ITS NEAREST ' EXISTING RELATIONS 



53 



case are the deep depressions between the ridges filled 

 up with cement, as in the horse. 



The skull is elongated and elevated posteriorly into a 

 transverse occipital crest. It has retained its primitive 

 condition in possessing no post-orbital processes or any 

 separation between the orbits and temporal fossae. The 

 nasal bones are large and stout, co-ossified, and stand- 

 ing out freely above the premaxillaa, from which they 

 are separated by a deep and wide fissure ; the latter 

 bones are very small, generally not meeting in the 

 middle line in front, often quite rudimentary, a special- 

 isation concurrent with the loss of the upper incisor 

 teeth. The brain cavity is very small for the size of 

 the skull. Vertebra— Cervical, 7 ; dorsal, 19-20 ; 

 lumbar, 3 ; sacral, 4 ; caudal, about 22. 



The ffliinocerotidce are all animals of large size, but 

 of little intelligence, generally timid of disposition, 

 though ferocious when attacked and brought to bay, 

 using the nasal horns as weapons, with which they strike 

 and toss their assailants. 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 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 or wallowing in the mud. None of the 

 species have been domesticated. The family once con- 



