In this note, a rare phenomenon of the wing variation of the diatom Planktoniella sol (Wallich) Schutt is described. This diatom exhibits widely differing wing structures which could lead to a mistaken identity. Although a few of this variations have been recorded before, and have been interpreted 'as developmental stages; some hitherto unrecorded forms are also presented in this note. It is suggested that some ecological factors may be responsible for bringing out these variations