North American species of Mycena.

296 NORTH AMERICAN SPECIES OF MYCENA

Material studied.-Smith, 32-672, 33-515, 526, 9391, 16578,
May 28, 1940, Michigan.
Observations.-I have found single specimens in Michigan, Washington, and California that apparently belong here, but have not
secured enough material to justify making a critical study. The
spores of the type measured 7-9 (10) X 5-6.5 A in one fruiting body
and 8.5-10.5 X 6-7, in another. The basidia of the latter were
two-spored; those of the former, mostly four-spored. The spores are
strongly amyloid, smooth, hyaline, and broadly ellipsoid. The
cheilocystidia are 27-34 X 8-12 A and clavate and are covered with
short, often contorted, projections. The smooth cystidia previously
mentioned (Smith, 1937) were very likely merely large immature
basidia. The pileus trama is characterized by a well-developed pellicle, the threads of which bear numerous short projections. A welldifferentiated hypoderm is also present, and the remainder of the tissue
is floccose. Both the gill and the cap tissue were characterized by the
presence of contorted lactiferous hyphae. The iodine reactions were
inconclusive except on the spores.
This species bears the same relationship to M. rugulosiceps that
M. hemisphaerica bears to M. galericulata. M. longipes superficially
resembles pale forms of M. megaspora, particularly in the long cartilaginous stipe, but again the small spores clearly distinguish it.
M. longipes apparently occurs in Michigan. Occasional specimens
of a long-stiped dark-gray Mycena have been found with the characteristic small spores. These had radicating stems. Murrill did not
get the base of the stipe in his specimen and failed to mention its
character in the description. Since there is a strong tendency among
the species of this group to develop a pseudorhiza it would not be
surprising to find such a structure typical of M. longipes.
144. MYCENA MEGASPORA Kauffman
Pap. Mich. Acad. Sci., Arts, and Letters, 17: 182. 1933
Illustrations: Plates 60, 61; Text fig. 35, nos. 3-4 (p. 295).
Pileus 1-4 (5) cm. broad, convex to obtusely campanulate when
young, becoming obtuse, broadly convex, campanulate or expanded
and plane to umbonate, umbo varying from nearly papillate in some
to very broad and low in others, margin connivent to the stipe when
young or incurved slightly, often remaining somewhat decurved in
age and occasionally becoming wavy, surface often hoary at first,
soon naked and polished, very finely radially wrinkled-striate and