During the XVI Century, France succeeded in establishing a few colonies in the Americas. Equinoctial France was a short-lived venture, but one that left an indelible mark upon the island of São Luis, in the State of Maranhão, Brazil. Two remarkable reports on the shape of the colony, its geographical features, climate, ethnography, botany, and zoology are among the first contributions to the natural history of Northeastern Brazil. Description of the habits of common animals, together with zoogeographical records are useful for the modem zoologist. This paper brings together the recorded information on the mammals of Maranhão, as described and depicted by two French friars and one Portuguese, who lived in the island during the first half of the XVIth Century.