Family BURSARIIDAE Dujardin, 1840

Syn.	Thylakidiidae

Body large and broad, with rounded posterior (though tailed in one species) end and truncate anterior end; buccal caviry prominent, funnel-like, opening at apical end of organism and remaining open down onto ventral surface for some distance; elongate, rod-like macronucleus, with up to 35 micronuclei; heavy-walled cyst; predominantly fresh-water forms.

Bursaria O. F. Müller, 1773. Few species.
Bursaridium Lauterborn, 1894. Several species.
Thylakidium Schewiakoff, 1892 (syn. Thylacidium). Single species.