4(3) Perithecia dark, olive, brown or black. 5 - Perithecia reddish brown, orange or golden, globose, with a neck. Spores black, limoniform. 116 5(4) Perithecia globose, surmounted by a dense tuft of greyish green hairs, which may be branched or simple, straight or curly. Spores olivaceous, limoniform. Asci clavate, soon disappearing. (A large genus not characteristic of dung, but occurring occasionally). _Chaetomium_ (fig. 16) - Perithecia more pyriform, or if globose then with a distinct neck, may be setose but not densely hairy, with clavate or cylindrical asci. 6 6(5) Each spore composed of 4 or more cells in a row (figs 17, 21). Asci bitunicate (figs 20, 23). 7 - Spores 1- or 2-celled. Asci bitunicate or unitunicate. 29 7(6) Spores 16-32-celled, united firmly together in a bundle both in the ascus and after discharge. Germ slits usually absent. (_Sporormia_) 8 - Spores each with 4 or more cells, each spore free and surrounded by its own gelatinous sheath. Germ slits usually present. (_Sporormiella_) 11 8(7) Spores 16-20-celled. 9 - Spores 29-32-celled, 130-160 × 4-6µm. _Sporormia mirabilis_ 9(8) Spores 16-celled, 85-116 × 5-6.5µm. _Sporormia fimicola_ - Spores smaller. 10 10(9) Spores 16-celled, 37-45 × 3µm. Asci 50-60 × 10-12µm. _Sporormia sp._ (fig. 17) [recorded as _S. fimetaria_ by Richardson (1972); see also Bell (1983) and Dissing (1992)] - Spores 16-20-celled, 50-57 × 3.5-4.5µm. Asci 70-80 × 12-16µm. _Sporormia fimetaria_ (These two taxa may represent the extremes of _S. fimetaria_). 11(7) Spores 4-celled. 12 - Spores more than 4-celled. 22 12(11) Spores more than 65-70µm long. 13 - Spores less than 65-70µm long. 15 [Illustration: FIG. 16. _Chaetomium_ sp., perithecium and spore.] [Illustration: FIG. 17. _Sporormia_ sp., ascus and spores.] [Illustration: FIG. 18. _Sporormiella ovina_, pseudothecium.] [Illustration: FIG. 19. _S. intermedia_, pseudothecium.] [Illustration: FIG. 20. _S. intermedia_, immature bitunicate ascus and mature ascus with outer layer ruptured.]