348 
May 11, 1874. 
THE PRESIDENT (PROFESSOR BABINGTON) in the Chair. 
The following communication was made to the Society : 
On the Bearing of the Distribution of the Portio Dura 
wpon the Morphology of the Skull. By T. H. Hux- 
LEY, Sec. R.S. 
In the first place, the distribution of the seventh nerve or 
portio dura in Man was compared with that of the same nerve | 
in the amphibia ; and it was shewn that, while the proper facial 
nerve, with the chorda tympani, corresponds in all essential 
respects with the posterior division of the seventh nerve in the 
Frog and other amphibia, the nervus petrosus superficialis major 
or vidian nerve, with its palatine branches and the nerve of 
Cotunnius, answers to the anterior division of the seventh, or 
so-called “palatine” nerve of the Frog. A branch which, in 
the Urodela, connects the portio dura with the Gasserian. 
ganglion, appears to be the homologue of the nervus petrosus 
superficialis minor. The tympano-Eustachian passage, in both 
Man and the Frog, is included between the two main divisions 
of the portio dwra.—The distribution of the seventh nerve in 
the Ray was next described. Its two divisions were shewn to 
have the same relation to the spiracle as they have to the 
tympano-Eustachian passage in the higher vertebrata. The 
anterior division, however, differed from that of the Frog and 
that of Man, in possessing no branch comparable to the nerve of 
Cotunnius. The place of this nerve appears to be taken by a 
large ‘palato-nasal’ branch of the fifth (as Bonadorff has already 
suggested), and it was suggested that the Cotunnian branches 
of the palatine nerves in the Frog and in Man really belong to 
the Trigeminal. The distribution of the portio dura was then 
