The Cranial Nerves of Varanus bivittatus. . 465 
A. Ramus anterior \ to innervate the eomplieated structure of 
B. Ramus posterior / the inner ear. 
IX. Nervus glossopharyngeus arises as a single not very 
thiek nerve from the mid-lateral line of the medulla oblongata, a 
short distance posterior to acusticus. It emerges from the skull 
through the large opening in the exoceipital bone which contains 
also the saceus peri-Iymphatieus. The foramen opens externally, 
posterior and ventral to that of facialis and close to the columella 
auris. -Atter a short course posterior the nerve receives the con- 
necting branches from facialis: 
A. Rami communicantes (deseribed above), and also one from 
vagus, at a point where one would expect to find the ganglion 
petrosum. This swelling, however, was not distinguishable in all 
the speecimens examined. In one specimen a distinet enlargement 
was visible at this point. In several others none at all could be 
perceived. 
From this point of union of the various elements two main 
nerves arise: 
B. Ramus sympathicus has been already mentioned as coming 
originally from ramus palatinus nervi facialis. This nerve runs 
directly posterior, close to nervus vagus and the earotid artery to the 
region of the brachial plexus where it forms a series of small ganglia 
and connects the main nerves of the plexus. At the point where 
nervus sympathieus enters the body cavity a slight swelling oceurs 
which may be considered the ganglion of truncus sympathiei, and from 
this point a small branch connects with ganglion of truncus vagi. 
C. Ramus pharyngo-laryngeus is the main end stem of glosso- 
pharyngeus proper. It curves around the lateral end of the anterior 
hyoid bone and running parallel to this bone near its posterior edge 
it passes over the ventral surface of muse. hyoglossus, covered from 
the ventral side by muse. geniohyoideus. When it reaches the 
anterior hyoid bone it passes dorsal to it and to muse. hyoideus 
and reaches the trachea where it takes the name of: 
a) Ramus pharyngeus and runs anteriorally to innervate the 
pharynx. Here it forms a sling, the laryngeal commissure, ‚with 
ramus recurrens nervi vagi, at which point a fine branch crossing 
ventrally to the larynx connects the branches from the two sides. 
From this sling fine branches are given off to the muscles of the 
larynx and a fine end branch sub-divides in the membrane posterior 
to the base of the tongue. 
