Skull, Brain, &c. of Di;idemodon. 



225 



is not shown accurately, because the sides of its fossa are 

 widely open for the internal carotids. From the extreme 

 lower edge of this region the two branches of the XII. nerve 

 leave the skull. Above the more anterior of these is the 

 process representing the X. nerve, which leaves relatively high 

 up on the side of the brain and is continuous with the cast of 

 the vestibule. 



Fisr. 3. 



" XlTT Vest Vij 

 IX.X.XI 



Cast of the posterior part of the brain-cavity of Dinde7no<Ju7i entomnjyhonus. 

 Upper figure, from below ; lower figure, right side, x 1. 



Floc. = flocculus ; L.L., impression of lateral lobe of cerebellum ; 

 Pd. = pituitary. Other references as before. 



In front of this region the brain suddenly expands, the 

 Lateral parts being formed by the flocculi, whieh are very 

 huge and directed outward and backward. Study of the 

 cast shows that the cerebellum is very much larger than in 

 any known reptile both laterally and vertically, the lateral 

 lobes being distinctly marked. 



Some distance in front of the flocculus is the exit of the 

 V. nerve, placed low down in the skull lateral to the 

 pituitary. The top of the cast in this region certainly does 

 not reproduce the brain. 



