SummaryGeographical variation in the Western WhipbirdPsophodes nigrogularisis reviewed by routine morphometric procedures. Four subspecies are recognised: nominotypicalnigrogularisin extreme coastal south-western Australia,oberonin the mallee heaths of eastern south-west Australia,lashmarion Kangaroo Island andleucogasterin the Murray Mallee and on Yorke and Eyre Peninsulas, South Australia. Two of the subspecies (oberonandlashmari) are described as new. The presence of two forms (nigrogularisandoberon) in south-west Australia raises questions about their taxonomic status and parallels the occurrence of other pairs of Bassian taxa in that region. Reconstruction of the evolution of such pairs identifies the highlands about the South Australian gulfs as an important refuge and source of speciation for Bassian birds during Quaternary and perhaps later Tertiary times. Implications for conservation are reassessed.