RAMUS MANDIBULARIS VII. 147 



far forward as the cephalic end of that arch (400). The 

 latter distributes in the same way to the mucosa overlying 

 the hyoid bones as far back as their articulation with the 

 hyomandibular. The epithelium in the region supplied 

 by this nerve is thicker than the adjacent pharyngeal lin- 

 ing and is thrown into deep folds, giving the appearance 

 characteristic of a sensory surface, but no taste biids, such 

 as are abundant on the dorsal surfaces of the gill arches 

 at the same levels, were found, though careful search was 

 made for them in several specimens along the whole 

 length of the hyoid arch. This region is, however, more 

 richly supplied with gland cells than usual and these 

 fibres not improbably are distributed in part to them. It 

 is important to note that the corresponding region in 

 Amia is innervated from the fourth branch of the r. 

 mandibularis V (Allis, '97, p. 612). 



The two bundles of the r. mandibularis VII continue 

 forward between the m. adductor mandibulae and the 

 symplectic bone, just above the dorsal edge of the preoper- 

 cular bone. In this position they again unite (465) and 

 there is more or less confusion of the fibres of the two 

 bundles. After their union they give off the fourth 

 branch {in. VII. 4)., which is composed chiefly of medium - 

 sized fibres and a few very large ones. It arises appar- 

 ently wholly from the lateralis component and takes its 

 course ventrad and slightly caudad along the outer face of 

 the preoperculum to the opercular canal. It pierces the 

 bony canal, the fibres running dorsally and laterally of the 

 membraneous canal to supply three naked organs lying in 

 the skin covering the canal, two caudad of and one ceph- 

 alad of the third opercular canal organ. 



On the opposite side of this specimen the fourth branch 

 and the corresponding sense organs caudad of the second 



