Watch List notes:

Constantius II (337-361). AR Siliqua, Aquileia mint, before 355 AD. Obv. D N CONSTANTIVS P F AVG. Laurel- and rosette-diademed, draped and cuirassed bust right. Rev. FELICI-TA-S PERPETVA. Victory advancing left, with wreath and trophy; in exergue, AQ•. RIC VIII 70. AR. 3.41 g. 21.00 mm. RR. Very rare. An overweight example, brilliant and superb. Absolutely minor nicks, otherwise good EF. ���

Under Constantius II, between 355 and 360, the weight of the siliqua was reduced from c. 3 g. to c. 1.9 g. but the unreduced siliqua continued to be minted quite
frequently, mostly in the West. In this regard, see RSC V. pp.7-8.