ENDOCRANIAL CAST FROM A REPTILE 139 
The epiphysis lacks the posterior prolongation, certainly it is 
not ‘subquadrate’ in form, and the lateral processes rise in front 
of, not at the sides of, the epiphysis. The olfactory tracts were 
much broader. The optic nerves did not escape through distinct 
foramina. Only the origin of the pituitary body is shown in 
Cope’s figures, but he describes it as small and occupying a 
fossa in the base of the cranial cavity. These characters support 
the evidence afforded by the bones of the skull that Desma- 
tosuchus must be placed, at least, in a distinct suborder from 
the Phytosauria. 
In considering the endocranial casts from the four very different 
primitive reptiles figured in this paper, it is certain that the brains 
of all had certain very distinctive characters in common. ‘The 
brain cavity was relatively long and narrow with small devel- 
opment of the cerebral hemispheres. The optic lobes and tracts 
were too small to leave any distinct marks on the casts, though 
they were probably well developed. The brain was sharply 
elevated in the middle portion with large epiphysial or para- 
physial processes. There was a sharp downward bend in the 
posterior portion. There is a considerable degree of constancy 
in the location of the origin of the cranial nerves. One thing 
is especially noticeable—the large size of the pituitary body in 
the giant forms. Tyrannosaurus was the largest of the cainivor- 
ous dinosaurs; Diplodecus was one of the largest creatures that 
has lived upon the earth; Triceratops was elephantine in size; 
Desmatosuchus, though not so large as the dinosaurs mentioned, 
was 10 or 12. feet long and probably a giant of its kind. In 
all of these forms the brain is exceedingly small relative to the 
body, but the pituitary body is very large relative to the size of 
the brain. The connection between the size and activity of 
the pituitary gland and the size and the proportions of the body 
in mammals is well known. MHyperpituitarism results in large 
size or the over-development of certain structures, as the fingers, 
features, etc. It is equally well known to paleontologists that 
one of the common variations among those which occur so 
abundantly in the senile stages of any phylum is giantism. 
The suggestion naturally rises that the disturbances which 
