Elagabalus AE16 Assarion of Markianopolis. 

AVT K M AVR ANTWNINOC, laureate head right.
MARKIANOPOLITWN, serpent emerging from cista mystica with 
lid open right.

Varbanov 1389 (this coin) (illustrated as 1390 in error); AMNG 677.

With permission of Numismatik Lanz, auction 2002, added Sept. 2011.