NERVES OF THE DOGFISH 



309 



innervates both muscles (figs. 5 to 7, 15 to 17, and 21). The 

 posterior ventral division of the nerve turns posteriorly and then 

 sharply vent-rally around the origins of the rectus dorsalis and 

 rectus internus on the optic stalk, passing between the ganglion 

 of the ramus ophthalmicus profundus and the rectus dorsalis 



OS.V3 7 / \\os.V2 [ \ 



muscle (fig. 31, IIIv.), then between the optic stalk and the 

 rectus lateralis muscle, farther ventrally between the latter and 

 the origin of the rectus internus, and still farther ventrally be- 

 tween the rectus lateralis and the rectus ventralis (figs. 8 to 

 11, 15 to 17, 20, and 21). In thus passing ventrally it divides 

 into an anterior and a posterior branch, both divisions turning 



