Corinth in Achaea, 193-211 AD., Septimius Severus, Æ25, BMC 656, pl. XXI, 18.

Corinth in Achaea, Septimius Severus, 193-211 AD.,
Æ25 (25-28 mm / 8,50 g),
Obv.: L SERT SEV[RE PT AVG IMP III] , laureate, draped and cuirassed bust of Septimius Severus right, seen from behind, before, round countermark: laureate bust right, in oval punch, 4 x 5 mm.
Rev.: C(olonia) L(aus) I(ulia) C - OR(inthus) , the Nymph Peirene, holding a Source Vessel in her r. hand seated left on rock.
BMC 656, pl. XXI, 18 ; Lanz Auktion 105, Münzen von Korinth Sammlung BCD 26 Nov 2001, no. 867 ; cf. Sear GIC 2141 (same obverse die, from the British Museum) ; for countermark: Howgego GIC 56 (89 spec.).
see Numismatic Commentary on Pausanias n° 24 and pl. CV-CVIII.

Thanks to Patricia Lawrence and Michel Amandry for identifying the reverse depiction.