chlamydomonas(n = noun.animal) genus chlamydomonas - type genus of the Chlamydomonadaceae; solitary doubly-flagellated plant-like algae common in fresh water and damp soil; multiply freely; often a pest around filtration plants;
the type genus of the Chlamydomonadaceae; they are solitary biflagellated plantlike algae common in fresh water and damp soil. They multiply freely and are often a pest around filtration plants. [WordNet 1.5]