Eight species of dasyurid marsupials have been typed for the electrophoretic mobility of 18 of their enzymes and proteins. The species were the Ningbing antechinus (Pseudantechinus sp.), Pseudantechinus macdonnellensis (formerly Antechinus macdonnellensis), Parantechinus apicalis (formerly Antechinus apicalis), Parantechinus bilarni (formerly Antechinus bilarni), Antechinus stuartii, Dasykaluta rosamondae (formerly Antechinus rosamondae), Dasycercus cristicauda and Planigale maculata. The results show that the Ningbing antechinus is a probable new species. The data suggest that its nearest relative is Dasycercus cristicauda. Analysis of the results by calculation of a modified x2 and an approximation to Nei's genetic distance indicates that all species have been the product of one radiation, possibly in the late Miocene or early Pliocene. Two races of P. macdonnellensis probably exist, separable by their transferrin types.