Montagu’s description (ISIS) is ckaracteristjÉ and in his examples the branchiæ
were likewise speckled with white. His specimens from Devonshire appear to have
been about the size of those from the Outer Hebrides, viz., 6 or 7 inches and i inch
in diameter. He thought the ventral shields were dorsal. The example figured had
a reproduced tail. He describes the tube as composed of slimy matter covered with
gravel and broken shells.
Dalyell (1858) procured his examples from Shetland. He gives no details of
structure, though seventeen pairs of bristle-bundles are represented in his plate. He
noted regeneration of the posterior extremity, the new region being grey at first, but
gradually darkening and becoming finely speckled in five months.
Claparède (1868) had doubts about the identity of Terebella Meclcelii, Belle Chiaje,
and T. nebulosa of Montagu, but the differences in size (the northern form being much
larger) and the colour of the tentacles cannot be depended on, and so far as can be
judged these forms are the same. He draws special attention to the rounded gland-
capsules in the pads or tori for the hooks, and considers them peculiar to the species.
Salensky (1883) gives a careful account of Terebella Meclcelii with excellent figures,
He describes the various stages, and the derivation of the various organs from the
epiblast, mesoblast and hypoblast (his entoderme).
The Terebella viridis, n.s. of Malm1 (1872), has three thinly branched branchiæ
somewhat after the condition in Nicoled, and is held to be a variety of the present form.
De St. Joseph (1894) describes six segmental organs, two small in the third and
fourth segments, a third in the fifth, and the last three in the sixth, seventh and eighth
segments. He found an encysted Distome in this species anteriorly.. He does not allude
to any commensalistic form in its tube. This author1 2 * (1906) found many specimens
of the G-regarine Doliocystis, some free without the epimerite, others fixed by the latter
to the wall of the intestine and having posteriorly a diaphanous membrane. He also
records Gregarines of the genus Ulivina, Ming. (Sycia, Léger), and of the genus
Selenidium, free stages of Gregarina terebellæ of Kôlliker.
Paton8 (1899) describes the heart-body in Polymnia as a cylindrical rod over which
the blood flows on its way to the gills, and attached to the wall of the heart by fine
processes. It is mesoblastic in origin in this form, and, as Eisig suggests, it may
be of the nature of intra-chloragogen, or modified peritoneal tissue, since “ the tissues
included under that designation” differ chemically. The heart-body being situated in
the stream of blood from the alimentary to the respiratory organs, Paton concludes that
its functions may be similar to the liver of the higher forms.
Fauvel considers the small Terebella Grubei procured by the “ Challenger ’ in
Australian waters this species, and the hooks certainly show little difference.
In the British Museum preparation 62.5.7.43 (labelled T. conchilega) is Polymnia
nebulosa from Polperro, where it lives in chinks of rocks.
1 ‘ Annul. Gôteb./ p. 97, Tab. i, fig. 7.
2 ‘ Ann. Sc. nat./ 9® sér., t. iii, p. 176, pi. iii, fig. 56.
8 ‘ Quart. Journ. Micros. Sc./ vol. xli, p. 288, pi. xxi, figs. 33, 35 and 36.
Genus CXLVI.—Lanice, Malmgren, 1865.
Cephalic region with small dorsal collar, the sides expanding into great lateral flaps
which almost or completely meet in the mid-ventral line'. The anterior margin of the
tentacular plate forms a spout-like border surrounding the mouth. Body typical.
Branchiae three finely-branched tufts on each side, more or less whorled toward the tip,
and situated on the first, second and third segments. Seventeen pairs of bristle-bundles
from the fourth segment backward. Hooks commence on the second bristled segment,
and range from eleven to twenty, biserial; they continue to the posterior end. Ventral
scutes distinct.
Marenzeller (1884) placed Lanice after Pista, which followed Leprea; that again, in
turn, came after AmphitHte.
1. Lanice conchilega, Pallas, 1766. Plate CXIIIa, figs. 2 and 2b—body; Plate CXIX,
figs. 8—8e—structure and tubes ; Plate CXXVa, figs. 4—4 c—bristles and hook.
Specific Characters.—Cephalic region as in the genus, the meeting of the lateral flaps
of the dorsal collar in the mid-ventral line perhaps being normal. Statocyst on each side
in thé second segment. Body 270 mm. long, of a salmon-pink hue, except where the
vessels give a deeper red or the intestine a dull greenish tint. Ventral surface anteriorly
is deep red or brown, the tentacles pale pink, and the branchiae dull red. Anus with
marginal papilla?. Ventral shields (fourteen to seventeen, Marenzeller) extend from the
lower lip almost to the termination of the bristles, each segment having its shield generally
divided transversely into two. A glandular belt occurs on each side in the line of the
bristle-bundles, and it extends considerably behind the bristled region. The third segment
has a greatly developed anterior lamella stretching from the edge of the ventral shield
almost to the second branchia. Anterior nephridia three on each side, the funnels
opening in the second, third and fourth segments. The posterior nephridia occur in the
sixth to ninth segments. Bristles with striated shafts, and a double serrated wing on
each side of the tapering tip. From the sixth to the ninth segment a small papilla exists
behind the bristle-tuft. Hooks present a stout base which narrows upward to the curved
neck, above which are the main fang and two teeth above it in lateral view; biserial from
the eleventh to the twentieth segment. Tubes lined by secretion, covered by fragments
of shells, Foraminifera, gravel, fragments of Echinoderms, Balani and Serpulids, with a
dendritic free end, the fimbria? often being attached to two flattened basal plates or
laminae.
Synonyms.
1766. Nei'eis conchilega, Pallas. Miscell. Zool., p. 1311, Tab. ix, figs. 14—22.
1767. Sabella chrysodon, Linnæus. Syst. Nat., edit, xii, p. 1269.
1791. Terebella conchilega, Bruguière. Encycl. Méth., pi. lvii, figs. 5—12.
1803. Sabella chrysodon, Montagu. Test. Brit., vol. ii, p. 546.
,, conchilega, idem. Ibid., p. 547.
1806, Terebella „ Turtoi/s Linn., p. 84,