Mamertini, Messana, Sicily, AE18. 220-200 BC. 5.63 g. 

DIOS and TR monogram, laureate head of Zeus right.
MAMERTINWN, Hermes standing left, holding branch and caduceus, ram at foot left. 

BMC 47; Calciati 36; SNG Cop 457; SNG ANS 437; Hoover HGC 856.
Very rare.

Courtesy of Art Coins Roma auctions on deamoneta.com.
Unsold at 256 Euros.