322 CHORDATA. 
obliguus superior with its trochlear nerve, and the rectus 
superior, externus and internus muscles. The rectus ex- 
ternus is supplied by the minute sixth (abducens) nerve 
which is not easily seen. The other four are supplied by 
the third or oculomotor. (For list of these muscles see 
page 410.) 
Running over the bases of the upper eye-muscles is a 
long nerve called the ophthalmicus superficialis. It enters 
the orbit posteriorly and leaves it anteriorly to pass for- 
wards to the rostrum. It is a compound nerve formed of 
the fifth and seventh. Entering the orbit and leaving it 
by the same foramina-as this nerve. is another, called the 
ophthalmicus profundus. It, however, lies below the three 
upper eye-muscles (¢e., rectus superior, obliquus superior, 
and rectus internus), though well above the other eye- 
muscles and the optic nerve. 
A very little dissection between the auditory capsule and 
the mandibular muscle will reveal a large nerve, the yo- 
mandibular, an important branch of the seventh nerve 
which can be traced to ampullz or sensory tubes in the 
skin and backwards to the front of the auditory capsule. 
It gives off a large external mandibular round the outer 
folds of the mandibular muscle and other branches which 
are the recurrent facial, internal mandibular,* facial proper 
and hyotdean. 
If the eye be now carefully removed by cutting the 
eye-muscles and optic stalk and the orbit be cleared, 
a number of deeper nerves are brought into view. The 
outer buccal (VII.) is a large branch easily found lying 
between the olfactory capsule and the mandibular muscle. 
It runs across the floor of the orbit and outwards to 
ampulle. Very deep in the orbit, below the ophthalmicus 
profundus, lies the zamer buccal (VII.) passing to the roof 
of the mouth. In the angle formed by the two buccals lie 
the maxillary (V.) to the upper jaw and the mandibular (V.) 
to the lower jaw. 
Lastly, in front of the spiracle is a palatine (VII.) with a 
branch, the prespivacular (VII.).t 
* This nerve is also sometimes termed the chorda tympani. 
+ These lie very deep on the actual roof of the mouth. 
