This volume merges all geographical and paleogeographical data on all groups of the arachnofauna. The book features topics such as the ecological factors, climate and other barriers that influence the distribution of arachnida. It also elaborates on the characteristics of the distribution such as arachnida at high altitude (e.g. Himalaya), in caves, in polar regions and highlights differences between the arachnofauna of e.g. Mediterranean regions vs Central Europe, West African vs Indomalayan and more. Furthermore, amongst other topics the volume also includes chapters on the systems of arachnida, fossil orders, dispersal and dispersion, endemics and relicts, regional arachnogeography, cave and high altitude arachnida.

ÿThe large genus Orthomorpha is rediagnosed and is shown to currently com-prise 51 identifiable species ranging from northern Myanmar and Thailand in the Northwest to Lombok Island, Indonesia in the Southeast. Of them, 20 species have been revised and/or abundantly illustrated, based on a res-tudy of mostly type material; further 12 species are described as new: O. atypica sp. n., O. communis sp. n., O. isarankurai sp. n., O. picturata sp. n., O. similanensis sp. n., O. suberecta sp. n., O. tuberculifera sp. n., O. subtuberculifera sp. n. and O. latiterga sp. n., all from Thailand, as well as O. elevata sp. n., O. spiniformis sp. n. and O. subelevata sp. n., from northern Malaysia. The type-species O. beaumontii (Le Guillou, 1841) is redescribed in due detail from male material as well, actually being a senior subjective synonym of O. spinala (Attems, 1932), syn. n. Two additional new synonymies are proposed: O. rotundicollis (Attems, 1937) = O. tuberculata (Attems, 1937), syn. n., and O. butteli Carl, 1922 = O. consocius Chamberlin, 1945, syn. n., the valid names to the left. All species have been keyed and all new and some especially widespread species have been mapped. Further six species, including two revised from type material, are still to be considered dubious, mostly because their paraterga appear to be too narrow to represent Orthomorpha species. A new genus, Orthomorphoides gen. n., diagnosed versus Orthomorpha through only moderately well developed paraterga, coupled with a poorly bi- or trifid gonopod tip, with at least some of its apical prongs being short spines, is erected for two species: O. setosus (Attems, 1937), the type-species, which is also revised from type material, and O. exaratus (Attems, 1953), both comb. n. ex Orthomorpha.

The result is a great increase in multi-disciplinary research and novel avenues incorporating spiders as model organisms.