North American species of Mycena.

EUMYCENA: TYPICAE

241

gated cystidia as well as on the vesiculose individuals, 36-52 X 9-16 u;
gill trama vinaceous brown in iodine; pileus trama with a thin pellicle,
a broad hypoderm, and a moderately broad filamentous portion, all
but the pellicle vinaceous brown in iodine; contorted metallic-appearing lactifers present in the flesh of the pileus and in the gill trama.
Habit, habitat, and distribution.-Gregarious to cespitose on leaves
and debris in hardwood forests; Tennessee, New York, Michigan, and
California in the United States and Manitoba in Canada. Very
common in Michigan in the spring on the forest-covered sand dunes
along Lake Michigan.
Material studied.-Smith, 32-43, 32-50, 32-113, 32-522, 32-563,
32-622, 33-210, 33-212, 33-369, 49, 6344, 9514, 15022, 15034, 15047.
Atkinson, 6029, 23394, 24092, 24132L, Cayuga Lake Basin, New
York. Hesler, 9625. Mains, 5075.
Observations.-The long, narrow, almost cylindric spores are the
outstanding character of the species. Its somewhat cespitose manner
of growth and its cylindric buttons, which at times remind one of
those of many species of Coprinus, are also distinctive. The cystidia
are fairly constant in size and shape in each collection, but vary
considerably among collections. Nos. 6344 and 9514 show the
variability found in the Michigan material.
111. MYCENA LEPTOCEPHALA (Fr.) Gillet
Les Hymen., p. 267. 1874
Agaricus alcalinus leptocephalus Fries, Syst. Myc., 1:143. 1821.
Agaricus leptocephalus Fries, Epicr. Syst. Myc., p. 109. 1838.
Agaricus ammoniacus Fries, ibid.
Mycena ammoniaca Quelet, Champ. Jura et Vosges, p. 106. 1872.
Illustrations:
Plates 39, 40 C; Text fig. 28, nos. 1-2 (p. 242).
Beardslee and Coker, Journ. Elisha Mitchell Sci. Soc., 40, pl. 22, lower
left figures (small specimens).
Lange, Flora Agar. Dan., 2, pl. 51, fig. A (as M. ammoniaca, normal
form), fig. D (as M. alcalina f. chlorinella); fig. F, robust form (very
good).
Ricken, Die Blitterpilze, 2, pl. 111, fig. 2.
Smith, Am. Journ. Bot., 22, pl. 1, fig. 2.
Pileus 1-3 (4) cm. broad, obtusely conic with the margin appressed
at first, becoming broadly conic to convex, sometimes broadly cam