Head somewhat hexagonal (Plate XXVIII, fig. 2), with a deep median groove at
the base of the tentacle, and two prominent peaks, each of which is at a. distance from
the tentacles. The eyes are comparatively large, and, judging from the conditions of the
largest example, increase with age and depth of water. Two slightly smaller are situated
in front of the nuchal collar, and look dorsally, and two somewhat larger rather in
front of 'the middle of the head, and lateral in position. In the example with the large
eyes (from 690 fathoms)/ the anterior pair show traces of a corneal lens. The median
tentacle is somewhat long, scarcely dilated below the filiform tip in the preparations, and
covered with moderately long cilia having a slightly bulbous tip. The lateral tentacles are
short, but also have attenuate tips. The tentacular cirri are similar to the median
tentacle. None of these organs show any signs of pigment in the preparations. The
palpi are of moderate length, and have rows of minute conical papillae, as De St.'Joseph
also found, whereas Marenzeller observes that their upper surface is smooth. In the
British forms one prominent papillose ridge occurs dorsally.
Body.—Somewhat narrow and elongated, slightly tapered towards the head, and
very gradually towards the tail. Forty-five segments bear bristled feet, and the tail is
not quite complete. Behind the distension caused by the included proboscis, the
segments are boldly marked by the lozenge-shaped transverse bars which stretch
between the bases of the scale-pedicles, or their homologues in the other feet. Each
segment thus shows an anterior and posterior paler belt, and a median darker area.
Traces of brownish pigment occur posteriorly at the bases of the feet and on the
lozenge-shaped transverse bars. In some the brown pigment is broken into a number
of symmetrically placed touches, two of which are on the bases of the feet, and
the rest in interrupted bands across the segments. Ventrally traces of pigment occur
on the lips, and the median iridescent depressed band is well marked. The conical
segmental (nephridial) papillae at the posterior border is directed upward between the
feet. A considerable portion of the body posteriorly is uncovered by scales.
De St. Joseph states that there are only seventeen papillae at the margin of the
proboscis, but so far as can be seen there are nine in each half.
Scales (Plate XXXII, fig. 8) somewhat thin, in number fifteen pairs. They are
rounded in front, reniform or irregularly rounded posteriorly, and of a uniform greyish
hue in the preparations, though some are quite pale. Their surface is nearly smooth to the
naked eye, but under a lens the whole is densely covered by a series of minute, pointed,
slightly brownish spines, and the free portion of the edge is profusely ciliated (Fig. 24),
the cilia being pellucid, tapering structures terminating in a bulbous tip. Marenzeller
speaks of the network formed on the surface by the pigment; and Hornell mentions that
the surface is mapped out into separate areas, each containing several spines. The
under surface is iridescent, and the scar for attachment is situated near the outer and
anterior border. Marenzeller shows, besides the spines on the edge of the scale,
cylindrical papillae, but these have not been observed in our specimens. The first scale
is ciliated all round with the exception of the short covered portion.
De St. Joseph often found a white touch in the centre of the scales, which were
marked with brown, grey, and whitish. Hornell’s figure of the scale differs from the
specimens referred to here.
Feet.—The base of first foot shows about two bristles, which conform to the type of
dorsal tuft, though they are considerably smaller. In the next foot the dorsal bristles
have attained great strength, though they are shorter than the typical forms, and much
broader towards the tip, which is little tapered. The bristle is therefore proportionally
more powerful than the typical form. They have a close series of spinous rows. The
contrast between the massive dorsal and the slender ventral bristles is marked, and the
tips of the longest of the latter extend «only a very little beyond the extremities of the
dorsal. Their tips seem to be brittle, and while the inferior are more elongated and
slender, the upper forms present the characteristic short broad tips of the typical bristles.
In the third foot the size of the ventral bristles has largely increased, and they
stand out nearly half their length beyond the dorsal. The tips now approach the
normal, except that those of the inferior series are longer, and the upper slightly shorter.
In the typical foot (Plate XLII, fig. 30) the dorsal bristles form a powerful fan, the
inner and outer borders of which have more slender forms, while the greater number
consist of strong, slightly curved and tapered bristles, with somewhat closely arranged
spinous rows, and a smooth spear-shaped tip (Plate XXXVIII, fig. 10), the latter having
a tendency in some to follow the shape of the same region in the ventral bristles
(Plate XXXVIII, fig. 11). Others, again, show a sharper tip, and at the inner border
of the tuft are one or two with a slender tip. The ventral division commences with
a series having very long spinous regions, and a short and characteristically shaped bare
tip (Plate XXXVIII, fig. 12). The rows of spines are much finer and more dense than
in Harmotho'e imbricata—indeed, in this respect they approach Acanthicolepis asperrima.
Those following the upper series show a distinct secondary process beneath the tips
(Plate XXXVIII, fig. 13). The length of the spinous tips diminishes in the usual manner
towards the ventral edge of the foot, the bare portion at the tip in several of the lowest
showing no secondary process. The papilla above the spine is long and filiform, and the
ventral cirrus extends beyond the bases of the adjoining bristles, and has sparsely
distributed and short clavate cilia. All the bristles are of a pale yellowish hue.
Posteriorly the dorsal division diminishes in length, and disappears in some of the