Gordian III & Tranquillina AE26 (5 Assaria) of Mesembria, Thrace. 

Obv: AVT K M ANT GORDIANOC AVG CEB TPANKVLLINA, laureate, 
draped & cuirassed bust of Gordian right, facing diademed 
& draped bust of Tranquillina left.
Rev: MECAMBRIANWN, Apollo standing left holding plectrum
and resting on lyre set on column to right.

With permission of Pegasi Numismatics Auction 140, lot 200. 
August 2011.