EXPLANATION OF PLATES.
P late 1.
Fig. 1. General view of the viscera of Dorie pilosa, the dorsal kin being laid open:—a, buccal mass;
b, portion of stomach ; c, intestine; d, pancreatic organ; e, e, liver; ƒ mucus-gland in
connexion with the female channel; g, portion of testis; h, spermatheca; i, accessory
spermatheca; j, pericardium; k, ventricle; l, auricle; m, m, lateral trunk-veins passing
into the auricle from the skin; n, trunk-vein from the branchiae leading into the
auricle; o, portal heart; p, p, upper wall of renal organ exhibiting network of vessels;
q, folliculated gland-like body apparently connected with the vascular system.
2. General view of the viscera of D. tuberculata seen from above:—a, buccal mass; b, stomach,
exhibiting on its surface a network of nervous filaments, with a few minute ganglia,
being a portion of the sympathetic system; c, intestine; d, d, liver, with the principal
arterial trunks of the liver and renal organ seen on the surface; e3 retracted penis;
f , mucus-gland belonging to the female channel; g, spermatheca; h, vagina leading
from the external orifice to the same; i, pericardium; j , ventricle, with the aorta passing
from the apex in front; k, auricle; l, l, lateral trunk-veins leading from the skin to the
auricle; m, trunk-vein leading from the branchiae to the auricle; n, portal heart,
opening into pericardium; o, gland-like body in connexion with the vascular system;
p, supra-oesophageal ganglions with the nerves passing from them; q, branchial ganglions
of the sympathetic system; r, retractor muscles of the channel of the mouth.
3. View of the buccal cavity of D. pilosa, from above:—a, oesophagus; b, membranous crop
at the commencement *of the same; c, oral opening; d, outer lip; e, inner lip;
f channel of the mouth; g, buccal lip; h, prehensile collar in connexion with the
same; i, rudimentary jaws; j , walls of the anterior portion of buccal cavity; k} fleshy
support of the tongue; l, tongue; m, external sac within which the tubular portion of
the tongue is lodged.
4. Side view of the tongue of D. pilosa, the fleshy support being removed:—a, anterior
prehensile portion; b, posterior tubular portion.
5. Portion of the tongue, more highly magnified, seen from above.
6. View of the buccal cavity of D. tuberculata, seen from above:—a, oesophagus; b, oral
opening; c, outer lip; d, inner lip; e, channel of the mouth; f , buccal lip; g, walls
of buccal cavity; h, fleshy support of the tongue; i, tongue: j , membranous septum
dividing the anterior from the posterior portion of the tongue; k, retractor muscles of
the channel of the mouth; l, l, retractor muscles of buccal mass.
7. Side view of the tongue of D. tuberculata, without the fleshy support:—a, anterior portion;
b, posterior or tubular portion; c, membranous septum dividing the two portions.
8. Central portion of two rows of spines from the tongue of D. tuberculata.
9. A single spine more highly magnified.
10. Central portion of two rows of spines from the tongue of D. repanda:—a, central spine;
b, lateral spines.
11. A single lateral spine more highly magnified.
jLi
Fig. 12. Digestive organs of D. pilosa:—a, channel of mouth; b, buccal mass; c, gizzard-like
portion of the same; d, salivary glands; e, oesophagus; f membranous crop at the
. commencement of the same; g, dilated portion of the same; h, liver laid open, exposing
the track of the alimentary canal; i, hepatic ducts opening into the anterior portion of
the stomach; j , stomach; k, pancreatic organ opening into posterior portion of the
stomach; l, l, intestine; m, anus.
13. Digestive and renal organs of D. bilamellata, the latter organ laid open:—a, channel of
the mouth; b, buccal mass; c, muscular gizzard opening into the same; d, external
sac for the reception of the tubular portion of the tongue; e, salivary gland; f oesophagus;
g, pancreatic organ opening into the stomach; h, h, intestine; i, anus; j , liver; k, k, renal
organ laid open longitudinally to expose network of vessels on its walls ; l, a bristle
passed into the renal cavity through external orifice; m, ventricle of h eart; n, auricle;
n , aorta; o, portal heart opening into pericardium; p, portion of the floor of pericardium
attached to the margin of orifice leading into portal heart; q, orifice leading from pericardium
into portal heart.
P late
Fig. 1. General view of the viscera of D. tuberculata, partially separated, the arterial system being
injected:—a, buccal mass; b, gullet; c, stomach; d, d, intestine; e, anal nipple;
f, liver mass; g, hepatic duct; h, salivary glands; i, pancreatic organ; j , retracted
penis; k, k, the two portions of the mucus-gland in connexion with the female channel;
l, spermatheca; m, copulatory channel or vagina, leading to the same; n, accessory
spermatheca; o, root of the aorta, the heart having been removed; branches from the
great systemic artery may be seen passing to all the viscera; p, portal heart; q, q, renal
organ, with the hepatic or renal arteries lining and appearing through its upper wall;
r, a bristle passed into the renal cavity through the external orifice; s, s, a glandular
body apparently in connexion with the vascular system; t, the supra-cesophageal ganglia
with various nerves passing off from them.
2. Entrance to the buccal mass of D. pilosa, seen in front, the channel of the mouth having
been removed :—-a, a, buccal lips; b, b, prehensile collar in connexion with them; c, the
free extremities of the rudimentary jaws; d, d, portion of the lining membrane’of the
channel of the mouth.
3. A portion of the prehensile collar, showing the arrangement of the spines.
4. A gronp of the spines more highly magnified.
5. Two of the spines still more highly magnified.
6. The rudimentary plate or jaws entirely exposed a, their free extremities; b, the portion
buried in the buccal lips.
f . Generative organs of D. tuberculata, removed from the body and unravelled;—a, channel
of the perns leading to external orifice; b, retracted penis; c, c, testis; d, ovary spread
ovct the liver; e, e, oviduct; f dilated portion of i t ; g, the point where it communicates
with the testis; A, A, semipellucid portion of the mucus-gland in connexion with the
female channel; i, opaque portion of the same; j , female channel leading to external
orifice; k, spermatheca; l, its duct leading to the oviduct; m, accessory spermatheca;
n, vagina, or copulatory channel leading from external orifice to spermatheca.