North American species of Mycena.

EUMYCENA: ADONIDAE

161

finely pruinose under a lens, appearing glabrous to the naked eye,
somewhat translucent white at first, soon chalk white.
Spores 6-8 X 9.5-3 j, subcylindric with a long oblique apiculus,
yellowish in iodine (nonamyloid); basidia four-spored; pleurocystidia
scattered to quite abundant, 36-60 X 9-12 1t, obtusely fusoid-ventricose to capitate or merely with a broad rounded apex, hyaline, with
or without an amorphous incrustation; cheilocystidia similar to
pleurocystidia or smaller, more or less incrusted; gill trama homogeneous, yellowish in iodine; pileus trama homogeneous, yellowish in
iodine, surface with numerous projecting filaments or with subeapitate
pilocystidia 12-20 X 3-9 1t, often with incrusted amorphous globules
of a resinous substance around the apex; caulocystidia similar to the
pilocystidia, rather abundant.
Habit, habitat, and distribution.-Gregarious to scattered on conifer debris and in sphagnum bogs during the summer and fall; Michigan
in the United States and Ontario in Canada. Apparently this species
is not so abundant as M. delicatella.
Material studied.-Smith, 4323, 4407, 15750, 15855.
Observations.-M. pseudolactea is most likely to be confused with
M. delicatella. The large, rounded, conspicuous pleurocystidia,
however, distinguish it at once. In addition, it characteristically
has a longer stipe, broader pileus, and, at least in my specimens, not
so distinct a resinous feel when a cap or a stipe is rubbed between the
fingers. I have found them growing together and must admit that
it would be very easy to get a mixed collection.
70. Mycena delicatella (Pk.), comb. nov.
Agaricus (Collybia) delicatellus Peck, Ann. Rep. New York State Mus., 30:
39. 1878.
Collybia delicatella Saccardo, Syll. Fung., 5: 224. 1887.
Gymnopus delicatellus Murrill, North Am. Flora, 9: 354. 1916.
Mycena crystallina Peck, Ann. Rep. New York State Mus., 41: 63. 1888.
Prunulus crystallinus Murrill, North Am. Flora, 9: 322. 1916.
Illustrations: Plate 11 D; Text fig. 15, nos. 3-6.
Pileus 3-10 mm. broad, obtusely conic to convex, the margin
usually incurved at first, soon becoming plane or with a slight umbo,
surface pruinose to minutely pubescent, remaining unpolished or
becoming glabrous only in age, very faintly translucent-striate (appearing hygrophanous if water-soaked), color watery milk white at
first, opaque and chalk white when faded or the disc becoming slightly