342
THE RE DISCOVERY OF LIMAX TENELLUS,
MULL., IN BRITAIN AND ESSEX.
By T. PETCH, B.A., B.Sc.
ALTHOUGH the first British example of this species was
discovered in Durham in 1853, and its occurrence placed
beyond question by an accurate coloured drawing by Mr. F.
Alder, the absence of other authentic records during the last fifty
years threw considerable doubt on its status as a British species,
and finally led to its exclusion from the list of British mollusca.
This year, the Rev. Robert Godfrey, whilst collecting slugs
for Mr. W. Denison Roebuck, found it in abundance in the pine
woods of Rothiemurchus, vice-county Easterness (Naturalist,.
Oct. 1904), and, what may be more interesting to Essex
naturalists. Mr. C. T. M. Plowright and myself found several
specimens in Epping Forest, near Loughton, on Oct. 2nd.
Limax tenellus resembles L. cinereoniger in its preference for
fungi. It is said to pass half the year underground, living on
fungal hyphae, appearing above ground with the fungi in
autumn. In the presence instance it was taken on Russula vesca
in company with Arion hortensis. In Germany it is almost
exclusively a pine-wood species, inhabiting, as at Rothiemurchus,
the accumulations of pine needles in the deeper parts of the
forests. In Epping it was found under pollarded hornbeams in
a somewhat open situation, where the ground was well grassed
over, a habitat for which it has been recorded from Russia and
Scandinavia.
Owing to its moderate size (30-40 mm.) and slender, delicate
appearance, this slug may easily be passed over as an immature
example of one of the larger species, but the black tentacles,
uniform yellow colouring, and yellow slime separate it from all
others. All the British examples are referable to the variety
cerea, in which the animal is "of a somewhat uniform waxy-
yellow colour, with only faint traces of lateral banding."
Mr. J. W. Taylor, to whom an Epping specimen has been
submitted, writes : "It is an undoubted example of Limax
tenellus var. cerea."