ll> I PHYSIOLOGICAL SBBIBS, 



lohus impar of the medulla. although superficially it 



apparently forms part of the cerebellum. The medulla is 

 remarkable tor the immense development of a lobe ujion 

 ite lateral and dorsal parts. This lobe (lobus impar) 

 probably repiv-mi- a fu>ion of a large median facial lobe, 

 Mich as that seen in the Carps, with a pair of vagal lobes. 

 The latter envelope the sides of the facial lobe and bound 

 with their upper swollen borders a depressed central area 

 the median parts of the t'aeial lobe. 



Presented by G. A. Boulemicr. /></. 

 Saumlers, Phil. Trans, vol. elxxiii. 1882, p. i27. 



D. 116. The brain of a Herring (Clnpea /t<or//<///.s) shown in .*//. 

 from above. It is remarkable for the great size of the 

 opt ic lobes and the shortness of the medulla. The optic lobes 

 arc oval with a slight lateral depression about the middle. 

 The outer layers of the tectum are deficient in the mid- 

 line at the posterior end, leaving a small triangular area of 

 mmi-Hiral fibres exposed. 



The basal ganglia are very closely applied to one 

 another in the mid-line, forming an apparently Dingle 

 globular mass ; they are continuous anteriorly with a pair 

 of conical olfactory bulbs. The cerebellum is oblong 

 and very deep from above downwards. The medulla is 

 much concentrated, and has a well-marked facial lobe 

 behind the cerebellum. 0. C. 1308 c. 



D. 117. The fore part of an Eel (AnguillQ mhiaris) with ihe 

 brain exposed from the dorsil a-pcct. In front of the 

 medulla the several regions of the brain are of approxi- 

 mately equal >i/.e, and a^ each is more or les- clearly 

 bilobed, the brain appears to consist of four pair- of 

 rounded e.|ti:il--i/e.| nodules >ituated one behind the other. 

 anterior pair (olfactory bulbs) an- .-lightly pointed in 

 trout and give otf two large olfactory nerves. The optic 

 1..1,,- mid cerebellum are divided down the middle by 

 ;i -.hallov. The cerebellum is considenil.lv broader 



than long, with its ant-rior and posterior borders parallel. 

 The medulla i> small and much shortened. 



D.118. The head of a Confer Kel ( ' O//,/, / ri// ;l ,iria) with ihe 

 brain expo>ed from above. The brain is more elongated 



