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have do special related epibranchial ganglion, runs outward behind 

 the eye directly to the skin in the infraorbital region, where it inner- 

 vates the infraorbital lateral sense organ or organs. Branch h is 

 quite certainly a nerve that I shall describe below as a branch of the 

 r. maxillo-mandibularis; and, as already stated, branch c, but for the 

 fact that it is said to run outward behind the eye, would seem to be 

 the nerve that I have described as the ophthalmicus lateralis. 



Trigeminus II. 



The maxillo-mandibularis, or Trigeminus II portion of the tri- 

 geminal ganglionic complex presents, in its anterior portion, two 

 somewhat separate regions, an antero-mesial and a postero-lateral one. 

 The antero-mesial portion projects forward as a slight and wholly 

 separate process. Posteriorly it fuses completely with the larger, 

 postero-lateral portion. The antero-mesial portion lies ventral or 

 ventro-mesial to the ophthalmicus ganglion, and it is the only part 

 of the maxillo-mandibularis ganglion that comes into close juxtaposition 

 with that ganglion. The postero-lateral portion of the ganglion lies 

 ventro-lateral to the posterior portion of the ophthalmicus ganglion. 

 The antero-mesial portion lies immediately dorsal or dorso-lateral to 

 the trabecula, and is separated from the overlying ophthalmicus 

 ganglion, through nearly its entire extent, by the sheet of fibrous 

 tissue, already referred to, that forms either the floor of the anterior 

 part of the trigemino-facialis chamber, or a horizontal partition in that 

 part of the chamber. 



From the anterior end of the antero-mesial portion of the ganglion, 

 a single nerve arises, which, from its distribution, will be called the 

 ramus palatinus trigemini. It separates immediately into two branches, 

 a dorsal and a ventral one. 



The dorsal branch runs forward across the bar of cartilage 

 already once referred to, that Ayers and Jackson consider as a short 

 thick, lateral process of the trabecula, and passing ventral to the 

 opticus reaches the ventro-mesial aspect of the ramus ophthalmicus. 

 In a part of its course up to this point it traverses a short, three- 

 sided tube formed by the trabecular cartilage ventrally, a stout fibrous 

 membrane dorso-laterally, and a similar membrane ventro-mesially. 

 These two membranes arise together as a single, thick, stout mem- 

 brane from the membranous side wall of the cranium, and spreading, 

 pass, the one to the lateral edge of the trabecular cartilage, and the 

 other to the mesial edge, thus straddling the nerve. This membrane 

 thus certainly represents a process or part of the membranous skull, 



