32 PISCES. 



PLATE XI. 



THE DOBSAL ASPECT OF THE NEKVOUS 

 SYSTEM OF THE SKATE. 



(RAIA BATIS.) 



THE olfactory nerve is seen passing to the nose and forming a large ganglion, 

 which is perfect on the right side, but on the left has been partly removed for showing 

 the cribriform membrane through which the nerves pass to the membranous olfactory 

 plaits. On the right side, the optic nerve is seen passing to the eye ; on the left, 

 it has been removed for giving a better view of the branches of the fifth. The third 

 nerve is seen passing to all the muscles of the eye, except the superior oblique and 

 abducent. The fourth is seen passing to the superior oblique muscle. The fifth is 

 seen giving off three principal trunks besides the auditory ; the first passes in two 

 divisions through the orbit, these become united at the anterior part of this cavity, 

 and the nerve is then continued forwards, giving branches to the cellular structure in 

 its course towards the end of the snout : the second trunk passes on the fore part of 

 the muscles of the jaw, gives a large branch which distributes branches on these 

 muscles and the upper and lower lips ; it gives a large branch to the cellular structure 

 on the ventral surface of the snout, this also gives branches to the upper lip ; it gives 

 a large branch to the cellular structure at the side of the head : the third trunk passes 

 behind the muscles of the jaw, gives branches to these, and is distributed on the skin 

 about the mouth and gills ; one of its branches forms a ganglion, which gives off 



