1 Basidia single-celled (fig. 55). 2 - Basidia transversely or longitudinally septate (fig. 55), or difficult to observe. 71 2(1) Fruit body agaricoid, i.e. mushroom-shaped with gills underneath cap (figs 56, 67). 3 - Fruit body not agaricoid, without gills (figs 65, 66). 69 3(2) Spore print white or pale coloured, hyaline s.m. (Usually on straw/dung mixtures, never on raw dung except when very old). 5 - Spore print coloured. 4 4(3) Spore print pinkish or pale cinnamon, honey-coloured s.m. (Usually on straw/dung mixtures, never on raw dung). 6 - Spore print darker, in shades of brown or black. 8 5(3) Stem eccentric. Fruit body pure white. Spores ellipsoid, smooth. _Pleurotellus_ s. lato (If gills pink and spores longitudinally ridged see _Clitopilus passackerianus_, fig. 67) - Stem central. 7 [Illustration: FIG. 55. From left, sketches of holobasidium, with mature basidiospore showing germ pore; auriculariaceous basidium; tremellaceous basidium, lateral view and as often seen in sections.] 6(4) Fruit body white, ivory or very pale tan, with a smell of cucumber. Gills decurrent. _Clitocybe augeana_ - Fruit body yellow, with scaly cap. Gills free or just adnate. Fruit body with distinct ring and granular veil. (Commonly in plant pots. Probably associated with peaty material more than dung). _Leucocoprinus birnbaumii_ (_L. cepaestipes_ and _L. lilacinogranulosus_ occur in similar situations). 7(5) Fruit body with amethyst/purple shades, with eccentric stem. Spores subglobose, slightly ornamented to nearly smooth. (On compost heaps in gardens). _Lepista nuda_ - Fruit body with pink gills and distinct volva at stem base. Cap white to pale hazel. Stem white. Spores broadly ellipsoid, smooth. _Volvariella speciosa_ 8(4) Spore print distinctly brown (fulvous, tawny, rust coloured etc.). 9 - Spore print some darker shade, fuscous, fuliginous or violaceous black. 20 9(8) Stem distinctly annulate, apex striate. _Conocybe percincta_ (Has been found on straw/dung mixtures, never on raw dung). - Stem lacking a veil. 10