Roman tombstone

Two drawings are shown on the same piece of paper, one above the other. One depicts the upper half of a tombstone, the other depicts the lower half of a tombstone. Both show part of the figure of a man on horseback. The two halves may or may not be part of the same tombstone. Although they seem to match quite well, the top fragment is shown to a much smaller scale than the bottom fragment, which suggests that the two fragments in fact belong to two separate tombstones, both probably to Roman cavalry officers. The inscription on the lower one is to L Vitellius.