This reverse is a bit more scarce and it has a pretty neat history.
In A.D. 383, Magnus Maximus defeated the Emperor Gratian and claimed the title of Augustus. Valentinian II fled his territory and Theodosius I moved to meet Magnus. Theodosius I temporarily occupied the mint of Thessalonica from 25 Aug 383 until autumn of 384. Theodosius returned control of the Western territories to Valentinian II including the mint in Thessalonica and this reverse type seems "to have been Valentinian's earliest issue after his flight from Italy." (RIC IX)
Arcadius
A.D. 383- 388
17mm 2.2gm
DN ARCAD-IVS PF AVG- pearl diademed, draped, cuirassed bust right.
VIRTVS-AVGGG- Emperor standing left, head right, on ship, holding phoenix on globe and standard. His right foot on captive; Victory on helm.
In exergue TES, in left field Γ
RIC IX Thessalonica 61c