Pergamum, Mysia, AR cistophoric tetradrachm. 189-133 BC. 12.59g.

Cista mystica, with serpent emerging, all within ivy-wreath.
Bow in bowcase ornamented with an aplustre, coiled serpents 
to left and right. PER monogram to left, caduceus to right.

BMC 86; SNG Lockett 2715 (this coin); SNG France 1705; SNG Cop 412; SNG von Aulock 7462.