“ One specimen, obtained by the otter trawl of the Oithona, miles S. by W.
of Rame Head, June 11th, 1909, in about 30 fathoms. Length 16 mm. Breadth
behind rhinophores 7 mm. Length of oral tentacles 6 mm., of rhinophores 4*5 mm.
Rhinophores fairly stout, wrinkled. Eyes prominent, situated at the base of the rhino-
phores, on their outer side. Foot broad, angles rather short, stout and acute. Body
stout, smooth and tapering gradually to a rather obtuse tail. Heart prominent. Papillse
fairly numerous, of moderate length, stout, tips obtuse; set in twelve rows, the first two
of which are double, and run forward almost to the base of the oral tentacles; nine to ten
papillae in each anterior row. The four anterior rows strongly erected on irritation.
“ Colours.—Foot, head and oral tentacles semi-pellucid white; dorsal area and about
the base of the papillae yellowish. Rhinophores tinged with orange, the tips faintly
freckled with opaque white; the tips of the oral tentacles are similarly marked. A
number of faint orange lines tinge the rhinophores, and form an orange area in front of
them. Papillae light brown, freckled with opaque white, the tips semi-pellucid white, the
dots becoming confluent and forming an irregular band in that area. The jaws large,
horny and dark brown in colour. The radula contained twenty-one plates; each plate
bears some thirty slender teeth on either side, the central cusp not very pronounced, and
flanked by two widely diverging, acute, lateral denticles.
“ It will thus be seen that the radula differs from those of both Molidietta glauca and
M. ctlderi in detail, although agreeing with both in general character.”
The arrangement in the synopsis (Part vii, pp. 48 and 50) implies that the animal
has not a radula like Eolis glauca, but as pointed out above under AmphoHna coerulea,
Alder and Hancock in making this synopsis rashly classified several species as if they had
examined the radula, when they had not done so.
I had previously come to the conclusion (/. c.) after examining a specimen which
Prof. W. Herdman regarded as Eolis angulata, that the species was identical with
Molidiella glauca, but the opinion of Alder and Hancock, now supported by Mr. Walton,
that the two species are distinct cannot be neglected. The animal described by Mr.
Walton is clearly an Molidiella, and it differs from Mila. glauca (1) in colour; (2) in the
broad foot with projecting angles; (3) in the cerata, which do not show the same curious
vermicular shape and movements; (4) in the shape of the teeth, in which the central
cusp is flanked by two denticles pointing outwards. I confess that I am not convinced
that these characters are really of specific value, for specimens of Molidiella apparently
referable to the same species show great variation both in external characters and in the
denticulation of the teeth. But pending the examination of further specimens, Mila,
angulata merits provisionally separate recognition. It is possibly the species from
Heligoland described by Heinke (1, p. 247) as Molidiella nov. spec. ? While thinking that
this form may merit recognition as much as Mila, alderi, I am inclined to agree with
Cuenot1 that all the so-called European species, glauca, alderi, angulata and sommeringii,
are really varieties of one, which ought to bear the first of the above names.
1 Faune d ’Arcachon, hlolidiens, p. 3.
CALMA A. & H.
Much confusion has arisen about this genus, for later authors have not paid sufficient
attention to the statements made about it by Alder and Hancock* and these statements,
which are scattered in various parts of the Monograph, are not always plain if taken
separately, though if taken all together they are clear' enough. Alder and Hancock
described the type species first in the letterpress to plate 22 (under the name of Eolis
glaucoides) as a very curious Eolis which will probably constitute a new generic type, and
pointed out the remarkable characters of the “ gastro-hepatic vessel ” and “ the ovary.”
Their language about the radula in this passage is wanting in precision, but in the
letterpress to plate 47 (Tongues of the Eolididse) they say that the tongue is very
slender, resembles a continuous band, and can only be seen in profile. The figure clearly
represents the tongue as I have found it, a continuous chitinous ribbon in which the teeth
are fused together and only appear as minute serrulations. On page 21 of the Appendix
they create the genus Calma fdr Eolis glaucoides, but unfortunately mention only the
external characters and do not refer to the anatomy.
Hence Trinchese, followed by Bergh (8, pp. 643—647, and 12, pp. 61—64) and
Vayssiere (1, pp. 84—88), regarded the genus as akin to Flabellina, and referred to it
the Eolis cavolini of Verany.
Later (Rend. Accad. Sci. Fis. Mat. di Napoli, xx, 5, 1881, pp. 121—122, and
Mem. Ac. Sci. Istit. di Bologna, S. iv, T. x, pp. 57—61) Trinchese described under the
name of Forestia mirabilis a Mediterranean ^Eolid having all the main characters of
Alder and Hancock’s Calma glaucoides—the thread-like undivided radula, the broad,
simple hepatic system, and the hermaphrodite gland arranged along the two sides of the
body. Friele and Hansen had also (1, 1875, pp. 78—79) described another species from
the northern Atlantic, calling it merely Eolis albicans, but indicating its affinities to the
genus Calma A. & H. Bergh (44, pp. 1025 and 1034) puts Eolis albicans under Forestia,
and makes- the genus Calma consist of C. glaucoides A. & H. and C. cavolini (Verany).
There can, however, be little doubt that the genus Calma is equivalent to the later
(1881) Forestia. I t will then contain three species.
c l. C. glaucoides A. & H. Atlantic.
1 2. C. albicans Friele and Hans. Atlantic.
3. C. mirabilis (Trinchese). Mediterranean.
C. albicans appears closely allied to C. glaucoides. C. mirabilis differs in having a
few separate teeth, as well as the continuous chitinous band, and it would seem that the
groups of papillge do not rise from a common stalk.
I t seems probable that Calma cavolini does not belong to this genus. It is regarded
by Bergh and Vayssiere as related to Flabellina, from which it differs in having no
perfoliations on the rhinophores. The radula is not like that of Calma glaucoides, but
has separate teeth of the usual pattern. There is some doubt whether it is triseriate or
uniseriate, the laterals being in any case very small. It would seem that in some points
the digestive and reproductive organs resemble those of C. glaucoides, but neither Bergh
nor Vayssi&re suggest that it resembles Forestia mirabilis. They had perhaps not seen