Description of Pirsonia guinardiae

Flagellates laterally flattened, about 10 microns long and 6 microns wide. Auxosome remains flagellated. Mature auxosomes apple-shaped, about 15 microns in diameter, generally detaching before division, giving rise to 4 (to 8) daughter cells which are infectious without a longer resting phase. Thick-walled cysts present.