Order: Hypostomial frange not extensive (Carey, 1992). Medium to large, some >100 μm long; oral polykinetids only next to left rear of cytostome; large cyrtos has complete palisade of nematodesmata (Illustrated Guide, 1985).
Suborder: With few to many "oral" polykinetids as frange from post oral region sidewise to left, sometimes onto dorsum (Illustrated Guide, 1985). Body usually large and cylindrical with simple holotrichous ciliation (Carey, 1992).
Family: Body ellipsoidal, uniformly ciliated; hypostomial frange short; prominent cytopharyngeal apparatus (Carey, 1992).
Genus: Synhymenium not separated from body kinetids by transverse cortical groove; synhymenium polykinetids surrounded cell body at 90 degree to its long axis (Illustrated Guide, 1985).
->> Description at WPRNO Google Image Search
Nassulopsis sp.
154 x 100 μm
Urawa
Saitama, 1999
Similar species --> Nassula;
