Genus Epistylis Ehrenberg, 1830

Diagnosis. Peristomial lip constricted into a projecting tube protruding outwards from apical end of cell (Figs 2D, E; 3C). Elongate macronucleus oriented longitudinally to main axis of cell (Figs 2D, E; 3C). Contracted zooid ovoid in shape, with conspicuous folds posteriorly (Figs 2D; 3C) (Corliss 1979; Lynn & Small 2002).