Gordian III and Tranquillina AE 28mm of Markianopolis, Moesia Inferior. 

AVT K M ANT GORDIANOC AVG CE TRANKULLEINA, laureate, draped 
and cuirassed bust of Gordian right, facing draped bust of 
Tranquillina left.
VP TERTVLLIANOV MARKIANOPOLITWN, Hades-Serapis, seated left, holding sceptre and extending right hand to Cerebus at 
foot left. E in left field.

Varbanov 2042 (this coin); AMNG 1175; Moushmov 838.

With permission of Numismatik Lanz, Munich, from an old auction. Added Sept. 2011.