Petz, Song & Wilbert (1995: 74, fig. 22)
In vivo c. 35–65 × 25–35 µm. Body asymmetrically obconical to ellipsoidal, variable, sometimes laterally flattened; cytostome apically protruding, retractile, eccentric and shifted somewhat to ventral side. Somatic kineties 21–25: 16–20 longitudinal, 4 long and 1 short (kinetofragmon) spiral kineties; spiral kineties equally spaced, with kinety 4 posteriorly shortened. Conspicuous cilia-free area on right. Adoral membranelles 6–8, in a semicircle to right of oral area. Nematodesmata 14–18, lining cytopharynx. Macronucleus 1; micronucleus 1. Contractile vacuole equatorial on left. Silverline system irregular, fine-meshed. Movement: moderately fast, rotating about main body axis.
Ross Sea, in the region 66.00°–76.60°S and 162.43°–164.97°W, in sea-ice and plankton (Petz, unpublished data); Weddell Sea (Petz et al., 1995).