216 MESSRS. HANCOCK AND EMBLETON ON THE ANATOMY OF DORIS. 
placed forwards, and has the great ducts* emerging from the apex of the funnel, 
and immediately joining the posterior end of the stomach which is lodged in the 
wider part of the concavity. From the cleft in the upper border of the base runs 
backward along the upper surface and median line of the organ, a considerable 
groove which lodges the trunk and the ramifications of the renal organ, and con- 
tains at its posterior part the trunk of the hepatic vein. The thin stratum of the 
ovarium lies spread out upon, and closely adherent to, the upper part and sides of 
the mass of the liver. The external surface of the liver itself is distinctly granular, 
and of a darkish brown colour, and together with the ovarium is overspread by the 
ramifications of the aorta which form a network upon these organs. Four or five 
principal ducts join together in the short wide common channel to the stomach, and 
if these ducts are traced into the substance of the liver, they are found to divide and 
subdivide very rapidly and minutely; and we believe, though we have not microsco- 
pically examined this, that the extreme branchlets end in the granules seen on the 
external surface of the organ. Owing to the number, size, and frequent division of 
the hepatic ducts, the interior of the liver has quite a spongy aspect ; and there can 
be no doubt that, from the great size of the principal ducts, the food during digestion 
can easily enter them, as was remarked formerly by Cuvier, and as is the case in 
the Eolididse. 
Varieties. — The liver in D. verrueosa^ is rounded in front, and less evidently cleft 
for the reception of the stomach, but is otherwise as in D. tuhereidata. 
In D. Johnstoni\ the organ is deeply cleft, but the right lobe or side of the cleft 
is much reduced in size, whilst the left is larger in proportion than the correspond- 
ing part in D. tuberculata. 
Iq D. hilamellata^ these modifications are carried to a much higher degree, so 
that the left lobe appears as a mere rudiment; and in D. pilosa\^ that lobe is no 
longer distinguishable, the liver appearing as if truncated on that side, which is per- 
forated by the cesophagus, as before mentioned. 
The texture of the organ in all appears to be the same, though the colour varies 
somewhat, being greenish or yellowish, or even inclined to orange, and sometimes of 
a deep purple brown. 
Generative organs. — The organs of this system are remarkable for their large size, 
high development, and complicated arrangement, being very analogous in their 
complex hermaphrodite character to those which we have elsewhere described in 
EoUs^. They lie on the right side of the body (with the exception of the ovary, 
which is spread upon the liver), in front of the hepatic organ, behind the buccal 
apparatus, and on the right side of the oesophagus and stomach. 
There is one common external aperture placed on the right side of the body, about 
a third of the way down from the head between the mouth and the foot. Imiiie- 
* Plate XII. fig. 1. t Plate XII. fig. 3. J Plate XII. fig. 2. 
§ Plate XII. fig. 5. II Plate XII. fig. 4. ^ Plate XI. figs. 1, 2, 3, 4; and Plate XII. fig. 1. 
