Three new strains of members of the family Oocystaceae collected in inland waters of Africa were studied microscopically and by molecular phylogeny. The new genus Elongatocystis was decribed, and the new combination Elongatocystis ecballocystiformis was proposed. The phylogenetic position of Oocystidium sp., and Quadricoccus ellipticus within the family was shown. The SSU rRNA phylogeny of Oocystaceae recovered a need for further studies to display the generic and species concept in this monophyletic group of green algae. The essential research steps were discussed.