[3] The species in this genus are fusiform with an apical anterior concavity and a longitudinal groove.
The flagellae arise from parallel basal bodies in a flagellar pocket.
The cell wall is a trilaminate pellicle with subpellicular microtubules and a micropore.
The cytoplasm contains a single, branched mitochondrion with tubular cristae, a supranuclear Golgi apparatus and large amounts of glycan granules.
The types II and III appear to be rhoptry and microneme like organelles respectively.