This is the last group in the series and is the culmination of all the previous design changes. On the obverse, a small head attached to the nose that the die engraver introduced in the previous group is elaborated on further. The chariot driver retains his body shape, but the internal design is brought into harmony with that of the pony's mane, the chariot drivers' hair, and the hair locks on the obverse. By the end of this group, the curl on the pony's mane is given a leaf, as is the driver's body, and these harmonize well with the curl and two leaves on the rein. The Coriosolite coinage probably all came to an end at about the same time. Series X is that part of it that was minted on the east side of the Rance. Series Y and Z are roughly contemporary in that it is fairly certain that at some time, all three mints were in operation.