408 Atnth of the. South African 



borders rounded oft". From the anterior end there runs a strong 

 ventral median keel which gradually dies away until it disappears 

 in the posterior third of the centrum. The whole vertebra is com- 

 pressed in the middle. The small diapophysis lies on the upper 

 half of the centrum. f-0 mm. from the anterior border. Below and 

 anterior to it is a small horizontal parapophysis. Between the two 

 is a fairly deep groove. The prezygapophyses extend well in front 

 of the centrum and have slightly convex facets. Seen from in front 

 they form between them a wide V-shaped groove for the reception 

 of the preceding postzygapophyses. Their lower borders are hori- 

 zontal, so tli at each process thickens rapidly laterally. The post- 

 zygapophyses are slightly shorter than the anterior processes. The 

 facets are slightly concave. The whole process is strongly built. 

 The neural spine is missing; but its base is long and narrow, and 

 the spine must have been low-. 



Dorsal. An anterior dorsal centrum (Cat. No. 3345a) has a length 

 of 102 mm.; its ends are 80 mm. high and 70 mm. wide. In the 

 middle the body is strongly constricted, having a width of only 24 mm. 

 The ventral border is concave and has a sharp longitudinal keel. 

 The ends are concave, equally so, and their ventral borders are 

 rounded off'. The parapophysis for the capitulum of the rib is midway 

 along the body in its upper half, directly below the transverse process. 

 The transverse process is 50 mm. long, placed above the middle of 

 the body. Its upper surface is Hat and horizontal, and its distal end 

 is considerably thickened so that its articular surface is roughly 

 triangular with a width of 30 mm., looking downwards and outwards. 

 The anterior border of the process passes directly into the outer 

 border of the prezygapophysis ; its hinder border is proximally emar- 

 ginate. The width between the facets of the transverse processes is 

 115 mm. The prezygapophysis extends in front of the centrum, and 

 is double the length of the postzygapophysis. The general shape of 

 the processes is of the normal Plateosaurian type. 



Two other dorsal centra are preserved (Cat. No. 3350) having the 

 following measurements : 



Length .... 105 mm. 110 mm. 



Height of anterior end. 80 ,, IX) ,, 



Height of posterior end 78 ,, 82 ,, 



Width of anterior end . 08 ,, 72 



Width of posterior end 03 ,, 72 ,, 



Median width 30 37 



