Zoothamnium Bory, 1826 (ref. ID; 2014) or Ehrenberg, 1838 (ref. ID; 1248)
Class Oligohymenophora: Subclass Peritricha: Order Peritrichida: Suborder Sessilina (ref. ID; 2014)
Family Zoothamniidae (ref. ID; 1248)

[ref. ID; 2014]
Colonial. Inverted bell-shaped zooids borne upon a contractile branched stalk which bends in a zigzag fashion (not spirally) by means of a continuous myoneme. This lies more less centrally within the stalk and is not sinusoidal when relaxed. The genus is most easily confused with Carchesium and Pseudocarchesium in which the myonemes are discontinuous.
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)

Zoothamnium adamsi Stokes, 1885 (ref. ID; 1308, 1620) reported year? (ref. ID; 1618)
Description; Attached to Cladophora. (ref. ID; 1618)
Measurements; About 60 um long; colony about 250 um high. (ref. ID; 1618)
Zoothamnium arbuscula Ehrenberg, 1839 (ref. ID; 1335, 1620, 1629, 4654) reported year? (ref. ID; 1618) or (Ehrenberg, 1831) Ehrenberg, 1838 (ref. ID; 4610)
Syn; Zoothamnium geniculatum Ayrton, 1902 (ref ID; ?) or 1903 (ref. ID; 4610)
Measurements; 40-60 um long; colony up to more than 6 mm. high. (ref. ID; 1618)
Zoothamnium niveum (Hemprich & Ehrenberg, 1831) (ref. ID; 4465)
Description; Marine ciliates. (ref. ID; 4465)