Case. 
IX 
CAMBRIDGE UPPER GREENSAND. 5 7 
Shelf. No. 
i 1—4 Atlas and axis anchylosed, cervical, mid¬ 
dorsal, and early caudal vertebrae. 
These bones are rather larger than the 
dark series h. 7—12, but show essen¬ 
tially the same characters. The atlas 
and axis are not well preserved; the 
axis has two tubercles for the rib, the 
upper one so large that but a very small 
part of the rib could have been sup¬ 
ported on the neural arch. The broad 
cervical vertebra similarly shows the 
upper facet large, concave, and entirely 
on the centrum. This structure prevails 
in all the cervical vertebrae of Cretaceous 
Ichthyosaurs in the Woodwardian Mu¬ 
seum, and no indications are seen of the 
upper rib-head being supported on the 
neural arch, as described from Lias spe¬ 
cimens by Professor Owen. 
i 5 —9 Early and late dorsal and caudal vertebrae. 
They are short from front to back. The 
caudal vertebrae are shorter than those 
from the dorsal region; vertically they are 
very high, narrow from side to side, and 
flattened on the ventral surface. 
i 10—14 Examples of early and lower dorsal vertebrae. 
Well preserved bones belonging to dif¬ 
ferent species. 
i 15 [? cervical] vertebra of Ichthyosaurus from 
the Hunstanton limestone of Hunstanton, 
not well enough preserved to determine. 
Under i are 4 large vertebrae rejected from 
the foregoing series. 
