Trachycystis iredalei H.B. Preston, 1912
Cavellia irregularis (H.H. Suter, 1890) New Zealand, North Island
Climocella isolata J.F. Goulstone, 1997 New Zealand, North Island
Gyrocochlea iuloidea (E. Forbes, 1851) New South Wales
Flammulina jacquenetta F.W. Hutton, 1883 New Zealand
Fectola jamiesoni F.M. Climo, 1978 New Zealand
Rotadiscus jamiesoni (F.M. Climo, 1978) New Zealand, South Island
Setomedea janae J. Stanisic, 1990 Queensland
Ptychodon janeirensis (K.H.J. Thiele, 1927)
Dentherona jemmysensis (C.J. Gabriel, 1947) Australia, Snowy River
Cavellia jenniferae (FOSSIL) B.A. Marshall& T.H. Worthy, 2017 † New Zealand, South Island
Fectola jessica (F.W. Hutton, 1883) New Zealand, Bealey
Protoflammulina johnsi F.M. Climo, 1971 New Zealand
Oreomava johnstoni (T. Iredale, 1933) Tasmania
Costallodiscus kaikoura B.A. Marshall& G.M. Barker, 2008 New Zealand, Kaikoura
Climocella kaitaka J.F. Goulstone, 1996 New Zealand, North Island
Allodiscus kakano B.A. Marshall& G.M. Barker, 2008 New Zealand
Lithocouperia kalkajaka Stanisic, 2016
Cralopa kaputarensis J. Stanisic, 1990 Australia, Narrabri3,5 mm
Canallodiscus karamea B.A. Marshall& G.M. Barker, 2008 New Zealand, Karamea
Afrodonta kempi (M. Connolly, 1925)
Rhophodon kempseyensis J. Stanisic, 1990 Australia, Miriam Vale
Rhophodon kemseyensis J. Stanisic, 1990 Australia
Climocella kenepuruensis (H.H. Suter, 1909) New Zealand
Allocharopa kershawi (W.F. Petterd, 1869) Tasmania
Rotacharopa kessneri J. Stanisic, 1990 Queensland
Pernagera kingstonensis (C.M.D.E. Legrand, 1871) Tasmania
Serpho kivi (J.E. Gray, 1843) New Zealand, North Island10 mm
Pilsbrycharopa kobelti (O. Böttger, 1908) Malaysia, Borneo
Vatusila kondoi G.A. Solem, 1983 Fiji Islands
Paryphantopsis koragae J. Slapcinsky, 2005 Papua New Guinea
Semperdon kororensis (R.H. Beddome, 1889) Palau
Kubaryiellus kubaryi (O.F. von Möllendorff,1900)
Mocella kuntzi G.A. Solem, 1960
Sinployea kusaieana G.A. Solem, 1983