Watch List notes:

Philistia, Uncertain mint. 5th Century B.C AR hemiobol (7.12 mm, .48 g, 2 h). Archaic beardless male head right / Head of griffin left partly in linear square frame within incuse square punch. Gitler & Tal -; HGC 10, -.. VF. Unpublished and possibly unique. 

Philistia is the cataloguers best guess as to the origin of this coin.