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and is seen as a slender nerve passing forwards over the 
eye and somewhat near the skin, which it supplies with 
general cutaneous fibres. It is not free from lateral line 
fibres, as shown by the little plexus mnervating sense 
organs 3 to 5 of the supraorbital canal. 
The Truncus infraorbitalis (¢. znf.), consisting of the 
T. maxillo-mandibularis + lateral line and communis 
components from the facial, arises ventrally from the 
Gasserian ganglion and passes sharply downwards and 
forwards. It soon splits into two large nerves as follows : 
3. R.maxillaris superior (or R. maxillaris—m.r. v.).— 
Closely accompanied by a lateral line component from the 
facial, which will be described in its proper place. It. 
consists largely of general cutaneous fibres, and possibly 
also transmits some communis vil. fibres. It passes 
straight forwards across the orbit on to the upper jaw, 
and gives off a cutaneous twig in front, accompanying the 
lateral line component, and is finally distributed mostly 
to the skin of the anterior part of the face. 
4. R. maxillaris inferior (or R. mandibularis— 
man. v.)—May also contain a communis component. 
Divides at once into a smaller upper and a larger lower 
branch. Both give off some purely motor branches, and 
the nerve is thereafter continued obliquely downwards 
and forwards across the orbit in two sections—a smaller 
upper and a larger lower. ‘The former contains a few 
motor fibres, the latter more of the same, the remaining 
fibres being of small calibre and staining very faintly. 
The upper one bifureates, each half containing both the 
sensory and motor fibres, and terminates in the posterior 
region of the orbit. The lower one passes forwards, 
following the ventral curve of the orbit, and giving off 
several branches on the way, on to the lower jaw, on which 
it ends. At about the anterior region of the orbit it gives 
