sentences:  Although it has been given elsewhere as ""Ioanna Arcensis"", ""Arcensis"" being in the nominative case and denoting "of Arc", Roman Catholic saints denominated toponymically in Latin generally are denominated ""de"" (which takes the ablative case) followed by the toponym, though, in post-classical Latin usage, ""de"" was used patronymically on occasion as well.In any case, in translating foreign names that did not have commonly recognized Latin equivalents, the oblique forms of the native names were also used on occasion.Due to the ambiguous meaning of the surname, the Latin "de Arc" is likely not a true toponym, but rather the Latinization of "d'Arc", despite the absence of apostrophes in French surnames during the life of St. Joan.