208 TYPES OF ANIMAL LIFE 



no less than three pairs of protuberances, each pair being- 

 placed side by side. One pair was on the nose, one in 

 front of the eyes, and one on the roof of the skull behind 

 the eyes. 



It is America which has alone made us acquainted 

 with four other very exceptional forms, a brief notice of 

 which must conclude this article. One of them was at 

 first thought to be a sort of gigantic llama, and, there- 

 fore named Macrochenia. And the bones of its neck are 

 formed on the type of those of the camels and llamas. 

 Its limbs, however, are partly like those of the odd-toed 

 and partly like those of the even-toed ungulates. Its 

 grinding teeth resemble those of a rhinoceros, while its 

 cutting teeth have " marks " like those of a horse. The 

 bones of its nose also seem to indicate that it had a short 

 proboscis. It must have been a very curious creature. 

 Another South American extinct mammal was discovered 

 by Darwin near Buenos Ayres and was about as big as a 

 hippopotamus. It seems to have been singularly inter- 

 mediate between the odd-toed and even-toed groups 

 of ungulates, and has been named Toxodon. Yet another 

 South American animal from the same region was rather 

 larger than the giant of the rat and squirrel order, the 

 capybara of the Rio de la Plata, which it resembles in 

 general appearance. Unlike all known ungulates it has 

 collar bones. It has been named TypotJieriwm. Num- 

 bers of allied kinds have also been discovered. Lastly, 

 in the Eocene rocks of North America the remains of a 

 group of animals have been discovered which have been 

 named by Prof. Marsh Tillodontia. Some of these kinds 

 were as large as a tapir. 



We said that the discovery of various fossil forms has 

 suggested the existence of relationships and affinities 

 between ungulates and other orders of mammals, which 



