Trajan Decius AE Dupondius. 

Obv: IMP C M Q TRAIANVS DECIVS AVG, radiate cuirassed bust right 
Rev: GENIVS EXERC ILLYRICIANI S-C, Genius standing left, holding patera & 
 cornucopia; standard to right. 

RIC 117d, Cohen 55.

[originally CNG, imported from dirtyoldcoins, Sept.07]