NERVOUS SYSTEM. VERTEBRATA. 95 



of the fore-brain show a distinct tendency towards a linear 

 arrangement, the olfactory bulb and corpus striatum of the 

 left side being thrust to a marked degree behind the corre- 

 sponding parts on the right. 



The lobi inferiores are globular and prominent. 



D. 95. The head of a Brill (Rhombus Icevis) with the brain exposed 

 from the right (blind) side. The brain is perfectly sym- 

 metrical. The optic lobes are relatively somewhat larger 

 than in the Sole. The corpora striata are very small, with 

 sessile olfactory bulbs at their anterior end. The left optic 

 nerve passes below the right. 0. C. 1380 Ail. 



D. 96. A similar specimen of the brain of a Hallibut (Hippoglossus 

 vulgaris) exposed from the right (ocular) side. It closely 

 resembles that of the Brill except for its larger size. The 

 infundibulum and saccus vasculosus are very prominent. 

 The right optic nerve is slightly smaller than the left, it 

 crosses beneath it ; both are of immense size. 



ACANTHOPTERYGII. 



D. 97. Part of the cranium of a Gilt-Head (Chrysophrys aurata) 

 with the brain exposed from the right side. The small 

 olfactory bulbs are sessile on the cerebrum ; each gives 

 rise to a stout olfactory nerve. The basal ganglia are 

 immensely developed ; each is a lobulated globular body 

 slightly larger than one of the optic lobes. The latter are 

 of moderate dimensions ; the lobi inferiores are large and 

 longitudinally elongated. The cerebellum is small, quadri- 

 lateral in outline, and of considerable dorso-ventral depth. 



The right optic nerve crosses beneath the left; its distal 

 part has been opened out to show its flat ribbon-like form 

 and pleated folding. 0. 0. 1380 A 20. 



D. 98. The brain of a Mackerel (Scomber scombrus) exposed 

 from the right and dorsal aspects. The olfactory bulbs 

 and corpora striata are small and closely contiguous, form- 

 ing together a pyramidal anterior extremity to the brain. 

 The lobi inferiores are small, but the optic lobes are of 



