Tacitus AE silvered Antoninianus. Lyons mint. 

IMP CM CL TACITVS PF AVG, radiate, draped, cuirassed bust right

MARS VICTOR, Mars walking right, holding spear and trophy.

Star in right field.
Mintmark II

RIC V (1) 29, rated common

Sold on ebay in March 2010 by French seller Philippe Lacoste.