EUMENIS.
directed towards the oesophagus; each row contains about twelve spines. The character of
the central portion was not ascertained.
The oesophagus passes from the posterior extremity of the buccal mass, and is a narrow
tube of no great extent; the configuration of the stomach was not precisely determined;
the intestine terminates at the anal aperture on the right side of the body, about half way
between the head and tail. The upper portion'of the stomach appears to be granular, and
from each side of it arise two tubes. The anterior one passes forwards and gives off branches
to the branchial membrane of the sides of thé head, which terminate in the papillae in the
form of blind sacs; the posterior tube, sloping a little backwards, penetrates in the same
manner the succeeding portion of the branchiae. The great central canal of the hepatic organ
lies below the ovary, as in Dendronótus, and, as in that genus, it is thick and glandular
throughout, and is much folliculated. From the sides of this portion three or four branches
are given off in pairs, penetrating to the branchiae, as in the rest of the Eolidida. At first
these branches are thick, but on reaching tlie skin they attenuate and ramify over it in a
radiating or dendritic manner. All the branches are glandular and folliculated.
The generative organs, as far as we have been able to trace them, resemble those of
E o lis ; the same extensive ovary, composed of lateral lobes, fills almost entirely the posterior
portion of the body; the mucous gland, attached to the female parts, is also largely developed,
and extends across the anterior cavity of the body, and the testis is a convoluted tube, lying
in front, at the right side, immediately behind the tentacle.
The cerebral ganglions are four in number, and are nearly of equal' size. The central
pair are of a sub-trianguliar form, and are not placed in contact, side by side, as in Eolis, but
are united across the median line by a short and stout, though 'distinct commissure: the
lateral pair are attached to the under side of the central ganglions, and are elliptical in
form: they'are united beneath the oesophagus by a Short, stout collar. The buccal ganglions
are small and oval, with the collar that joins them to the cerebral ganglions more constricted
than in Eolis. The nerves, nine pairs of which were made out, radiate from these centres
in the usual manner. Ganglions were also observed at the base of the tentacles.
EXPLANATION OF THE FIGURES.
Fig. 8. General view of the viscera of Eumenis marmorata, the dorsal skin being laid open and turned
back, and the heart removed:—a, buccal mass; b, oesophagus; c, stomach; d, d, d, d,
branches passing from the stomach to the anterior branchial lobes; e, intestine;* f , central
mass, or folliculated channel of the liver; g, g, g, g, branches from the central channel going
to the skin and branchial papillse; h, testis; i, great mucous gland belonging to the female
parts; j , ovary, with the posterior portion removed to show the hepatic organ beneath; k,
cerebral ganglions.
9. Lateral view of the buccal mass:—a, oesophagus; b, channel of the mouth; c, corneous jaws,
imbedded in the muscles.
10. Internal view* of a corneous plate.
11. External view of the same.
12. Spines, or teeth, from the tongue.
13. Cerebral ganglions:—a, a, central pair; b,b, lateral pair; c, buccal pair.
* The intestine, oesophagus, and stomach were imperfectly made out. The delineation of these
organs, therefore, is in part from conjecture.