Rimostrombidium Jankowski, 1978

See the description of genus Strobilidium.

Rimostrombidium armeniensis (Zharikov, 1987) n. comb. (ref. ID; 4613 redescribed paper)
Syn; Strobilidium armeniensis Zharikov, 1987 (ref. ID; 4613)
Description; 1) Size in vivo (?) about 55-60 um. 2) Body of silver nitrate-impregnated specimens roughly hemispherical with anterior end transversely truncated and posterior broadly rounded. 3) Macronucleus near anterior end of cell, globular. 4) Contractile vacuole in posterior end, as in R. lacustris. 5) Cytoplasm like colourless. 6) About 12 longitudinal bristle (ciliary) rows. 7) Oral apparatus occupies anterior end of cell, consists of about 31 membranelles forming prominent, circular adoral zone. 8) Movement likely rapid, probably as in R. lacustris. (ref. ID; 4613)
Comments; This species was overlooked by Petz & Foissner (1992), who transferred most Strobilidium species to Rimostrombidium because they have slightly spiralling somatic ciliary rows not extending to the posterior end of the cell, that is, do not form a caudal spiral as in Strobilidum caudatum. Detailed redescriptions needed, especially of live specimens. This species is unique by it globular macronucleus. In all other freshwater strobiliids, the macronucleus is semicircular and underneath the adoral zone of membranelles. Other oligotrichs have conspicuous extrusomes (Pelagostrombidium, Limnostrombidium) or prominent jumping bristles (Halteria, Pelagohalteria). (ref. ID; 4613)