A revision of the Diplopsalis group of dinoflagellates (Dinophyceae) based on material from the British Isles

SEM has made possible a detailed re-examination of the thecal plates of marine dinoflagellates belonging to the Diplopsalis group which have been collected in an extensive survey of the seas around the British Isles. Six genera are recognized: Diplopsalis, Diplopsalopsis, Dissodium, Oblea, Zygabikodinium and the new genus and species Boreadinium pisiformis Dodge & Hermes. The confused taxonomic history of the group is discussed, the valid species are listed and a key for the identification of the genera is given.