★ An apparently unpublished and seemingly unique Hemiobol ★

WESTERN GREECE AND THE IONIAN ISLANDS, Uncertain. Circa 450-400 BC. Hemiobol (Silver, 5 mm, 0.41 g, 7 h). Scallop shell. Rev. A within shallow incuse square. Apparently unpublished and unknown. An interesting and clear piece. Porous surfaces, otherwise, about extremely fine.

From a Swiss collection, ex obolos 5, 26 June 2016, 211.

First things first, when this coin first appeared the shell on the obverse was identified as a 'cockle', which is, alas, quite wrong. This is a 'scallop' - a member of the Pectinidae, which can be 100% correctly identified by the two triangular auricles - 'ears' - found on either side of the hinge on both the top and bottom shells. Cockles, however, are members of the Cardiidae and have no auricles. Going through numismatic literature you will find vast numbers of wrong identifications: the scallop - with 'ears' - symbol on coins of Tarentum is called a cockle by some; while what appears to be a cockle - no 'ears' - on coins of Zankle is often termed a scallop! Anyway, what we have here is a scallop.
But where does it come from? This coin looks somewhat similar in fabric to coins from the Ionian Islands off the western Greek mainland. Korkyra/Corfu immediately comes to mind; but the large A on the reverse almost certainly rules that city/island out as the mint for this coin. However, the A does remind us of the early issues of the Akarnanian League, and could well stand for Anaktorion, which did have a 5th century coinage, albeit primarily Corinthian type staters. Unfortunately a firm attribution is at present impossible, though the general area from which it must come is sure.