New taxa are described as follows: Ralfsia confusa, sp. nov., Ralfsia integra sp. nov., Pseudolithoderma nigra sp. nov., Diplura simulans gen. et sp. nov., Endoplura aurea gen. et sp. nov. Lithodermataceae is included in Ralfsiaceae. An emended description of Ralfsia californica is given. Distributional records are also given.