MARTINICA Pegler in Pegler and Singer, Mycotaxon 12: 94. 1980.
MATOUBENSIS Pegler in Pegler and Singer, Mycotaxon 12: 94. 1980.
MAXIMA Burlingham, N. Am. Fl. 9: 229. 1915.
MEPHITICA Pegler in Pegler and Singer, Mycotaxon 12: 95. 1980.
MESOSPORA Singer,.Bull. Soc. Mycol. France 54: 161. 1938.
METACHROMATICA Singer, Kew Bull. 1952: 297. 1952.
METACHROMATICA Singer subsp. NOTOLEUCA Singer in Singer et al. Beih. Nova Hedwidgia 77: 246, pl. l9c. 1983. nomen nudum.
METACHROMATICA Singer subsp. TARUMAENSIS Singer in Singer et al.Beih. Nova Hedwidgia 77: 245. 1983.
MEXICANA Burlingham in Murrill, Mycologia 3: 26 1911.
MICHIGANENSIS Shaffer, Brittonia 14: 281, flgs. 12, 18. 1962.
MICROSPORA Singer, Bull. Soc. Mycol. France 55: 262. 1939.
MODESTA Peck, New York State Mus. Bull. 116: 78. 1907.
MONTANA Shaffer, Beih. Nova Hedwidgia 51: 234, pl. 54, figs. 19-22. 1975.
MONTIVAGA Singer, Rev. Mycol. 15: 131. 1950.
MORDAX Burlingham, Mycologia 28: 258, fig. 3-b. 1936.
MORGANI Saccardo, Sylloge Fungorum 5: 468. 1887.
MURINA Burlingham, Mycologia 28: 254, fig. l-b, 1936.
MURRILLII Burlingham, Mycologia 5: 310. 1913.
MUTABILIS Murrill, Bull. Torrey Bot. Club 67: 146. 1940.
MUTANTIPES Murrill, Lloydia 8: 267. 1945.
NANELLA Singer in Singer et al. Beih. Nova Hedwidgia 77: 271, fig. 26. 1983.
NEODISCOPODA Singer in Singer et al. Beih. Nova Hedwidgia 77: 211, fig. 9. 1983.
NIGRESCENTIPES Peck, Bull. Torrey Bot. Club 33: 214. 1906.
NIGRICANS (Bull.) Fr. subsp. ECCENTRICA Singer, Sydowia 11: 146. 1957(1958).
NIGRODISCA Peck in Macoun in Jordan, Fur Seals N. Pacific 3: 583. 1899.
NITIDA Fr. var. OIROTICA Singer, Bull. Soc. Myco1. France 54: 160. 1938.
NITIDA Fr. var. TRASIENS Singer, Bull. Soc. Mycol. Fance 54: 160. 1938.