"Topographic notes on the Headwater Region of the Fly River (with map)" 1/10 One of the chief products of the Archbold expedition to New Guinea has been the careful checking and completion of the observations and maps of earlier explorers of the upper reaches of the Fly River with elimination of a number of geographical synonyms. This work has been enormously facilitated by the cordial cooperation of Mr. Leo Austin and Dr. Claude Champin, two of the original observers, who have not only put their field notes and knowledge at my disposal but also gave considerable time to the interpretation of those notes. The men who explored and mapped the region under discussion are Sir William MacGregor, Mr. Leo Austin, Messrs. Davies and C.H. Ivan Champin, and the members of the 1936 Archbold Expedition which worked under the auspices of the American Museum of Natural History, New York. D'Albertis 1. Macgregor, Sir W. Ann. Rep. British New Guinea. 1889-90 pp. 43-64 2. Austin, L. Geogr. Journ. LXII, 1925, pp. 325-349 (Tedi R.); J. and Proc. Austral. Hist. Soc. XI, 1926, pp. 251- (Extent of D'Albertis voyage); Geogr. Journ., LXVII, pp. 434-441 (Tully R.) 3. Davies, C.H., over