Watch List notes:

SICILY. Gela. Circa 480/75-475/70 BC. Obol (Silver, 11 mm, 0.51 g). [CΕΛΑ] Forepart of man-headed bull to left. Rev. Wheel with four spokes. Buceti 18 (this coin). Cf. Jenkins, Gela, 189 ff (but river-god to right). Extremely rare, perhaps the only known Geloan obol with river-god to left). Bold and with a dark patina as found. Rough surfaces, otherwise, good very fine.
From the "Collection sans Pareille" of Ancient Greek Fractions, and from the collection of A.D. Moretti, The New York Sale XIV, 10 January 2007, 36.