Four keys are presented. Keys 1 and 2 (MJR) 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. The information for the identification of these fungi is dispersed throughout the literature, and many new species are still being discovered and described. Some appear to be world-wide in their distribution, others more restricted, with a prevalence of reports from either arctic, temperate or tropical regions. These keys are not exhaustive, since there are far too many species to make it practical to include them all. They do, however, include most genera, and the commoner or well known species of temperate regions. Specific (and even generic) limits in some cases (e.g. _Coprotus_ / _Ascophanus_ / _Ryparobius_ / _Thelebolus_) are still the subject of debate and the choice of names to use in the key for a few taxa has been a compromise. Key 2 includes the original 'plectomycete' key (RW), which contains fungi which may not be strictly coprophilous in the normal sense, but fungi which occur on hair, horn, bone and cadavers, and may thus be found on carnivore dung or pellets of owls and other birds of prey. Key 3 (RW, p. 52) is to the basidiomycetes of dung and associated debris. The part of the key dealing with the agarics attempts to be as complete as possible. Since the toadstools have always been thought of as the best known of the coprophilous fungi, attention to their taxonomy has often been careless. In this key the opportunity has been taken to adopt a rather narrow species concept, and to provide in certain places indications of where distinct taxa, even autonomous species, may be found after further laboratory work. Many of these types have been cultured and appear to differ vegetatively in ways which support observations of gross morphology. Coprophilous agarics are popular material for genetic studies and additional information on veil structure, spore number etc. of individual species is given, even when these are not 'key characters'.