192 THE ESSEX NATURALIST
were forms occurring on leaves, and included Comatricha rubens
Lister and Trichia contorta (Ditmar) Rostafinski from the plan-
tation at the Warren, Loughton. Nearby an old poplar log bore
a large mass of the yellow form of Arcyria ferruginea Sauter
which attracted attention at a distance of some yards. Collo-
derma oculatum (Lippert) G. Lister occurred both in March and
April, and it was probably due to the snowfall in February that
Diderma laxafila G. Lister and Ross matured in March on green
bramble leaves. D. laxafila and Physarum vernum Sommerfelt
var. iridescens G. Lister developed on. an oak leaf in Hawk
Wood, Chingford. The Ph. vernum was remarkable, as although
most of the sporangia were without lime in the walls, a few did
contain lime; all the sporangia tested had the large lime granules
in the lime knots and because of this are considered to be the
variety, which is the usual form in Epping Forest.
Possibly it was through the unfavourable conditions of the
preceding autumn that Trichia persimilis Karsten made an early
appearance on June 8th. Four days later Trichia floriformis
(Schweinitz) G. Lister was found in much weathered condition,
but with some sporangia not burst. During July masses of
Cribraria argillacea Persoon matured on much-decayed wood of
the Wild Service-tree and remained there in more or less weathered
condition until November; Cribraria vulgaris Schrader occurred
on the same crumbling log. Craterium aureum (Schumacher)
Rost. was found in July, August and September.
It was not until the rains of August had thoroughly moistened
the leaf beds that Diachea leucopoda (Bulliard) Rost. developed;
it was also found in September and October. The occurrence of
Tubifera ferruginosa (Batsch) Gmelin was similar; this species
appeared on old poplar logs at the Warren. These logs, with
others, were sold to firewood merchants, but were found to be so
decayed that they were not removed. Badhamia foliicola Lister
occurred on grass near Hawk Wood in August and September,
and in the same months Physarum viride Pers. and Craterium
leucocephalum Ditm. were found. Physarum cinereum Pres.,
Ph. sinuosum (Bull.) Weinmann and Diderma floriforme (Bull.)
Pers. developed in September, but Physarum bitectum Lister,
Diderma radiatum (L.) Morgan var. umbilicatum Meylan and
D. montanum Meyl. were not reported during the period.
By the end of October sixty-one species had been recorded,
but the next four months brought only five more into the list,
these including Badhamia macrocarpa Rost. (found by Mr. S.
Waller in Wanstead Park in November), Didymium trachysporum
G. Lister and Margarita metallica (Berkeley and Broome) Lister.
In 1946-47 the number of species recorded was sixty-eight and in
1947-48 sixty-two.