GANGLIA AND NERVES OF SQUALUS BE 
settled on older material than that at my disposal. From the 
material at hand the evidence seems to be against such a view. 
If they are found in other vertebrate types they should certainly 
be expected in such a generalized type as the shark. 
17. THE GLOSSOPHARYNGEAL GANGLION AND ROOT 
The glossopharyngeal ganglion is elongated in its dorso- 
ventral axis, extending from the middle of the medulla ventrally 
and slightly caudad nearly to the level of the roof of the pharynx. 
It contains two easily recognizable divisions; the proximal is 
the lateralis IX ganglion (figs. 1 and 6, G.L.JX) and the distal 
and ventral division is the visceral division or ganglion petro- 
sum (figs. 1 and 6, G.V.JX). The proximal division extends 
from the point of contact with the medulla to the point of ori- 
gin of the ramus supratemporalis IX (figs. 1 and 6, R.St.1X). 
The two ganglionic masses are in contact at this point and can- 
not be distinguished with certainty but throughout the re- 
mainder of the extent of the lateralis ganglion the visceral gan- 
glion is represented by a fibrous root apparently not accom- 
panied by ganglion cells. A short distance ventral to the origin 
of the ramus supratemporalis the lateral line ganglion cells 
cease and it could not be determined with certainty that no 
lateral line fibers entered the truncus glossopharyngeus. No 
lateral line primordia are innervated, however, by that nerve 
beyond those mentioned below and presumably no lateral line 
fibers enter it at this stage. 
The root of the lateral line IX (fig. 1, Rt.L.7X+X) passes 
dorsally, mesial to the posterior end of the auditory capsule, 
along with visceral sensory and motor fibers of the. truncus 
glossopharyngeus. In that part of their course between the 
proximal end of the ganglion and the medulla both the lateral 
line root and the visceral sensory and motor roots are fibrous 
and form a compact bundle. Unless, however, the lateral line 
fibers change their position in this region of the root, the vis- 
ceral fibers, both motor and sensory, enter at a somewhat more 
ventral level where they join a more mesial column than the 
