THE EHINOCEROTID^. 361 



■wtich the orbit and temporal fossa form one cavity. The 

 nasals are immense, and are separated from the premaxillse 

 by a -wide extent of the maxilla on each side. The pre- 

 maxillse are relatively small, and reduced to little more 

 than their palatine portions. The glenoidal sm"face of the 

 mandible is transverse and convex. The squamosal sends 

 down an immense post- glenoidal process, which is longer 

 than either the post -tympanic or the paramastoid. It unites 

 with the post-tympanic to form a kind of false auditory 

 meatus, in the absence of any proper ossified canal of that 

 kind. The periotic and the tympanic bones are ankylosed, 

 the tympanic being a mere irregular hoop of bone. The 

 pars mastoidea is completely hidden by the junction of the 

 short post-tympanic with the long paramastoid. The hinder 

 margin of the bony palate is opposite the middle of the 

 antepenultimate molar. 



The mandibular condyle is transverse and convex. The 

 perpendicular portion of the ramus is large, and the coro- 

 noid process ascends slightly above the condyle. In a 

 vertical and longitudinal section of the skull, the form of 

 the cerebral cavity is seen to be similar to that of the 

 Horse. The inner and outer tables of the bony roof of the 

 skull are separated by great air- cavities. 



The spine of the scapula has no acromion, but gives 

 off a strong recurved process from the middle of its 

 length. 



The radius and ulna are complete, but are ankylosed. 



The carpus has the eight ordinary bones. In the manus 

 the digits ii. iii. iv. are complete, and a bony tubercle 

 articulated with the outer facet of the cuneiforme repre- 

 sents digit V. The digit iii. is largest and longest, and its 

 phalanges are symmetrical in themselves; those of the 

 digits ii. and iv. are not symmetrical in themselves. The 

 terminal phalanges have somewhat the form of the coffin 

 bone of the Horse. 



The ilia have wide transversely directed crests, as in the 

 Horse. The femm* is provided with a very strong third 

 trochanter. The tibia and the filDula are complete, and 



