Maupasella nova Cépède was discovered by Maupas (1877) in the alimentary canal of an Algerian earth-worm and subsequently described by Cépède (1910). As was well remarked by the latter author, this ciliate varies much in size and in form, long specimens measuring 80–95 by 25μ., and short ones only 50–75 by 27–47μ. The essential characters of Maupasella are: (1) the presence of an anterior fixing apparatus in the form of a conical process derived from thickened ectoplasm, (2) an elongated ribbon-like macronucleus, (3) irregularly disposed contractile vacuoles, and (4) dense ciliation. Moreover, the micronucleus (PI. VI, fig. 18 and m in all the other figures), which is often difficult to see, is spindle-shaped, with its axis parallel to that of the ciliate's body, strangulated in the middle and with the chromatin condensed into a disc lying in the strangulated portion of the spindle.