A family of 22 small (1-3mm) nondescript brown or black beetles in Britain, strongly associated with fungi and very rarely found away fungoid situations.  Most species are associated with particular genera of bracket fungi, particularly Trametes, Ganoderma, Piptoporus, Fomes and Stereum spp., and can be abundant within them.  Several species are scarce (e.g. Cis dentatus Mellie and Cis jacquemarti Mellie) but many others are widespread and can be common, including the non-native Cis bilamellatus Wood, an Australian species first found in Britain at Kew Gardens.