Family: Paoral membrane prominent, may be large and may project stiffly (Carey, 1992).
Genus: Ovoid to ellipsoid; peristome begins at anterior end and extends for 2/3 the body length; a conspicuous membrane at both edges; one to many posterior stiff sensory cilia (Kudo, 1966). Swimming as leaping movement.
cell body 19 μm long, 9 μm wide,
x 400, x 640, Japan 199? by Y. Tsukii
50 μm 100 μm 150 μm; x 400 : 31 μm 63 μm 94 μm; x 640
Pleuronema setigerum Calkins, 1902: 40-50 μm long; long peristome with large undulatory membrane; long cilia; several large caudal cilia (How to know the protozoa, 1979). Elongate, 50 μm long; rather pointed in the posterior; cytostome and undulating membrane (velum) lie in the posterior region; somatic ciliation uniform with very long caudal cilia; macronucelus ovoid, located centrally (Carey, 1992).