36 THE MYCETOZOA :
found several times associated with B. panicea on elm bark in
the autumn.
B. rubiginosa (Chev.) Rost. var. dictyospora.—Found once
only, and then in great profusion, on a deep heap of holly leaves
in the forest near Cook's Folly, November 1896.
Physarum viride (Bull.) Pers.—Not uncommon from May
to November on old stumps and on fallen oak boughs. The
var. aurantium, with orange sporangia, is less abundant. The
var. incanum, with nearly white sporangia, has been obtained
twice in the Forest ; it resembles typical P. nutans externally,
but has yellow lime-knots.
P. pusillum (Berk. & Curt.) Lister.—Apparently rare in
this district. The typical form, with slender dark red stalks,
was found in the Loughton forest in November 1896. A
robust form, with both stalked and sessile sporangia, occurred
on a stump in Wanstead Park in October 1904. This gathering
resembles Badhamia panicea in so many respects that it seems
to represent a transition stage between the two species.
P. nutans Pers.—One of our most abundant species, occurring
from May to January on fallen wood and stumps, rarely on
dead leaves. The typical form, with nodding sporangia on
slender stalks, passes into the stouter var. leucophaeum by
gradual stages. The latter, with sporangia on short brown
stalks or sessile, merges into var. robustum. This is a large
form with abundant deposits of lime granules stowed away in
the lime-knots, in the sporangium wall and sometimes in the
stalk also. It has been abundant the last few years on fallen
beeches at High Beach and on elm trunks in Wanstead Park.
When the stalks are white from lime deposits, this variety bears
a considerable resemblance to P. leucopus Link, a more slender
species occurring on dead leaves and moss. Specimens recorded
as P. leucopus from Bedfordshire and Hertfordshire should be
referred to P. nutans var. robustum.
P. compressum Alb. & Schwein.—Not common in Epping
Forest, but found abundantly some years in summer and autumn
in the Avenues, Leytonstone, and in Wanstead Park, on
the bark of fallen poplars and elms. The sporangia are stalked
or sessile, scattered or clustered, but in all forms P. compressum
can generally be recognised even with a pocket lens by the
very numerous rounded lime-knots of the capillitium.