Hostilian as Augustus, AR Antoninianus, AD 251. Antioch, 25 mm, 4.48 g. 

C OVAL OSTIL MES COVINTVS AVG, radiate, draped and cuirassed bust right, three dots beneath the bust.
ROMAE AETERNAE AVG, Roma seated left, holding Victory and spear, shield at her side. (Reverse of Treb. Gallus).

Hybrid of RIC 204b (obv) and RIC 89 (Treb. Gallus, rev.); RIC -; RSC -. 

Note - this hybrid, although not in RIC, is not all that 
rare. I found 7 of them on CoinArchivesPro in May 2019.

With permission of Leu Numismatik, Auction 4, lot 955, May 2019.