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H. W. NORRIS AND SALLY P. HUGHES 



mandibularis and the ramus maxillaris such as Landacre de- 

 scribes. But during the progress of this research attention was 

 called to a laboratory dissection of an adult Squalus in which 

 there is a large anastomosis between the ramus mandibularis 

 and the infraorbital trunk. It arises from the ramus mandibu- 

 laris, as the latter is passing around the palatoquadrate bar, and 

 runs anterolaterally, then anteromesially, over the preorbital 

 muscle across the floor of the orbit to join the infraorbital trunk 



Fig. 33 A horizontal section through the trigemino-facial foramen, showing 

 chiefly the gasserian and geniculate ganglia. X30. 



at the region where the latter breaks up into its chief large 

 branches destined to the skin and lateral-line organs. It seem- 

 ingly joins a maxillary branch, and probably consists of somatic 

 sensory fibers that belong primarily to the ramus maxillaris. 

 As the ramus maxillaris is leaving its ganglion it gives off a 

 minute twig which passes ventrolateral^ around the ventral 

 I .order of the ramus buccalis VII out to the ramus mandibularis 

 V as the latter is passing around the lateral border of the palato- 

 quadrate bar. The small nerve in question does not unite with 



