[PALEONTOLOGY]. OSBORN, Henry Fairfield. The Titanotheres of Ancient Wyoming, Dakota, and Nebraska. Washington: GPO, 1929. Large 4tos. Profusely illustrated in color and black and white. 2 volumes. Publisher?s full brown cloth, boards ruled in blind, spine lettered in gilt (bindings toned, rubbed, soiled, corners bumped, occasional soiling in text). Very good. THE RARE FIRST EDITION OF OSBORN?S GREATEST WORK. ?Osborn was also a master of synthesis, a capacity illustrated by his enormous monographs on the titanotheres and the proboscideans?? (DNB). Measurements: 14 x 14 x 2?.