Caracalla, AE26, Amasia, Pontus.

AY KAI M AYR ANWNINOC, radiate head right
AD CE ANT AMACIA MH NE PR P ET CH, Serpent left on 
garlanded altar. 

Similar to the reverse of coins of Antoninus Pius (e.g. 
von Aulock 6698), the altar types of Caracalla usually 
have a tree in the left field and, at most, an eagle or
other sacrificial victim on the altar.
This reverse for Caracalla is not in any of the usual 
reference works e.g. SNG Cop, Berlin, von Aulock, 
RecGen, BMC, McClean, Lindgren, Hunter, Imhoof, etc.
Only in "L'Atelier d'Amaseia du Pont: Recherches historiques et numismatiques" Julie Dalaison, no. 418.

With permission of Roma Numismatics, October 2008.