A wide range ofthallus organisation is found in algae. Unicellular motile (Chlamydomonas), unicellular nonmotile (Chlorella), Colonial motile (Volvox), Colonial non-motile (Hydrodictyon), siphonous (Vaucheria), unbranched filamentous (Spirogyra), branched filamentous (Cladophora), discoid (Coleochaete) heterotrichous (Fritschiella), Foliaceous (Ulva) to Giant Kelps (Laminaria and Macrocystis).