386 H. W. NORFJS AND SALLY P. HUGHES 



do. Fibers can be traced from the ganglion or its vicinity an- 

 teriorly into the main nerve as it passes through the foramen in 

 the cranial wall (fig. 6). From ganglion 1 there runs ventrally 

 a fiber tract along the lateral border of the posterior (ventral) 

 division of the III nerve, into a ganglion situated on the antero- 

 lateral border of the latter (figs. 9, 16, 17, 21, and 31, gcil.2). 

 As described in the account of the ramus ophthalmicus profundus 

 V, the posterior ciliary nerve includes a non-medullated constit- 

 uent that turns ventrally and posteriorly to join the ciliary plexus. 

 This non-medullated nerve passes, as stated, ventrally and pos- 

 teriorly between the rectus dorsalis and the rectus lateralis muscles 

 and enters ganglion 2. In some instances there is a small gang- 

 lion imbedded in the rectus dorsalis muscle between ganglion 2 

 and the ramus ophthalmicus profundus. Farther ventrally on 

 the mesial posterior border of the third nerve at the point where 

 the ventral division separates into branches, one for the rectus 

 ventralis and the other for the obliquus ventralis muscle, there 

 occurs another ganglion (ganglion 3) (figs. 10, 15, 17, and 21, 

 gcil.3). Fibrous connection between ganglion 2 and ganglion 3 

 is plainly discernible as a flat band between the third nerve and 

 the rectus lateralis muscle (fig. 20, til.), as it passes around to the 

 posterior mesial border of the third nerve. In some instances 

 ganglion 2 and ganglion 3 are almost confluent (fig. 17) ; in other 

 instances there seems to be another ganglion (ganglion 3a), dis- 

 tinct from ganglion 3, and situated in the forking of the nerve 

 (fig. 10). 



Ganglion 1 seems to correspond to Cast's 'rectus' ganglion, 

 though possibly the latter also includes ganglion 2. Gast's 'cil- 

 iary' ganglion seems to correspond to ganglion 3. Hoffmann's 

 two ciliary ganglia in Acanthias are evidently ganglia 2 and 3. 



Ventral to ganglion 3, in the region of the ophthalmic artery, 

 the ciliary sympathetic cord divides into two branches. One of 

 these passing laterally around the posterior border of the oculo- 

 motor branch which supplies the ventral rectus muscle and then 

 between the two oculomotor divisions, follows the ophthalmic 

 artery out to the eyeball. On the way a ganglion (ganglion 6) 

 occurs from which a small nerve runs anteriorly along the ventral 





