170 Wortman — Studies of Eocene Mammalia in the 



seen perforating the transverse process at its junction with the 

 lateral mass of the bone. The anterior continuation of this 

 canal is a deep groove turning sharply upward to reach a 

 second perforation or deep notch in the anterior edge of the 

 superior arch, at the upper extremity of the oval cup-shaped 

 cotylus. This latter notch or foramen is known as the sinus 

 atlantis, and serves for the entrance of the vertebral artery 



104 



Figure 104. — Basal view of the skull of Nyctipithecus felinus. 



apf, anterior palatine foramen : ppf, posterior palatine foramen ; mf, 

 malar foramen ; vc, venous canal ; tof, temporo-orbital foramen ; fo, fora- 

 men ovale; ec, eustachian canal; pgf, postglenoid foramen ; earn, external 

 auditory meatus ; ace, accessory carotid canal ; cc, carotid canal ; smf, stylo- 

 mastoid foramen ; ftp, foramen lacerum posticum ; cf, condyloid foramen. 



and the exit of the first spinal or suboccipital nerve. Now, in 

 the lemurs and lower monkeys, a strong bony bridge is thrown 

 forward from the transverse process to the upper extremity of 

 the cotylus, so as to cover in that part of the canal or groove 

 where it turns sharply upward, and give separate openings for 

 the superior and inferior (anterior and posterior of anthro- 



