Watch List notes:

BITHYNIA, Nicomedia. Æ (34mm, 20.49 g). Struck during the reign of Galba, April–June AD 68. (standard) ΓAΛY in rectangular countermark on a Greek-legend Perinthus mint bronze of Nero. Pangerl –; Howgego 525. Host Good Fine, c/m Near VF, rough brown surfaces. Very rare, with a more clear countermark than the specimens seen by Howgego.

From the Richard Baker Collection.

This rare countermark is apparently related to the more common countermarks of Galba applied in Thrace.