Owing to a critical examination of the taxonomic characteristics ofOscillatoria, such as gas vacuoles, calyptra, sheath, arrangement of the trichome, etc., this family has to be redefined. It is divided into two tribes:
1.
The ‘Vaginariées’ or rather the Schizothricées (Oscillatoria which have developed sheaths withseveral trichomes).
2.
The ‘Lyngbyées’, with or without sheath which only contain one trichome.
The first tribe includes the speciesSchizothrix (encompassingHydrocoleum, Dasygloe, Oligoclonium, Lyngbyopsis), Microcoleus (withSirocoleus) andPorphyrosiphon. The tribe of the ‘Lyngbyées’ is composed of theOscillatoria species (includingSpirulina, Arthrospira, Spirulinopsis, Glaucospira [?] andJuguspira [?]),Lyngbya (withPhormidium, Symploca, Katagnymene, Pelagothrix, Haliarachne, Proterendothrix, Cirrosiphon, Cyanohydnum) andCrinalium.
The systematic position fo the four speciesIsocystis, Borzia, Sinaiella andPseudanabaena is somewhat doubtful and must be examined more closely for clarification.