Genus Parachaos Willumsen, Siemensma & Suhr-Jessen, 1987

Diagnosis: Locomotive form commonly polypodial, 100 to 500 µm, or monopodial up to 900 µm in length. Multinucleate with 8 to 50 spherical, or slightly oval, nuclei per cell. Nucleolar material parietal as single layer or irregular fragments or a central nucleolus. Cytoplasm rich in bipiramidal or plate-like crystals and zoochlorellae in many isolates. Usually with villous-bulb uroid.

Type species: Parachaos zoochlorellae (Willumsen, 1982)

Ecology: Freshwater.

Remarks: Similar to Chaos but at the ultrastructural level Parachaos can be distinguished by an amorphous cell coat without filaments and nuclei with no internal laminae.