186 Messrs. Hancock and Embleton on the Anatomy of Kolis. 
mass to the skin. It then passes forwards and inwards, and is 
lost upon the sides of the channel of the mouth. 
The tenth and eleventh pairs are small, come off from the same 
ganglion still further back and just in front of the eye, and = 
directly outwards into the skin. 
The twelfth and thirteenth arise from the junction of the an- 
terior and lateral cerebral ganglia, and passing outwards and 
downwards first, then incline downwards and backwards and run 
half-way down the body, one above the other, in the skin between 
the border of the foot, and the rows of branchial papille. 
The fourteenth and fifteenth, very minute pairs, emerge from 
the line of union of the anterior and the lateral ganglia, and 
are then placed directly under the eye. The former of these 
nerves goes to the skin of the side of the head between the oral 
and the dorsal tentacles, the latter to the skin immediately be- 
hind the situation of the former. 
The sixteenth or optic nerves are stout but very short, and 
have the organ of vision at their extremity. They are inclined 
forwards and upwards from the line of union of the anterior and 
lateral ganglia. 
The seventeenth or auditory are mere rudiments of nerves, and 
are attached to the anterior ganglia quite close to the bases of 
the optic nerves, and immediately behind them. The auditory 
capsule and the eye will be described further on with the other 
organs of special sense. 
The eighteenth pair, one of the largest, issues from the outer 
borders of the lateral ganglia, rather in front of the middle, 
passes outward and bifurcates. very. soon after; each of these 
branches again bifurcates and is distributed by many twigs to _ 
the muscles and skin of the foot, both anteriorly and posteriorly — 
(the pedial nerve). 
The nineteenth, also of considerable size, come out of the ex- 
ternal borders of the lateral ganglia, behind the middle, separated 
by a considerable interval from the eighteenth, and passing 
slightly outwards take a backward course, and can be traced in 
the skin for a long way down the sides of the back, giving off 
chiefly externally numerous branches that supply the ‘skin, This 
we presume is the respiratory nerve. 
The twentieth are seen to come forth from the posterior mar- 
gins of the anterior ganglia, and are of a size little inferior to the 
last. They can be traced in the skin of the back between the 
last-described nerve and the dorsal median line nearly as far as 
the tail, giving off twigs from their outer sides like the nineteenth 
pair to the skin. 
The twenty-first, twenty-second and twenty-third pairs are all 
small nerves coming out successively from the posterior borders 
