Watch List notes:

Hostilian. As Caesar, A.D. 251. AR antoninianus (20.8 mm, 3.56 g, 1 h). Rome, A.D. 251. Rare. C VALENS HOSTIL MES QVINTVS N C, radiate and draped bust right / MARTI PROPVGNATORI, Mars advancing right holding spear and shield. RIC 177b; RSC 15. aVF.