Baesuri, Portugal, lead Triens, ca 50 BC,5.94 g. 

BAES beneath stylized ship left.
Ear of barley with narrow sprouts. 

Burgos 181; Gomes BAE 01.12 (this coin). Burgos_181

With permission of Numismatica Ars Classica, May 2010
Very rare. 
Estimate: 400 CHF.