Aelius. CAL series AR Denarius. 209-208 BC. 3.88 g. Sicily. 

Head of Roma right, X behind head.
The Dioscuri on horseback galloping right, CAL ligate and ROMA in partial linear frame below. 

Crawford RRC 75/1a; Syd. 198; Aelia 2. 
Very rare. 

With permission of Numismatica Ars Classica auction 100, Lot 199, May 2017.