516 ON A NEW FORM OF AFEICAN RHINOCEROS, [Juue 6, 



The question is to what species of Ehiuoceros these two horns 

 (which I now exhibit) are to be referred. It will be seen that 

 they are remarkable for their length, thinness, and especially for 

 their comparative roundness and their small size at the base. 



Since the publication of Mr. F. C. Selous's excellent paper on 

 the African Rhinoceroses (P. Z. S. 1871, p. 725), it has been gene- 

 rally agreed by naturalists that there are only two known species 

 of this genus in Africa — the Black Rhinoceros {R. hicornis) a,nd the 

 White Rhinoceros (R. simus). Of the Black Rhinoceros a fine 

 series of horns has been figured by Mr. Selous (^.s. c), showing 

 the variations that exist in the comparative length of the anterior 

 and posterior horns. The anterior horn of the Black Rhinoceros, 

 though, save in very exceptional cases, always longer than the 

 posterior horn, seldom reaches more than 24 inches in length, 

 though occasionally longer \ On the other hand, the front horn 

 of Jl. simus grows, as is well known, to an extraordinary length, 

 varying from 18 to 48 inches, and reaching even 57 inches in 

 abnormal specimens. This horn is, however, of great thickness at 

 the base and much more compressed laterally than is the case with 

 the specimens now in question, and in fact of quite a different 

 character. Moreover R. sinms, now almost extinct", has never been 

 known to occur north of the Zambesi. It is not possible, therefore, 

 to refer Mr. Holmwood's specimens to R. simus. There remains 

 the question whether they can belong to abnormal individuals of 

 R. hicornis, to which form of Rhinoceros they would appear from 

 general characters to be most nearly related. Before considering 

 the question I will shortly describe the specimens. 



a (fig. 1) is 42 inches in length from the base of the thickened 

 pedicel along the curve to the top of the horn. The pedicel is 

 nearly circular, about 5 inches across on its lower surface. It is 

 rounded, not flattened in fi'ont. At about 5| inches from the base 

 the true horn emerges from the pedicel ; here it is ovate in shape, 

 about 2-5 from front to back and 2-1 from side to side. It is 

 nearly straight at the base, but curved gently backwards in the 

 last third of its length. It is very smooth and of a uniform dark 

 brownish black in colour. 



b (fig. 2) is generally similar, but not quite so long (41 inches), 

 thicker at the base, where the horn emerges from the pedicel, and 

 much more rapidly curved backwards. It is also much paler in 

 colour. 



On comparing these horns with anterior horns of the Black 

 Rhinoceros (two pairs of which Mr. Selous has kindly lent me for 

 the purpose), it will readily be seen that they are at once recog- 



'■ There are two horns in the British Museum, referred to this.«!pecies (1.520 h 

 and 1.')20j), 42 and 40 inches iu length respectively. See Hand-1. Edent. p. 52 

 (1873). 



^ A recent letter, addressed to the ' Field ' by Mr. Selous (Field, vol. 80, 

 p. 803,Nov. 26th, 1892), shows that the White Rhinoceros still exists in Northern 

 Mashonaland, a herd of six having been met with by Messrs. Eyres and Coryn- 

 don about 100 miles N.W. of Salisbury. 



