Macrinus, AE28, Nikopolis ad Istrum.

AV K OPPEL CEVH MAKRINOC, laureate head right.
VP AGRIPPA NIKOPOLITWN PROC IC, Macrinus and Diadumenian
in quadriga right, led by soldier holding vexillium,
trophy and two seated captives above.

Varbanov 3355 (this coin cited)

Courtesy of Akropolis Ancient Coins
http://akropoliscoins.com.

Original information lost in website attack, March 2009. 
Re-added in July. 2011.