Watch List notes:

ROMAN COINS

Diocletian, 284-305. Antoninianus (Billon, 23mm, 3.84 g 6), Lugdunum, 287-289. IMP C DIOCLETIANVS P AVG Radiate, draped and cuirassed bust of Diocletian to right, seen from behind. Rev. IOVI TVTATORI AVGG / P Jupiter standing left, holding Victory on globe in right hand and scepter in left; at feet to left, eagle standing left. Cohen 295.RIC 54. Nearly fully silvered. Extremely fine.

The reverse legend, which is unique to the mint of Lugdunum, boasts Jupiter as protector of the Augusti (i.e. Diocletian and Maximian).