388 H. W. NORMS AND SALLY P. HUGHES 



micus profundus V, and ramus palatinus VII. The medullated 

 fibers given off from the ramus ophthalmicus profundus for the 

 innervation of the eyeball, and passing to their distribution 

 through the branches tentatively designated by the writers as 

 anterior and posterior ciliary nerves, are apparently the equiv- 

 alent of the ciliares longi of the higher vertebrates. They have 

 nothing to do with the ciliary ganglion. The non-medullated 

 constituent of the posterior ciliary fibers is the equivalent of the 

 radix longa of human anatomy. Just where the oculomotorius 

 gives its limited contribution to the ciliary nerve is difficult to 

 determine, probably in the region of ganglion 1. A radix brevis 

 is not clearly in evidence. The nerve that runs to the eyeball 

 from ganglion 3 is without doubt the short ciliary nerve. 



In Mustelus calif ornicus there occurs a small group of ganglion 

 cells where the oculomotor branch for the rectus superior muscle 

 separates from the main nerve, corresponding apparently to 

 ganglion 1 in Squalus. The ramus ophthalmicus profundus gives 

 off a posterior ciliary branch as in Squalus, a medullated com- 

 ponent of which passes posterolaterally to enter the posterior 

 wall of the eyeball by two terminal branches, and a non-medul- 

 lated part passes into the ventral division of the oculomotorius, 

 but not through a small ganglion (ganglion 2) as in Squalus. 

 The non-medullated element passes with the third nerve around 

 the posterior border of the rectus inferior muscle and with the 

 nerve runs anteriorly. A small ganglion occurs on the non- 

 medullated element shortly after turning in the anterior direc- 

 tion. From this ganglion there pass three ciliary branches. One 

 of these runs posterolaterally along the ophthalmic artery to the 

 eyeball, entering the latter in a few small branches, near the en- 

 trance of the artery. This branch bears a ganglion, having also 

 a small ganglion near its origin. A second branch from the gang- 

 lion passes posteromesially with the ophthalmic artery to the 

 junction of the latter with the pseudobranchial artery and along 

 the latter posteriorly to a junction with a branch of the ramus 

 palatinus VII. From the relation of these two ciliary branches 

 to the ganglion it would seem that the latter represents in a gen- 

 eral way ganglion 3 in Squalus. The small ganglion on the 



