258 AFRICAN RHINOCEROSES CHAP. 
« 
Coryndon! that the calf of Ah. simus “always runs in front of 
the cow, while the calf of Rh. bicornis invariably follows its 
mother.” Both animals of course have two horns, and upon the 
varying proportions of the horns a large number of “ species ” have 
been made in the past. It 1s stated that the longest horn of the 
“White Rhinoceros” known measures 564 inches; while that of 
hi » ; 
Mi 
Ag 
— 
Fic. 133.—Head of Rhinoceros bicornis. 
kt. bicornis is shorter, 40 inches being apparently the maximum. 
But the animal is smaller. 
The possible third African species of /¢hinoceros* has been 
provisionally named after Mr. Holmwood, and is based upon two 
horns 41 and 42 inches long, which may be abnormal horns 
of Rh. bicornis ; but they are thinner and have a smaller pedicel. 
Extinct Rhinocerotidae.— The existing Rhinoceroses are thus 
confined to Africa, to certain parts of the continent of Asia, and 
to some of the large islands lying to the south of that continent. 
But formerly the genus, and allied genera, had a wider range. 
As far back as the Miocene we meet with remains of Rhinoceroses 
closely allied to existing forms. The more ancient forms have, as 
is natural, more ancient characters. Thus in Rh. schleiermacheri 
of the Miocene, canines appear to have been present. The 
Miocene Aceratheriwm, primitive in the absence of horns as its 
1 Proc. Zool. Soc. 1894, p. 329. See also Mr. Selous’ paper in Proc. Zool. Soc. 
1881, p. 275. 
2 P. L. Sclater, Proc. Zoal. Soc. 1893, p. 514. 
