in section showing the columnar or prismatic sporangia,
which are normally six-sided, having at the edges six simple threads,
the remains of peridium, extending from base to apex, where the peridium
remains intact, arcuate; hypothallus prominent, radiating far around the
aethalium, silvery white; spores in mass, ochraceous, or dull brownish
yellow, by transmitted light almost colorless, rough 9-10 mu.

Not rare, on decaying logs, especially of _Tilla americana_, where in
the same place successive fructifications follow each other sometimes
for weeks together in the latter part of summer and early fall. The
aethalium is generally elliptical or elongate, 2-3 cm. in extent,
sometimes irregular or branched, varying in color according to degree of
maturity, weathering, etc. Plasmodium at first watery, then pink, or
flesh-colored.

Eastern United States; common. Toronto;--_Miss Currie._

_E._ CRIBRARIACEAE

Sporangia distinct, more or less closely gregarious, stipitate, the
peridium opening, especially above, by a well-defined network formed
from thickenings in the original sporangial wall.

=Key to the Genera of the Cribrariaceae=

_A._ Peridial thickenings in form of an apical net
with definite thickenings at the intersections
of the component threads 1. CRIBRARIA

_B._ Peridial thickenings in form of parallel
meridional ribs connected by delicate
transverse threads 2. DICTYDIUM

=Cribraria= (_Pers_) _Schrader._

1794. _Cribraria_ Persoon, Roemer, _N. Bot. Mag._, I., p. 91, in part.
1797. _Cribraria_ Schrader, _Nov. Gen. Plant._, p. 1, in part.
1875. _Cribraria_ Rostafinski, _Mon._, p. 229.

Sporangia distinct, gregarious or closely crowded, globose or obovoid,
stipitate; the stipe of very varying length; the peridium simple, marked
within by distinct and peculiar, granular, thickenings, which below take
the form of radiating ribs, supporting the persisting cup, _calyculus_,
and above, by extremely delicate anastomosing branches, unite to weave a
more or less regular net with open polygonal meshes; spores various,
more often yellowish or ochraceous, sometimes brown, reddish, or
purple.

The genus _Cribraria_, as limited by Persoon, included all forms in
which the peridium is thin, evanescent half-way down, or entirely, and
in which capillitium, as Persoon regarded the case, is formed of a
network of ret