Watch List notes:

SICILY. Akragas. Circa 490-483 BC. Didrachm (Silver, 17.5 mm, 8.51 g, 5 h). AKRA Eagle standing to left. Rev. Crab seen from above. SNG ANS 943-5. Westermark, 141 (O57/R87). Attractively toned. Uneven tone on the reverse, otherwise, very fine.
From an old collection in Davos, Grisons, formed before the 1990s.