On the Cranial Nerves of Elasmobranch 'Fishes. 535 



of the oculomotor. Further, the ciliary nerves, instead of springing 

 from the trunk of the nerve some distance in front of the ganglion, 

 as in Lcemargus, usually spring from the under surface or outer 

 margin of the ganglion, and hence the branches (ciliary) of the 

 oculo-motor nerve, in passing to join the ciliary branches of the pro- 

 fundus, have to pass under the ganglion of the ophthalmicus pro- 

 fundus ; the ganglion of the ophthalmicus profundus thus seems to 

 be in a sense connected with the oculo-motor nerve, which doubtless 

 explains why so many observers have described the ganglion of the 

 ophthalmicus profundus as belonging to the oculo-motor. Were the 

 root and trunk of the ophthalmicus reduced to slender filaments, the 

 conditions found in some of the higher vertebrates would be arrived 

 at, and the ganglion of the ophthalmicus profundus would appear to 

 belong to the oculo-motor rather than to a branch of the trigeminal 

 or an entirely separate nerve. 



The oculo-motor, pathetic (2, 8, fig. 2), and abducens resemble the 

 VOL. XLV. 2 N 



