BRITISH
NUDIBRANCHIATE MOLLUSCA.
i .
W hen examining in 1905 the specimens and papers which were left by Alder and
Hancock and deposited in the Hancock Museum at Newcastle-on-Tyne, I found that
they had contemplated the publication of a supplement to their Monograph on the
British Nudibranchiata and had collected some materials for this purpose. This supplementary
part was to have contained ten or twelve plates illustrating the anatomy of the
Limapontiidse and Elysiidas together with figures of the following species: Doris
testudinaria, D. loveni, D. ulidiana, Grimora papillata, Doto cuspidata, Embletonia 'pallida,
Lomanotus portlandicus, *Eolis adelaidm, E. ccerulea, *E. farrani var., *E. pellucida, *E.
landsburgii, Antiopa hyalina, *Limapontia nigra, IAmapontia depressa, *Acteonia coclcsi,
*Acteonia corrugata, Elysia viridis, *Diphyllidia lineata. Neither the anatomical drawings
nor those of the species marked with an asterisk are forthcoming.1 Some of them were
probably coloured or improved reproductions of the figures accompanying the article “ On
a Proposed New Order of Gasteropodous Mollusca ” (Alder and Hancock 3) published
in 1848. The remainder are preserved and a selection from them forms the basis of the
present work. They are mostly by Hancock, who, contrary to what might, have been
expected of so careful an anatomist, was untidy in his handwriting and drawings. Most
of the animals are represented by several rough sketches, somewhat uncertain in outline
and only partly coloured. They were apparently revised and copied several times, and
the sets of figures representing Lomanotus, Eero, IAmapontia and Antiopa (= Janolus) are
noted as complete. Of the other species there are as a rule only one or two figures
sufficiently finished to merit reproduction. Only three of the figures (two of Elysia
viridis and one of Eolis inornata) are by Alder; they are complete and carefully executed.
The total number of old figures reproduced is forty-five, and I have added to them
twenty-three new ones drawn from living specimens of D. testudinaria, D. maculata,
1 Or at any rate not identifiable with certainty. Several figures of ASolids, though fairly well
executed, are marked only by numbers, and it seems useless to reproduce them or to discuss what they
represent. E. pellucida and E. landsburgii are figured in the Monograph, but Hancock has left a
note that he thought the plates unsatisfactory. I have, however, found nothing better among his
papers.