183 
Structure of Amphibola avellana. 
ing a salient angle directed anteriorly, from which the row 
curves backward and outward on each side. This salient gets 
smaller and smaller in the rows lying behind the first, until it 
disappears near the middle of the odontophore, and all the 
posterior rows form a single curve with the concavity directed 
forwards. The apices of the teeth point forwards*. 
The oesophagus tapers gradually, and then again dilates. It 
then suddenly contracts to form an oblong crop slightly con¬ 
stricted in the middle (fig. 3, e). From the crop to the stomach 
it is straight; and in the anterior half of this portion a small 
caecal, clavate diverticulum opens on the right side (fig. 3,/). 
The stomach is complicated, being formed by a short simple 
anterior pouch and a long posterior one, which is culled and 
crenated on its posterior and left border (fig. 3 ,g). On the 
right of the stomach lies a globular gizzard (fig. 3, A), formed 
of two strong muscular hemispheres, with a double canal be¬ 
tween them. The food passes into this canal on the left lower 
side of the gizzard, upward on the right side (where the canal 
forms a projection between the lobes), and out on the left 
upper side. The duodenum is large, and tapers gradually 
into the intestine, bending over to the left. The intestine 
runs straight forward to the heart; it then turns to the right 
and passes backward to the albumen-gland f, round which it 
makes five reversed coils (only three are shown in the figure), 
and ends with a straight rectum. The anus is bifid below 
(fig. 8, b) . The oesophagus and the whole of the intestine 
are longitudinally folded; and the folds in the intestine form 
purple streaks. Both are ciliated internally. The liver is 
large, single, branched, botryoidal, and purple in colour. It 
contains numerous lenticular chocolate-brown concretions. 
The hepatic duct opens into the pylorus, just opposite the 
gizzard (fig. 3, t). The salivary glands are linear, saccu¬ 
lated, and attached by their ends to the upper surface of the 
oesophagus (fig. 3, c, and 4, d). 
The nervous system consists of a gangliated oesophageal 
ring, sending fibres to all parts of the body. The two cere¬ 
bral ganglia (fig. 9, a) are small and far apart, and connected 
by a strong supracesophageal commissure. The pedal ganglia 
are approximated, connected together and with the cerebral 
ganglia (fig. 9, b). The parieto-splanchnic system consists of 
seven ganglia—three on each side (fig. 9, c), and an azygos 
* Some mistake must have been made with respect to the drawing of 
the teeth of Amphibola, gixen in the ‘ Catalogue of the Pulmonate Mollusea 
in the British Museum,’ part i. p. 5; for it does not in the least resemble 
the real thing. 
t This is the supposed testicle of MM. Qnoy and Gaimard. 
