304 Journal of Comparative Neurology. 



opercular pore are totally wanting, though it should be 

 noted that on that side the first and the sixth branches 

 supply each an additional naked sense organ and that the 

 latter encroaches somewhat upon the area supplied by the 

 fourth branch. 



A short distance farther cephalad the fifth branch (/«. 

 VIL 5) of the r. mandibularis VII, composed wholly of 

 coarse fibres, separates, takes a course nearly parallel to 

 that of the fourth branch and enters the opercular canal 

 to supply its third organ. 



At almost the same point as the last the sixth branch 

 (in. VII. 6) arises. It is composed of medium or small 

 fibres with very densely staining sheaths of the same type 

 as those of the first and fourth branches. It passes di- 

 rectly ventrad and into the bony opercular canal by a 

 separate foramen in the preopercular bone. It then turns 

 cephalad, running dorsally of the membraneous canal, and 

 supplies three naked sense organs, two lying superficially 

 of and a short distance caudad of the second and first 

 organs of the opercular canal respectively, and one just 

 cephalad of the latter. The origin and course of this 

 branch are strictly analogous with those of the first and 

 fourth branches, which it closely resembles. 



On the opposite side this branch supplies four naked 

 sense organs, two cephalad of the second opercular pore 

 and caudad of the second opercular canal organ, one 

 cephalad of the first opercular pore and immediately cau- 

 dad of the first canal organ, and one cephalad of the first 

 canal organ. 



In another specimen we have an arrangement of the 

 first six branches of the r. mandibularis VII which differs 

 from either side of the specimen figured. The two sides 

 of this specimen agree in the following arrangement. 

 The first branch is represented only by its dorsal twig for 



