The present Descriptive Catalogue of the Nests and Eggs of Australian Birds, has been prepared by Mr. A. J. North, who has been engaged by the Trustees as an Assistant in the Zoological Department of the Museum. It contains a careful description of such authentic eggs of each species as have been accessible to the author, wherever there was any doubt as to the authenticity of the eggs of any species they have been discarded, typical specimens have always been selected, supplemented with descriptions of such other distinct varieties as occasionally occur. No egg is here described of which the history is unknown, with the exception of a few taken from Gould's "Handbook to the Birds of Australia."