NO. I THE WHITE RHINOCEROS HELLER 35 



in a recent paper 1 carried the knowledge of the occurrence of the 

 white rhinoceros of the Upper Nile, back to the ancients, and has 

 fastened upon this species the identity of the unicorn mentioned by 

 these early historians. The author has apparently been led astray by 

 the assumption that the females of the square-lipped species carry 

 normally a single, long, slender horn, and that all the early accounts 

 of single horned rhinoceroses in Abyssinian and Sudan territory 

 refer to this species. As a matter of fact there is no record of a single 

 horned specimen of white rhinoceros from Sudan territory. 2 All the 

 known specimens are two horned, the front horn usually being com- 

 paratively short and stubby and showing only slightly greater 

 development than in the black rhinoceros. Notwithstanding the 

 conspicuous structural differences found in the heads, particularly the 

 shape of the snout, which these two species exhibit, travelers have 

 often failed to distinguish them. This confusion is no doubt due to 

 the close similarity in bodily size, color and horn development. The 

 great bodily bulk of these animals has prevented sportsmen from 

 preserving such parts as .the skulls which show the systematic char- 

 acters. 



Strangely enough the black rhinoceros is not found associated in 

 the Lado Enclave with the square-lipped species, but occurs abun- 

 dantly on the opposite or east bank of the river, and also to the west 

 about Lake Tchad and the Niger watershed. The black rhinoceros, 

 however, is a widespread species, its range covering most of the 

 country from the Cape north to Abyssinia, Somaliland and the Nile 

 Valley. Further west it is widely spread in the Lake Tchad and 

 Nigerian region. In range it covers Africa generally, being wanting 

 only in the Congo Basin. The ancient accounts of African rhinoce- 

 roses refer to this widespread species, which has long been well 

 known to the Arabs. Although the species is almost invariably two 

 horned, occasional variations of one and three horned specimens are 

 met with. 



In length of front horn, specimens of the white rhinoceros range 

 from a few inches to 62 inches ; seldom, however, exceeding 30 inches. 

 At the extreme base in front the horn has a square or straight base 

 which follows the outline of the snout, while in the black species this 

 basal part of the horn is rounded. A further distinguishing peculi- 



'Le rhinoceros blanc du Soudan (Rhinoceros simus cottoni), Trouessart, 

 E. L. Proc. Zool. Soc. London, 1909, p. 198-200. 



2 There are only a few records of single horned specimens among the hun- 

 dreds of C. simum shot in South Africa. 



