(Quennerstedt, 1867)
Petz et al., 1995a
Body broadly lanceolate, variable (depending on nutritional state), broadly rounded posteriorly, highly flexible; laterally compressed. Spines along entire periphery of cell. Macronuclear nodules 4 in number (sometimes 3), 2-3 micronuclei. 3-7 contractile vacuoles in row along dorsal margin. Extrusomes more or less regularly distributed along ventral and dorsal margins. No extrusome warts. About 18-22 somatic kineties on right side. Row of papillae along anterior right ventro-lateral margin. Size in vivo 70-350 x 55-105 µm. Usually a mesopsammal species.
Ref.: Kahl (1931), Dragesco (1960, 1965), Dragesco and Dragesco-Kernéis (1986).