Carausius AE Antoninianus. 

Obv: IMP CARAVSIVS PF AVG, radiate draped bust right 
Rev: PAX AVG, Pax seated left holding patera and cornucopiae. 
Mintmark: XXX. 

RIC V-1, 1089, unattributed British mint, rated rare. 

(fully attributable because it is the only Pax seated type with XXX in the exergue)

Contributed by Dane for George Clegg (biggyg2), August, 2006.