4O4 UNGULATA 
(as in Fig. 167), the crotchet and combing-plate do not completely 
join, although the fossette is distinctly indicated. The first upper 
premolar may occasionally be preceded by a milk-tooth. The Rhino- 
ceroses differ from the Horses and agree with the Tapirs in the 
direction of the cecum. 
The living species of Rhinoceros are all animals of large size, but of 
little intelligence, generally timid in disposition, though ferocious when 
attacked and brought to bay, using the nasal horns as weapons, by 
which they strike and toss their assailant. Their sight is dull, but 
their hearing and scent are remarkably acute. They feed on herbage, 
shrubs, and leaves of trees, and, like so many other large animals 
which inhabit hot countries, sleep the greater part of the day, being 
most active in the cool of the evening or even during the night. 
They are fond of bathing and wallowing in water or mud. None 
of the species have been domesticated. Animals of the group have 
existed in both the Old and New Worlds since the latter part of 
the Eocene period. In America they all became extinct before the 
end of the Pliocene period. In the Old World their distribution 
has become greatly restricted, and they are no longer found in 
Europe and North Asia, but only in Africa and portions of the 
Indian and Indo-Malayan regions. 
Existing Species.—The existing (as well as many of the extinct) 
species of Rhinoceroses naturally divide into three groups, which are 
regarded by some zoologists as of generic value. 
Lthinocerotic, or Typical Group.—The adults with a single large 
compressed incisor above on each side, and occasionally a small lateral 
one; below, a very small incisor and a very large, procumbent, 
pointed canine. Nasal bones pointed in front. A single nasal 
horn. Skin very thick, and raised into strong, definitely arranged 
ridges or folds. 
There are two well-marked species of one-horned Rhinoceroses. 
(1) The Indian Rhinoceros, R. wnicornis (Fig. 169) of Linneus,! the 
largest and best known, from being the most frequently exhihited 
alive in England, is at present only met with in a wild state in the 
terai region of Nipal and Bhutan, and in the upper valley of the 
Brahmaputra or province of Assam, though it formerly had a wider 
range. The first Rhinoceros seen alive in Europe since the time 
when these animals, in common with nearly all the large remark- 
able beasts of both Africa and Asia, were exhibited in the Roman 
? Many authors use Cuvier’s name, R. indicus, in preference to this, on the 
ground that there are more than one species with one horn, forgetting that the 
name substituted is equally inconvenient, as more than one species live in India. 
The fact of a specific name being applicable to several members of a genus is no 
objection to its restriction to the first to which it was applied ;_ otherwise 
changes in old and well-received names would constantly have to be made in 
consequence of new discoveries. 
