FROM THE LIAS. 
127 
Case. Shelf. Specimen. 
88 c poral foss. Where the pterygoid is fractured 
in front it is seen to be underlain by a 
lamellar bone which extends inward to the 
pre-sphsenoid, and extends outward and 
forms the bony floor to the orbit. This 
bone externally meets the malar behind and 
corresponds with the maxillary in turtles 
and most reptiles. The malar appears to be 
style-like, bent so as to curve upward behind 
the orbit, where it is met above by the cres¬ 
centic post-orbital bone, which makes the 
back of the orbit, reaching up to the squa¬ 
mosal, which forms the outer border of the 
temporal foss; below the squamosal and pos¬ 
terior to the post-orbital is a squamous bone 
imperfectly preserved, the super-temporal of 
Owen, sometimes called supra-quadrate. 
On the superior surface is seen the frontal in 
front, giving off the post-frontals on each 
side. And posteriorly it will be noticed 
that the bones have been removed from the 
mesial region so as to expose part of the 
internal cast of the brain cavity, which is 
partly cut away behind. Supposing the brain 
to have filled the whole cavity, the cerebral 
lobes were large, high in front, and con¬ 
vex. 
In the orbital cavities are the remains of the 
eyes, large sub-hemispherical organs defend¬ 
ed with numerous thin plates of bone, which 
overlap each other, and in front leave an 
uncovered central part half the diameter of 
the eye. The eyes are vertical and look 
outward and forward. 
The lower jaw is in situ; and the form of the 
articular bone, which is partly exposed be¬ 
hind, is worth examination, being character¬ 
istic of all Ichthyosaurs. 
