In their revision of the order Oscillatonales, Anagnostidis and Komarek (1988) created a number of new genera (in addition to Planktothnx) appropriate for some members of Oscillatoria (as defined here), some of which (such as Gomontincma or Tychoncmct) may be suitable for some of the other morphological and genetic clusters in the PCC. Oscillatoria cluster 2 conforms to the newly created genus Gomontinema (sensu Anagnostidis and Komarek 1988), but clusters genetically relatively closely with strains identified as Tychonema (scnsu Anagnostidis and Komarek 1988} (see Wilmotte and Herdman, this volume). Thus, further analyses are required prior to adopting a new generic name.