SummaryThe relation betweenNeositta leucopteraandstriatais discussed. A critical examination of the records of their occurrence in northern Queensland suggests that they are allopatric and do not interbreed. The barrier between them may lie between the Flinders and Leichhardt Rivers, and coincide with a barrier already noted between other bird species. It is proposed to call this the‘Carpentaria Barrier’.The validity ofN. leucocephalais examined critically in the light of its contact withchrysoptera.It is concluded that a narrow zone of unnamed hybrids between the two occurs in north-eastern NSW and south-eastern Queensland, that Gould'sleucocephalais the correct name for white-headed birds with type locality Moreton Bay, and thatlumholiziis a synonym.