In the late summer of 1971 a tiny whitish agaric was collected by the algologists C.J. den Hartog and V. N. de Jonge on dead leaf-sheaths of Juncus maritimus in the saltmarshes of the Mokbaai on the island of Texel (prov. Noord-Holland). When the material arrived at the Rijksherbarium it was in a bad condition because of age and transport, and a thorough microscopical analysis was therefore difficult to make. During the three following years, however, I succeeded in collecting more material in a better state from the same locality and also from another salt-marsh on the island of Goeree (prov. Zuid-Holland) in the south-western part of the Netherlands. The fruit-bodies of this characteristic species are marasmioid, about 1 cm high with a white or yellowish pileus, slightly decurrent, white lamellae and a pruinose, blue-grey stipe.