1896. Sabella pavonina, Roule. Camp. “ Caudan” (Ann. TJniv. Lyon), p. 161.
1897. ,, pavonia, Miohaelsen. Polycli. deutsch. Meere., p. 182.
1898. „ Idem. Grönland-Armel., p. 130.
1901. ,, pavonina, Whiteaves. Mar. Invert. E. Canada, p. 72.
1902. „ ,, Marenzeller. Denkschr. Mat.-Nat. CI. Kaiser). Akad. Wiss. Wien, Bd. lxxiv,
1904.
1906.
1909.
1910.
1911.
1912.
1913.
1915.
1916.
1917.
p. 23.
„ Journ. M. B. A., vol. vii, p. 231.
„ Bohn. Ann. Sc. nat., 9e sér., t. iii, p. 129 (movements).
„ Fauvel. Bull. Inst. Oceanogr., cxlii, p. 41.
„ Lo Bianco. Mitt. Zool. St. Neap., Bd. xix, p. 586.
„ Fauvel. Ann. Sc. nat., 9e sér., t. x, p. 209.
,, Southern. Proc. Roy. Irish Acad., vol. xxviii, p. 241.
,; . Elwes. Journ. M. B. A., vol. ix, p. 65.
pavonia, Riddell. Proc. Liverpool Biol. Assoc., vol. xxv, p. 64.
pavonina, Crawshay. Journ. M. B. A., vol. ix, p. 346.
„ Giard. OEuvres Diverses, p. 57.
pavonia, Hofsommer. Wiss. Meeresunters. Kiel, Bd. xv, p. 317, Taf. iv, figs. 1 and^2.
pavonina, Southern. Proc. Roy. Irish Acad., vol. xxxi, No. 47, p. 138.
,, Fauvel. Campag. Scient. Monaco, xlvi, p. 312. -
„ Allen. Journ. M. B. A., vol. x, p. 641.
„ . Southern. Irish Sc. Invest., No. 3, p. 49.
pmicillus, McIntosh. Ann. Nat. Hist., ser. 8, vol. xvi, p. 2.
pavonina, Rioja. Anél. Poliq. Cantâb., p. 63.
Habitat.—Tossed on shore in great numbers after storms on the West Sands, St.
Andrews, and the tube is often encrusted by Alcyonivm digita.tvm. It was a common
accompaniment of other forms from deep water entangled in the lines of the fishermen j
Moray Firth; Orkneys (Fauvel) ; Dingle Bay, Ireland, 50 fathoms; Shetland (J. G. J .) j
Plymouth (Spence Bate and P. Rowe, Allen, Crawshay) ; Dublin Bay, Blacksod Bay and
West Coast, Ireland (Southern); Torquay Harbour (Elwes); off Forth (Cunningham
and Ramage). In the river Roach, near Burnham, Essex, the tubes are usually small
(Punnett), whereas in the Channel they are the size of block-tin gaspipes (British
Museum). It is common on the south coast and all along the eastern and western shores.
Norway (H. Rathke); North Sea (Kroyer); Greenland (Michaelsen); in 81 fathoms
(826 metres?) off Cape Finisterre, " Porcupine,” 1870; Sweden (Malmgren); shores of
France (De Quatrefages, De St. Joseph); shores of Cantabria (Rioja); Canada (Whiteaves);
Atlantic coast, U.S.A. (Stimpson, Verrill); Naples, in a depth of 25—100 metres in a
colony with Aglaophenia myriophyllum (Lo Bianco).
When the branchiae of this species are thrown off the cephalic region presents a
truncated surface, in the centre of which is a frilled eminence which, when carefully
inspected, shows two lateral membranous wings, which unite in the middle line below and
send a process ventrally between the two great ventral laminae, whilst the upper edges
pass above the mouth in a series of short frills. In the mid-dorsal line over the mouth
is a triangular flap with an acute apex, the base of which is grooved dorsally, the whole
resembling an epistome. Dorsally the cephalic plate is deeply grooved by the dorsal
fur row, the firm and thick edge of the rim which carries the branchias being severed and
neatly curved on each side; the rim then passing ventrally to the base of the great flaps
is folded inward and upward, and is fused on each side with the firm median mass over
the mouth. In the perfect condition with the branchiae attached the pedicle between the
ventral flaps passes upward as a bifid process, then expands on each side into a lateral
flap or wing, which after a short progress bends backward and upward, makes a kind
of frilled knee, and becomes continuous with the investing membrane of the branchiae of
its side, its outer border inferiorly passing into the basal semicircle of the branchiae, to
which it is fixed throughout. Such is the arrangement connected with the floor of the
mouth and the lower lip. Dorsally the membrane forming the roof of the mouth splits
considerably in front of the median fissure of the lower lip into two limbs, each of which
at the base has an axis with a narrow ventral web, and a thinner and broader dorsal web-
which tapers distally and goes much further along the axis than the former, the axis
finally tapering to a long, delicate tip. The whole forms the so-called tentacle, which in
the preparations is concealed in each branchial semicircle. Viewed from the inner
surface of each branchial fan the “ tentacle ” has the web on its dorsal edge connected
with the dorsal edge of the fan, whilst its ventral web passes ventrally to the central
region dorsad of the mouth. The inrush of water along the inner surface of the branchial'
fan would thus be swept toward the mouth, the tentacles and their webs probably aiding
in this function, and keeping the stream in each fan to its own side as it rushes down the
groove by the outer border of the smaller anterior web into the mouth.
The branchial fan arises on each side from the firm base formerly mentioned, a spiral
twist being evident dorsally and more especially ventrally at its commencement. Each,
in preservation, has the ventral edge curved inward, and a narrow membranous web
passes from the frill of the inferior oral membrane for some distance along its edge..
This ventral border is the thickest and gives origin to the majority of the branchial
stems, the rest springing from the middle and posterior parts of the basal semicircle.
The number of these filaments varies, the two sides seldom being equal; thus, for
instance, thirty-eight may occur on the right and forty-one on the left. The fan on each
side is long and graceful, banded with regular markings of dull red and white. The-
circles of colour do not go evenly round the expanded fan, but start from the ventral
fissure. Dorsally a. greenish hue occurs in some at the base of the fan. In others green
or purple predominate, and the fluid in which the animals lie is always tinged with green
(Dalyell)*
Each filament has an elastic chordoid and camerated axis, the earnerge being after
the fashion of the bristles of Nereis or Aricia. The filaments are united by a web inferiorly
(about the level of the first pigment-band), but free throughout the rest of their extent,
and are somewhat flattened processes with a smooth external edge, near which the axis
lies, whilst the inner edge is fringed with a dense series of slender pinnse, which likewise
have a translucent axis jointed at intervals like the bristles of the Chloroemidge. The
filaments and their translucent axis gradually diminish distally, but the axis can be traced
almost to the extremity. Toward the tip of the filament the pinnge gradually diminish
in length, finally forming mere papillge, and thereafter the tapering tip is smooth and of
moderate length. When the branchige have lost their distal ends and regeneration has