Monograph on Dimorphodon. 131 
of the orbit, and covers the greater part of the cerebrum 
which consisted of two hemispheres, in which Oken recognized 
a resemblance to higher animals. 
“ The posterior vault of the skull is bird-like. The double 
arietal bone succeeds behind the principal frontal bone, and 
18 constituted as in birds. Geoffroy, regarding the mastoid as 
the parietal, described this bone in birds as the interparietal. 
“ upraoceipital seems to be single as in birds, and 
tolerably well expanded; it generally forms that part of the 
skull which lies furthest back. The side bone of the occiput 
{exoccipital] lies lower down x and was probably directed some- 
as in birds, and not as in mammals and reptiles. 
* Froriep's Neue Notizen, No. 5, Bd. xx. Oct. xm 
