62
THE ESSEX NATURALIST.
granular refuse deposits clothing the remainder of the walls.
On maturity these bands form prominent shining ridges and
along them dehiscence takes place; the peridium then opens
in angular reflexed lobes, minutely roughened on the outer
surface, shining and polished on the inner surface. When highly
magnified the margins of the lobes are seen to be studded on the
inner side with minute teeth or pegs, which apparently fit into
those of the adjacent lobe. The spores in mass are dark brown;
when freshly formed and highly magnified they have a greyish-
brown shade; this induced Rostafinski to place the species in a
new genus, Protodermium, included in his large section Amauro-
sporales, which is characterised by having purplish-brown—or
violet-brown spores. The grey tinge soon fades, however, to
olive-brown in L. pusilla, and Schrader's original name is there-
fore retained. The spores measure 13 to 17μ diameter, or may
be even larger; they are closely and minutely warted over three-
quarters of their surface, the remaining quarter is smooth and
represents the area where germination will occur.
Licea pusilla is usually found on coniferous wood, but its
appearance on oak has also been observed several times. It is
recorded in the British Isles from Surrey, Hampshire, Derby-
shire and Yorkshire, also from Forfarshire and Aberdeenshire.
In Europe it is not uncommon and has been found in Sweden,
Germany, Switzerland, Poland and Moldavia. An old reference
to its occurrence in the United States is not, Professor Macbride
considers, reliable.
It is curious that Licea flexuosa Persoon, a larger and
generally common species, which in Surrey often occurs in great
profusion on old chips and sawdust of coniferous wood, has not
yet been recorded for Essex. Of the six species of the genus,
only one other, L. tenera, Jahn, has been found in our county.
On December 17th, 1898, a small group of the glossy olive-
yellow sporangia was found by my father and myself on a stick
of elm in Wanstead Park, but was not described. The two
other known gatherings of this most inconspicuous species are
the type specimen obtained by Dr. Jahn in December, 1915,
on a culture of sycamore bark brought from Hohenschwangau
in Upper Bavaria, and a gathering reported by Professor Brandza
in the Carpathian Mountains at Neamtz, Roumania, on decayed
branches of walnut, in July, 1924.