Local in fens, bogs, moorland, damp grassland and marshes throughout much of England. In Hampshire and on the Isle of Wight there are scattered colonies in bogs and marshes in all three vice-counties, with occasionally wanderers elsewhere. Wingspan 20-22 mm. The most likely confusion species is Muslin Footman Nudaria mundana
, which differs in having two rather poorly-defined zigzag fasciae running across the less-rounded forewing, and fewer spots than Round-winged Muslin. Larva feeds on various lichens and various mosses.