Feet.— The second foot has a small dorsal division, which projects anteriorly, and no
dorsal cirrus. The dorsal bristles are tapering and spinous from the skin outwards, as m
other parts of the body. On the other hand, the ventral division has more slender bristles,
with longer and more tapered spinous tips than elsewhere. When seen antero-posteriorly
they somewhat approach the pinnately spiked forms of the Aphroditidm, though, of
course, differing in character. The long tentacle-like ventral cirrus comes , from the
anterior and inner base of the foot, and is directed forwards, thus diverging both m
size and relation to the parts of the foot from the subsequent organs. , ' ,
The third has become more or less normal in structure, except that the ventral
division has not attained the size of that in the fully-developed foot. The serrated dorsal
bristles spring from an elevation on the upper and anterior border, the only representative
of the dorsal division, if we except the elevated crest bearing the dorsal cirrus The
ventral bristles are stronger, the serrated tips somewhat shorter, and the points slightly
hooked. The slender inferior series alon||still resemble those in the second foot. The
ventral cirrus has now the normal position and form. • '
The fourth foot, though smaller, is nearly typical, and the short curved dorsal
bristles are also present. The ventral bristles have tips only a . little longer than
those of the central feet. The ventral cirrus is in the normal position, but the long
papilla of the segmental organ does not appear till the eighth foot, and k continues to
the penultimate one. . .
The typical foot (Plate XLII, fig. 25) is massive, and presents little differentiation
of dorsal and ventral divisions * h e r than the bristles and spines, for the mam masslef
the foot is formed by the ventral division. The dorsal bristles rise from a papilla placed
far back on the dorsal edge and in the front of the cirrus^where that is present, and
their tips, as a rule, extend little beyond the bases of the ventral bristles. In structure
they consist of long, tapering, spinous bristles (Plate XXXVII, fig. 13), the spines being
arranged in close rows from base to apex, a few on the dorsal edge being- shorter and
stouter, with coarser spikes (Plate XXXVII, fig. 12). The ventral bristles,|Plate
XXXVII, figs. 9 and 10) have slightly longer tips than in L. ehma, and the two spines at
the tip of the rows are characteristic.
The shape of the foot does riot essentially alter posteriorly, and tlm ventral bristles
of the last foot have tips only a little longer than in the centre of the body, a feature which
almost disappears in that next in front.
The dorsal cirri spring from a dilated base (ceratophore) which has anteriorly and
posteriorly an area in whioh a whitish granular amorphous substanoe is deposited.
The deposit, indeed, marks the bulbous region on each side. The column is pale, but at
the dilatation is a blackish band, while the filiform tip is pale.
The dorsal bristles are generally covered with fine mud and parasitic growths. The
general hue of the ventral is golden, but it varies in intensity, some of the northern
forms, e. g. from Norway and the Gulf of St. Lawrence, having darker bristles. In one
large example from St. Abb’s Head one side had golden bristles, while in the other all were
of a pale colour. The same form had an enigmatical, hyaline, stalked'structure, with
numerous rootlets on a posterior scale. An occasional foraminifer and a small patoh of
Lepralia also are met with in large examples.
The large deep-water forms (forty fathoms off St. Abb’s Head) seem to be softer
than those between tide-marks, and have the scales more or less abraded.
Reproduction.—Large examples from the neighbourhood of St. Abb’s Head were
loaded with ova and ripe sperms on August 1st, 1884, and the Irish examples were so in
July. At St. Andrews nearly ripe as well as ripe males and nearly ripe females occur from
the beginning of May to the end of June, and it is probable that the spawning period
is in June and July. The males are distinguished by their pale hue, whereas the ripe
females are of a slate-grey. The spermatozoa have a globular or slightly ovoid head and
a long tail, as in Nereis. Ho ova could be pressed out of the long segmental (nephridial)
processes with their dilated and truncated ends, but they readily issued from ruptures of
the parietes of the body. The segmental papillae are alike in both sexes, of moderate
length, and with a little dark pigment at the trumpet-like ends.
Young examples of about 3. mm. in length occur in July (‘ Irish Exped.,’ 1886, to
Gweedore). These show proportionally larger cilia, larger and fewer bosses on the scales,
and the cirri have more elongate tips, with scarcely a trace of. the enlargement below.
The ventral bristles have proportionally longer tips.
When disturbed in their native haunts, their motions are comparatively slow and
cautious, so different from the restless activity of Harmothoe i/mbricata or Evame. They
cling tenaciously, partly by aid of their bristles, to rough surfaces, so that, for instance,
the tubes of Filigrana give way in extracting them, and it is difficult to pull them from
grooves in shells and similar hollows. Eine examples are procured in rock-pools under
large stones that have been little disturbed for many years, where, for instance, Mgirus
punctiluceus and patches of Alcyonium occur. They are partial to hollows and crevices;
thus one thrust itself into the tube of Protula, and being preserved therein has retained
the cylindrical shape. Hitherto, however, they have not been found commensalistic in
the tubes of other annelids, but occupy their sites independently under stones in rivulets
and rock-pools near low-water mark, and for some distance landwards. In confinement,
specimens of Evame and Harmothoe will occasionally cling to the dorsum, and small
examples may even insinuate themselves along the dorsum under the scales.
The crustacean parasite, Sellius bilobus, Kroyer,1 is found on this species in northern
waters, while Perigonymus repens2 occurred in great beauty on the anterior scales of fine
specimens trawled in thirty-five to forty fathoms off St. Abb’s Head.
While they are not infrequently found in the stomach of the cod and other fishes, it
| is curious that young green cod in the tanks refused them and other Polynoidas, such as
Harmotho'e and Lagisca, while they readily devoured Nereis, Traphonia, and Girratulus;
the mode in which the Polynoidse curved themselves and kept the bristles prominent,
showed that they were aware of the value of such protective organs. Taken into the
month of the green cod they were at once rejected, and fell to the bottom of the tank,
where they were engulfed by Gottus, but with a similar result, viz. immediate rejection.
0. E. Müller, in his ‘ Wurm-Arten,’ calls this species “ die gedüpfelte Aphrodite
mit rauhen einfarbigen Schuppen.”
1 ‘Natur hist. Tidskrift./ lste R., i, 1837.
2 This zoophyte recalls the loss lately sustained by science in the death of the Rev. Dr. T. Hincks,
whose patient and accurate work amongst the Hydroids and Polyzoa will long be remembered.
37