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Show 1897.] BLUE BEAR OF TIBET. 423 they approach in size, these specimens differ very remarkably. Taking the half-grown and sub-adult specimens (the latter of which is here figured, figs. 3 & 4), it will be found that the profile forms a continuous convex arch, almost like that of U. torquatus, although the skull is much longer than in the latter. The difference is also observable in the fully adult specimen, in which there is no trace of the concavity at the root of the nasals so conspicuous in the Kamschatkan Bear. The palate (fig. 4) is also peculiar on account of its extreme elongation and narrowness, the pterygoid fossa being narrower and not extending so far forwards. The pterygoids themselves are also very different bones, being much larger and of a distinctly oblong form. The premaxillae, too, Fig. 4. Palatal aspect of skull of Ursus arctus yesoensis. extend farther back on the palate, reaching behind the alveolus of the canine, instead of stopping short near the middle line of that tooth. The fourth lower premolar is very short, with scarcely any inner tubercles, the hinder of which is well marked in the Kamschatkan Bear. So far as I can see, these peculiarities are constant in all three skulls. Compared with Dr. Merriam's figure of the sub-adult skull of the |