1046 
MR. J. W. HURKE OK THE OSTEOLOGY 
or sacral foramina. The root of each lower tranverse process is therefore connected 
with two centra, that of the first transverse process, stouter than the others, being 
attached to the terminal lumbar and the first sacral centrum. The construction is 
that which is usual in the dinosauria. The length of the sacrum represented in 
Plate 75 of one in Mr. Fox’s collection is 8’3 centims., and the average length of 
the centrum is 17 miliims. The length of the last lumbar vertebra in another 
skeleton in the same collection is 18 miliims., the diameter at the constricted 
middle is 14 miliims., and that of the expanded posterior end is 18 miliims. The 
superior bulk of the last lumbar centrum 
is well shown in 
two sacras 
in my own 
collection. 
Dimensions of centra in two sacra. 
Horizontal 
Horizontal 
Horizontal 
Length. 
diameter at 
diameter at 
diameter at 
1. In Mr. Fox’s Collection.- 
front. 
middle. 
posterior end. 
—1st sacral 
15 
21 
10 
15 
2nd „ 
15 
15 
10 
15 
2. In No. 110 Coll. Hulke.- 
—1st. sacral 
17 
19 
13 
16 
2nd „ 
17 
16 
14 
In the sacra to which reference has been made, the last centrum is too mutilated for 
description. One from a larger individual is 22 miliims. long. Its anterior articular 
end, marked with the diverging striae present before anchylosis, has a vertical diameter 
of 14*5 miliims., and a horizontal diameter of 19'5 miliims. The shape of the centrum 
is cylindroid. A mutilated transverse process, preserved on the left side, is attached 
to the upper part of the side of the centrum, at its front, for a space of 13 miliims., 
and since the sutural surface of the process projects 3 miliims. in advance of the 
anterior articular end of the centrum, it must to this extent have rested on the cen¬ 
trum in advance. The fifth sacral nerve escaped behind the transverse process 
through the intervertebral foramen between this and the first caudal vertebrae. The 
prsezygapophyses look upwards, and slightly outwards. The spinous process, 21 
miliims. long and 14 miliims. wide at its free end, has a slight backward slant. 
Post-sacral or caudal vertebrce (Plate 74, figs. 9-13 ; Plate 75).—The first is known 
by the absence of chevron-facets, and the second by the presence of a single facet, the 
first chevron bone being articulated with the second and third caudal vertebrae. In 
shape the two foremost caudal centra resemble the last sacral, but the lateral surfaces 
below the transverse process are more flattened, which makes the third and succeeding 
centra less cylindroid. Transverse processes are present in about the first fourteen 
vertebrae, counted from the sacrum. Those of the first caudal are small and short, they 
project from the side of the centrum immediately below the neuro-central suture. Those 
of the second caudal vertebrae are longer and flatter. The length of the transverse 
process increases until about the eighth vertebra, behind which it rapidly shortens 
