North American species of Mycena.

454 NORTH AMERICAN SPECIES OF MYCENA

8. Spores 12-16 X 4-5 j,, nonamyloid (4-spored)...... M. avellaneigrisea
8. Spores 11-14 X 5.5-7,, nonamyloid (2-spored)....... O. petasiformis
8. Spores smaller, 7-11 u long..................................... 9
9. Cheilocystidia long and filamentous, 51-73 X 3-5,...... M. testacea
9. Cheilocystidia not as above.................................... 10
10. Spores 8-11 X 6-7,, amyloid; cheilocystidia with brownish content
when revived in KOH............................ M. gracilipes
10. Spores narrower, 4-5,u........................................ 11
11. Lamellae adnate to adnexed................................... 12
11. Lam ellae decurrent........................................... 13
12. Cap 2 cm. broad; spores 7-9 X 5-5.5,; cheilocystidia smooth
M. carbonicola
12. Cap 6 mm. broad, spores 7-8 X 4 j; cheilocystidia not differentiated
M. cinereiavellanea
13. Gills violaceous brown when dried................. 0. subscyphoides
13. Gills not distinctive in dried condition............................ 14
14. Spores amyloid....................................... O. cuticolor
14. Spores nonamyloid............................................ 15
15. Stipe long, 4 cm. or more........................... 0. tepeitensis
15. Stipe short, about 1.5 cm........................... cuspidatella
MYCENA ARGILLACEA Murrill
Mycologia, 8:220. 1916
Prunulus argillaceus Murrill, North Am. Flora, 9: 341. 1916.
"Pileus small, delicate, conic to campanulate, reaching I cm.
broad; surface striate, glabrous, avellaneous, margin entire, concolorous, appressed when young: lamellae adnate, broad, subcrowded,
white: spores globose or subglobose, smooth, hyaline, 4-6 u: stipe
slender, equal, smooth, glabrous, hollow, white, 1.5 cm. long, 1 mm.
thick.
"Type collected on a wet, much-decayed log in a moist virgin
forest on a mountain side at Motzorongo, near Cordoba, Mexico,
about 300 m. elevation, January 15, 1910, W. A. & Edna L. Murrill
1053 (herb. N. Y. Bot. Gard.).
"Distribution: Known only from the type locality."
The type consists of one very small fruiting body. The spores
measure 7-8 X 4 j, and are borne on four-spored basidia. They are
ellipsoid, smooth, and hyaline. The iodine reaction was not taken.