~Stropharia semiglobata~ (Fries) Quélet Dung-roundhead _Cap_: width 10-35 mm. _Stem_: width 4-7 mm; length 25-50 mm. _Description_: Cap: hemispherical or slightly umbonate, sometimes flattened and hardly expanding even with age, very viscid, smooth, pale yellow-ochre or yellowish tan. Stem: slender, straight, white then yellowish, smooth, viscid, but then dry and shiny below an imperfectly formed, thin ring. Gills: adnate, almost triangular in shape, crowded, dark brown to purplish black, but with ochraceous areas at maturity. Flesh: pale ochre. Spore-print: purplish brown. Spores: very long, dark brown under the microscope, smooth, ellipsoid with large germ-pore and about 18 × 10 µm in size (17-20 × 9-10 µm). Facial cystidia: spindle-shaped, thin-walled and filled with amorphous contents which become yellow in solutions containing ammonia. Marginal cystidia: spindle-shaped or flask-shaped, numerous, thin-walled and typically yellowing as above. _General Information_: ‘Semiglobata’ means hemispherical and refers to the shape of the cap of _S. semiglobata_; it is a very variable fungus in both size of the cap and the prominence of the ring. The Dung-roundhead grows only on dung which is acidic in its soil status, whilst _Panaeolus semiovatus_ (Fries) Lundell next described (p. 210) grows on slightly to distinctly base-rich dung. This may explain why in Britain the Dung-roundhead is the commoner of the two species. However, _P. semiovatus_ was formerly placed in the genus _Stropharia_ because of its blackish spores and distinct ring. The spores of _Stropharia_ in the mass are violaceous black whilst those of _P. semiovatus_ are brownish black. Under the microscope they are also differently coloured and have different chemical compositions as their reaction with dilute solutions of ammonia shows; the spores of the first species turn purplish olive in ammonia and those of the second species become very dark brown. _Illustrations_: F 33^{b}; Hvass 171; LH 153; NB 31⁵; WD 75³. [Illustration: Plate 70. Dung-fungi] Mottle-gills--on dung from Spring until Autumn. ~Panaeolus semiovatus~ (Fries) Lundell _Cap_: width 20-70 mm. _Stem_: width 5-10 mm; length 80-160 mm. _Description_: Cap: oval or bell-shaped, not expanding, dingy whitish or pale clay colour, smooth, slimy when moist, but soon drying and then becoming shiny, often wrinkled and cracked, and ornamented with fragments of veil at the margin. Stem: dull, straight, rather rigid, tapering upwards, white, and striate at apex above a whitish erect and membranous, often collapsing, ring; yellowish below the ring and whitish and cottony at the slightly swollen base. Gills: adnate, greyish then black, mottled and crowded. Flesh: whitish or pale ochre. Spore-print: black.