This monograph provides a comprehensive treatment of all 44 butterfly species in the riodinid subtribe Napaeina (including the genera Hyphilaria, Napaea, Voltinia, Ionotus, Hermathena, Ithomiola). Introductory biology chapters discuss habitats, phenology, rarity, mate location, mimicry, adult nutritional ecology, hostplant use, and immature stage biology. Introductory biogeography chapters discuss patterns of regional and community species richness, patterns of speciation, conservation, and historical biogeography. Eight new species and one new subspecies are described in Napaea, Hermathena, and Ithomiola, in addition to the new monotypic genus Ionotus. Adults of all species are illustrated on eight colour plates. Male and female genitalia, where known, are ﬁgured for all species. The book also contains a species-level phylogenetic analysis using 78 characters of adult morphology, and locality data from 30 collections. The literature is listed and mapped for all species.