398 SOLIPEDIA. 
Asiatic continent during the pliocene period. The species 
of Hqguus which existed during that geological period in 
both North and South America, appears to have been 
blotted out of the Fauna of those continents before the 
introduction of Man. The aborigines whom the Spanish 
Conquestadors found in possession of Peru and Mexico, 
had no tradition or hieroglyphic indicative of such a quad- 
ruped, and the Horses that the invaders had imported 
from Europe were viewed with astonishment and alarm. 
The researches of Mr. Darwin and Dr. Lund have, how- 
ever, indisputably proved that the genus Hyguwus was repre- 
sented in South America during the pliocene period by 
a species (Hyuus curvidens) which I have shown to be 
distinct * both from the European fossils and the existing 
species. Fossil remains of the Horse have likewise been 
discovered in North America. The geographical range 
of the genus Hquus at the pliocene period was thus more 
extensive than that of Rhinoceros, of which both the ex- 
tinct and existing species are confined to the continents 
of the Old World of geography. The Horse, in its ancient 
distribution over both hemispheres of the globe, resembled 
the Mastodon, and appears to have become extinct in 
North America at the same time with the A/astodon 
giganteus, and in South America with the Mastodon An- 
dium and the Megatherium. Well may Mr. Darwin say, 
‘Tt is a marvellous event in the history of animals, that 
a native kind should have disappeared, to be succeeded 
in after ages by the countless herds introduced with the 
Spanish colonist !” + 
* “Catalogue of Fossil Mammalia in the Museum of the Royal College of 
Surgeons,’ 4to., 1844, p. 235. 
+ * Voyages of the Adventure and Beagle,’ vol. iii. p. 150. 
