This edition contains about one half more species than the 1982 edition. Four keys are presented. Keys 1 and 2 are to the coprophilous ascomycetes, a very diverse group which, although not covering all the possible types of reproductive structure found in the class, contains many of the important types. Key 3 is to the basidiomycetes of dung and associated debris. Key 4 is to the Zygomycota (phycomycetes) which are characteristic of dung and among the first to appear when freshly dropped dung is incubated.