eBay: HJB-Rare Anonymous As with Ass Symbol, 

 
Rare Anonymous As with Ass Symbol,  

169-158 BC, 21.24g. Cr-195/1, Syd-298 
  (R6). Obv: Janus, I above. Rx: Prow, ass above, 
  ROMA below. Rare. VG; ass very clear