2. Spinther miniaceus, Grube, 1860. Plate XXIV, figs. 1, 2.
Specific Characters.—Parapodia without cirri; the dorsal lamellae are prominent
processes with leaf-like external borders. The supporting bristles are bifid and more
slender than in the previous species, and arranged in a radiate manner in the leaf-like
lateral lobes. The distal end of the shaft of the hook is smooth. The ventral surface
appears to be smooth, but it has rows of minute warts.
S ynonyms.
1850. Oniscosoma arcticum, Bars. Nyt. Mag. f. Naturvid., vol. vi, p. 240 (210 Sars’ paper).
1860. Spinther miniaceus, Grube. Archiv f. Naturges, Jahrg. 26, Bd. i, p. 74, Taf. 3, figs. 3—3 b.
1861. ,, ,, Grube. Ein Ausflug nach Triest, pp. 31 and 140, Taf. 3, figs. 3—3 6.
‘ ,, „ arcticus, Sars. Ssersk. aft. Yidensk. Forthandl., p. 3.
1862. ,, ,, Sars. Christiania Vidensk. Selsk. Forhandl., p. 52.
1867. „ ,, Malmgren. Annul. Polychset., p. 1.
1876. „ oniscoides, McIntosh. Trans. Z. S., vol. ix, p. 373, pi. lxvii, figs. 1—3. •
1879. .,, arcticus, Tauber. Annul. Danic., 77.
1883. ,, ,, Levinsen. Vidensk. Meddelelser; Kjobenhavn, p. 125..
1884. ,, miniaceus, J. V. Cams. Prodr. Faunas Medit., p. 208.
1885. „ „ Dräsche. Beiträge zur Anat. Polychset., Heft. 1, Taf. ii, Wien.
1887. ,, ,, Graff. Zeitsch. f. w. Zool., vol. xlvi, p. 93, Taf. i—y, and woodcuts..
1890. „ „ McIntosh. Ann. Nat. Hist., Aug., 1890, p. 182.
1891. „ oniscoides, Hornell. Trans. Liverp. B. S., p. 239t
1896. „ miniaceus, Racovitza. Arch. Zool. Exp., p. 197, pi. iii, figs. 22—26.
HaMtat^The Minch, near North Uist, on a yellowish sponge (McIntosh); on
Antennularia ramosa and yellow Halichondria in seventeen fathoms off Holy Island,
Anglesey (Hornell). Finmark and west coast of Norway; Bay of Muggia at Trieste on
reddish sponges (Tedania) ; north coast of Denmark (Liitken), Stimpson (1853) found
the American example of the genus also on a yellowish sponge.
Colour.—The Hebridean specimen was of a straw-yellow hue, the lamellar processes
at the side being pale and marked with opaque-white spots. The Mediterranean examples
are of a cinnabar tint, or dull reddish, brownish, or violet-brown, according to the colour
of the sponges which they frequent.
Head.—The caruncle presents no feature of interest. The exserted pharynx is
smooth and trumpet-like, thus diverging from the condition in S. arcticus.
Body.—Ranging from ‘9 to 8*5 mm., the Hebridean example being about 5 mm., with
a thickness in the centre of 1 mm. in the largest, ovate or somewhat oblong, with the
sides flanked by the translucent lamellae, which dorsally form a series of symmetrical
processes provided only with bifid bristles, and in the largest examples 0’4 mm. in
height. The lamellae on the two sides of the body are separated by a median furrow.
Ventrally the surface is more or less smooth, only minute warts being present, and there
is no well-defined median furrow. This surface is covered with areolae (polygonal spaces)
in the Mediterranean examples. The segments range from twelve to twenty-four. The
body terminates posteriorly in two somewhat globular anal cirri.
The bristles of the dorsal lamella are all bifid (Plate XXXV, figs. 5 a and 5 6), the somewhat
delicate process resembling a web stiffened by the spiculae. They are arranged with
considerable regularity, and are all characteristically curved. A sensitive papilla also
occurs at the tip of each lamella laterally.
Feet.—These are more or less cylindrical. One conspicuous hook (Plate XXXV,
fig. 5 c) in the British example projected beyond each foot, generally another of similar
form (but shorter) within the tip, and the developing extremities of two.in the tissues.
A group of simple bristles (eight to twelve) with tapering tips also accompany the
central hook.
Von Graff found considerable variation in the condition of the alimentary canal, so
that he made two series, viz. the Stenoccela and the Euryccela. He mentions also, as
Grube had previously done, that the ova wander into the bases of the feet, and probably
are the “ opaque white spots ” seen in the Hebridean example. The ripe ova have short
protoplasmic processes in the body, which elongate subsequently into structures like
pseudopodia, somewhat symmetrically arranged as in a Radiolarian. The spermatozoa
present a head with an acute tip, two granules at the base, and a long filament.
Grube’s original description was carefully drawn up, and he gave the chief features
in regard to form and coloration, though his examples were small, having only twenty-
two parapodia"." He, however, placed too much reliance on the reddish-orange colour as
distinctive from Johnston’s species. Von Graff was at first inclined to place the
Hebridean example under S. arcticus, Wir6n, but further investigation showed that it
was S. miniaceus}
It is probable that the Spinther arcticus of Sars (1861) is this species, and there is
nothing in his description to invalidate this view. As already mentioned, the adoption of
his name would lead to considerable confusion.
Genus IV.—Euphrosyne, Savigny, 1820.
Body generally short* oblong, equally narrowed at either end, segments not
numerous; two thick styles posteriorly. Cephalic lobe narrow, frontal part narrowest,
a band passing downward to the inferior ridge. Eyes both on the dorsal and ventral
surfaces. One median tentacle situated in front of eyes. Lateral tentacles two, very
short, springing in front of the inferior eyes. Fascicles of bristles arranged on each side
of the segments. Superior bristles forming a transverse row, no barbs; inferior grouped
in a broad pencil. Capillary bristles unequally bifurcate. Dorsal cirri two (or three—
Ehlers) on each side, the one at the inner border of the fascicle, .the other at the outer
margin. Ventral cirri single. Branchiae dorsal, in rows, and more or less ramose.
Palpi forming fixed lobes on each side of the mouth. Mouth opening on the ventral surface
and extending over several segments: Buccal apparatus complex, alimentary, canal
simple.
1 Vide ‘ Ann. Nat. Hist.,’ August, 1890, p. 182.