North American species of Mycena.

EUMYCENA: DEMINUTIVAE

101

Spores 6-7 (9) X 3-3.5 (4.5) /,, narrowly ellipsoid, smooth, bright
blue in iodine (amyloid); basidia four-spored; pleurocystidia and
cheilocystidia not differentiated; pileus trama homogeneous, surface
hyphae with scattered rodlike projections over their walls, no pilocystidia or caulocystidia; tissue of pileus and stipe yellowish in iodine.
Habit, habitat, and distribution.-Gregarious on sticks of conifers
(small twigs and branches which have fallen to the ground); November 24, 1935, Booth, Oregon. Known from New York and Oregon.
Material studied.-Smith, 3618, and the type.
Observations-The description was drawn from the Oregon collection cited. The type has been examined; the spores measured
7-8 X 4-5 /. No differentiated cystidia were found. The iodine
test was not applied because of the small amount of material available
and because spores were rare in the one mount which was made.
In view of the risk involved it seems more sensible to interpret Peck's
species as having amyloid spores than to describe a new species just
like Peck's but supposedly differing in the reaction of its spores to
iodine. Peck's original description is given below:
"Pileus membranaceous, broadly convex or nearly plane, glabrous,
umbilicate, slightly striate on the margin when dry, white; lamellae
few, distant, decurrent, white; stem slender, filiforn, flexuous, glabrous, white; spores subglobose or broadly elliptic,.0002-.00024 of an
inch long,.00016-.0002 broad.
"Pileus 1-2 lines broad; stem 3-5 lines long. On humus and decaying twigs under pine trees. Delmar, Albany County, August.
"This is one of the smallest species of Omphalia known to me.
The lamellae are very narrow, sometimes branched and sometimes
absent. It is a smaller mushroom than Omphalia integrella, and
differs from it in its umbilicate pileus. The stem is hollow but the
cavity is minute."
33. Mycena cylindrospora, sp. nov.
Illustrations: Text fig. 4, nos. 3-4 (p. 74).
Pileus 1-2 mm. latus, convexus vel planus, candidus, nonlamellatus;
stipes 10-15 mm. longus, filiformis, candidus; sporae 10-13 (14) X
4-5 (6) /, cylindricae. Specimen typicum in Herb. Univ. Mich.
conservatum. Legit A. H. Smith, n. 9848, prope Grassy Patch,
Great Smoky Mountains National Park, Tenn., Aug. 6, 1938.
Pileus 1-2 mm. broad, convex to plane, snow white, glabrous or
appearing frosted, translucent in age, opaque when faded, not striate