122 



THE SNAIL 



CEsophagus 



I /j N- Salivary duct 



Pharynx 

 Buccal Ganglion > 



External labial 



nternal labial 



Retractor muscle 

 '' of Eye 



Dart sac 



Spermathecal duct 



_/. Right pallial 



Common duct 



Left pallial 



Ir— Median pallial 



Fig. 38. — The Nervous System of the Snail {Helix aspersa). 



C.G. Cerebral ganglia ; C.p.c. Cerebro-pedal commissure ; CpLcom. Cerebro-pleural commissure ; 

 Ot.N. Optic nerve ; P.G. Pedal ganglia ; Vise. Gang. Visceral ganglia. 



