St. Euphemia

13th century, intermittently restored
Mosaic
St. Mark's Cathedral, Venice

This is the first-century Euphemia who was one of the four Virgin Martyrs of Apuleia who are portrayed in the pendatives of the South (Leonard) Cupola in St. Mark's. Each holds a cross in her right hand, all wear copes, and all but Euphemia have crowns of various designs in the left hand.
More of the Virgin Martyrs of Apuleia

Photographed at St. Mark's by Richard Stracke, shared under Attribution-NonCommercial-ShareAlike license.