7540 PISCES— FISHES, 
IV. The pathetic or trochlear are small nerves emerging 
dorsally from between the mid- and hind- brain, 
and supplying the superior oblique muscles of 
the eye. 
VY. The trigeminal, or nerve of the “mouth-cleft,” 
arising from the medulla oblongata (as do all 
that follow), has a (Gasserian) ganglion on its 
root, and three main branches—the sensory 
maxillary, which unites with the inner buccal 
of VII.; the motor mandibular, which inner- 
vates the muscles of the jaws; and the sensory 
superficial ophthalmic (or orbitonasal), which 
runs over the eye to the snout, closely united 
(inside the same sheath) with a similar branch 
of VII. ; 
Parallel to these superficial ophthalmics, internal 
to and above the inner buccal of VII., there is 
a ganglionated ophthalmicus profundus, which 
sends branches to the eyeball, snout, etc. 
VI. The abducens, a slender nerve, arising near the 
mid-ventral line, adjacent to V. and VIII., and 
hidden beneath the former, supplies the external 
rectus muscle of the eye. 
WII. The facial, the nerve of the spiracular cleft, 
supplies all the five groups of ampullz on the 
head, and has numerous branches. 
1. The ophthalmicus superficialis runs over and past 
the eye, in intimate association with the similar 
branch of V., and supplies ampulla on the 
snout. 
2. The inner buccal runs under the eye, through the 
nasal capsule, to inner buccal ampulle. The - 
outer buccal runs under the eye, external to the 
olfactory capsule, to outer buccal ampullee. 
3. The large hyomandibular runs directly outwards 
behind the spiracle to hyoid ampulle. It gives 
off minor hyoidean nerves. 
4. The external mandibular runs behind and outside 
of the mandibular muscle to mandibular ampulle, 
and is a branch of the hyo-mandibular. 
5. The palatine descends in front of the spiracle to the 
roof of the mouth. Close beside it there is a 
prespiracular. 
