[ref. ID; 5694]
Circumscription: Heterotrophic flagellates, four similar flagella inserting at the head of a broad ventral groove, ingesting algae via the groove.
Ultrastructural identity: Mitochondria with tubular cristae, dictyosomes present, cells without walls, scales or other excrescences.
Synapomorphy: None at this time. The one ultrastractural study to date lacks detail, possibly related to Diphylleia.
Composition: Several species.
References: Klaveness 1995.