Caracalla. AE 16; Caracalla; 198-217 AD, Trajanopolis, Thrace, AE 16, 3.63g. Obv: Laureate head r. Rx: Snake emerging r. from half-opened cista mystica. Ex CNG 41, 19 March 1997, lot 1378. Rare; this coin is the only example found on Coin Archives.. EF