SUMMARYBoles, W. E. 1979. The relationships of the Australo-Papuan flycatchers. Emu 79: 107–110.Australo-Papuan flycatchers, robins, monarchs, fantails, whistlers and shrike-thrushes have been divided among four different subdivisions of flycatchers, ranging from tribal to familial level. Gradation with other groups, such as babblers and thrushes, and the adaptive nature of most taxonomic characters used in the systematics of flycatchers have created problems in delimitation of higher taxa. A synthesis of the previously unused characters of syringeal morphology and egg-white protein show that the Australo-Papuan flycatcher complex is part of a larger, nearly endemic assemblage of passerines that is not particularly close to the other Old World muscicapine flycatchers. Monarchs and fantails are closely allied and the robin-flycatchers grade into whistlers and shrike-thrushes. Because they are closely related and because their inclusion with the typical flycatchers produces a polyphyletic grouping, the complex of Australo-Papuan flycatchers is segregated as a distinct family, the Pachycephalidae.