Gordian III and Serapis, AE26 of Odessos, Thrace.

AVT K M ANTWNIOC GORDIANOC AYG, laureate draped bust of 
Gordian right, facing bust of Serapis left, wearing polos.
ODHCCEITWN, Demeter standing left, holding corn-ears and sceptre.
Retrograde E in right field.

Varbanov 4482 var (retrograde epsilon listed).