NO. I THE WHITE RHINOCEROS HELLER 21 



tons of both species show the Indian one to be but little smaller in size. 

 The black rhinoceros of East Africa stands several inches lower 

 and measures less in height of head and body. This inferiority in 

 length, however, is due largely to the much shorter head. The supe- 

 riority in size of the white rhinoceros over the other living species, 

 however, is not at all well established. In size the sexes are very simi- 

 lar ; the male exceeding the female but little. 



The species is normally two-horned, the front horn greatly exceed- 

 ing the rear one in size. The front horn is situated on a prominent 

 bony boss at the tip of the nasal bones and is immediately followed by 

 the rear horn, which is much compressed laterally and placed on the 

 suture between the nasal and frontal bones. The front horn is 

 squared in front where it partakes of the shape of the snout, and is 

 normally curved backward as in the black rhinoceros. The usual 

 length of this horn is 2 feet, although occasional specimens attain a 

 length of 5 feet. The record horn for the South African race is 62^2 

 inches. Such enlarged horns are attained only by the females in 

 which they sometimes project forward in advance of the snout. The 

 rear horn is usually low, sharply conical and considerably compressed, 

 it seldom exceeds more than a few inches in height, and is occasion- 

 ally wanting. The rear horn never approaches the front one in size 

 as in the keitloa variety of the black rhinoceros, in which the two horns 

 are quite equal. The rear horn is so small that it is obviously disap- 

 pearing, the species showing a marked tendency to become single- 

 horned, though actual single-horned specimens are rare. 



COLORATION 

 The skins of white rhinoceroses cannot under the most lenient 

 consideration be classed as white. They are, however, distinctly 

 lighter than those of the black species, and may on this account be 

 allowed to retain their popular designation of white. The blackness 

 of the mounted specimens in the British Museum is due to the black 

 pigment put on by the taxidermists, and such specimens consequently 

 do not represent the natural color of the animal. Their true color is 

 smoke gray of Ridgway. 1 a color conspicuously lighter than the dark 

 clove-brown of their geographical ally, Diceros bicornis. The four 

 adult skins in the collection show some variation, the color ranging 

 from smoke-gray to broccoli-brown. The two male skins are lighter 

 than the female skins, but the color differences are not consistent, the 



1 Ridgway, Robert T. : Color standards and color nomenclature, Washington, 

 I9I3- 



