Co'i'TREFJ.. — Anafoiii !/ of Siphoiiaria ol)li(|uata. 



589 



runs obliquely ticross tlio floor of the body-cavity, and is distributed to 

 the walls and the mantle. There is a corresponding nerve from the right 

 pleural, but it does not run so far back, going on to the body-wall just 

 behind the penis. The pleural ganglion on this side also gives a stout 

 nerve to the penis. 



The visceral gangUon gives off a nerve passing back to the stomach 

 (fig. 5; ^), and another obUquely to the right ; the branches of this latter 

 nerve go to the body- wall and rest of the Viscera. Close to the pleural 



el ,. it 



pi-''—/ / I 



Fig. 5. — NEEVotrs System. 



Buccal ganglion ; he, cerebro- buccal connective ; c, cerebral ganglion ; cc, cerebral 

 commissure ; el, external labial nerve ; g, gastric nerve ; il, internal labial nerve ; 

 fa, parietal ganglion ; pc, pedal commissure ; pc', para-pedal commissure ; 

 fl, pleural ganglion ; ipl.n, pleural nerve ; fn, pedal nerves ; ipn' , penial nerve ; 

 p, pedal ganglion ; yv, pleuro-visceral connective ; v, visceral ganglion. 



ganglia on the underside of the oesophagus lie the pedal gangha, one on 

 each side. These are connected by a stout commissure which is much 

 shorter than the cerebral commissure. It is supplemented by a second 

 (para-pedal) commissure of about half its own thickness (fig. 5 ; f, fc, fc). 

 The pedal gangha are, of course, connected to the cerebral by connectives. 

 These lie anteriorly, and so close to the other ganglia that they are not 

 easily seen. The pedal ganglia give rise to several stout nerves, which 

 innervate the muscles of the foot. 



