218 



Further back the bulbi, which in comparison with the fore-brain 

 are considerably big, decrease in size according as the fore-brain becomes 

 larger. On the median side tliej are separated by a deep groove. 

 Whereas in most Teleosts with sedentary bulbs, this groove extends 

 over the dorsal and lateral side of the bulbus, so that the front 

 point of the fore-brain projects in the ventricular cavity above the 

 bulbi; this is not the case in the Synbranchidae ; the foremost point 

 of the telencephalon has already united with the bulb. 



On this boundary between the bulb and the fore-brain the 

 ependyma, which forms the roof of the fore-biain, is attached to 

 the dorsal and lateral sides of the olfactory bulb, while on the 

 medial side the place of attachment lies on the bulb rather before 

 this boundary (see tig. 2). Except for a small fold on the front, 

 the membranous roof lies flat over the whole fore-brain. To the 

 ventro-lateral side of the hemispheres in the fissura endorhinalis 

 (not lateral from it, as in many other Teleosts), the tela choreoidea 

 is attached and the ependyma passes over into the subventricular 

 ependyma, which even extends over the hemispheres themselves. 



sulcus iimitans telencephaii 



Slriarum 



6UICUS palaeopaii.o • epismancus j^j^^^j ypsiliTormis 



Fig. 1. Monopleus albus. Wax model of the fore-brain Lateral side. 



The fissura endorhinalis is very deep owing to the great develop- 

 ment of the lateral portion of the fore-brain (tuberculum laterale 

 and tuberculum posterius of Sheldon (6)). As Sheldon has described 

 of the carp, so also in Monopterus this fissure deviates at the 

 place of the sulcus ypsiliformis rather decidedly in a lateral direction. 



