of two to three ganglion cells. The eyes are sessile and the otocysts contain a single
otolith apiece. The hermaphrodite gland is segmentally arranged in the spaces between
the liver diverticula. Each segment contains a male loculus which is studded with
female acini and which opens into a longitudinal hermaphrodite duct running along the
median line below the kidney. The mucus gland is of the type usual in jEolids. The
single spermatotheca opens into the atrium but does not communicate with the upper
oviduct as in JEolidia papillosa. The male and female orifices are separate, much as
in Fiona, the former lying in front of the first row of papillae, the latter between the
first and second rows. The penis is retractile into a sheath which runs longitudinally
between these two openings and is indicated externally by a bulging ridge.
STILIGER BELLULUS (d’Obbigny): _
= Calliopsea belhila, d’Orbigny, Mag. de Zool., 1837, pp. 12—14.
Stiliger marise Bergh 2, pp. 137—144; id. 13, pp. 12—17.
Bergh has published two detailed descriptions of this species, from which it appears
that it resembles Bermaea in its internal structure. There is no ingluvies buccalis; there
are two main liver-canals which enter the stomach one on each side and give off branches
which enter the cerata. The genitalia are very complicated, and comprise two recep-
tacula seminis and two accessory ramified glands.
It would appear that this species ought to be called St. bellulus, not St. marise.
The genus was created by Ehrenberg (1831) for an animaLfound in the Red Sea and
having the same external characters as this species, though the radula is unknown.
Until the original Stiliger ornatus (not modestus, as it is sometimes quoted) is re-examined,
some doubt must exist as to the identity of Calliopsea and Stiliger, though that identity is
highly probable. .
In 1837 d’Orbigny gave the name of Calliopsea bellula to a mollusc whose external
characters are quite recognizable from his description. In 1865 Meyer and Mobius
(Fauna der Kieler Bucht) described an apparently identical animal as Embletonia marise,
wrongly regarding it as an JEolid. ‘Bergh refers both forms to Stiliger, and brackets
them together, but gives the preference to Meyer and Mobius’s name, although
d’Orbigny’s name has undoubted priority if his species is admitted to be a Stiliger.
Through the kindness of Mr. Farran I have received three specimens from
Ballynakil, Co. Galway. They are indifferently preserved, and have lost some or all of
the cerata. The best specimen is 7 mm. long and has thirteen cerata remaining. They
were apparently set in two rows and are of an ovoid shape. The posterior cerata of the
inner row are relatively very large (2 mm. high). The rhinophores are distinct and white.
The ground colour is greyish white, with brownish or olive markings on the cerata
and body. The foot is greyish white without markings. The opaque white internal
organs, especially the hermaphrodite gland, can be seen through the integuments.
When alive the animal appears to be like an Embletonia, whitish, but with rust-coloured
mottlings on the back and cerata, which latter are stout and ovate. They are set in
about five groups on either side, each group containing only one or two.
The radula contains five teeth in the ascending and twelve in the descending
slightly spiral portion. They are as represented by Bergh, but so transparent that they
are seen only with difficulty.
The species is recorded from West Ireland, the Atlantic coast of France, Kiel, and
Trieste.
ALDERIA Allman.
Three species of this genus have been described.
1. A. modesta (Lov6n).
2. A. coinosa A. Da Costa. Naples (Ann. del Museo Zoologico, Napoli, anno iv,
1864, p. 32, and pi. ii, 3).
3. A. harvardiensis (Agassiz). East coast of North America (Gould 1, pp. 254—255,
pi. xvi, 226—228).
Alder and Hancock published some account of the anatomy of A. modesta in their
Monograph, but only the external features of the other two species are known. A.
comosa is green, with numerous long cerata, and the anal papilla lies behind the pericardium.
It must be regarded as very doubtful if A. harvardiensis is really distinct from
A. modesta. I t differs in being darker, in having fewer and smaller cerata, and, if
Gould’s figure may be trusted, in the more angular shape of the head. But the description
and the figure do not quite agree as to the disposition of the cerata, and the colour
of A. modesta is very variable.
ALDERIA MODESTA Lovbn.
(Plate VII, figs. 3—5.)
Alder and Hancock, Monograph, Genus 17, Fam. 3, pi. 41; Eliot 1, pp. 376—379, and plates,
in which some additional figures illustrating the anatomy are given.
I am indebted to Mr. W. I. Beaumont for several specimens of this interesting form,
labelled “ Ardfrv, County Galway, May, 1904.” In some unpublished MSS. of Albany
Hancock preserved in the Hancock Museum at Newcastle-on-Tyne I have found the
following notes on the living animal:
“ The foot exhibited beautiful dendritic markings.1; The glands in the papillae are
considerably branched. The animal yields a quantity of mucus, has a strong sugar
smell, and is sluggish in its motions. The papillas are remarkable for their rhythmical
pulsations. They dilate and contract simultaneously between thirty and sixty times a
minute. The contraction is very forcible, the posterior surface; of the papillas being most
contracted. This pulsation has all the appearance of being connected with the circulation.
The papillge are much depressed when in a state of contraction.”
The colour of the preserved specimens varies from white to yellow, with darker
mottlings on the back and upper side of the cerata. The variations in shade are consider-
1 Due apparently to the ramified diverticula of the alimentary canal being seen through the
semi-transparent sole.