NERVES OF THE DOGFISH 333 



dorsomesial to the profundus fibers, shift their position so as to 

 run ventral, and enter the dorsomesial part of the gasserian 

 ganglion. Distal to the level of the profundus ganglion this 

 first division of the ramus oph. spf. V. runs at first along the 

 ventral border of the r. oph. spf. VII, then shifts to its lateral 

 border. The final distribution of the terminal branches is 

 around the ventral edge of the supraorbital crest of the skull to 

 the skin dorsal to the eyeball (figs. 5 to 9, 15 to 17). The fibers 

 of 2) may be traced proximally, soon curving ventrally around 

 the mesial border of the r. oph. spf. VII to join the fibers of 1). 

 The two nerves do not always unite, but fibers of 1) may pass 

 into 2) and the reverse. The fibers of 2) end in a mass of large 

 cells on the dorsal border of the gasserian ganglion. Distally 

 2) passes anteriorly between the r. oph. spf. VII and the lateral 

 cranial wall, and rising to the dorsal border of the nerve trunk 

 divides into a few small branches that pass along with lateral 

 line branches of the r. oph. spf. VII through the supraorbital 

 crest of the cranium to the top of the head, where they are dis- 

 tributed to the skin dorsally, mesial and lateral to the supra- 

 orbital canal. If any fibers of this second division of the r. v 

 oph. spf. V remain with the main trunk of the r. oph. spf. VII, 

 they become indistinguishly blended with its branches. A num- 

 ber of small nerves, which from their distribution must be re- 

 garded as functionally a part of the r. oph. spf. V, pass into the 

 anterior end of the gasserian ganglion in the vicinity of the en- 

 trance of nerves 1) and 2). Peripherally, they are distributed 

 to the skin dorsal to the orbit. They pass into special cell masses 

 on the lateral border of the gasserian ganglion (figs. 7 to 11, 22, 

 31, 32, and 35, os. V 3, gos. V). The distribution of the ramus 

 ophthalmicus superficialis V in its entirety is on the dorsal side 

 of the head posterior to the area of distribution of the ramus 

 ophthalmicus profundus. 



In one specimen a few fibers were found to join intracranially 

 the extreme anterodorsal tip of the gasserian ganglion, just ante- 

 rior to the root of the portio minor (figs. 21, 22, and 35). Traced 

 peripherally, the fibers are found to pass anteriorly and dorsally 

 intracranially, then through a canal in the anteromesial wall of 



