The aim of this volume in the British Micropalaeontological Society (BMS) Occasional Publication Series is to review the present state of knowledge concerning the stratigraphic distribution of dinoflagellate cysts in British sediments. Since the BMS Series in 1978, it has been obvious that a gap has existed in its range. The principle reasons for the lack of a dinoflagellate cyst volume is that the intensive study of these microfossils is relatively new to geological science (relative to the levels of maturity reached in foraminiferal and ostracod studies, for example). This volume seeks to fill this gap, covering dinoflaggellate cysts of the Triassic, Jurassic, Cretaceous, Tertiary and Quaternary System.