Mr. R. Lydekker on Hornless Okapies. 225 



wliich it agrees with the typical specimen presented by Sir 

 Harry Johnston to the British Museum, and described by 

 Sir Ray Lankester in the ' Transactions of the Zoological 

 Seciety/ vol. xvi. pt. 6 (1902). In respect of their large 

 stature, both these specimens differ from the two horned 

 okapies exhibited in the Museum alongside the one presented 

 by Sir H. Johnston. The skull associated with it indicates, 

 from the circumstance that the premolars are not fully pro- 

 truded, that the latter is immature ; and although the stature 

 of the animal may have attained its full development, it is 

 probable that there would have been some increase in the 

 size of the skull. Although no sexual features are shown in 

 the skin, Sir Harry Johnston's specimen is now generally 

 regarded as a female ; and if this be the case, the same will 

 hold good for the one recently in the possession of Mr. Ward. 

 Of the former the shoulder-height (as mounted) is 5 feet 

 1 inch (153 cm.), while that of the second is 5 feet and ^ inch 

 (152"3 cm.). On the other hand, the horned example pre- 

 sented to the Museum by Major Powell-Cotton stands only 

 4 feet 8^ inches (144'5 cm.) at the shoulder, while the some- 

 what younger one given by the late Mr. Boyd Alexander is 

 4 feet 5£ inches (136*5 cm.). The former of these, as indi- 

 cated by the skeleton mounted in the same case, is adult, 

 although not old, and has, I infer, approximately reached its 

 full size. The length of the skull is 339 mm. 



In the memoir by M. Fraipont published in the l Annales' 

 of the Congo Museum no details are given with regard to the 

 height of the mounted specimens referred to ; but a horned 

 example at Madrid described by Senor A. Cabrera in 1907 is 

 stated to stand 4 feet 5 inches (137 cm.) at the withers, and, 

 so far as I can recall, none of the mounted specimens with 

 horns which have been shown from time to time at Mr. Ward's 

 establishment were equal in size to the aforesaid hornless 

 examples. 



So far, then, as the evidence of the five specimens men- 

 tioned is concerned, it is manifest that the hornless individuals 

 exceed in height those with horns to an extent which can 

 scarcely be explained by difference of age, especially when it 

 is borne in mind that one of the hornless examples is imma- 

 ture, while at least one of those with horns is adult. Neither 

 does it seem that such differences are within the ordinary 

 limits of individual variation. 



On the other hand, it has to be mentioned that while the 



skull of Sir H. Johnston's immature hornless specimen 



measures 375 mm. in length, that of a horned okapi in the 



Tervueren Museum has a length of 377 mm. (Lankester, op. 



Ann. <& Mag. N. Hist. Ser. 8. Vol vi. 1 5 



