Seriphos, Cyclades, AR Stater, ca 530 BC, 11.03 g. 

Frog seen from above. 
Incuse square irregularly divided. 

Rosen 242; Dewing 1967; Sheedy 6 (listed as 3 in error); Babelon Traité II-1, 1937.

Very rare.

With permission of Numismatica Ars Classica auction 84, Lot 627, May 2015