North American species of Mycena.

EUMYCENA: OMPHALIARIAE

363

Omphalia campanella, but the nonamyloid spores again distinguish it.
In iodine the spores of M. thujina assume a strong yellow to yellowishbrown tint. There appear to be two color forms if one examines my
specimens, but this difference is more than likely due to the length of
time the fruiting bodies stood before being collected. In No. 4444
(the type) the colors were "cinnamon" at maturity, and the specimens dried a dull buffy brown. No. 33-531, from Whitefish, Michigan, is similar in color to the type. No. 33-438 from Au Train, and
Mains, No. 5964, from Leland, Michigan, dried more or less bister,
the color of the fresh young carpophores.
177. Mycena Brownii, sp. nov.
Illustrations: Text fig. 43, nos. 6, 9 (p. 349).
Pileus 2-5 mm. latus, 3-6 mm. altus, conicus, glaber, griseus vel
fuscus, valde striatus; lamellae subdistantes, latae, late adnatae vel
subdecurrentes, pallide griseae; stipes 6-15 mm. altus, 0.5 mm.
crassus, pallidus, aequalis, bulbosus, glaber; sporae 9-11 X 4-6 A;
cheilocystidia 21-32 X 3-7 u, irregularia. Specimen typicum in
Herb. Univ. Mich. conservatum. Legit C. A. Brown, prope Lake
Quinault, Washington, Nov. 1, 1925.
Pileus 2-5 mm. wide and 3-6 mm. high, conic with an appressed
margin, remaining conic or the margin flaring somewhat, occasionally
convex, surface moist, glaucous gray to fuscous over the disc, paler
toward the margin, conspicuously striate when moist, opaque when
faded; flesh thin and membranous, moderately pliant, odor and taste
not recorded; lamellae subdistant, broad, arcuate or arcuate-decurrent, pale grayish, edges pallid; stipe up to 1.5 cm. long, 0.5 mm. thick,
pallid, equal above a distinctly enlarged abruptly bulbous base,
glabrous above, bulb only faintly mycelioid and grayish to pallid.
Spores 9-11 X 4-6,. narrowly ovoid, smooth, amyloid; basidia
four-spored; pleurocystidia not differentiated; cheilocystidia embedded in the gill edge, 21-32 X 3-7 y, often contorted or irregularly
branched; gill and cap tramae weakly amyloid (pale sordid brown in
iodine); pileus trama with a thin adnate pellicle made up of slender
cells with numerous short rodlike projections arising from their walls,
hypoderm well differentiated, the cells 18-32, in diameter and having
dark smoky-brown contents, filamentous portion of trama greatly
reduced in thickness (20-30 u); stipe with scattered contorted hairs
(similar to cheilocystidia); no gelatinizing layer present.