Severus Alexander, AE29 Pentassarion of Istros, Thrace.

Obv: AV T K M AVR CEB ALEXANDROC, laureate, draped, cuirassed bust right.
Rev: ISTRIHNWN, Nemesis standing left, holding scales and 
sceptre. E in lower right field (value mark).

Varbanov 667.

Courtesy of Numismatik Lanz, Jan. 2010.