392 



THE DOGFISH 



form and size. Connected witli the dorsal region of the 



Fig. 105. —Dorsal view of the ln.un of the Scyllium caniaila. 



1 he posterior division of the brain is the medulla oblongata (NB), 

 on the dorsal surface of which is shown one of the cerebral ventricles 

 {F. rho).  



The large cerebellum (HH) nearly covers the optic lobes {MH). 

 The diencephalon (ZH) shows in the middle one of the cereVjral ven- 

 tricles, and the place of attachment of the pineal stalk {Gp). 



The prosencephalon ( VH) gives off the olfactory lobes {IVo, L, oL). 



The follovifing nerves are shown : — optic (//), trochlear (/^), tri- 

 geminal ( V), facial { VJI), auditory ( VIII), glossopharyngeal {IX), and 

 vagus {X). 



(From Wiedersheim.) 



diencephia)on is iht pineal body (Fig. iot,, pin), representing 



