Fig. 19. Nervous system of fresh water bryozoa. A. General view of the 

 nei'vous system of Cyistatella. B. Oi'al surface of upper end of cen- 

 tral nervous system of Crisfatelta. C. General plan of the nervous 

 system of CtintatelUi. The tentacles are all cut away in one arm 

 and partly cut off in the other. The position of the alimentary canal 

 is indicated. D. Side view of a portion of the chief ganglion show- 

 ing the nerves of the epistome. E. Diagram of sense cells and nerve 

 bands connected with a single tentacle. F. Diagram of a section 

 from side to side of the central ganglion showing the cerebral cavity. 

 A-D, I after Gerwerzhangen from CrisfateUa. E, F, G, and H. Sur- 

 face longitudinal and cross sections through the ganglion of a fresh 

 water bryozoan from Oka. 



