114 
PROFESSORS T. W. BRIDGE AND A. C. HADDON 
arches of any of the modified anterior vertebrm (fig. 31). The spinous processes of 
the third and fourth vertebrae are distinct and divergent, the former being directed 
obliquely forwards to its connection with the exoccipitals and supraoccipital, while 
the latter which is much the longer inclines obliquely backwards (fig. 31, n.s.^). 
The spine of the fifth vertebra is much shorter and inclines forwards and may abut 
against the posterior margin of the preceding spine (?i.s.®). The remaining spines 
are bifid and normal. 
The transverse processes of the fourth, fifth, and sixth vertebrae are all more or less 
fiattened and expanded, suturally articulating with one another by slightly serrated 
margins ; their distal extremities are free, being separated by wide clefts. By the 
expansion and sutural union of these processes an unusually extensive wing-like 
lamina of bone is formed on each side of the anterior vertebrae, which is somewhat 
concave from before backwards and also from side to side, in conformity with the 
convex dorsal w^all of the anterior chamber of the air-bladder (fig. 32). The transverse 
process of the fourth vertebra is the largest of the three, and distally is cleft into the 
usual anterior and posterior divisions {t.p.hi., The anterior division 
is much thickened and, in addition, is slightl}^’ decurved at its free extremity so as to 
form a partial support to the lateral portions of the anterior wall of the bladder ; 
anteriorly, the distal end of the process articulates by means of a roughened facet 
wdth the outer extremity of the inferior limb of the post-temporal, and also with the 
cleft stem of that bone, thus forming an incomplete posterior boundary to the socket 
for the head of the clavicle (fig. 34, t.p.'^a.). The posterior division is a broad thin 
horizontally disposed lamina. The transverse process of the fifth vertebra (fig. 32, t.p}) 
is nearly as large as the preceding process, the posterior division of which it very 
closely resembles. The transverse process of the sixth vertebra though more 
expanded than any which succeed it, is by far the smallest of the modified processes 
and carries the first rib (r.'). 
A thick layer of superficial ossified deposit appears to invest the lateral and ventral 
surfaces of the anterior vertebral centi'a from the first to the sixth, inclusive, and also 
to extend laterally on to the adjacent ventral surfaces of the roots of all the modified 
transverse processes, thus converting the lateral grooves for the posterior cardinal 
veins into canals of exceptional length (fig. 32, cd.c.). Apparently as the result of 
the ventral growth of the ossifications round the dorsal aorta, the artery in this part 
of its course is completely enclosed within a bony canal (figs. 31 and 32, ax.) which 
appears to burrow its way through the different centra, and opens anteriorly on the 
body of the first vertebra and posteriorly on the centrum of the sixth. The sutural 
lines between the modified transverse processes may be traced inwards on the super- 
ficial ossifications investing the different vertebral centra in the form of irregular 
wavy lines, wdiich roughly indicate the position of the intervertebral sutures but 
without precisely coinciding therewith (fig. 32). The dorsal laminae are represented 
on each side by a thin narrow process of bone (fig. 32, d.l.) which extends from the 
