segments, the first, in a line with the first bristle-bundle. Eye-specks as in the former
species. Ventral scutes 15. Lateral papillge as in T. cincinnatus. Setigerous and
uncinigerous processes similar to T. cincinnatus, but the former bears somewhat stouter
bristles with slightly broader wings, and in the hooks the stud-like process on the prow
(anterior end of the base) has a different angle, and a different process beneath it, whilst
the posterior indentation is perhaps better defined. The upper teeth and the crown are
much larger than in T. cincinnatus, though such may be a variation.
Brownish-violet or orange in colour.
1855.
1864.
1865.
1869.
1870.
• 1871.
1875.
1884.
1885.
1894.
1896.
1900.
1901.
1904.
1906.
1909.
1910.
1914.
1915.
1916.
1917.
Synonyms.
Terebella triserialis, Grube. , Arch. f. Naturges., 21 Jahrg., p. 118, Taf. iv, fig. 16.
\ j} - „ idem. Insel Lussin, pp. 85 and 128.
Phenacia setosa, De Quatrefages. Annel., t. ii, p. 376 (only 2 branchiae on second and third
segments).
Terebella triserialis, idem. Ibid., t. ii, p. 364.
Neottis ■ „ Malmgren. Nord. Hafs.-Annul., p. 388.
Phenacia setosa, Grube. Schles. Gesell., 1868—69, p. 110.
„ . „ idem. Arch. Naturges., 1870, p. 332.
Terebella triserialis, Grube. Jahresb. Schles. Ges. f. Vaterl. Cult., p. 49.
Phenacia „ Panceri. Atti Soc. Ital., vol. xviii, p. 531.
Thelepus „ • Marenzeller. Sitzb. der K. Acad. Wiss., Wien, Bd. lxxxix, p. 58, Taf. ii,
fig. 3.
„ Carus. Fauna Medit., i, p. 266.
setosus, De St. Joseph. Ann. Sc. nat., 7® ser., t. xvii, p. 230, pi. x, figs. 259—262.
cincinnatus, var. profundus, Roule. Camp. “ Caudan,” p. 459.
triserialisj Ehlers. Schwed. Magell. Annel., p. 16.
and Neottis spectdbilis, Pratt. Proc. Lit. and Philos. Soc. Manchester, p. 14.
triserialis, Ehlers. Polych. Magell. u. Chil., p. 212.
setosus. Journ. M. B. A., vol. vfi, p. 229.
thoradcus, Gravier. Nouv. Arch. Mus., ser. 4, t. viii, p. 218, pi. iv, figs. 228, 229.
triserialis, Fauvel. Bull. Instit. Ocean., cxlii, p. 37.
setosus, idem. Ann. Sc. nat., 9® ser., t. x, p. 209.
„ Southern. Proc. Roy. Irish Acad., vol. xxviii, p. 238.
,, idem. Ibid., vol. xxxi, No. 47, p. 125.
. „ idem. Irish Sc. Invest., No. 3, p. 47.
„ Fauvel. Arch. Zool. Exper., t. Iv (Fasc. 10), p. 466, figs. 3—6.
„ Rioja. Anel. Poliq. Cantab, p. 57.
triserialis, Hessle. Zool. Bidr. Uppsala, Bd. v, p. 217-.
setosus, Fauvel. Arch. Zool. Exper., t. lviii, p. 455.
Habitat.—Between tide-marks, under stones in Guernsey and Herm, and also
dredged off St. Peter Port. Dredged in 10 fathoms in Lough Poyle, Ireland, in the
“ Porcupine ” Expedition of 1869. Dublin Bay (as T. setosus); in laminarian roots
and amongst Zostera in Blacksod and Clew Bays (Southern).
In the Mediterranean near Sicily, Villafranca and Lussin Piccolo, etc. (Grube and
Marenzeller). Atlantic coast, N. America (Verrill). Shores of France, Madagascar,
Australia (Fauvel). Shores of Cantabria (Rioja). Magellan (Ehlers). Falkland Islands
(Fauvel). Red Sea (Gravier).
The cephalic collar and the arrangement of the parts of -the anterior end are similar
to those of the foregoing species', but no pigment-specks remained m the preparations
behind the collar, though in life they were present. A distinction, however, immediately
appears in the branchial region, the surface of which is more: extensive, the filaments more
numerous and more slender. Moreover, they arise from three segments, viz. the second,
third and fourth.,. The first and largest forms a transversely elongated row of filaments
bn segment 2, its outer edge passing ventrally considerably below the first bristle-tuft
behind it. The second springs from the dorsum of the third segment within gie. dorsal
to) the first bristle-tuft and is smaller, whilst the third, which is somewhat longer, arises
on the dorsum opposite the second bristle-tuft. The first pair is widest apart, the third
neareTr heea cbho dotyh egre.nerally resembles that of the foregoing form, but is often smaller, and
the dorsal and ventral surfaces, glandular scutes and plates do not materially differ. The
bristle-tufts range from thirty to forty, the posterior region in one having about forty
segments devoid of them, as in T. cmdrmatus. It tapers posteriorly to a slender tail, and;
the, uncinigerous processes seem to go on to the tip, thus differin g from those of T. dndn-
natus. The anus appears to have a papillose margin.
The first bristle-tuft arises opposite the second branchia, and as mentioned, is above
the level of the first branchia, and the setigerous processes are continued along the dorsolateral
region to the posterior region, as in Thelepus cinrinnatus, where they cease,. They
are vertically flattened in front and throughout the greater part of their course, but
posteriorly, they diminish to conical papillae. The anterior bristles (Plate CXX V1, fig. 9,
and a curved one in fig. 9 a) appear to be somewhat shorter than m T. cincinnatus, but
are similarly arranged in two series, a longer and a shorter. The wings in both are
slightly broader than in T. cincinnatus, both sets of bristles being proportionately shorter
and thicker. They increase in length in the middle of the body, but posteriorly diminish
both in size and number, especially before ceasing, yet retaining the same arrangement as
regards shorter and longer series. The wings in the terminal bristles are narrow. All
the bristles have a pale golden hue, and whilst the first few sets of bristles are directed
outward, the majority slope outward and backward, the terminal tufts, however, in the
preparations, projecting outward or even slightly forward.
The rows of hooks commence on a fillet at the fifth segment, that is, opposite the
third bristle-tuft at the posterior part of the segment, and they slightly increase in length
to the fifteenth series, when a gradual diminution occurs; the rows, moreover, by-and-by
are elevated on processes, and instead óf being nearly straight they are convex forward
about the twenty-fourth, and this arrangement appears to ‘be retained in the longer
posterior uncinigerous processes, where they occur on the anterior face of the tip. As
the bristles diminish and disappear the uficinigerous processes increase in prominence and
are ventro-lateral in position. Finally, they are minute toward the tip of the tail. The
hook (Plate CXXVI, fig. 9 b) is similar (generally) to that of T. dndinnatus, yet differs in
detail. Thus it is proportionally larger, the base longer, the stud at the anterior end of
the base (prow) has a different angle with the outline, is truncated at the tip, and the
process beneath is more prominent, though there are variations in this respect; moreover,
traces of a second tooth on the crown above the main fang are common. Marenzeller’s