P-i, 3 



EXPLANATION OF THE PLATES. 



08 oesophagus 



pc pedal ganglion 



peg precerebral ganglion 



pcm pericardium 



ph pharynx 



pi lateral ganglion 



ps pedal sinus 



r radula 



re seminal receptacle 



rs radular support 



s anterior vertical septum 



sc subradular commissure 



sg ventral salivary gland 



sgl shell gland 



sn subradular ganglion 



so sense organ 



sp spicule 



sr dorsal gill retractor 



sro subradiJar organ 



sto stomach 



sv seminal vesicle 



vr ventral gill retractor 



vs ventral dia|)hragm 



