Constans AE4, Siscia, 346-348 AD.

CONSTAN-S PF AVG, rosette-diademed, draped, cuirassed bust right.
GLOR-IA EXERC-ITVS, two soldiers holding spears and shields 
with one standard between them. Chi-rho on banner.

Mintmark: Delta SIS
RIC VIII Siscia 87, Scarce.

From Dane's collection, August 2010.

Known mintmarks for this RIC number:
Delta SIS only