In the semi-cylinder of the apse six hierarchs, are depicted full figure, jointly celebrating Mass: Epiphanius, Athanasios, John Chrysostom and Basil, Gregory the Theologian, and Spyridon, three by three, holding inscribed scrolls, while Spyridon is also holding the tile whose composition from clay, water adn fire was used to prove the consubstantiality of the Holy Trinity during the First Ecumenical Concil of 325 AD.