van der Wiel (1982): Microfossils hyaline, irregularly globose, 39 × 32 µm. Surface covered with small hairs about 2-3 µm long. Provided with a few scattered pores 3 µm in diameter.
van der Wiel AM (1982) A palaecological study of a section from the foot of the Hazendonk (Zuid-Holland), based on the analysis of pollen, spores and macroscopic remains. Rev. Palaeobot. Palynol. 38:35-90.