Genus: Ovoid, inhabiting a mucilaginous sac or lorica; vestibulum large and shallow, occupying 1/3 of ventral surface; on the right of the vestibulum lie a short row of long curved cilia; a macronucleus; contractile vacuole subterminal (Carey, 1992). Species:

50 μm 100 μm 150 μm; x 400 : 31 μm 63 μm 94 μm; x 640

Cyrtolophosis mucicola Stokes, 1885: 28 μm long; vestibulum large and shallow; a macronucleus central; a contractile vacuole subterminal; inhabiting a mucilaginous lorica (Carey, 1992). Only one contractile vacuole subterminal; length of cell < 40 μm; elongated cilia at anterior end; lives in dwelling-tube; cell body ellipsoid (Foissner, 1993).

Cyrtolophosis bursaria (Schewiakoff, 1892) Kahl, 1926: Only one contractile vacuole subterminal; length of cell < 40 μm; elongated cilia at anterior end; lives in dwelling-tube; cell body ovoid [ poorly defined species, synonyms of C. mucicola ?? ] (Foissner, 1993).