EOLIS AURANTIACA, A l d e r a n d H a n c o c k .
E. luteola, subrobusta; brancbiis robustis, tricoloribus,—infra purpureo-fulvis, medio albidis, supra
aurantiacis,—scriebus densis 10—11 digestis; tentaculis dorsalibus aurantiacis, corrugatis, tentaculis
labialibus breviusculis; anguiis anterioribus pedis obtusis.
Eolis aurantiaca, Aid. and Hanc., in Ann. Nat. Hist., v. 9, p. 84.
bellula, Loven, Index Moll. Scand., p. 8. ?
Hah. Under stones near low-water mark, and in shallow water, Whitley and Cullereoats, Northumberland,
rather rare, A. H. Ardrossan, Ayrshire, rare; Fowey Harbour, Cornwall, frequent, J.A.
Both/ about half an inch long, rather stout, tapering to a fine point behind, of a delicate
buff colour. Dorsal tentacles moderately long, tapering, a little wrinkled, of an orange flesh-
colour, a little paler above and below ; generally inclining forwards, their bases approximating.
Oral tentacles rather shorter than the superior pair, nearly colourless, linear, and slightly
flattened, with blunt points: they are set a little above the margin of the head, which is
produced laterally beyond their insertion. Branchiae numerous, placed along the sides of the
hack in ten or eleven close, but well defined, transverse rows; the anterior rows containing
five or six papillae each, the posterior, two to four. They are linear-oblong, and stout in
proportion to the length; the upper portion is bright orange coloured, beneath which is a
belt Of white, the remainder, varying from two thirds to three fourths of the entire length, is
of a warm purplish red, inclining to orange; the colouring of the upper portion is exterior,
that of the lower proceeds from the central vessel, the margins of which are undulating, and
the surface indistinctly granular. Foot transparent white, produced, and, Slightly lobed in
front, tapering to a fine point behind.
The colours of this species vary considerably, as well as the proportions in which they
are distributed on the branchiae; sometimes the prevailing colour is much paler than here
described, but in south-country specimens it is generally brighter, the colour of the branchiae
frequently approaching to scarlet. On one occasion we obtained an individual with the
central vessel of the papillae of a warm yellowish olive. The tricoloured character of these
organs is prevalent throughout all the varieties; once or twice only have we found the
terminal orange portion indistinct or wanting.
Eolis aurantiaca, though by no means common, has been found in three widely distant
localities in this country, so that its range is pretty extensive; and if, as we think, the Eolis
teUula of Loven is a variety of this species, its distribution will be still further extended
in the European seas, M. Loven’s specimens having been obtained on the coast of Norway.
On the Northumberland Coast this species is usually found on TubularitB. The spawn
occurs in June and July; it forms a broadish, circular, depressed b e lt; in which the eggs are
divided into transverse masses, somewhat triangular in form.
Eigs. 1, 2, 3. Eolis aurantiaca, different views.
4. Two of the papillae more highly magnified.
5. Spawn.