FIGURE 7 



Section of head of 20 mm. human embrj'o, passing through foramen magnum, 

 otic capsules and tip of dorsum sellae. 



1, Occipital wing 



2, Lamina alaris 



3, Jugular recess 



4, Internal occipito-capsular groove 



5, Commissura occipito-capsularis 

 6 Utriculus 



7, External canal 



8, Posterior canal 



9, Membranous anlage of side wall 



of skull 



10, Tip of dorsum sellae 



11, Commissura praefacialis 



640 



