Family: Anterior preoral kinetal arcs of all, body tapers at forward end (Illustrated Guide, 1985). Thigmotactic zone broad but no specialized adhesive area; cell body broad and flattened dorsoventrally; broad lobe projects to the left of the body; no isolated rows of somatic ciliature (Carey, 1992).
Genus: Cell body ovoid, with pre-oral suture skewed left to a point; ventrally flattened, dorsally convex (How to know the protozoa, 1979). With distinct postoral ? beak or unciliated field in ventral body cilia; preoral kinety complete (Illustrated Guide, 1985). Dorsal surface lacks bristles (cf. with bristles Trithigmostoma) ; central zone devoid of cilia (Carey, 1992).