Constans. AV Solidus, Trier mint. AD 337-350. 22 mm, 4.29 g. 

FL IVL CONSTANS AVG, laureate, draped and cuirassed bust right.
SECVRITAS REI PVBLICAE, Securitas standing right, legs 
 crossed, resting left arm on column, right hand resting on top of head.

Mintmark TR.

RIC VIII Trier 3; Depeyrot 1/3; Biaggi 2111 (this coin).
Ex Biaggi de Blasys Collection, 2111; Münzen und Medaillen AG XI (Jan. 1953)

With permission of cngcoins.com, auction Triton XIX, Lot 628, Jan. 2016.