Watch List notes:

MOESIA. Istros. Circa 425/410-380/350 BC. Hemiobol (Silver, 8.5 mm, 0.50 g, 12 h). Two facing male heads side by side, one upright and the other inverted - a tête-bêche pair. Rev. ΙΣΤΡΙ Sea eagle standing left on dolphin; between them, Ι. AMNG I -. Creusy 1, 2012, 227 (this coin). SNG BM Black Sea -. SNG Stancomb -. A very rare, perhaps unpublished, variant. Nicely toned and well-centered. Nearly extremely fine.
From the "Collection sans Pareille" of Ancient Greek Fractions, ex Creusy 1, 1 December 2012, 227.