| Noun | 1. | order Volvocales - chiefly freshwater green algae; solitary or colonialprotoctist order - the order of protoctists Chlorophyceae, class Chlorophyceae - algae distinguished chiefly by having flagella and a clear green color, their chlorophyll being masked little if at all by other pigments family Volvocaceae, Volvocaceae - unicellular or colonial biflagellate free-swimming flagellates Chlamydomonadaceae, family Chlamydomonadaceae - green algae some of which are colored red by hematochrome |