which are obliquely truncated at their hinder ends by the chevron- 



