Watch List notes:

CARIA. Knidos. Symmachy coinage, Circa 404 or circa 394-387 BC. Obol (Silver, 8.5 mm, 0.64 g, 10 h). Σ - Υ - Ν The infant Herakles kneeling to right, strangling a serpent with each hand (= Herakliskos Drakonopnigon). Rev. Κ - Ν [...] Head of Aphrodite to right, her hair rolled, wearing a pendant earring and a pearl necklace; all within an incuse square. H. Voegtli, Ein Obol der kleinasiatischen Symmachie von 394 v. Chr., SM 24, 93, 1974, pp. 1-3 and fig. 1 (this coin). Apparently unique, probably the rarest coin of the Symmachy series. Struck from dies of fine style. Some porosity, otherwise, good very fine.
From the "Collection sans Pareille" of Ancient Greek Fractions, ex Monnaies et Médailles 52, 19 June 1975, 191 and enlarged on pl. 53.