Strigula aquatica H.Harada, previously known only by the holotype from Okayama- ken, western Japan, has been recently found at several localities in Chiba-ken, central Japan. Some specimens from Chiba were collected in freshwater habitats like the holotype, but the others were found in terrestrial habitats on forested hills. The specimens from Chiba show great variations in involucrellum and ascospore size. A description and figures are provided