Group C coins are neater in appearances than those of the preceding groups: the pony's body is compacted, and the overall design becomes more cohesive. A problem in the earlier groups was that the dies were too large for the planchets, and much of the design would be off the coin. Several features define this group: on the obverse, the mouth is V-shaped, and the front whisk and nose are combined into one smooth curve; on the reverse, there is a distinctive curl that hangs from the lower rein. The chronology is as follows:
9, 10, 11.
There is a straight hair between the front two curls of the hair.
The reverse of Coin 9 depicts the curl hanging from the reins that defines Group C. The pony's head is shaped somewhat like that on Coin 4 of Group A, with the integral mane curl-and-diadem. There is a neck indicated between the reins. The driver's head is neater than on Coin 4, and the shape of the cheek section is affected by the presence of a line, very slightly curved in a S shape, behind the bead of the mouth. While this line may only delineate the face, it is tempting to perceive in this a representation of a Celtic moustache. The driver's neck, shoulder and arm are portrayed simply by a chevron pointing backward, the lower limb curving down.
There are some minor differences in the obverse design of Coin 10: the lower part of the ornament in front of the nose does hang from the second bead, as in the previous die, but both beaded lines emanate from the same point. There is a space between the lower part of this ornament and the terminal of the ornament in front of the chin. The whisks are smaller, and there are five of them. There are no straight hairs between the three curls at the front of the head.
The pony's head on the reverse of Coin 10 omits the pointed part of the cheek section, and the front of the head is now delineated by a crescent that descends from the bead of the nose. This feature will be repeated on all the remaining dies in Series X. The driver's head is similar in design (although not in the proportions or in the way the hair is engraved) to that on Coin 4 of Group A. His body is derived from that of Coin 4 and 5, omitting the chariot horn shape, exaggerating the upper crescent, and combining the body and arm into one unit. The leaves that perhaps represent the side of the chariot are now detached.
Coin 11 marks the transition from Group C to Group D. Rybot noted several dies, but combined these variations in one illustration with additional three details. For the sake of clarity, I have assigned the major obverse illustration to Group C, with the small detail to Group D. On the reverse, the two small details belong to Group C while the main illustration is part of group D. The variations included in Group C are described as Coin 11, while those of Group D are described as Coin 12. In such transitions, considerable die linking between varieties is to be expected, as well as some uncertainties on the part of the engraver in evolving the design. Accordingly, Group C/D mules are likely.
Whereas, on the obverse of Coin 10, the bottom section of the ornament in front of the nose was left to hang awkwardly from the middle of the bottom curve at the center of the ornament, in Coin 11 this flaw is resolved. On Coin 11, the nose is set vertically, and the bottom section of the ornament detaches completely from the turn in the spiral, forming instead into an S-scroll that mirrors the configuration of the top section of the ornament. Note that the leaf of the ornament in front of the nose is set parallel to the straight line of the nose.
Since, in Coin 11, an actual neck replaces the neck ornament, and the whisk that was attached to the neck ornament becomes attached to the chin, there is extra space available, now filled by a scroll without a leaf in opposition to the chin-whisk. This lower scroll is mirrored by the curl of hair behind the neck
In this coin, it is possible to trace a spiral composition that starts at the front curl of the head, follows the curls round the back of the head to the scroll beneath the chin, and then upwards, though the whisks in front of the face to join the whisks around the top and back of the head, finally terminating at the whisk with no leaf, at the bottom left of the design.
The reverse of Coin 11 as the variety depicted in the inset of Rybot's illustration; the driver is derived from Coin 9 and 10. His head is similar to that of Coin 9, by reason of the "moustache," but in Coin 11, the problem of the driver's body and the chariot is resolved by turning them into an S-scroll from which a large leaf hangs. This leaf is made large to balance with the pony's tail and is positioned to harmonize with it. In this coin, the driver's arm and hanging leaf create a kind of wishbone shape, with the S-scroll of the driver's body mounted on the point. The driver's head is connected to the arm with a short neck, a feature that disappears in Coin 12.
It can be seen from this that the exact chronology of Coins 9 and 10 is difficult to ascertain. The driver's head is more advanced in Coin 9, and the pony's head is more advanced in Coin 10. The weight of evidence points to the order I have provided; the die engraver was either unsure of the new design of the driver's head, or he simply forgot, and so reverted back to the earlier design.
While the reverses of Group C can be distinguished by the presence of a curl that hangs from the lower rein, the chariot and driver are a continuation of those to be found on Coins 4 and 5 of Group A. The pony's head evolves slightly in this group, so that on Coin 10, the pony's mouth becomes a line running parallel to the pony's diadem, and the curve of the lower part of the cheek is echoed by the curl of the mane. A lash from the sceptre to the emblem, prevalent in the earlier groups, is completely absent from this one. It can be seen in this, and in the previous two groups, how the die engravers' struggle with major problems, like making the design smaller, led to the synthesis and balance to be found on the obverse of Coin 11, an alternative reverse die of which begins Group D.