North American species of Mycena.

EXCLUDED AND DOUBTFUL SPECIES

493

mens were in hand, they could very easily be misinterpreted. It
seems best to regard M. viscidipes as a doubtful species, at least until
the type can be found and the microscopic characters determined.
Mycena vitrea (Fr.) Quelet. Reported by Stover (1912).
Omphalia clavata Peck, Ann. Rep. New York State Mus., 51: 285.
1898.
Omphalopsis clavata Murrill, North Am. Flora, 9: 313. 1916.
"Pileus thin, convex, becoming nearly plane, glabrous, pallid or
subcinereous, the margin decurved; lamellae narrow, distant, very
decurrent, pallid; stem long, slender, glabrous, stuffed, commonly
enlarged at the top, slightly villous-tomentose at the base, pallid;
spores globose,.0002 to.00024 in. broad.
"Pileus 2 to 4 lines broad; stem about 1 in. long, 5 lines thick.
"Dead prostrate trunks of arbor-vitae, Thuja occidentalis....
"The base of the stem is clothed with a few long loose whitish filaments, and the thickened upper part is often fluted by the long decurrent lamellae. The clavate form given to the stem by this enlargement is suggestive of the specific name."
I have examined the type, but did not make tests with iodine.
The spores are smooth, measure 5-6 X 4-5 t,, and are globose to subglobose. The basidia are four-spored. Pleurocystidia and cheilocystidia, which are abundant, are of the fusoid-ventricose type and
smooth. They measure 34-52 X 7-12,j. The hyphae of the surface
of the pileus are quite compact, and numerous pilocystidia project
from them.
Superficially this species appears to resemble the members of the
section Omphaliariae, but an examination of the type indicates that
it may belong in Marasmius. Further study, especially of fresh
material, is necessary to determine its true relationships.
Omphalia cuspidata Quelet.
Reported from Asheville, North Carolina, by Beardslee, but microscopic details were not given. There are numerous species in
North America with the stature illustrated by the published photograph.
Omphalia niveicolor Murrill, Mycologia, 8: 219. 1916.
Omphalina niveicolor, North Am. Flora, 9:348. 1916.