MUE.^NOSAUEUS. 



99 



vertebrae, sloping backwards at its base and then turning to a vertical direction ; its 

 upper end is abruptly truncated by a surface for cartilage. Near the base of the spine 

 on both the anterior and posterior edges there is a deep vertical groove for the 

 attachment of ligaments ; on the posterior surface this groove separates the posterior 



Text-fig. 54. 



Middle dorsal vertebra of MurcBUOsaurm durobrivensis, from frout. (E. 2863, f nat. size.) 



a.z,, anterior zygapophysis ; n.c, neural canal ; n.s., neural spine ; )'./., facet for rib ; 



t.p., transverse process. 



zygapophyses (p.z.). These form strong prominences and their articular surfaces, 

 which are convex from side to side, look nearly directly downwards. The anterior 



o2 



