A large family of flies in Britain with over 290 species. Since the publication of d'Assis Fonseca's Handbook for the Identification of British Insects there have been a number of changes to classification at the subfamily level. These changes are reflected in the keys below.
The examination of the genitalia of Muscidae and other calypterate flies is often necessary and this document goes through how to go about it
Genera Azelia, Drymeia, Hydrotaea, Muscina, Neohydrotaea, Potamia and Thricops. The key to genus includes keys to the British species of genera Muscina, Drymeia and Potamia.
Genera Eudasyphora, Mesembrina, Morellia, Musca, Neomyia, Polietes, and Pyrellia in Tribe Muscini along with Haematobia, Haematobosca and Stomoxys in Tribe Stomoxyini.
Genera Graphomya, Gymnodia, Hebecnema, Mydaea and Myospila
Genus Atherigona in Tribe Atherigonini, genera Helina, Lophosceles and Phaonia in Tribe Phaoniini.