Ancient Roman silver Siliqua of Constantius II / Constantinople

This is a nice ancient Roman silver Siliqua of emperor Constantius II struck between 351-355 AD.

Obverse: D N CONSTANTIVS PF AVG "Our Lord Constantius Pious Fortunate August" - pearl-diademed, draped, cuirassed bust right

Reverse: VOTIS XXX MVLTIS XXXX "vows (prayers) on the Thirtieth anniversary (of the emperor's rule), and for his (anticipated) Fortieth anniversary" in four lines within the wreath. 

CULTURE: ROMAN

DENOMINATION: Siliqua

MATERIAL: Silver

DATE: 337 - 361 AD. (this coin was minted between 351 - 355 AD)

MINTMARK: C.IA (iota alpha) for the 11th Officina at Constantinople

SIZE: 19.5mm dia

WEIGHT: 2.10 grams

ATTRIBUTION: RIC-102, Cohen 341

PROVENANCE: Private collection Oslo, Norway.