I just saw this tweet. It contains this image:
(taken from here, where we gather that the map was drawn in the early 1700s)
with the following Latin sentence:
ex septentrione longissimeque dissitis regionibus venisse ductuque mirabili migrasse versus meridiem mexicanos olim incolae produnt.
(I think, please double check that I have typed it correctly)
Am I correct in saying that the translation is the following?
From the northern extremely distant and widely removed regions, came through marvelous guidance and migrated towards the south and [became mexicans?]
Unfortunately I can't make full sense of "mexicanos olim incolae produnt".