NERVOUS SYSTEM 



343 



TABLE IV. — Continued 



Conven- 

 tional 

 Numbers 



VII. 



Name 



Facial 



VIII. 

 IX. 



X. 



XI. 

 XII. 



Auditory 

 Glosso- 

 pharyngeal 



Pneumo- 

 gastric or 

 vagus 



Spinal 



accessory 

 Hypoglossal 



Origin and distribution 



Inside the skull it has a genicu- 

 late ganglion. Four main 

 branches. 



1. Superficial ophthalmic ; 



close to that of V. 



2. Buccal; across orbit 

 'vith maxillary branch of 

 V, and then to infraorbital 

 region. 



3. Palatine ; through orbit 

 behind maxillary branch of 

 V and mandibular branch 

 of V to roof of mouth. 

 Small. 



4. Hyomandibular ; divides 



into : 



4.1 Prespiracular ; small. 



4.2 Postspiracular, which 

 divides into : 



4.21 Internal mandi- 

 bular ; mucous 

 surface of lower 

 jaw and mouth. 



4.22 External mandi- 

 bular ; to hyoid 

 region. 



and 



or 

 re- 



To ear. 



Its ganglion is the petrosal ; to 

 ist gill cleft ; pre- and post- 

 trematic branches before and 

 behind cleft respectively, 

 dorsal pharyngeal branch. 



Its ganglion is the vagus 

 jugular ; many roots, to 

 maining gill clefts. 



1. Four branchial branches 



with distribution and com- 

 position as in IX. 



2. Lateral line nerve. 



3. The main part continues as 



the intestinal or visceral 

 branch, to gut and 

 heart. 

 Absent from the dogfish. 



Absent from the dogfish. 



Chief fibres 



Lateral line 

 Lateral line 



Visceral sensory 



Visceral sensory 



Visceral sensory 



Visceral motor, 

 visceral sensory, 

 and lateral line, 

 the first two 

 parts being some- 

 times distin- 

 guished as the 

 hyoidean. 

 Lateral line 

 Visceral sensory 

 fibres in all, and 

 visceral motor 

 in the post- 

 trematic. 



Lateral lino 

 Visceral sensory 

 and motor 



