North American species of Mycena.

EUMYCENA: HYDROPUS

395

tents, their walls occasionally with a thin incrustation when revived
in KOH, beneath the surface layer the trama proper composed of
very broad hyphae (15-28, in diameter), as well as interwoven narrow
connective hyphae and numerous lactifers 5-12 /i in diameter, nonamyloid; surface of stipe furnished with short or long caulocystidia
(26-57 X 8-15 ji), which are subeylindric with obtuse apices or subclavate, and are filled with a dark-brown pigment.
Habit, habitat, and distribution.-Scattered to gregarious on conifer
logs, spring and fall; North Carolina and Washington.
Material studied.-Smith, 3176, 13920, 14127, 14284, 14607, 14736,
16183, 16299. Hesler, 10751.
Observations.-This species is very easily recognized by its marginate gills and the drops of liquid which ooze from the cap when it is
cut with a sharp instrument. In my specimens the amyloid reactions
have been very unsatisfactory. The spores usually remain hyaline,
and very rarely have I found groups of immature individuals which
gave a pale-grayish reaction. They are therefore classed here as
weakly amyloid. I have never observed them to be yellowish in
iodine. The reactions of the gill trama and the flesh of the pileus were
also inconclusive.
Fries, in Systema Mycologicum, 1: 113, obviously took his description and concept of the species from Persoon, but in his later works
apparently applied the name to a different fungus. I have cited the
authority of the species in accordance with the rules which require
that Fries be used as the starting point, but have retained the concept
of Persoon and that of Fries in Systema Mycologicum, which is also
the concept established by Josserand and Maire (1931).
199. MYCENA MARGINELLA var. rugosodisca (Pk.), comb. nov.
Agaricus (Omphalia) rugosodiscus Peck, Bull. Buffalo Soc. Nat. Sci., 1: 48.
1873.
Mycena rugosodisca Saccardo, Syll. Fung., 5: 293. 1887.
Omphalia rugosodisca Peck, Ann. Rep. New York State Mus., 45: 34. 1893.
Omphalia marginella var. rugosodisca Josserand and Smith, Mycologia, 29:
721. 1937.
The variety differs only in its nonmarginate gills.
Material studied.-Smith, 399, 4489, 9763, 10636. Hesler, 6514,
9128, 9061. Kauffman, three collections, 1905, Michigan. Overholts, 5952. Sharp, 6520. Wehmeyer, 686.
Observations.-This variety, which is quite abundant on coniferous