TERTIARY YERTEBRATA OF THE EATtjM. 
and tlic oxocci])ital, internally by the basioccipital and basisphenoid, and anteriorly by 
the alis])lienoid, tlie foramen lacerum medium [ f.l.m.), and perhaps the pterygoid. 
I'iXternally the bone seems to send a narrow wedge-shaped process between the 
post-tyrnpanic ])rocess and the inner end of the glenoid surface, thus helping to 
Text-fi". 49. 
tAL 
The base of the skull and part of Ihe palate of : A, raJevomastodon ; B, Elephas. 
nl.r., alisphenoid canal ; «?s., alisphenoid ; a.o.f., antorbital foramen; ?>oc., basioccipital ; fep., basisphenoid; 
eu., eustaebian opening ; exo., exoccipital ; f.l.m., foramen lacerum mc'dium ; fd-])-, foramen lacerum 
posted us ; /.o., foramen ovale ; p?., glenoid surface for mandible; i.c.c., foramen for internal common 
carotid ; i.n., internal nares ; ju., jugal ; m. 2, m. ‘A, second and third molars ; ])alatine ; p.p-f-i 
posterior palatine foramen ; ]xu’occi[)ital process ; , pterygoid ; post-tyitipanic ])rocess of 
squamosal ; st.rnf., stylo-mastoid foramen ; tympauo-byal ; ty., tympanic ; v., vomer, .j nat. size. 
eu 
I jell. 
hoc. 
ICC. 
form the floor of the inner end of the external auditory meatus. In front of this the 
bone is excavated by the deep fossa referred to above ; this seems to have opened into 
