Kent, 1881
With characters of suborder. Paroral membrane is dominating feature, sometimes as stiff velum, curling distinctly around subequatorial mouth; segment "b" rarely multifragmented. Usually with long, stiff caudal cilia. Some species possibly with trichocysts. In marine and freshwater habitats, occasionally associated with invertebrates as ectocommensals.
Planctonic species recorded:
Pleuronema crassum