and continued within the peridium as a pronounced more
or less calcareous columella; hypothallus more or less prominent,
yellowish or brownish; capillitium dark, purplish-brown, of sparingly
branching threads radiating from the columella; spores dull
purplish-brown, minutely roughened, 10-12 mu.

A singular species, rare, but easily recognized by its peculiar, placoid
scales, large and firmly embedded in the peridial wall. The internal
structure is essentially that of _Diderma_ or _Didymium_. The species
occurs in hilly or mountainous regions, on moss-covered logs. The
plasmodium pale yellow, some part of it not infrequently remains as a
venulose hypothallus connecting such sporangia as are near together.

New England to Washington and Oregon; Vancouver Island.

2. LEPIDODERMA CARESTIANUM (_Rabenh._) _Rost._

1862. _Reticularia carestiana_ Rabenh., _MS. Fung. Eur. exsic._,
No. 436.
1875. _Lepidoderma carestianum_ (Rabenh.) Rost., _Mon._, p. 188.
1891. _Amaurochaete minor_ Sacc. & Ell., _Mich._, II., p. 566.

Fructification in the form of flat, pulvinate plasmodiocarps, or, anon,
sporangiate, the sporangia sessile, sub-globose, ellipsoidal, elongate,
irregular, confluent, yellowish-grey, the peridium covered more or less
completely with dull white, crystals or crystal-like scales; columella,
where visible, yellowish-brown, calcareous; capillitium, coarse, rigid,
more or less branched and united, or colorless, delicate, forming a
definite net; spores distinctly warted, purple 10-12 mu.

This is a most remarkable species. The sporangiate forms little resemble
those distinctly plasmodiocarpal. In the former the calcic scales and
crystals are distinct and quite as in _L. tigrinum_; in the latter they
are cuboid, irregular. The wall of the peridium in the plasmodiocarps at
hand is black, and the covering accordingly shows white; in the
sporangial forms the wall is brown, and the scales have a yellow tinge
as if tinged with iron. In the sporangial presentation the capillitium
is intricate delicate; in the plasmodiocarp, rigid, dark-colored, etc.
This looks like a didymium and in so far justifies the opinion of
earlier students. Fries, of course, includes all these things with the
didymiums, and _D. squamulosum_ probably often sheltered them under
extended wing.

_Didymium granuliferum_ Phill., _Grev._, V., p. 114, from California is
by European authors referred here. The capillitium carries calcareo