Constantine I, AE follis, Ticinum.

Obv: CONSTAN-TINVS AVG, laureate head right.
Rev: DN CONSTANTINI MAX AVG around VOT XXX within wreath.

Mintmark: PT

RIC VII Ticinum 174 unlisted var.
This series is listed has a crescent beneath the number XXX. 
This particular example has no such crescent within the 
wreath. Very rare.

From Dane's collection, November 2010. ex-Roma Numismatics.