In the present paper a survey is given of species belonging to the genera Avrainvillea, Chlorodesmis, Rhipilia, Rhipiliopsis, Tydemania, and Udotea collected during the Indonesian-Dutch Snellius- II Expedition (1984) in the Banda, Sawu and Flores Seas. The morphology and anatomy of these seaweeds are discussed, biogeographical data are added and some comparison is made with the material from the earlier Siboga Expedition (1899-1900).