North American species of Mycena.

306 NORTH AMERICAN SPECIES OF MYCENA

tum. Legit A. H. Smith, n. 10759, prope Grassy Patch, Great
Smoky Mountains National Park, Tenn., Sept. 1, 1938.
Pileus 1-3 cm. broad, obtuse when young, the margin incurved,
becoming plane to slightly depressed in age, the margin either remaining decurved or becoming variously lobed, wavy, or recurved,
surface moist and glabrous, dark watery gray on the disc, pale watery
gray toward the margin, translucent-striate, moist, opaque and more
or less wrinkled when faded; flesh thin and lax, grayish, no odor, taste
not recorded, no latex present, and no color changes noted; lamellae
adnate to hooked and subdecurrent, narrow (3 mm. ~), subdistant,
two or three tiers of short individuals, pruinose from the cystidia,
pallid gray, almost concolorous with the pileus; stipe 1.5-3 cm. long,
1.5-2.5 mm. thick, equal, fragile, hollow, pale watery gray or concolorous with the pileus, densely innately fibrillose-punctate to somewhat striate, pruinose to white-scurfy above, more or less glabrescent
in age, base sparsely white-mycelioid at point of attachment, not
rooting.
Spores 6-8 X 3.5-5,, subellipsoid (usually narrowed toward the
apiculus), smooth, hyaline, amyloid; basidia four-spored; pleurocystidia and cheilocystidia abundant, 50-90 X 10-16 u, subclavate to
subfusoid, finally nearly cylindric, smooth, hyaline; gill trama of
interwoven hyphae, faintly amyloid; pileus trama with a poorly differentiated pellicle (the cells radially arranged and 4-8, thick), no pilocystidia seen, hypoderm distinct, of one to two rows of enlarged cells,
which are filled with a smoky-brown content, the filamentous tramal
body below the hypoderm well developed, contorted metallic-appearing lactifers scattered through it, all parts weakly amyloid; stipe
when young more or less covered with long mucronate caulocystidia
measuring 80-120 X 10-20 A.
Habit, habitat, and distribution.-Single to gregarious on beech
logs, during late August and early September; Great Smoky Mountains National Park, Tennessee. The type (10759) was found at
Grassy Patch, September 1, 1938, and an additional collection was
made at Indian Camp Creek, August 30, 1938.
Observations.-The fungus resembles Collybia lacerata in its thin
flabby pileus, but the cystidia readily distinguish it. It appears to be
closely related to M. scabripes and M. trichoderma but lacks the pilocystidia of the latter and has a different habitat as well as smaller
stature. The narrow gills, lignicolous habitat, and squatty stature