Atopodinium Kahl, 1932 (ref. ID; 2014)
Class Polyhymenophora: Subclass Spirotricha: Order Odontostomatida (ref. ID; 2014)

[ref. ID; 2014]
Body discoid, laterally compressed with flat left and convex right sides and covered in pellicular armour with 4 posterior spines and 1 short spine-like anterior extension of the dorsal keel. In addition there is distinct tooth-like spine above the AZM which is characteristics of all odontostomes. Somatic cilia greatly reduced and exist only as a single row in the terminal region. Perizonal complex short, consisting of 5 upper single rows and 2 lower double rows. Single macronucleus and adjacent micronucleus. Sapropelic. Most easily confused with Saprodinium in which there are cilia in both anterior and posterior regions of the body. Single species genus.
Quote; Colin R. Curds, Michael A. Gates and David McL. Roberts "British and other freshwater ciliated protozoa Part II Ciliophora: Oligohymenophora and Polyhymenophora" Cambridge University Press, 1983 (ref. ID; 2014)

Atopodinium fibulatum Kahl (ref. ID; 1335, 1618, 1621, 4610)
Measurements; 40-50 um long. (ref. ID; 1618)