FS GASTEROPODA. APLYSIADZ. 
ganglia receive several pairs of nerves from the muscles and 
general covering of the body. The intestines and liver send 
their nerves to a kind of sympathetic ganglion, from which they 
again pass to join the lateral ganglia. 
The heart is oval, and its parietes very thin, its inner surface 
furnished with muscular pillars, which cross in every direction. 
At its junction with the auricle, the passage is guarded by two 
mitral valves. The great artery, at its exit, is divided into 
great branches: the first passes out from the pericardium on 
the left side, and enters the abdomen, distributing its branches 
to the liver and intestinal canal; the second branch turns to 
the right, and gives a branch to the stomach and to the ceso- 
phagus, and then passes through the pericardium on the right, 
sending branches to the right side, to the lower parts of the 
mouth, and to the foot. That part of the second great branch 
within the pericardium is furnished with two erests, composed 
of vessels which are given off by it, and return mto it. Cuvier 
supposes these vessels may secrete a liquor with which the 
pericardium is filled. All the veins return the blood into two 
muscular vessels, which convey it to the branchiz, from whence 
it is returned to the auricle, and from thence is passed to the 
ventricle. 
Mouth without jaws ; its lips furnished with a thin cartilagi- 
nous plate, which is smooth ; and a cartilagmous tongue, armed 
with hooks, which turn backwards. At the anterior extremity 
of the cesophagus, the ducts of the salival glands open on each 
side. 
The cesophagus is straight, and soon dilates into a pouch lined 
with thin membranaceous matter, without appearance of glands. 
This is followed by a short cylindric gizzard, with strong mus- 
cular sides, bearing pyramidal and rhomboidal protuberances, 
composed of semicartilaginous matter *, which have but a slight 
attachment to the surface. The third stomach, which is as large 
as the first, has its surface on one side armed with curved spines, 
which are not more strongly attached than the protuberances in 
the second stomach. Near the pyloric extremity are orifices 
* These parts were remarked by Apuleius, who was accused of magic, 
from having been seen with these animals in his possession. pul. Apel. 47. 
