North American species of Mycena.

124 NORTH AMERICAN SPECIES OF MYCENA

Material studied.-Smith, 566, 1477, 6385, 8413, 14907. Kauffman, North Carolina and Michigan. Oches, Michigan. Krieger,
Ontario.
Observations.-The difference in color between M. Swartzii and
M. fibula is very striking and, at least so far as the material examined
is concerned, there is a distinct difference in the shape of the pleurocystidia, as is shown in the drawings. Because of these characters
M. Swartzii has been given the rank of a species rather than of a
variety.
47. Mycena pseudogrisella, sp. nov.
Illustrations: Text figs. 9, no. 10 (p. 120); 10, nos. 1-2.
Pileus 3-8 mm. latus, convexus vel subdepressus, hygrophanus,
avellaneus; lamellae subdistantes, albidae, breviter decurrentes, ventricosae; stipes 10-18 mm. longus, 1.5 mm. crassus, fragilis, aequalis,
pruinosus, avellaneus; sporae 7-8 X 3-3.5 g, nonamyloideae; pleurocystidia et cheilocystidia (36) 50-80 X 8-15 (20) ut, subclavata. Specimen typicum in Herb. Univ. Mich. conservatum. Legerunt E. B.
Mains et A. H. Smith, n. 33-690, prope Ontonagon, Mich., Sept.
14, 1933.
Pileus 3-8 mm. broad, convex or the disc slightly flattened, in age
very slightly depressed, margin straight when young, becoming
crenate in some at maturity, hygrophanous but unpolished, margin
becoming sulcate-striate, surface pruinose when viewed under a lens,
color pale avellaneous, whitish along the margin; lamellae subdistant,
white, short-decurrent, often ventricose near the cap margin and
narrow in the notch (the opposite of the triangular type), edges even;
stipe 10-18 mm. long, 1.5 mm. thick, watery and fragile, equal,
densely pruinose at first but becoming glabrous, concolorous with the
pileus or more sordid.
Spores 7-8 X 3-3.5 y, narrowly ellipsoid, smooth, nonamyloid;
basidia 25-Q7 X 4-5 A, four-spored; pleurocystidia and cheilocystidia
abundant and similar (36) 50-80 X 8-15 (20),, subcapitate and
ventricose to subelavate, obtuse, smooth, thin-walled, hyaline; gill
trama yellowish in iodine, parallel to subparallel, of long-cylindric
cells; pileus trama homogeneous beneath a turflike covering of pilocystidia similar to the cheilocystidia or more elongated (not a compact
palisade), yellowish in iodine; stipe covered by caulocystidia at least
near the apex (similar to the cheilocystidia).