Loxophyllum helus (Stokes, 1884) Penard, 1922

Loxophyllum helus — Matis 1988: 57; Matis & Tirjaková 1992: 52; Tirjaková 1993: 134; Szentivány & Tirjaková 1994: 94; Tirjaková 1998: 16; Tirjaková 2001: 16; Tirjaková 2004: 7; Krno et al. 2006: 308; Tirjaková & Vďačný 2013a: 671.

Nomenclature. Matis (1988) erroneously used “ L. helus, Stokes, 1884 ” instead of “ L. helus (Stokes, 1884) ”.

Main morphological characters (according to Foissner et al. 1995). Length 75–300 µm in vivo. Body lanceolate with narrowly to broadly rounded posterior body end. Two macronuclear nodules with a single micronucleus in between. Contractile vacuole terminal to slightly subterminal. Two size types of extrusomes distributed along entire ventral margin: type I rod-shaped and slightly curved, 10 µm long, while type II oblong and only 1–3 µm long; type I also clustered into 8–10 warts on dorsal margin. Somatic ciliary pattern Loxophyllum - like; about 15–25 right and about 20 left kineties.

Distribution. Loxophyllum helus was found in organic mud from activated sludge plants in Bratislava (Matis 1988); in the backwaters of the Danube River in Čičov (Matis & Tirjaková 1992); in the periphyton and benthos of the Turiec River (Tirjaková 1993); in the benthos of the Karlova Ves (Bratislava) Branch of the Danube River (Szentivány & Tirjaková 1994); in the benthos from a tributary of the Hron River (Tirjaková 1998); in mosses from the Hincov potok stream, High Tatra Mts (Krno et al. 2006; Tirjaková 2001, 2004); in the sediment from the littoral zone of the upper Váh River near the village of Bystrá (Tirjaková & Vďačný 2013a).