SEA-FISHERIES LABORATORY. 231 
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 externai openings of the gonads, and slightly 
above the 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 (con.cp.) rans 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 commissure running 
over the dorsal wall of the mouth. 
These are all the nerves that can be observed in the 
