Ceratium contortum var. longinum (Karsten) Sournia, 1967 Dataset GBIF Backbone Taxonomy Rank VARIETY Classification kingdom Chromista phylum Myzozoa class Dinophyceae order Gonyaulacales family Ceratiaceae genus Tripos species Tripos longinus Name Homonyms Ceratium contortum var. longinum (Karsten) Sournia, 1967