GANGLIA AND NERVES OF SQUALUS 31 
line. The second primordium lies ventral to the anterior border 
of the eye and just anterior to the nasal capsule. There are 
six or seven twigs given off to this primordium which represents 
the anterior supraorbital lateral line organs. 
10. RAMUS BUCCALIS VII 
The ramus buccalis VII (figs. 1 and 4, R.B.VII), a pure lat- 
eral line nerve, arises from the ventral angle of the dorsal later- 
alis VII ganglion. It pursues a course directly ventral and 
slightly posterior to that of the r. max. VII, which it conceals 
partially from the lateral view. At the point of exit of this 
ramus from the ganglion and in the angle formed by the r. 
buccalis and r. oph. sup. VII on the anterior. border of the gan- 
glion arise two short twigs which run laterally to a primordium 
of a lateral line organ (fig. 1, Z.1). This is apparently the 
-primordium of the most posterior organs of the infraorbital line. 
When the r. buccalis reaches the level of the ventral border of 
the lens it gives off a twig to a primordium of lateral line organs 
(fig. 1, 1.3), after which it runs slightly cephalad and ventral 
to end under the posterior border of the eye. Near its termina- 
tion it gives off a twig to a second primordium of lateral line 
organs (fig. 1, £.4). Beyond this point it becomes an extremely 
delicate twig and disappears while in contact with the ecto- 
derm. While there are no primordia of lateral line organs be- 
yond this point, the relation of the terminal ramus to the ecto- 
derm leaves no doubt that it is lateralis in type. 
At the opposite posterior border of the ganglion and at a 
slightly more dorsal level near the point of contact between the 
dorsal lateralis ganglion with the auditory ganglion arises a 
second twig (fig. 1, R.O.), the first three divisions of which in- 
nervate a lateral line primordium (fig. 1, L.2) which is located 
where the supraorbital and infraorbital lines will probably join. 
This cannot be stated definitely, of course, since the lateral line 
organ primordia are discontinuous at this stage, as in Amelurus 
(Landacre, ’10). It would be interesting to follow the history 
of these primofdia in a close series in view of the author’s hypo- 
thesis based on a study of Lepidosteus (Landacre and Conger, 
