lateral view above the main fang, and pressure occasionally causes the second to project,
whilst others in the same position show two teeth above the main fang—even in the same
row with those having only the main fang and a single tooth above it. In one male most
of the hooks showed this third tooth, but it does not appear to be a sexual character.
Many examples of the species (N. venustula) show a single tooth above the main fang
in front, and two in the posterior hooks.
Malmgren distinguished what appears to be a variety of the foregoing as Nicolea
arctica from Spitzbergen and Greenland, but so far as recent examinations go it seems to
be unnecessary to give it specific distinction, and this is also the view of Levinsen and
Marenzeller, though Wiren follows Malmgren. In this variety the structure of the collar
agrees with N. venustula. The body has from forty to seventy segments, with about
fourteen ventral shields, the last three being rudimentary.
The colour of the male variety (N. zosteiicola) is whitish, of the female reddish with
a white lateral line. Branchise two, apparently with finer branches than in N. venustula
and more widely spread. The setigerous processes number fifteen pairs, the bristles in
two groups with golden shafts, short, tapered tips with narrow wings. The hooks have
two teeth above the great fang (Plate CXXVI, figs. 4 and 4 a.). The tube is composed
of mud. This variety was dredged in deep water off Shetland and at Station 8 to the
west of Ireland in the “ Porcupine ” Expedition of 1869. It is probable that the Terebella
longicwrnis of M. Sars1 (1829) is a Nicolea.
Hessle (1917) found most of those on the Scandinavian coast had fifteen pairs of
bristles.
In the British Museum, prep. 62 . 7 . 12.47 from Polperro, labelled “ Terebella constrictor,”
appears to be Nicolea venustula.
A variety of this widely distributed form was procured by the “ Knight Errant ” in
the trawl at 640 fathoms at Station 8, 22nd August, 1880, and it was from certain
peculiarities considered at first "to belong to a different type. Further examination,
however,demonstrates that it may more fitly be placed as a marked variety of Nicolea
venustula, Montagu. It was originally described as Melinella Macduffi.3 The cephalic
lobe agrees with that in the genus, and ventrally the buccal segment forms a rim behind
the mouth. Ten glandular scutes occur anteriorly on the ventral surface instead of
thirteen in the ordinary form and the ten anal papillae are longer than usual. There
are eighteen pairs of bristles anteriorly instead of the ordinary seventeen. Two branchiae
only occur on the first segment as two slightly branched organs supported on pedicles.
The tip is dichotomously divided in some parts, whilst in others it is irregular. Not
more than a dozen filaments occur in each branchia. The setigerous processes, which
commence on the third segment, are minute and appear to be about eighteen in number.
Each bears a small tuft of translucent bristles with delicately tapered slightly curved
tips with narrow wings (Plate CXXV, fig. 4) and arranged in two series, a longer and a
shorter, the shorter, however, being only a little within the tips of the longer.
1 ‘ Bidrag. Soedyrenes Nafcurhistorie/ p. 28, Tab. i, figs. 7—9, Bergen, 1829. This is a noteworthy
production for a theological candidate.
3 * Ann. Nat. Hist./ ser. 8, vol. xiii, p. 109, 1914.
The rows of hooks commence with the bristles, and in a single series. Each hook
(Plate CXXY, fig. 4 a) generally agrees with the type of Nicolea, having two distinct
teeth above the great fang, a somewhat narrow space inferiorly, as the process on the
anterior outline is high and an excavation exists below it. The posterior outline has a deep
dimple, the inferior margin of the base is convex and the prow rounded. The posterior
hooks have the same structure but are smaller, and the hispid crowns are proportionally
large. After the cessation of the bristles the uncinigerous processes become more distinct,
and posteriorly they form in front of the tail a conspicuous series of serrations.
The tube is of moderate length and composed of secretion strengthened by glittering
sponge-spicules and minute Foraminifera, so that it forms a somewhat thick or rough,
hirsute tunnel. They seemed to have formed groups. These sponge-spicules constitute
a large part of the wall of the tube and form a very efficient protection. The inner
secretion is somewhat tough.
It is probable that such a form as the foregoing would stand for Malmgren’s
Scione lobata.
Genus CXLIX.—Pista, Malmgren, 1865.
Terebella, Linngeus, Cuvier, etc.; Terebellse Idolise, Savigny, De Blainville, Grube.
Cephalic plate with a thick dorsal collar, the margin externally and ventrally joining,
after a notch, the anterior fold. Supra-oral fold short. Slender, grooved tentacles.
Behind the mouth is a. tongue-shaped process. Body rather short, tapered posteriorly
to a slender tail with four large anal papillae. Ventral scutes seventeen, besides four
or five small terminal scutes. Anteriorly behind the dorsal collar the setigerous processes
approach the median line. Behind and above the third and fourth bristle-tufts is a
long papilla, and occasionally two are found behind the fourth. Branchia arises on
the dorsum of the third segment on each side by a long stem (sometimes two are
present), and the distal region is finely branched, the whole forming an arbuscle.
Setigerous processes commence on the fourth segment and are seventeen in number;
bristles curved, tapered and distinctly winged. The avicular hooks commence on the
fifth segment, are in a single row anteriorly, double from the seventh to the sixteenth.
Each has a deep basal region, a short, stout main fang with three or four teeth (in
lateral view) above it, and a nearly straight posterior outline till it reaches the point of
attachment of the powerful shaft. The first six tori have hooks with a long posterior
process. The anterior nephridia are small or absent, the posterior with long ducts.
Marenzeller (1884) reviewed the history of the genus and rectified the synonymy.
In a careful note on the genus Pista, illustrated by excellent text-figures, Caullery1
(1915) rightly uses both the anterior and the posterior hooks in diagnosis, and shows
that the great size of the posterior inferior process really corresponds to the shaft of an
ordinary bristle, as had been pointed out in such Sabellids as the Jasmineira-group,
thus homologising the parts in both bristle and hook. He places the known forms under
two genera,, viz., Pista, Malmgren, and Eupista, McIntosh, the type of the former being
1 * Bull. Soc. Zool. France/ t. xi, p. 68.