Northern Pearly Eye (Enodia anthedon) is often confused with the Appalachian Brown (Satyrodes appalachia).
In the Northern Pearly-Eye, the wing margins are slightly scalloped, the bands through both wings are wider, the underwings have a more gray coloration and the second eyespot on the forewings is always much smaller (sometimes absent; see photo 4 & 5).

Pondicherry Wildlife Refuge, Jefferson, New Hampshire, USA, 4 August 2017