424 MR. ST. GEORGE MIVART ON THE 
with each lateral margin extremely concaye, through the two parapophysial processes 
which the centrum throws out. The preaxial one of these is the more considerable. 
The neural foramen of the centrum is again rather larger. 
THE THIRTY-FOURTH VERTEBRA. 
This vertebra (figs. 59, 60, & 61,6) has again its neural arch supported on two 
centra; but it rests rather more on its own. It has a larger dorsal defect of ossification 
(fig. 61, 6) than in the thirty-third vertebra, extending quite from the diapophysis to 
the neural spine. 
The neural spine is slightly less extended, though still anchylosed both pre- and post- 
axially, even in the young. 
Its diapophysis is rather longer (fig. 61, d°) than in the last vertebra, and inclined 
more preaxiad. Both the pre- and postaxial intervertebral openings are smaller. 
Its centrum, the ventral surface of which is exceedingly short antero-posteriorly, forms 
half of a large parapophysial surface (fig. 60, p°) at its preaxial part, and the greater 
part of a very much smaller parapophysial surface at its postaxial part. 
The neural foramen of the centrum is again large; it is here almost at its maximum 
(fig. 61, 6). 
THe THIRTY-FIFTH VERTEBRA. 
This vertebra (figs. 59, 60, & 61, 7) rests mainly on its own centrum. The postaxial 
intervertebral opening is bounded below by its neural arch. The defect of ossification 
of this neural arch is at its maximum (fig. 61,7), and more dorso-ventrally extended 
than in the thirty-fourth vertebra. 
The diapophysis is longer, almost as slender as in the last vertebra, and inclined more 
preaxially (fig. 61, 7). 
The parapophysial surface is much smaller, and is formed less by its own centrum 
than by that of the more preaxial vertebra. 
The postvertebral interspace is again rather smaller. 
The neural foramen of the centrum is smaller. 
THE SACRAL VERTEBRA. 
Tue Tuirty-sixtH VERTEBRA. 
This vertebra (figs. 59, 60, & 61, 8) is distinguishable in the adult as that which fur- 
nishes (from the preaxial end of its centrum) the first of those three parapophysial roots 
which ascend and meet together to form the large bony plate which abuts against the 
ilium just behind the acetabulum. 
In the young it is easily distinguishable as the most preaxial one which develops from 
the preaxial end of its centrum a suture-united parapophysial process or capitulum of 
a rib (fig. 60, p*). 
—~— oe 
Pag ON 
