lemur (n.) Look up lemur at Dictionary.com
nocturnal Madagascar mammal, 1795, coined by Linnaeus, from Latin lemures (plural, singular lemurum) "evil spirits of the dead" in Roman mythology, a word of uncertain origin. De Vaan finds it likely that it and Greek lamia are borrowings of a non-Indo-European (perhaps Anatolian/Etruscan) word malevolent spirits.
The oldest usage of "lemur" for a primate that we are aware of is in Linnaeus's catalog of the Museum of King Adolf Frederick of Sweden (Tattersall, 1982); .... In this work, he explained his use of the name "lemur" thus: "Lemures dixi hos, quod noctu imprimis obambulant, hominibus quodanmodo similes, & lento passu vagantur [I call them lemurs, because they go around mainly by night, in a certain way similar to humans, and roam with a slow pace]" [Dunkel, Alexander R., et al., "Giant rabbits, marmosets, and British comedies: etymology of lemur names, part 1," in "Lemur News," vol. 16, 2011-2012, p.65]
Lemuria (1864) was the name given by English zoologist P.L. Sclater (1829-1913) to a hypothetical ancient continent connecting Africa and Southeastern Asia (and including Madagascar), which was hypothesized to explain phenomena now accounted for by continental drift. Earlier it was the name of the Roman feast of the Lemures.