Calephelis perditalis, commonly known as the rounded metalmark or lost metalmark, is a butterfly in the family Riodinidae. It is found in Texas in the United States and Mexico, south to Venezuela. The wingspan is 18–24 mm. The upperside of the wings is brown with indistinctly chequered fringes. There may be a dark median band. Adults feed on flower nectar, including the nectar of Chromolaena odorata. The larvae feed on Chromolaena odorata and Eupatorium glabratum.