Watch List notes:

KINGS of PONTOS. Polemo II, with Tryphaena. Circa AD 38-64. AR Drachm (17mm, 3.22 g, 3h). Struck circa AD 54-57. Diademed head of Polemo right / ETOVC [...], diademed and draped bust of Agrippina right. RG 33 (Polemo and Agrippina); cf. RPC I 3823-7. Fine, toned, some roughness and scratches. Very rare.

RPC I identified the female on these drachms as Tryphaena, the mother of Polemo II, based on the portrait's similarity to silver and bronze issues which also bear her name, while RG favored an attribution to Agrippina the Younger.