NOT IN RIC
UNLISTED ISSUE. Not attested in RIC but probably belongs to the group described in footnote 2 to ANTIOCHIA 23a on p. 615: "This and the following issue [ANTIOCHIA 23b], together with Galerius' Soli Invicto (no. 26), fall within the range of 6.7-6.6 gm., ie. rather more than a gramme heavier than the mintmarked issues. Classified by Pink as 'Festmünzen auf die Beendigung des Perserkrieges 299', they are possibly small medallions, though not (as usually the case with medallions) any recognizable multiple of the aureus".
See examples of ANTIOCHIA 23b (Wien RÍ 24728, 6.65 g, 20.9 mm), ANTIOCHIA 26 (Rollin et Feuardent 1887, lot 638, 6.50 g) and another ANTIOCHIA 26 (Ars Classica - Naville III 1922, lot 171, 6.58 g, 21 mm; could be the same specimen with the hole repaired).
Listed in Depeyrot (p. 141, no. 17/1). Coin should be listed in RIC before ANTIOCHIA 26.
ANTIOCHIA [before 26], CONSTANTIUS, UNLISTED ISSUE [MARTI PROPVGNATORI]