The geographical distribution of animals, with a study of the relations ...

—chap. x.J THE PALiEARCTIC REGION. 187strengthen our view of their radical distinctness, by showing tohow considerable an extent the former is inhabited by peculiar,and often very remarkable generic types.Insects :Lepidoptera.—The Diurnal Lepidoptera, or butterflies,are not very abundant in species, their number being probablysomewhat over 500, and these belong to not more than fifty genera.But no less than fifteen of these genera are wholly confined tothe region. Nine of the families are represented, as follows :1. Danaidce; having only a single species in South Europe.2. Satyridce ; well represented, there being more than 100 speciesin Europe, and three peculiar genera. 3. Nymphalidce ; ratherpoorly represented, Europe having only about sixty species, butthere is one peculiar genus. 4. Libytheidm ; a very small family,represented by a single species occurring in South Europe.5. Nemeobiidce ; a rather small family, also having only onespecies in Europe, but which constitutes a peculiar genera.6. Lyccenidw ; an extensive family, fairly represented, havingabout eighty European species ; there are two peculiar generain the Palasarctic region. 7. Pieridm ; rather poorly representedwith thirty-two European species ;two of the genera are, however,peculiar. 8. Papilionidce ; very poorly represented inEurope with only twelve species, but there are many more inSiberia and Japan. No less than five of the small number ofgenera in this family are wholly confined to the region, afact of much importance, and which to a great extent redeemsthe character of the Palaearctic region as regard this order ofinsects. Their names are Mesapia, Hypermnestra, Doritis,Sericinus, and Thais ; and besides these we have Parnassius—the " Apollo " butterflies—highly characteristic,and only foundelsewhere in the mountains of the Nearctic region. 9. Hesperidcc; poorly represented with about thirty European species,and one peculiar genus.Four families of Sphingina occur in the Palsearctic region,and there are several peculiar genera.In the Zygmnidm there are two exclusively European genera,and the extensive genus Zygoma is itself mainly Palaearctic.The small family Stygiidas has two out of its three genera