division is somewhat truncate, sloped from above downwards and inwards, and has a
small papilla internal to the bristles, which superiorly are whorled, then finely serrate at
the tip. Next follow larger bristles, with the distal end of the shaft curved and spinous.
The distal region is segmented, and tapers to a fine bifid point (minute beak). Yentrally
is a dense group of similar forms, but without spines at the end of the shafts. They
are most slender at the ventral edge.
S ynonyms.
3830.
1834.
1840.
1848.
1851.
1855.
1857.
1865.
1875.
1876.
1884.
1898.
Sigalion Mathildse, Cuvier. Règne An., 207.
„ „ Rathke. Fauna Norweg., 151. .
,, ,, . Aud. and Edwards. Annél., 105, pi. ii, ff. 1—10.
,, ,, G-rube. Actin., Echinod., &c., p. 84.
„ „ Gervais. D’Orbigny, Diet. d'Hist. Nat., xi, p. 601.
,, ,, Grube. Fam. d. Ann., p. 38.
„ ,, Peters. Archiv f. Naturges., vol. xxi, p. 38.
„ ,, Kinberg. Eugen. Resa, vol. ii, Zool., 2, p. 9.
„ „ De Quatrefages. Ann., i, p. 279.
,, Gamngtonii, Carrington. Proceed. Lit. and Philos. Soc. Manchest., vol. iv, p. 179.
,, Mathildse, McIntosh. Invert, and Fishes St. Andr., p. 118.
„ „ . idem. Trans. Zool. Soc., vol. ix, p. 408.
„ . „ Y. Carus. Faun. Medit., p. 204.
,, squamaivm, De St.-Joseph. Ann. d. sc. nat., Zool. (8), vol,-v, pp. 239, 241, pi. xiii, ff.
22—29.
Habitat.—Generally distributed round the British shores. Of large size and rather
abundant between tide-marks in the Channel Islands and at St. Andrews, while those
from Shetland are small. Most of the specimens are littoral, generally under stones,
though occasionally small pale specimens occur in sand, as at Southport. I t extends,
however, to some depth in the adjoining waters. I t is] occasionally tossed on the sands
at St. Andrews in considerable numbers after storms, and is also not uncommon in the
stomachs of cod, haddock, and flounders (E. M.J. The first two are especially partial
to this species. They sometimes take refuge in tubes of Terebella when cast ashore.
The species seems to be partial to sand. In the * Porcupine 5 it occurred off the Algerian
coast between Capes Falcon and Tenez.
Head (Plate XXIX, fig. 6) somewhat elongated from before backwards, oblong or
cylindrical in outline. The anterior border is truncate, with a slight peak at each end.
Behind the latter are two pairs of small black eyes, situated close together on each side
of the middle line, the pairs not far apart. The anterior pair are nearer each other and
also somewhat larger than the posterior pair. From the elevation of the head they look
forward and upward. Posteriorly only a transverse furrow marks the boundary of the
head. The head bends downward in front, and has soldered to it the two short and
somewhat conical lobes of the first feet, which bear externally (dorsally and ventrally)
short subulate cirri, and dorsally and internally a tuft of very slender, tapering bristles,
most minutely serrated and directed upwards and inwards. Beneath is the long}
tapering palpus, the tough cutiele of which is usually thrown into fine transverse
wrinkles, so that it resembles in a decayed specimen the trachea of an insect. The head
is thus raised above these processes, and is confined to the dorsal region. A short
conical process on the inner and upper border of the foot may indicate the lateral
tentacle.
Body three to five inches in length, and with segments about as numerous as in
Sthenelais boa (180), elongate, very little tapered anteriorly, so that in the preparations
it is almost truncate, and gradually diminishing posteriorly, though terminating in by no
means a slender tail, from the tip of which a remarkably long and slender caudal style or
cirrus extends. The functions of this delicate appendage would appear to be sensory,
and it is curious that the tail is often specially modified in sand-dwellers, such as
Nephthys, certain Opheliidse, and Spionidse. The dorsal arch is slightly rounded laterally,
flattened in the middle when the scales are present, the prominent papillas for the latter
occupying most of the surface, and in the ripe forms showing ova through the walls.
The ventral surface is in life flattened, and in the preparations usually presents the
aspect of a long riband with rounded edges. A segmental eminence occurs at the base
of each foot, but no distinct papillae could be made out.
In life the colour of the dorsum is greyish-brown with a central bluish-green mark,
or dull greyish-white or pale pinkish in front with a dark grey stripe from the' proboscis.
In some a pale brown streak marks the inner margin of each scale. The ventral surface
is iridescent, bluish-green or pale pinkish, with the red central vessel.
Proboscis.—The number of papillae on each side (dorsally and ventrally) is about
sixteen, though from overlapping one or two more may occur, e. g. seventeen or eighteen.
The teeth bite alternately, the lower passing to the right of the upper.
Scales (Plate XXXIY, fig. 14) about sixty.-four pairs, and of the hue already
mentioned. They are firmly adherent. The surface is smooth, and they have the
external border supplied with a series of pinnate processes. The first pair are smaller
and somewhat triangular in outline, with a series of the typical pinnate processes along
the outer border. Moreover at the bases of these are a few simple papillge, and in some,
instead of the pinnate process, a group of long, simple papillas occur at one, end of the
series. The scales gradually assume a quadrate outline, the outer border bearing the
papillaa being nearly straight, while the posterior and inner corner is rounded off. The
processes1 (Fig. 38) have a stout central stem, which tapers to a slender point. The
axis is granular. The pinnaa or papillge arise on the scale even below the process, and
are continued on it somewhat irregularly at the base, but by-and-by assume a more
uniformly pinnate arrangement. The papillge are pale throughout. Occasionally one of
the processes is bifid. In vertical section the dorsal and ventral coverings of the scale
are joined by a close series of fibrous strands. Both surfaces are remarkably smooth.
As we proceed backwards the scales become more elongated transversely, but again
diminish posteriorly.
The first scale shows no branchial process, but all the rest are provided with such,
the organ being long and sickle-shaped as well as richly ciliated.
Feet.—The second foot is bifid, presenting an elevated dorsal lobe with a tuft of
simple, tapering, finely serrated bristles as. in the first foot, the spine issuing at their
1 ‘ Ann. Nat. Hist.,’ August, 1898, pi. ii, f. 14.