272 ORDER VII. 



large species more recently described by Dr. Smith, 

 possesses two lofty nasal horns, a pale whitish hide, 

 and resides in the interior of Africa, beyond the 

 boundaries of the Cape colony, where it seems two 

 more undescribed species are known, one approxi- 

 mating in character to Keitloa, and the other of 

 much more attenuated form, and bearing one horn, 

 is affirmed to be the true unicorn, a species which 

 Riippel appears likewise to have 'heard of on the 

 north side of the equator. 



The fossil species are numerous, and much diver- 

 sified in the structure of the skulls, in the presence 

 or absence of lower incisors, and in the obliquity 

 of the posterior surface of the cranium : some have 

 the bony septum and nasal bones prolonged and 

 firmly attached to the incisive, forming a fitting 

 basis for enormous horns, far surpassing in solidity 

 any of the existing species. 



The species enumerated are, R. tichorinus, R. in- 

 cisivus, R. leptorhinus, R. minutus, R. elatus, R. 

 pachyrhinus, R. hypsetorhinus, R. Goldfusii, and R. 

 leptodon. Of these R. minutus, not larger than a 

 hog, shows a reduced size compatible with the 

 next. 



Genus HYRAX. The Proboscideans have several 

 points of approximation to the Rodentia and the 

 Hyrax in size, and part of its structure offers a still 

 nearer similarity, though, in other respects, it may be 

 viewed as a minute rhinoceros without horn, having 

 similar molars, and the incisors may be termed f , 

 although the upper external are perhaps more pro- 



