The Australian species of the spider family Hersiliidae are revised and compared in a key. Hersilia australiensis, sp. nov., is newly described, the first record of the genus Hersilia from Australia. For all other Australian species a new genus, Tamopsis, is erected and the species formerly included in the genus Tama Simon are transferred to it. Of the species so far recorded from Australia, only T. eucalypti (Rainbow) and T. fickerti (L. Koch) are recognised; Tama novaehollandiae (L. Koch) and Tama brachyura Simon are regarded as doubtful species, because the types are either juveniles or lost and the species are not recognisable from descriptions. For T. eucalypti (Rainbow) a lectotype and a paralectotype are designated; for T. fickerti (L. Koch) a neotype is designated from the material at hand. The following new species of Tamopsis are described: T. platycephala, sp. nov.; T. amplithorax, sp. nov.; T. brachycauda, sp. nov.; T. tweedensis, sp. nov.; T. brisbanensis, sp. nov.; T. daviesi, sp. nov.; T. kochi, sp. nov.; T. centralis, sp. nov.; T. reevesbyana, sp. nov.; T. grayi, sp. nov.; T. darlingtoniana, sp. nov.; T. queenslandica, sp. nov.; T. raveni, sp. nov.; T. cooloolensis, sp. nov.; T. brevipes, sp. nov.; T. arnhemensis, sp. nov.; T. circumvidens, sp. nov.; T. tropica, sp. nov.; T. trionyx, sp. nov.; T. pseudocircumvidens, sp. nov.; T. leichhardtiana, sp. nov.; T. rossi, sp. nov.; T. perthensis, sp. nov.; T. occidentalis, sp. nov.; T. fitzroyensis, sp. nov. The species of the genus Tamopsis are arranged in nine species-groups. A character-state analysis of several characters is provided for all species, and the phylogenetic status of species-groups and of included species is derived. It is concluded that four main lineages exist in Tamopsis: a high-eyed lineage (arnhemensis – circumvidens – tropica groups, 11 species), and three low-eyes lineages, namely the platycephala group (two species), the eucalypti group (two species), and the daviesi – queenslandica groups (10 species). In addition, the brachycauda and tweedensis groups are very primitive, each consisting of one species of obscure relationships. The origin of the genus Tamopsis is obscure, because no reliable information is available on the hersiliid fauna of neighbouring areas (New Guinea, south-eastern Asia). Phylogenetic and zoogeographical evidence, however, suggests that both high-eyed and low-eyed lineages originated in northern Australia. Perhaps the high-eyed lineage originated in or immigrated into northernmost Northern Territory, and the low-eyed lineages in northern Queensland. Within the arnhemensis – circumvidens – tropica lineage, as well as in the daviesi – queenslandica and the platycephala lineages, migration proceeded in a clockwise direction from the Northern Territory and northern Queensland respectively, through eastern Australia to south-western Australia and, in the tropica group, eventually to north-western Australia, where today the most derived Tamopsis species lives. The independent migration of species of different lineages probably explains the rich and diverse Tamopsis faunas in south-eastern Queensland and eastern New South Wales, as well as in south-western Australia. Both regions can be regarded as major centres for evolution of Tamopsis.
