276 Journal of Comparative Neurology. 



small twig leaves the r. oph. sup. V and runs dorsad along the 

 inner side of the r. oph. sup. VII. When the nerve for the 

 fourth canal organ enters the canal through its foramen, in the 

 frontal bone, this nerve accompanies it and passes directly 

 up through another foramen in the roof of the canal to dis- 

 tribute to the skin over the canal cephalad of the fourth organ 

 and of the supra-orbital commissure. 



A very little farther cephalad a similar twig leaves the r. 

 oph. sup. V, which runs dorsad along the outer side of the r. 

 oph. sup. VII and distributes in several minute branchlets to 

 the skin over the cephalic part of the orbit, one running out 

 upon the cornea. Other similar twigs follow as we pass ceph- 

 alad, one large one in the anterior part of the orbit. 



The main nerve spreads out to the skin of the top of the 

 snout about the cephalic end of the supra-orbital canal, remain- 

 ing in very intimate union with the r. oph. sup. VII until that 

 nerve sends its last large branch to supply the first supra-orbital 

 organ. Indeed the association of the two nerves is continued 

 beyond this point, as the terminal twigs of the r. oph. sup. V 

 are accompanied by facialis fibers for the pit-organs of the top 

 of the snout. 



7. The Hyoniandibiilar Trunk. 



The truncus hyomandibularis, as in Menidia, receives the 

 whole of the ventral lateral line root, which composes the r. 

 mandibularis externus VII, and a band of general cutaneous 

 fibers from the Gasserian ganglion, but it receives no communis 

 fibers from the geniculate ganglion, so that it lacks the r. man- 

 dibularis internus VII. 



The general cutaneous component arises from the extra- 

 cranial portion of the Gasserian ganglion as a moderately large 

 nerve which runs outward, downward and backward to enter 

 the hyomandibular trunk. This agrees in every way with the 

 corresponding nerve in Menidia except that it is larger in Gadus, 

 is single rather than double and passes more directly into the 

 truncus. 



Fully one half of these general cutaneous fibers go out at 



