80 Records of the Indian Museum. [Vor. VII, 
(3) A number of small nerves behind and laterally to the 
surrounding structures (including the dorsal por- 
tion of the foot). 
Left pedal ganglion.—This is closely connected with the left 
pleural ganglion. It is connected to the opposite ganglion by an 
inter-pedal commissure. The nerves from the ganglion are :— 
(1) A short stout nerve to the otocyst. 
(2) Several stout nerves to the foot. 
Right pleural ganglion.—This ganglion is similar to that on 
the left side. It gives off :— 
(1) A pallial nerve to the mantle and the penis and 
penial sheath in male. 
(2) The supra-intestinal nerve is given off from the right 
pleural to the supra-intestinal ganglion. 
(3) A nerve to the small right siphon flap. 
Right pedal ganglion.—This is similar to the left one in all 
respects. 
The secondary commissure from the left pleural to the supra- 
intestinal ganglion is a stout and short nerve which lies in a canal 
on the left side of the dorsum of the foot in the same sheath with 
the pallial nerve. The position of the nerve can be clearly dis- 
tinguished by a translucent line on the integument over it. 
Supra-intestinal ganglion.—This ganglion is a fusiform body 
lying in a small sinus of connective tissue on the left side. The 
cavity in which it lies is covered over by a thin translucent mem- 
brane so that the position of the ganglion can be easily pointed 
out through the integument. The ganglion receives the supra- 
intestinal nerve from the right pleural ganglion on its right side 
and is connected to the left pleural ganglion by a secondary con- 
nective. ‘The left visceral nerve arises from its posterior end. 
It gives off the following nerves :— 
(rt) An accessory pallial nerve. It arises from the left 
side of the ganglion and passes up to the mantle 
flap lying just in front of the posterior border of 
the thick rim, and parallel to the pallial nerve of 
the same side. 
(2) Two small nerves from the left side of the ganglion 
passing to the mantle flap. The posterior divides 
into two branches at a little distance from its 
origin. 
(3) A fine nerve from the right side to the dorsal integu- 
ment of the foot. 
The supra-intestinal commissure is a fine nerve passing from 
the left pleural over the anterior end of the crop to the supra- 
intestinal ganglion. The track of the nerve is sometimes repre- 
sented by a translucent line on the integument over it. 
