North American species of Mycena.

158 NORTH AMERICAN SPECIES OF MYCENA

characterize the species. The stipe is not particularly fragile, but
the pileus breaks up very easily, with the result that it is difficult to
get the specimen back to the laboratory in perfect condition. The
taste may seem nitrous, but this is a false impression since taste and
odor cannot be readily distinguished when testing a fungus of this
type. If one chews a pileus for a minute the nitrous effect vanishes,
and then there is no appreciable taste. In one of my collections the
odor was absent (14464).
The type of M. leucophaea is well preserved, but I was unable to
demonstrate the presence of any gelatinous layers on either the pileus
or the stipe, and hence doubt whether they were viscid. The spores
measure 5-6 X 2 1u, but only a few were found. Fusoid-ventricose
cystidia were noted on both the sides and the edges of the gills. They
measured 32-40 X 7-11 u, and are similar in shape to those of M. delectabilis. An occasional individual cystidium was observed with a
slight incrustation over the apex, apparently formed by a dried
mucilaginous substance. Iodine reactions were not obtained. In
all its aspects the type resembles a specimen of M. delectabilis so
closely that I have no hesitation in referring M. leucophaea to it as a
synonym. M. delectabilis is very common in western Washington,
and Murrill could hardly have failed to collect it.
68. Mycena Rickenii, sp. nov.
Illustrations: Text fig. 14, nos. 8-9 (p. 154).
Pileus 5-8 (15) mm. latus, obtuse conicus dein umbonatus, pruinosus, albidus; lamellae confertae, angustae, adnatae, albidae; stipes
1-3 cm. longus, 1.5-2 mm. crassus; aequalis, cartilagineus, pruinosus,
deorsum strigosus; sporae 5-6 X 4-5 /; cystidia 30-60 X 9-18 M, subcylindrica vel clavata; basidia bispora. Specimen typicum in Herb.
Univ. Mich. conservatum. Legit A. H. Smith, n. 33-996, prope Ives
Lake, Huron Mts., Mich., Sept. 16, 1933.
Pileus 5-8 (15) mm. broad, obtusely conic, becoming expanded
umbonate, pruinose at first, soon glabrous, translucent-striate toward
the margin, soon opaque, pure white; flesh thin, white, fragile, odor
and taste not distinctive; lamellae close to crowded, adnate, narrow
but becoming slightly ventricose, white, edges even and concolorous
with the sides; stipe 1-3 cm. long, 1.5-2 mm. thick, equal, tubular,
pliant-cartilaginous, white, base strigose, remainder densely pruinose,
somewhat glabrescent in age.