70 
ICHTH YOSA TJRIA FROM TEE 
Case. C'ornp. Drawer. Specimen. 
J f iii 56—65 upon it is a partially developed tooth 
with a circular base, still surrounded 
with the walls of the old tooth fang, 
now absorbed to extreme thinness. On 
the left is the smallest of germs just 
growing in a cavity on the fang, to 
which it appears to be adherent. 58— 
61 are teeth of Ichthyosaurus which 
have lost their external enamel and so 
present smooth crowns. 
J f iv 1—23 Associated vertebrae, chiefly neck and tail 
bones of an Ichthyosaurus. They in¬ 
clude basi-occipital, atlas and axis, 9 
cervical vertebrae, 3 dorsal and 9 early 
caudal vertebrae. With them were found 
as many more of the bones of the back 
in a bad state of preservation. The 
cervical vertebrae have the heads for the 
ribs wide apart, the lower one below 
the middle of the bone and adjacent to 
the anterior border, while the superior 
one is much larger, a little further 
backward, and so placed that while the 
upper head of the rib must have touched 
the base of the neural arch it was yet 
chiefly supported on the centrum. The 
caudal vertebrae numbered 20, 21 and 
22 are remarkable for the flatness of 
the outer part of the articular cup. As 
usual the caudal and dorsal vertebrae 
are larger in the outline of the cup than 
the cervical vertebrae. 
v 1—25 Much of the vertebral column of an Ich¬ 
thyosaurus, presented by J. F. Walker, 
Esq. 1, atlas and axis. 2—9, probably 
cervical vertebrae, though from the low 
j / 
