fauna (n.) Look up fauna at Dictionary.com
1771, collective name for animals of a certain region or time, from Late Latin Fauna, a Roman fertility goddess, wife, sister, or daughter (or some combination thereof) of Faunus (see faun).

Popularized by Linnaeus, who adopted it as a companion word to flora and used it in the title of his 1746 catalogue of the animals of Sweden, "Fauna Suecica." First used in English by naturalist Gilbert White.