Cristigera Roux, 1899 (ref. ID; 2014) or 1901 (ref. ID; 3690)
Class Oligohymenophora: Subclass Hymenostomata: Order Scuticociliatida (ref. ID; 2014)

[ref. ID; 2014]
Small oval to pyriform ciliate with transversely truncate apical pole that is unciliated. Prominently dorso-ventrally flattened. Peristomial region about half length of body beginning sub-apically. There is a large, prominent undulating membranelle forming a pouch-like structure at its posterior end close to the oral aperture. Somatic ciliation not uniform, anteriorly it is dense, posteriorly it is sparse, caudal cilium present. Contractile vacuole in posterior body half. Spherical macronucleus centrally situated.
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)

Cristigera media Kahl, 1928 (ref. ID; 1622) reported year? (ref. ID; 1618)
Description; In salt water. (ref. ID; 1618)
Measurements; 45-50 um long. (ref. ID; 1618)
Cristigera phoenix Penard, 1922 (ref. ID; 1622) reported year? (ref. ID; 1618, 3690, 3771)
Syn; Lembadion duriusculum (ref. ID; 1622)
Description; In fresh water. (ref. ID; 1618)
Measurements; 35-50 um long. (ref. ID; 1618)