This coin just sold for $345.00. It is a nice example of the cryptogram which reads as “eros†which in Latin is amor which is a palindrome for Roma.
Crispus
A.D. 320
20mm 3.1gm
CRISPVS NOB CAES; laureate and cuirassed with spear pointing forward and shield on left arm.
ROMAE AETERNAE; Roma std. r., shield in lap inscribed X/V
in ex. R eros (in Greek) S
RIC VII Rome 197
http://www.constantinethegreatcoins.com/ROMAE/