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Show 346 DR. C. I. FORSYTH MAJOR ON [Nov. 18, appearance in the Okapi, suggesting that they had not been covered by skin. This would imply that very probably the tips of the horns are shed. As this question will doubtless very soon be resolved by the arrival of new material, I find it safer to leave it open for the present, the polishing being possibly due to some other cause. I have classed the characters of the Okapi, cranial and others, first of all into four categories, according to their agreement with or disagreement from, the nearest related fossil forms, Palceotragus ( = Samotherium) on the one hand, and the Giraffe on the other; a fifth category gives the characters according to which it holds an intermediate position. I. The characters which the Okapi shares with Palceotragus, besides those which both have in common with the Giraffe, are the following:- 1 & 2. Proportionate length of the limbs and of the neck. I have formerly stated 1 that in this respect the Okapi closely agrees with the fossils. 3. One pair of horns only, situated on the frontal bones alone, and presumably present only in the male sex (see text-figs. 63-66). 4. Elongated and horizontal parietal region. 5. Lower contour of mandible convex (almost horizontal in the Giraffe), anterior portion of mandible turned upwards and more massive than in the latter ; for characters 5 and 6 compare the text-figs. 6 (Samotherium) and 7 (Okapia) on p. 73 of my former paper with text-figs. 11 and 12 (Giraffa) on p. 76. 6. Lower contour of prsemaxillaries and of adjoining anterior portion of maxilla horizontal (bent downwards in the adult Giraffe). II. Characters in ivhich the Okapi differs from Palceotragus. 1. Smaller size of incisors and canine, a feature pointed out already by Prof. Lankester. 2. Cheek-teeth more brachyodont, at any rate more so than in the larger fossil form, Samotherium boissieri. 3. Air-sinuses of the cranial bones much more developed, extending even to the basis cranii. 4. Narrow frontal region, orbits not telescopic (compare text-figs. 63 and 64 with text-figs. 65 and 66). 5. Orbits situated more forward in relation to the cheek-teeth series. 6. Horns placed farther backward and comparatively smaller. 7. Mandibular angulus more produced backward. 8. Five tarsal bones-cuboid; scaphoid; cuneiforms 1, 2, & 3- are fused into one bone (in Palceotragus into three, as in the great majority of Ruminants). 1 ‘ La Belgique Coloniale,' May 25th, 1902, p. 245 ; P. Z. S. 1902, ii. p. 78. |