Propyxidium Corliss, 1977 (ref. ID; 2014)
Class Oligohymenophora: Subclass Peritricha: Order Peritrichida: Suborder Sessilina (ref. ID; 2014)

Synonym; Pyxidiella Corliss, 1960 (ref. ID; 2014); Pyxidium Kent, 1881 (ref. ID; 2014)

[ref. ID; 2014]
Solitary. Inverted bell-shaped zooid mounted upon unbranched non-contractile stalk and peristome without a lip. Some authorities consider the genus to be synonymous with Opercularia, a colonial genus. Most easily mistaken for Rhabdostyla which has a definite lip to the peristome.
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)