Van Geel et al. 1989: Hyaline microfossils (often folded), 39-63 X 21-42 μm, normally with ca. 1 μm high protuberances 1.5-3.0 μm apart and ca. 0.5 μm in diameter below the tips, slightly widened at the tip. Rarely smooth-walled. Undamaged specimens show a characteristic furrow in the central part of the microfossil.
van Geel B, Coope GR, van der Hammen T (1989) Palaeoecology and stratigraphy of the Lateglacial type section at Usselo (The Netherlands). Rev. Palaeobot. Palynol. 60:25-129.