(Fig. 8)
Material examined. Soil sample from Wangsan-ri, Jung-gu, Incheon, South Korea (37°26ʹ47ʺN 126°23ʹ40ʺ E), in February 2018.
Diagnosis. Cell size 90-105 × 35-45 μm in protargol preparations, shape ellipsoid; 27-30 adoral membranelles; cortical granules reddish color; paroral membrane with hooked distal end in the typical Notohymena -pattern; 2 macronuclear nodules with 2 or 3 micronuclei; 18 frontal-ventral-transverse cirri, 3 frontal, 1 buccal, 4 frontoventral, 3 postoral ventral, 2 pretransverse ventral, and 5 transverse cirri; 1 left (18-20 cirri) and 1 right (20-22 cirri) marginal cirral row; 5 dorsal kineties; 3 caudal cirri.
Remarks. Notohymena rubescens mainly differs from other Notohymena species because of the reddish color of its cortical granules (N. antarctica, yellowish; N. limus and N. pampasica, colorless; N. quadrinucleata, yellowish to citrine; N. saprai, dark green) (Berger, 1999; Kuppers et al., 2007; Kamra and Kumar, 2010; Foissner, 2016; Naqvi et al., 2016).
Deposition. Three slides (NNIBR2018113 IV1948 - NN IBR2018113 IV1950) have been deposited at the Nakdonggang National Institute of Biological Resources (NNIBR), Korea.
Genus Sterkiella Blatterer et al., 1991