Watch List notes:

ARABIA, Bostra, Trajan (A.D. 98-117), silver tridrachm (10.16 g), struck in 111 A.D., obv. laureate head of Trajan to right, AVTOKP KAIC NEP TRAIANOC CEB **GERM DAK* around, rev. Arabia standing facing, head to left holding branch and bundle of cinnamon sticks, camel at left side, around **DHMARX EX UPAT*E, (S.-, Metcalf Tell Kalak 2 = SNG ANS 1153, Sydenham Caesarea 182, BMC 59-61, RPC III, 4051, Kindler Biostra 4). Toned, very fine and rare.

Ex Spink & Son, London, December 1999.
Traditionally thought to be tridrachms, but more recently termed tetradrachms (ss K. Butcher, "The silver coinage of Roman Arabia Judaea and Rome in Coins 65 BCE - 135 CE", [London 2012], p.208)