ce.g. 



vis.g- 



ped.g. ce.g 



os.g. 



Fig. 390. Comparison of gasteropod nervous systems. From Shipley and 

 MacBride. A, Haliotis tuberculata. B, Limnaeaperegra. ce.^. cerebral ganglia ; 

 ct. ctenidium; ma.n. nerve to mantle; os.g. osphradial ganglia; pa.g., ped.g., 

 pl.g. parietal, pedal and pleural ganglia ; ped.n. non-ganglionated pedal nerves 

 of Haliotis connected by commissures ; vis.g. visceral ganglia. 



