4 vols. in orig. publishers paperbinding, 756-632-821-843pp., 16x24.5cm., num. b/w illustr., 3 col. illustr. and 1 fold. map of Congo, spines of vol. 2 and 3 slightly damaged, otherwise a very fine and rare compl. 4 volume set. "Bulletin of the American Museum of Natural History, part 65, 75, 75A and 75B.".