346 DB. 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 iossil iorms, Palceotragus 

 ( = Samotlm^ium) on the one hand, and the Giraff"e on the other ; 

 a fifth category gives the characters according to which it holds 

 an intermediate position. 



I. The characters tohich the Okapi shares with Palmotragus, 

 besides those which both have in common with the Girafie, are 

 the following : — 



1 & 2. Proportionate length of the limbs and of the neck. I 



have formerly stated ^ 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 

 Girafl^e), 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 (Okajna) on p. 73 of my former 

 paper with text-figs. 11 and 12 {Giraffa) on p. 76. 



6. Lower contour of prtemaxillaries and of adjoining anterior 

 portion of maxilla horizontal (bent downwards in the adult 

 Giraffe). 



II. Characters in lohich the Okapi differs from Palceoiragus. 



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, 

 extendmg 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. 



