During a study of small marine flagellates belonging to the Chrysophyta the second author observed that a species described by him as Pavlova mesolychnon (van der Veer 1969) has in its cytoplasm highly refractive inclusions. In the Chrysophyta these are supposed to contain a water-soluble storage product usually indicated in the older literature as leucosin (Fritsch 1935). More recently the term chrysolaminarin has been coined on account of the similarity of the products involved, at least in Hydrurus and Ochromonas species, to laminarin, the storage product of Phaeophyta. For references see Meeuse (1962). In Pavlova mesolychnon two types of inclusions could be distinguished, which appeared to be granular and on which we have collected some further data.