1870. ] HULKE—KIMMERIDGE PLESIOSAURIAN REMAINS. 615 
out the rest of the neck, and in the vertebre referred to the early 
thoracic segment of the spinal column, no anchylosed transverse 
process occurs; but the side of the centrum bears a costal pit at a 
higher level than the line of attachment of the transverse processes 
in the earlier cervical vertebree. This pit, when relatively low on the 
side of the centrum, is a circular or roundly oval hollow, with swollen 
edges ; but as it rises upwards towards the root of the neurapophysis 
(or descends from it, in the case of the lumbar vertebree) it becomes 
elongated vertically, until its vertical diameter in some vertebre is 
nearly double the horizontal. With the recession of the transverse 
process, and later of the costal pit, from near the under surface of 
the centrum, this surface becomes less flattened, it is more convex 
transversely, and the narrow median ridge is replaced by a broader 
swelling. The vascular foramina are in many instances more than 
two, and they are not regularly placed. All the dorsal vertebree are 
more or less mutilated and crushed. The contour of their centrum 
is more circular than in the other regions, owing to the absence of 
transverse processes from its outer surface. The articular faces 
are gently hollow: their contour is a full oval figure, emarginate 
above at the canal. Some mutilated neural arches severed from 
their centra have been preserved. The neurapophyses are stout, 
shorter antero-posteriorly than in the neck. They rake slightly 
forwards. ‘The transverse processes stand outwards and upwards 
from the arch. They are strong, horizontaliy compressed blades, 
having a stout and straight upper edge, and a thinner concave lower 
one. Their outer end expands slightly, and it is obliquely cut as 
in Plesiosawrus brachistospondylus. ‘The caudal vertebree are distin- 
guished by the flatness of the under surface of the centrum, as 
well as by the chevron-facets. These latter are absent altogether 
from the largest (first?) caudal; and the second to the fifth of the 
series have them on the posterior margin only ; while the sixth and 
all those succeeding it have two facets on the anterior, and two on 
the posterior margin. In the hinder caudals the four chevron-facets 
enclose a deep hollow. The transverse processes have a conical base 
projecting horizontally from a prominent tubercle on the side of the 
centrum, about midway between its under surface and the neurapo- 
physis. Most of them are anchylosed to this tubercle, the line of 
union being marked by a slight cingulum. In a few of the hind- 
most caudals the transverse processes were not anchylosed and have 
become detached, discovering a deep excavation in the end of the 
process-bearing tubercle. 
Ribs.—Of these a very large number of fragments have been pre- . 
served. Most of these represent broad, horizontally compressed, 
flattened and channelled ribs, with a simple, vertically extended, 
roughened capitulum, corresponding in shape and size to the termi- 
nal surfaces of the transverse processes of the middle dorsal region. 
A smaller number of fragments indicate short subcylindrical ribs with 
a simple, smooth, rounded capitulum ; they are doubtless the flanking 
ribs detached from the prethoracic and lumbar yertebree. In ad- 
dition to these two kinds of vertebral ribs, a great many smaller 
VOL, XXVI.—PaRT I. az 
