Fig. [10], Lower enlarged end of œsophagus, where entering the
stomach, viewed from one of the sides bearing the discs
of teeth;
a, upper cut off end of œsophagus;
b, the lower end and natural opening;
c, thickened rim, having a somewhat beaded structure.
[11], The same; diagram giving a transverse section of the above
in the line of the discs of teeth;
c c c c, four thickened beaded edges;
e e, two other but narrower and less prominent beaded edges;
d d, discs of teeth;
f, rows of fine bristles; the almost double row of bristles on each side
under (d) is not of course seen in this section.
[12], Lower end of œsophagus viewed from a position at right
angles to that in fig. 10; or from the side e, of the
diagram, fig. 11; the two discs of teeth are consequently
shown in profile;
a, upper cut off end of œsophagus;
b, lower natural end;
c, c, thickened edges;
e, narrower thickened edge, projecting towards the beholder;
d, disc of teeth seen in profile.
[13], Portion of one of the cirri;
a, lower segment of pedicel;
b, upper segment, supporting the two rami.
[14], Segments of one of the rami much enlarged;
a, thickened shield-like portion of membrane.
[18], Larva in the last or pupal stage, on four times the scale of
fig. 15-17;
a, antennæ;
b, apodeme and eyes;
c, abdominal bristles. A male would have been developed from
this pupa.
[19], Male on same scale as the pupa, fig. 18; a, three terminal
segments of the antennæ of the pupa; d, orifice of the
sack.
Fig. [1], Antenna of the pupa (three terminal segments of), with a portion of one of the two threads, enclosing the cement-ducts, by
which the body of the [Proteolepas] is attached; the upper
portion of the thread, and the adjoining part of the body,
are represented in section.
a, part of the great mass of cellular matter within the ovarian
sack, in process of development into ova, and changing
its character as soon as it enters the tube or cement-duct.
b, membrane forming the ovarian sack and the cement-ducts,
the latter enclosed within the threads of attachment.
c, corium lining the outer membrane of the body, and the upper
part of the threads.
d, outer membrane of body.
e,””becoming suddenly thicker where
forming the outer membrane of the thread.
e′, outer membrane of the thread in the lower part, here not
shown in section.
f, main or second segment of the pupal antenna, the basal segment
having, as in all cases, been moulted, with the carapace
of the pupa.
g, disc-segment, apparently with a small orifice for the issuing
of the cement.
h, terminal segment with the shorter spines broken off.
[2], Compounded mandibular organ, sketched by the camera;
a, supposed mandible;
b, perhaps portion of the mandible;
c, maxilla;
d, ligamentous fibres giving attachment to muscles.
[3], Mouth seen from the ventral side, sketched by the camera;
r, articulation separating the mouth from the body;
c, compounded mandibular organ;
d, palpus, united to the opposite
palpus and to the crest of the labrum; the latter
forming the back of the hollow in which the compound
mandibles work.
[4], Diagram of the mouth of an ordinary cirripede, seen from above;
a, outer maxilla;
b, maxilla;
c, mandible;
d, labrum.
[5], Diagram, illustrating the supposed changes in position of the
gnathites in [Proteolepas], causing them to stand back to back;
a, outer maxilla;
b, maxilla;
c, mandibles;
d, labrum.