38 RHINOCEROSES 



on each side not having yet come into use, while the last pre- 

 molar has not been replaced by its permanent successor. On 

 contrasting this specimen with skulls of the typical southern race of 

 Rhinoceros siinus I was somewhat surprised (considering the distance 

 separating the haunts of the two animals) to find how comparatively 

 slight are the differences. Of the two southern skulls used in the 

 comparison one belongs to a male specimen in the Museum obtained 

 some years ago by Mr. R. T. Coryndon, while the other is a specimen 

 which has been long in the Museum, and of which the sex is unknown. 

 They both indicate fully adult animals, having the last molar teeth in 

 use. As the second skull differs somewhat in form from the first, 

 it may possibly be that of a female. 



As regards the teeth, there seems no difference between the 

 southern and the northern skulls. The latter is, however, readily 

 distinguished by the shorter and wider form of the nasal bones which 

 support the front horn. In the skull of Mr. Coryndon's specimen 

 these bones project 6 inches in advance of their lateral supports, and 

 measure 'j\ inches in maximum width in front ; whereas the corre- 

 sponding dimensions in the Lado skull are 5^ inches and 7f inches. 

 If the second South African skull were used as the basis of comparison, 

 the differences would be greater ; but that skull, as already mentioned, 

 may pertain to a female. It may be added that if the Lado skull were 

 fully mature, the width across the nasal bones would probably be still 

 greater, as a character of this nature is one which might naturally be 

 expected to intensify with age. 



The Lado white rhinoceros thus presents an exaggeration of the 

 feature from which the species received its designation of siinus 

 ("snub-nosed," or "blunt-nosed"), and the difference appears sufficiently 

 marked to admit of its being regarded as a separate local race, for 

 which the name of Rhinocei'os siinus cottoni was proposed by myself in 

 the Field newspaper for February 22, 1908 (vol. cxi. p. 319). The 

 horns of the Museum specimen present no characters by which they 

 can be satisfactorily distinguished from southern examples. The front 

 one has an extremely massive basis, and curves very sharply back- 

 wards ; its total length being 30^ inches. The two horns in the 

 Museum referred to above as having been brought from the Lake 

 Tchad district in the early part of last century by Messrs. Denham 

 and Clapperton, although of small size, doubtless belong to R. simus 

 cottoni. I have never seen female rhinoceros horns from Equatorial 

 Africa of the long and slender type of those upon which Gray founded 

 the so-called Rhinoceros osivelli ; and the absence of horns of such a 



