87 



the dorsal palp ; four conspicuous nerves leave the ganglion 

 on each side, and are easily observed. 



The cerebro - visceral connectives (Con.cv.) run back- 

 wards and upwards in the loose tissue surrounding the 

 ganglion ; they pierce the muscular body-wall, and pass 

 through the upper portion of the viscero-pedal mass 

 embedded in the substance of the digestive gland. Leaving 

 the latter they again pierce the posterior muscular body- 

 wall near the external openings of the gonads, and sHghtly 

 above tlie origin of the retractor muscles of the foot. Then 

 they pass along the lower wall of the renal sinus to join 

 the parieto-splanchnic ganglion. 



The pedal connective of each side (coji.cp.) runs down- 

 wards in the loose tissue round the ganglion for a short 

 distance, then pierces the anterior muscular wall of the 

 viscero-pedal mass, and passes vertically downwards on the 

 internal surface of the latter to the pedal ganglion. The 

 connectives are quite distinct, but lie close together in the 

 middle line of the body; about half-way down in the course 

 of each, a nerve is given off which passes backwards into 

 the visceral mass. 



A large nerve, the anterior common pallial nerve 

 {N.pa.), leaves the anterior surface of each ganglion, and 

 passes along the lower surface of the anterior adductor, 

 and outwards from this on to the most anterior and dorsal 

 corner of the mantle lobe. Just before leaving the adductor 

 each pallial trunk bifurcates. 



A very small nerve, the anterior adductor nerve {N.add.), 

 leaves the ganglion near the origin of the anterior pallial 

 nerve, and plunges into the posterior surface of the anterior 

 adductor muscle. 



Lastly, there is the strong cerebral connnissure running 

 over the dorsal wall of the mouth. 



These are all the nerves that can be observed in tlie 



