8o Annals of the Transvaal Museum 
a single lumbar vertebra. The anterior ribs are long and slender, while the 
posterior ones are short. In some of the ribs the proximal end is complete 
and is seen to be double-headed. 
Sacral Vertebrae. 
There is not much visible of the sacral vertebrae. The second shows its 
ventral surface, while the third shows its left side and partly its ventral surface. 
The posterior end of the first sacral protrudes from under the proximal end of 
the right ischium. The length of the centrum of the third sacral is 15 mm., 
while that of the second is 26 mm. The anterior corners of the ventral surface 
of the second sacral are truncated, probably by the articulation faces for the 
sacral ribs. These truncations reach backwards till past the middle of the 
ventral surface. A similar truncation is visible at the left anterior corner of 
the surface shown by the third sacral. 
There is a large brown patch with remains of bone to the right of the 
second sacral. I take this to be the second sacral rib of the right side. It lies 
at a distance of about 1 cm. from the vertebra. As preserved, the proximal 
end of this rib is very narrow and the distal end very broad. The anterior 
edge shows the original margin of the bone, 'which is very concave. None of 
the other margins have been preserved, except the anterior portion of the 
distal margin. The anterior portion of the distal end is very thin, and its 
outer margin is convex ; its upper surface is concave. The upper surface of the 
posterior portion of the distal end seems to have been convex and the whole 
distal end therefore shows a wavy appearance. The breadth of the distal end 
as preserved is 31 mm. and that of the proximal end 14 mm. The length of 
the rib as preserved is 20 mm. Behind the second there are remains of the 
third sacral rib. This is accompanied by its fellow on the other side of the 
third sacral vertebra. Both ribs lie at a distance of about 1 cm. from the 
vertebra. They are very badly preserved, but the contour of the distal end 
of the right rib seems to be complete on the slab figured on Plate IX. The 
anterior and posterior margins of the ribs are concave and the distal end is 
broad. Its outer margin is convex. The third sacral rib is very much narrower 
than the second. The length of the rib on the right is 21 mm., the breadth 
of its distal end 14 mm. and that of its proximal end 7 mm. 
The third sacral vertebra has been identified as such through analogy with 
other Anchisauridae and Plateosauridae . The specimen itself does not show 
any character which would class it immediately as sacral; on the contrary, 
its size and the shape and size of its sacral ribs agree so closely with the 
corresponding properties of the first caudal vertebrae, that without the know- 
ledge of other Theropoda one would without doubt regard it as the first caudal. 
Moreover, there is some doubt with regard to the second sacral. There is a 
slight suggestion in its shape that it represents two coalesced vertebrae; if 
these are the first and second sacrals, then it is difficult to conclude what the 
small bone may be which protrudes from under the right ischium. Its con- 
vexity and its convex free border strongly suggest the hinder end of a lower 
surface of a vertebra. Could it perhaps be a fifteenth dorsal? I doubt it and 
therefore I have regarded it as the first sacral. However, what is here called 
second sacral may be the coalesced second and third. But this is very im- 
probable, because of the first sacral not being coalesced. Moreover, the second 
sacral rib seems to form an unbroken series with what has been styled the 
third sacral rib and the first three transverse processes; the actual third sacral 
rib would then be missing. I do not see any reason which forces one to this 
conclusion, and therefore I have described these bones as above. Still it is 
