are well marked, the former showing a slight dilatation of the shaft at the commencement
of the wings and a long, curved, tapering, serrated tip. She shorter bristles have a
proportionally stouter shaft, with a distinct twist or bend in the flattened blade after the
wings cease, the tips thereafter being finely tapered.
The branchise arise from a short stem, and split up into a number of branches, each
dividing into two, the whole forming a dense tuft.
The anterior hooks' (Plate CXXXVIII, figs. 6) have a more erect character
than those of A . cirrata, and the slope made by the base comes nearer a right angle,
whilst the hollow in the posterior outline is median, not near the inferior angle as
shown by Malmgren, so that the Canadian form may differ, whereas that procured in
the “ Porcupine’’ more nearly corresponds. There are five or six teeth above the main
fang. The .posterior hcfbks (Plate CXXXVIII, fig. 6«) have a more erect figure, with
a shorter,.and-more'massive base.
Hessle (1917) places this under his genus N eo-am phitrite, but the distinctions do not
appear to be such as to warrant the complication.
3. Amphitbite apfinis, Malmgren, 1865. Plate CXX, fig. 10—branchia; Plate CXXV,
figs. 6-—66—bristles and hook.
. Specific Characters.—Body typical. A nterior- region presents a transverse shield
behind the mouth, passing dorsally to join the smooth area in rear of the collar. Eleven
shields follow besides several rudimentary. The dorsal edge of the seoond segment
extends to the base of the first branchia, whilst the dorsal edge of the third falls short
of its branchia. A still longer gap separates the first bristle-tuftof the next segment from
the third branchia. Behind the shields a deep groove occupies the ventral median- line;
Branchiae three, on second, third and fourth segments, small, and. with rather short and
thick terminal divisions. Seventeen pairs of setigerous processes, the first opposite the
third branchia. Bristles pale golden,'the tip having narrow wings, which soon cease
the translucent region beyond being flattened like a long knife-blade* serrated on the
edge, and tapered into, a very long hair-like extremity. Hooks in a double row, each
having a small base and a large neck and crown, with three teeth above the main fang,
in lateral view, and a process in the gulf below it. It is distinguished from the hook
of A . cirrata by the fact that the posterior outline more nearly forms a right angle with
the base, the angle being more obtuse in A . cirrata.
Synonyms.
1865. Amphitrite t
Jims, Malmgren. JNord. Hafs.-Annul. 1867.
040,idem. Annul. Polych., p. 107.
p. iaD. xxn, ng. 1883. „
Wiren. Chastop. “ Yega ” Exped., p. 419.
1894. „
Levinsen. Yid. Meddel. Nat.Forh. Copenhagen, p. 174.
Bidenkap. Christ. Yid. Forh., No. 10, p. 128. ’ c
1912. „
1913.
Wollebask. Skrift. Selsk. Krist., Bd. ii, No. 18, p. 101, pi. xxxiv,figs. 1_7.
1914. „.
Augener. Zool. Anz., Bd. xli, p. 268 (Franz-Joseph Land).
---- 1915.
- » Southern. Proc. Roy. Irish Acad., vol. xxxi, No. 47, p. 121.
McIntosh. Ann. Nat. uHiiosvt..,, OseOrI.. O8,, vVWolI.. AxvV,, pppp.. .97 and 44.
1917. Neoamphitrite affinis, Hessle. Zool. Bidrag Uppsala, Bd. v, p. 179.
H abitat.—Dredged in the “ Porcupine ” Expedition of 1869, at 808 fathoms at
Station 11, off the Irish coast, in sticky mud. Dredged by the “ Knight Errant”
at Station 11, 28th August, 1880, in 535 fathoms; Clew Bay (Southern).
Abroad it has been found in Spitzbergen (Malmgren); Norway (Danielssen, Wolle-
bsek); Iceland and Siberia.
The cephalic region presents a broad horse-shoe fold over the mouth, continuous at
its outer and inferior edge, with the larger collar which bounds the tentacular area
posteriorly. A deep groove, wide in the middle and tapered at each side, is thus formed.
Below the mouth is a short fold bounded by the first-mentioned horse-shoe arch at
each side, and ventral to this a broader band or lip.
The body is typical, so far as it goes, is rounded dorsally, whilst ventrally are twelve
distinct shields and several rudimentary ones posteriorly. Behind the mouth is a
transverse shield which dorsally joins the smooth region behind the collar. Two
segments with ventral shields follow, the dorsal edge of the first passing to the base of
the first branchia, whilst the dorsal edge of the second falls short of its branchia. In
all twelve shields are present. A still larger gap separates the first bristle-tuft of the
next segment from the third branchia. Behind the shields a deep groove occupies the
ventral median line. A ridge (marking the nerve-cord) is continued from the last ventral
plate or shield along the groove to the posterior end of the body.
Marenzeller describes the colour of the body as reddish grey, brownish in front and
pale posteriorly. Tentacles streaked and punctated with brown. In the examples from
the “ Porcupine” brownish pigment still remained anteriorly at the cephalic folds and
between the ventral shields.
The branchige are three in number, proportionally small and with short and rather
thick terminal divisions. The first (Plate CXX, fig. 10) has a short stem which splits;
each branch consists of a few short, slightly curled filaments, some with bifid tips. The
second is a little less, and the third is again smaller. Both sides are alike, and on the
whole the organs seem to be somewhat shorter than in A . cirrata.
There are seventeen pairs of bristle-tufts, the first commencing opposite the third
branchia. The bristles (Plate CXXV, fig. 6) are pale golden, the shaft being deeply
inserted in the tissues, only a short free portion occurring below the wings, which are
narrow and soon cease, the translucent tip beyond being flattened like a long knife-blade,
boldly serrated at the edge, and tapered to a very long hair-like tip. One or two shorter
forms occur amongst the others, but apparently no regular series as in other genera, and
some may be developing long bristles. In these little of the winged region projects
beyond the surface, and the flattened blade is occasionally split into spikes. Amongst
the bristles are long curved forms with narrow wings (Plate CXXY, fig. 6') and
finely tapered tips. The bristles issue from an elevation at the dorsal edge of the ridge
for the hooks, and they form a vertical series in each tuft. Moreover, six small papillas
(third to ninth segments) occur immediately beneath them, situated at the posterior
border of the ridge for the hooks.
The hooks (Plate CXXV, figs. 6 a and 6 a'), when fully developed, form a double row,
the large fang facing that of the opposite hook. The base is comparatively small and
the crown and neck large (Plate CXXVI, fig. 2 b). The crown presents in lateral
184