Fauré-Fremiet (1924: 37, fig. 10)
Alekperov & Mamaeva (1992: 8)
Fixed specimens 180–265 × 205–300 µm. Body subspherical to lenticular. Somatic kineties c. 240–250 longitudinal, not extending to apical pole; anterior portions non-ciliferous, posterior to these 1 equatorial ciliary band of c. 35 µm long cilia, with rows of short cilia posterior to this. Macronucleus almost forming a complete ring; micronucleus 1. Movement: rapid, rotating about main body axis.
Atlantic (Fauré-Fremiet, 1924); Bering Sea (Alekperov & Mamaeva, 1992).
The species was only tentatively identified by Leakey et al. (1994) from the Atlantic sector of the Southern Ocean. However, a Cyclotrichium species was found in sea-ice and plankton of the Ross Sea, in the region 68.95°–76.60°S and 134.98°–162.43°W (Petz, unpublished data).