56 
ICHTHYOSAURIA FROM THE 
Case. Shelf. No. 
IX g 1—14 The vertebrae (#.10 and 11) are worth 
examination, as they are from near the 
most flexible part of the tail, having the 
intervertebral articular surfaces round¬ 
ing and extending to the mesial part of 
the centrum. It was on the evidence 
of such like vertebrae that whales were 
attributed to the Cambridge Greensand 
fauna. 
IX h 1—6 Cervical, early and late caudal vertebrae. 
These most resemble in form and size the 
series on Shelf #, but in antero-poste- 
rior extent are shorter; the neural arch 
also is smaller, and the costal tubercles 
are relatively large, though not elon¬ 
gated as in d. 3—9. h.6 is a very 
cetoid-looking bone. 
h 7—12 - Early dorsal, mid-dorsal, and caudal. 
An animal with the early and mid-dorsal 
vertebrae broader from side to side than 
in any of the foregoing series. The 
elevated rounded bosses for the ribs are 
wide apart; the neural arch is wide. 
The haemal surface is rounded. 
h 13—17 Examples of caudal vertebrae. 
13 and 14 are vertical sections through an 
early caudal vertebra, to show the con¬ 
vexity of the outer two-thirds of the 
cup characteristic of caudal vertebrae. 
16 and 17 are from beyond the region of 
ribs, near the termination of the tail. 
They differ from most of the vertebrae 
from that region in their remarkable 
shortness. 
