head is fixed inferiorly to the massive bases of the tentacular cirri (first foot). Externally
two tapering cirri of considerable length occur, one, the longer, from the dorsal edge, and
another a littleshorter from the ventral edge above the palpi. Behind the dorsal tentacle
is a T-shaped ciliated process (ctenidium). To the inner side of the ventral cirrus is a
sickle-shaped blunt appendage (cuilleron céphalique, or buccal ctenidium), richly ciliated
and continuous with a well-marked ridge on the inner surface of the basal process. On
the inner side of the bristle-tuft superiorly, again, is another short subulate cirrus, the
homologue of the lateral tentacle (Pruvot and B-acovitza). The long subulate and smooth
palpus springs from the middle of the ventral face of the basal process, and has a scoopshaped
flap (ctenidium) ensheathing it internally. The first foot carries a double series
of bristles directed forward and inward, and consisting of somewhat stiff, long, slender,
curved bristles closely spinous towards the tip. The upper series of bristles had many-
stalked infusoria like Bhabdostyla.
Body four to eight inches in length ; elongate, not much tapered anteriorly, but
gradually diminishing posteriorly ; rounded dorsally and flattened ventrally, composed
of 170 to 200 or more bristled segments. The dorsal surface is marked anteriorly by
transverse lines, and the median region forms an elevated ridge, and sometimes has a
bluish-green or ochreous colour. The post-cephalic ridge has at its sides small
ciliated processes, which at first sight resemble parasites. The ventral surface
is of an iridescent flesh-colour, or bluish-green (from eggs) marked by the red
central vessel, and with a raised transverse line between the centres of the feet.
Posteriorly the body terminates in two tapering caudal styles.1- A segmental eminence
occurs at the base of each foot, and on the adjoining region is a little funnel-shaped
papilla, but apparently unconnected with the former. In the anterior feet the funnel is
in the centre of the base of the foot, but it by-and-by moves forward, so that throughout
the rest of the body it is near the anterior edge of the foot. The funnel-shaped
papillæ are continued from the fourth bristled feet to near the top of the tail; about
twenty segments, however, are devoid of them. In the males this funnel-shaped
organ does not appear to be present, but the segmental eminences are very prominent,
and have an oblique crest. In spirit the sperms sometimes form masses of a rope-like
character externally, as if they had issued (on immersion in spirit) from a minute pore.
The cuticle is considerably thickened over the nerve-area.
The proboscis hâs eleven papillæ on each half (dorsally and ventrally). These are
large and somewhat conical, slightly constricted at the base, and with a projection
internally about the middle. The teeth do not seem to bite alternately, as in the
Polynoidæ, but the lower pass in front of the upper pair (Plate XXVI a , fig. 21).
No pregastric cæca are present, but short intestinal cæca occur laterally.
Scales (Plate XXXIII, fig. 16), 156 pairs, covering the entire dorsum, of a greyish
hue, the anterior especially showing numerous dark brown grains ; all however possess
them, unless when recently reproduced. Towards the posterior end they have a
broad band of dark grey or brownish grey along the posterior border internally, and
occasionally externally a dappled condition or grains of the same dark grey colour. A
1 Body terminated by four small cirri (De Saint-Joseph).
very pretty and symmetrically tinted arrangement thus pertains in this region. The
first pair of scales are somewhat ovate, the rest more or less reniform, and they are
tough,—adhering, moreover, with considerable tenacity to the tubercles. Their surface is
entirely covered with minute papillae, which are often tinted brownish, and along the
anterior and neighbouring part of the outer border are a series of massive and simple
cilia, somewhat constricted at the base, then dilating and tapering to a blunt tip. Some
show a branch or knob near the base. In the other scales a portion of the outer and
anterior region is devoid of the minute papillse, whilst amongst the cilia of the outer
border are numerous minute globular papillse. Both extend here and there within the
border. The inner or rounded anterior lobe of the scale has the papillse up to its border.
The scales occur on the first bristled foot, third, fourth, sixth, eighth to twenty-fourth,
twenty-sixth, twenty-seventh, &c., to the end of the body. In the terminal region the
small scales retain the same characters, though a patch devoid of papillae occurs on the
anterior part of the rounded inner lobe, and the cilia along the external border are
smaller, more slender in proportion, and more numerous. The minute papillae on the
surface occasionally project beyond the border posteriorly in all the scales, and the gradual
elongation of the cilia externally shows that they are modifications of the same organs.
The largest papillae occur on the exposed part of the scale. Finely branched nerves
supply the entire organ. The scales often have a blackish or brownish deposit of
granular matter on their surfaces. It seems to be the same as that which occurs in the
Polynoidae. In young examples the papillae on the scales are proportionally large, and
occasionally sand-grains adhere. The cilia also are somewhat larger.
Feet.—The second foot shows dorsally two ciliated lobes. It has two powerful
spines. The dorsal division is indicated by the nature of the bristles and by the issue of
the spine beneath them. The dorsal bristles consist of the same slender, elongated,
finely spinose forms seen in the previous process, the tips of most being broken. They
have the infusorial parasites formerly indicated and fine filaments of an alga. The
ventral division bears much stronger bristles, the stout shafts of which merge into the
distal spinous region without evident change. The slightly alternate rows of spines are
prominent, and this region ends in a long, tapering, articulated appendage terminating
in a bifid tip, the dorsal process being hooked. Just above the lower edge of the ventral
region a series of large, lobate papillse project, and below the bristles are a curved series
of minute papillae. The ventral cirrus, as in the previous groups, is large and
tapering, its tip extending considerably beyond the fleshy part of the foot. The funnel-
shaped papilla external to this organ is absent.
The third foot shows a T-shaped ctenidium dorsally. The dorsal division of the
foot is more clearly indicated by a fissure, and its lower border is furnished with large
clavate papillae. The bristles curve upward and inward, their convexity being thus
external. The bristles of the ventral division have already a tendency to form groups.
Thus the upper six of the ventral series consist of moderately stout shafts with simple
tapering tips which are coarsely spinous inferiorly and finely spinous distally, the tip
being smooth. Then follow the stouter forms, as in the second foot, with spinous
regions distally and a jointed, tapering, bifid appendage. Amongst these, however, are
some with an unjoin ted terminal appendage, a powerfully hooked tip, and a strong