Severus Alexander. Sestertius. 231 AD. 

IMP ALEXANDER PIVS AVG, laureate, draped bust right
PM TR P X COS III PP, Sol standing left, holding whip 
and raising right hand. 

RIC IV-2, 513 var (bust type 5d). This obv. legend (5) 
and Sol holding whip is listed as Sest. only 
as having slight drapery on left shoulder (5b). Rare.

With permission of Roma Numismatics, March, 2010