Herrick, Cranial Nerves of Anibly stoma. 195 



lateral angle the various rami of the vagus spring. These rami 

 fall into four groups, three of which pass caudad and were not 

 traced to their terminations. Thejburth group contains several 

 rami which pass directly dorsad to end in the skin. 



The glossopharyngeus leaves the ganglion at the cephalo- 

 lateral angle and immediately breaks up into three rami. One 

 of these (5) passes laterad and caudad to the side of the neck, 

 and gives a small twig to the skin of this region. It then dips 

 ventrad into the first gill and turns abruptly cephalad, pursuing 

 its course immediately beneath the first epibranchial bar. A 

 little behind the point where this epibranchial bar passes 

 into the cerato-branchial cartilage this nerve gives off several 

 ramuli to the muscles of the first gill (r. br. 1); it then courses 

 forward to terminate in the sensory papillae of the dorsum of the 

 tongue. These latter fibres constitute the ramus lingualis. 



The second ramus of the glossopharyngeus (6) passes 

 forward immediately under the lateral border of the otic capsule 

 and divides into two ramuli, one passing laterally to the roof of 

 the pharynx, the other passing farther mesad in company with a 

 large blood-vessel lying between the otic capsule and the roof 

 of the pharynx. It was traced forward as far as the cephalic 

 limit of the otic capsule, where it forms an anastomosis with the 

 ramus palatinus caudalis of the seventh nerve. 



The third ramus of the glossopharyngeus (7) is the r. com- 

 municans cum n. faciali. In the earlier part of its course it 

 passes near to and parallel with the ramus last described. It 

 increases in size as it approaches the facialis and gives off one or 

 two small branches which are directed caudad to the under sur- 

 face of the m. masseter and which are probably derived from 

 the facialis. 



The acustico-facial nerve. The combined seventh and eighth 

 nerves arise by two roots which lie in immediate contact with 

 each other, but are quite sharply distinguishable. These roots 

 penetrate the medulla at the same transverse level, the ventral 

 one being considerably larger. The dorsal root (d) divides im- 

 mediately, one moiety passing directly into the ventral root, 

 the other passing forward to enter the Gasserian ganglion. 



