Genus Lagenodifflugia Medioli & Scott, 1993
Diagnosis: Shell pyriform, often with a constriction of the neck, most frequently circular in cross-section but sometimes slightly compressed, composed mainly of agglutinate mineral particles bound by an organic cement; aperture terminal, circular; internally the shell is partitioned into two regions by a diaphragm constructed as part of the shell wall but having a single central orifice.
L. vas (Leidy, 1874) (Type species)
L. bryophila (Penard, 1902)
L. montana (Ogden & Zivkovic, 1983)
L. epiouxi (Chardez & Gaspar, 1984)
Remarks: For the function of this diaphragm, see rotifers. For more information about the differences between Pontigulasia, Lagenodifflugia and Zivkovicia look here. For the species described by Penard look here.