Tasmanian Iulomorphidae are here assigned to the genera Amastigogonus Brölemann, 1913, Atelomastix Attems, 1911 and Equestrigonus gen. n. Descriptions or redescriptions are given for Amastigogonus danpicola sp. n., Amastigogonus elephas sp. n., Amastigogonus fossuliger Verhoeff, 1944, Amastigogonus hardyi (Chamberlin, 1920), Amastigogonus hellyeri sp. n., Amastigogonus michaelsae sp. n., Amastigogonus orientalis sp. n., Amastigogonus peninsulensis sp. n., Amastigogonus tasmanianus Brölemann, 1913 (type species of Amastigogonus ), Amastigogonus verreauxii (Gervais, 1847), Atelomastix bonhami sp. n., Atelomastix smithi sp. n. and Equestrigonus tasmaniensis gen. n., sp. n. The synonymy of Amastigogonus nichollsii Verhoeff, 1944 with Amastigogonus hardyi is accepted, and lectotypes are designated for Amastigogonus nichollsii and Amastigogonus tasmanianus .