OF THE SKULL IN THE URODELOUS AMPHIBIA. 
549 
as if the process in question divided the foramen of exit of the trigeminal nerve into 
two parts. 
“ The ganglia of the trigeminal and of the seventh nerves are situated, close together, 
above the trabecula, 'where it passes into the floor of the auditory capsule — the Gasserian 
ganglion [Plate 22. fig. 4] lying in front of the anterior wall of the capsule, while 
the ganglion of the seventh, which is very closely connected with the auditory nerve, is 
placed rather on the ventral side of the anterior end of the capsule [Plate 22. fig. 5, 
7 )]- 
“ The posterior division of the seventh nerve (which answers to what is commonly 
called the facial nerve, and may be termed the hyomandibular division of the seventh, 
runs directly in front of the auditory capsule, and beneath the otic process of the 
suspensorium [fig. 5, ot.p., 7 2 ]. The anterior division (palatine or Vidian division) 
of the seventh [7 1 , fig. 5], on the contrary, passes directly forwards, close to the pedicle 
of the suspensorium, parallel with the orbito-nasal, and below but external to it” 
(Huxley, op. cit. pp. 191, 192). The ganglion of the glossopharyngeal and vagus nerve 
(9, 10) is seen wedged in between the posterior internal face of the auditory capsule 
and the investing mass ( iv .). The auditory or eighth nerve cannot be seen in these 
views ; it enters the inner face of the capsule not far behind the Gasserian ganglion. 
Before leaving this 4 th stage, I would remark upon the importance of the new ptery- 
goid wing that has grown backwards from the dentigerous, primary palatine. In this 
now enlarged tract we have one bony centre reaching from the quadrate to the vomer. 
I have already remarked upon the presence of this bone in the “ Dipnoi ” — a group 
where we see the dermal plates appearing as deep layers, and becoming especially 
correlated to certain territories of the chondro cranium. We have a similar relation of 
a few subcutaneous or submucous bones to the cartilaginous endocranium in the low 
Urodeles and in the larvae of the higher types. 
It is, however, extremely remarkable that in many of the “ Sauropsida ” one bony 
bar runs from the quadrate to the vomer — in Snakes and Lizards to the greatest extent, 
the elongating face necessitating the intercalation of the whole (Snakes) or part (Lizards) 
of the palatine between the end of this palato-pterygoid bar and the vomer of that 
side. 
In Anguis fragilis the palatine intervenes very little, and, contrary to what is general 
in Reptiles, the fore half of the palato-pterygoid bone is segmented from the hind half 
to form a “ mesopterygoid;” we shall see this state of things higher up. 
In Hatteria (Gunther, Phil. Trans. 1867, part 2, plate 1, p. 5) there is a long 
palato-pterygoid bone, undivided, and reaching the whole distance from the quadrate 
to the vomer of that side. In the Ostrich ( Struthio camelus) (see my paper on the 
skull of the Ostrich tribe) the pointed end of the pterygoid scarcely reaches the huge 
vomer (a double coalesced bone) ; but in the other types (Rhea, Rromceus , Casuarius , 
Tinamus ) these bones meet. 
But in the Carinate birds generally (and I have examined and figured these parts in 
