518 WALTER EDWARD COLLINGE. 
former as innervating the ventral portion of the mandibular 
branch of the sensory canal. 
I find that the ramus mandibularis—which is quite distinct 
from the ramus hyoideus—passes beneath the proximal head of 
the hyomandibular to the angle of the jaw, where it bifurcates 
and further divides into smaller branches (P1. 40, fig. 12, 7”.2’.). 
It innervates some of the primitive pores of the sides of the 
head and mouth, but not the mandibular branch of the sensory 
canal, as described by van Wijhe, which is supplied by the 
ramus opercularis superficialis No. 4 (Pl. 40, fig. 12, 7.0. 4). 
4, The ramus hyoideus is a large branch passing beneath 
the hyomandibular around the angle of the jaw and along the 
cerato- and epi-hyal. It does not branch from the ramus 
mandibularis, but is the ventral division of the ramus opercu- 
laris superficialis (P]. 40, fig. 12, 7..). It passes from the 
brain to the angle of the jaw beneath the hyomandibular 
branch of the sensory canal, and dorsal to the ramus man- 
dibularis. 
I regard van Wijhe’s ramus hyoideus (PI. 40, fig. 9, 7. A.) 
as homologous with the ramus opercularis superficialis No. 4, 
(Pl. 40, fig. 10), while I think he has mistaken the true 
hyoidean branch for what he describes and figures as the 
ramus mandibularis ext. (Pl. 40, fig. 9, 7. m”.). 
5. The ramus opercularis superficialis arises with the ramus 
hyoideus. Dorsal to the hyomandibular branch of the main 
sensory canal it divides into four branches. Nos. 1 and 2 
pass backwards and break up into a series of finer branches, 
The branch, 7. 0. 3, fig. 10, traverses the region between Nos. 1 
and 2 and the branch 4, This latter passes dorsally along the 
whole length of the hyomandibular branch of the main sensory 
canal, which it innervates, and its cluster of primitive pores. 
At the angle of the jaw, in the region of the symplectic car- 
tilage, it divides into two branches, which innervate the canals 
of the upper and lower jaws and the majority of the primitive 
pores. 
The ramus opercularis superficialis would seem to be a 
special branch of the facial for the innervation of the primi- 
