Messenius
Could not find Messeniorum in Logeion dictionaries.
Messeniorum Proper-name adjective: masculine genitive plural, Proper-name adjective: neuter genitive plural of Messenius
1. Messēnius, s. Messāna.
2. Messēnius, s. Messēnia.
Messēnĭus, a, um (Μεσσήνιος), de Messène ou de Messine : Ov. M. 2, 679 || Messenii, les Messéniens : Liv. 36, 31.