The "I" is placed on the Pergamo-Gerame stretch (8B4), where the first two letters of the distance figure XXV are separated to accommodate it.
The final "A" is placed on the Pella stretch (9B1). To accommodate it, the name Pella is placed at the end of the previous (Evmenia) stretch.
Note the exceptional interval between the "I" and final "A". Really, such a short name is inadequate to cover the span required by the mapmaker. One expedient would have been to repeat it (as he does with MONS TAURVS at 10B5-11B2 and 11B1-11B3, for instance); but he chose just to stretch it to an extreme instead.