P. Blas. AE sextans, 22 mm, 6.06 g. 169-158 BC, Rome Mint.

Draped bust of Mercury right, wearing square petatos, two dots above. 
P BLAS above prow right, two dots to right, ROMA below. 

Crawford 189/5; Cornelia 10; Syd. 370d.
Very rare. 

With permission of Numismatica Ars Classica auction P, Lot 1684, May 2005