OCCURRENCE OF OLIGONEMA NITENS (LIB.) ROST. IN ESSEX. 181
Kent, as in the previous year. Complete information is not
available as to what has happened this year, 1942, but Black
Redstarts have been recorded as occurring in summer in
Cambridgeshire, Devon, Herts, Kent, London, Suffolk, Sussex
and Yorkshire.
Time alone can fully answer my opening question, but what
knowledge we now possess suggests that the Black Redstart is
in process of establishing itself as a regular breeder in at least
the southern half of England.
ON THE OCCURRENCE OF OLIGONEMA NITENS
(LIB.) ROST. IN ESSEX.
By GULIELMA LISTER, F.L.S.
ON October 17th, 1942, Mr. J. Ross conducted a party of
Field Club members through the Chingford Forest, when,
under his direction, a considerable number of Mycetozoa was
found. Amongst these was a gathering made by Mrs. D. J.
Scourfield, on dead wood, of clusters of minute shining yellow
sporangia, looking at first sight much like a small Trichia.
Microscopic examination shows it to belong to the nearly allied
genus Oligonema, and to be O. nitens, a species not recorded
before from Epping Forest, or indeed from Essex. The genus
is distinguished from Trichia, in which it was formerly included,
by the minute firm-walled sporangia being heaped together and
very lightly attached to the wood from which they developed.
The elaters are short and scanty, and show only very faint
traces of the spiral bands characteristic of Trichia, and are
sometimes quite smooth ; the spores in O. nitens closely resemble
those of Trichia persimilis Karsten, and are marked with a network
of raised pitted bands. This beautiful little species has been
recorded from Cornwall, Dorset, Sussex, Herefordshire, Shrop-
shire, Cumberland, Staffordshire, Yorkshire, Norfolk, Surrey
and Kent. It has also been recorded once from Scotland, and is
widely distributed in Europe, Canada and the United States. It
occurs on sticks and dead wood which has been submerged for
part of the year—a situation in which the present gathering was
probably found : it is also not unfrequent on old sawdust.
Although the sporangia are minute, measuring from 0.2 to 0.4mm.
in diameter, they can be recognised in the field by the way in
which their clusters are easily detached from the substratum.
This brings the number of Mycetozoa found hitherto in Essex to
105 species.