I04 NERVE COMPONENTS OF BONY FISHES. 



and inserts into the first pbaryngo-branchial bone, thus passing more 

 obhquely and serving as a levator as well as a protractor. It is inner- 

 vated from the IX nerve. 



The fourth pharyngeal branch {pJi. X. 2.) arises directly 

 from the ganglion immediately behind the origin of the 

 truncus. It is mixed, containing both communis and 

 motor fibres. It passes directly ventrad and mesad to the 

 roof of the pharynx near the mid-line, passing along the 

 mesal face of the very strong m. obliquus dorsalis superior 

 and receives an anastomosing branch from the pharyngeal 

 branch of the third branchialis vagi, as described below. 

 In the roof of the mouth it turns cephalad, supplying 

 richly the racemose glands of this region, the taste buds 

 at their mouths and the small striated muscles at their 

 bases. 



The pre-trematic and post-trematic rami are as in the 

 preceding case. (Fig. i). 



V. — Third Truncus Branchialis Vagi. 



This trunk divides into pre- and post-trematic branches 

 immediately upon leaving the ganglion. Each of these 

 branches gives off a large pharyngeal ramus, the aggre- 

 gate number of these latter fibres being miich greater 

 than in any of the preceding branchial nerves. These 

 pharyngeal rami (/»//. X. j) pass ventrad to the superior 

 pharyngeal teeth; they probably also supply taste buds 

 adjacent. They anastomose freely with each other and 

 with the most caudal pharyngeal ramus of the second 

 division, so that the innervation of the roof of the pharynx 

 in this whole region is very intricate. These plexiform 

 anastomoses are not entered upon the plots. There are 

 also two motor rami. One passes directly from the gan- 

 glion to the fourth m. levator arcus branchii externus 



