FROM THE LIAS. 
125 
Case. Shelf. 
88 b 
Specimen. 
6 
the middle of the basal part of the inner 
side of the fang may be regarded as absorbed 
by the pulp-cavity of the successional germ 
tooth, just forming. 
two teeth of the Ichthyosaurus platyodon type, 
crushed and associated with jaw-bones. Pre¬ 
sented by Pev. W. Stokes. 
several smaller teeth of the Ichthyosaurus pla¬ 
tyodon type, associated in a slab with jaw¬ 
bones. 
associated teeth of Ichthyosaurus in a slab. 
The crowns are curved inward, and the 
sharp subdividing ridges upon the crown 
are continuous with the ridges on the fang; 
and where the thin enamel is removed from 
the crown there is no distinction between 
crown and fang. 
jaws of a blunt-nosed Ichthyosaurus, teeth with 
slender quadrate fangs, cut and polished to 
display the folds in the tooth substance. 
The denser substance of the crown may also 
be observed. 
a very slender tooth of Ichthyosaurus, finely 
striated. 
88 c 1 section through the jaws of a long-nosed Ich¬ 
thyosaurus to show the arrangement of the 
bones of the face and mandible, ps the 
median bone is the pre-sphenoid somewhat 
V-shaped in section, concave above, convex 
below, v 13 on each side of the pre-sphe¬ 
noid is the oblong section of the vomer, m 21 
on each side of the vomer is the maxillary. 
The cavity on the under side of m 21 appears 
to be the groove for the teeth. These bones 
form the palate at the upper and outer side 
of the mouth in this region; m 21 gives 
