2, anil Plato 35, fig. 3 of this Atlas. The figure of Skull N in Plate 17 is from a photo- 

 graph supplied by the Madrid Museum. 



Skull 0. — In the Genoa Museum. From a photograph supplied by the Genoa 

 Museum. Skull is without horns, and is evidently not the skull of the same animal as 

 the skin mounted in the Genoa Museum, of which the legs are figured in Plate 3-t, fig. 1. 



Skidl P. — In the Paris Museum (Museum d'Histoire Natnrelle). The skull of a com- 

 plete skeleton. From a photograph supplied by the Paris Museum. The ossicones are 

 figured in Plate 2. The skull is figured by M. de Rothschild and H. Neuville, 'Ann. Sci. 

 Nat., Zool.,' vol. x, Nos. 1 and 2, 1909, pp. 15, 22, and 29. Apparently this is not the 

 skull corresponding with the mounted skin in the Paris Museum, of which the legs are 

 figured in Plate 35, fig. 1 ; for although in the paper by Rothschild and Neuville the 

 skeleton and skin are regarded as from the same animal (p. 2, " Un seul specimen . . . 

 d'Anatomie comparee "), Fraipont states that the skeleton (No. 501) corresponding with 

 the Paris skin (No. 503) Avent to Stockholm, and that the skin (No. 531) corresponding 

 with the Paris skeleton (No. 535) is at Tervueren (' Annales du Musee du Congo, Zool.,' 

 ser. 2, vol. i, " Okapia," 1907, p. 14, paragr. 7 and 9). In this case Skull P corresponds 

 with the le^s figured in Plate 38, fi<r. 2. 



Eleven of the above fifteen skulls were examined at the British Museum (Natural 

 History), and the relative ages of these may be approximately determined by the following 

 particulars of the dentition and sutures. J is clearly the youngest of the series; the 

 deciduous molars are only moderately worn, and the third true molar has not yet developed. 

 F is somewhat older than J ; the three deciduous molars are in use, the third molar is 

 present, but has not yet cut the gum. C is older still ; the three deciduous molars are in 

 use, the third molar has cut the gum and is slightly worn. A and D are almost of the 

 same age as C, but a little older ; the third molar shows rather more signs of wear. The 

 three deciduous molars are still in use in both. In the extent of wear of the hindermost 

 molar tooth in the loAver jaw, and in the fact that the left permanent canine is already in 

 use, D would appear to be slightly older than A ; but in D the third deciduous incisor has 

 not been shed, whereas in A it has, and the posterior or fifth cusp of the third molar in 

 the lower jaw is not so freely exposed as in A. 



In the following skulls there are no milk teeth remaining. B is a little older than A 

 and I), and E, G, H, K and L are the oldest of the series, and hardly distinguishable the 

 one from the other as regards age. In B the horns or ossicones are not yet ankylosed 

 to the skull, and the parieto-frontal suture is very distinct. In E, G, H and L the ossi- 

 cones are fused on, and the parieto-frontal suture is obliterated. In K there are no ossi- 

 cones, and the parieto-frontal suture is obliterated. In E and H the lachrymo-malar and 

 fronto-malar sutures' persist; in K the lachrymo-malar . suture is present, but not the 

 f ronto-malar ; in G and L both have disappeared. 



Xll 



