NERVOUS SYSTEM. VERTEBRATA. 99 



D. 105. A Dragonet (Callionymus lyra) with the brain and spinal 

 cord exposed from above. The optic lobes are very strongly 

 developed. The cerebellum very closely resembles that of 

 Lophius ; it is a small rounded eminence lodged between 

 the hinder margins of the optic lobes, and protrudes slightly 

 over the rhomboid fossa. The medulla is small and shows 

 no clear separation from the cord. In this specimen the 

 corpora striata have been removed. 0. C. 1308 I. 



PHARYNGOGNATHI. 



D. 106. The head of a Wrasse (Labrus sp.) with the brain 

 shown in situ from above. The brain occupies the greater 

 part of the cranial cavity. It is remarkable for the great 

 development of the basal ganglia, which equal, if they do 

 not exceed, the optic lobes in size. Each is roughly 

 triangular when seen from above, and is contiguous in the 

 mid-line with its fellow by one of its sides. Their surface 

 is distinctly lobulated. The cerebellum is tongue-shaped ; 

 its greater part hangs backwards over the rhomboid fossa 

 but there is also a small anterior lobe. Its surface is 

 crinkled, probably by shrinkage. The crura cerebelli are 

 well-marked. 0. C. 1308 G. 



PHYSOSTOMI. 



Mayser, Zeits. wiss. Zool. Bd. xxxvi. 1882, p. 259. 



D. 107. The brain of a Carp (Cyprinus carpio) shown in situ from 

 above (fig. 28) . In the Carp family the brain is distin- 

 guished by the great development of the vagal and facial 

 lobes. This development renders the medulla unusually 

 broad and defines it abruptly from the cord. The vagal 

 lobes form a pair of large wing-like swellings on either 

 side of the rhomboid fossa, and embrace between their 

 anterior ends the unpaired facial lobe a rounded body 

 situated in the dorsal mid-line behind the cerebellum. 

 This " lobus impar " represents apparently a fusion of 

 the two small facial lobes seen in the Cod (Goronowitch, 

 /. c. p. 23) . The cerebellum, though much elevated, is of 

 moderate size ; it hangs slightly backwards over the 

 medulla. The optic lobes are superficially very large, but 



