46 



In the Post-Pliocene, the extinct Felidce include species nearly 

 as large as a lion, and smaller forms very similar to those still 

 living. Bears, Eaccoons and Weasels have also been found. 



In the Pliocene of South America, Machairodus represents 

 the Felidte, while the genera Arctotherium and Hycenarctus 

 belong to the Bear family. Species of J\Justela and Canis have 

 also been found. In the caves of Brazil, the fauna of which 

 is regarded as Post-Pliocene, one species of Machairodns is 

 known, and one of Syncelurus. Ca?iis and Icticyon, still living 

 in Brazil, and the extinct genus ^eotlios, represent the Canidce. 

 Mephitis and Gcrficiis, among the Weasels, were also present, 

 and with them species of Nasua and Arctotherium. 



We come now to the highest group of Mammals, the Pri- 

 mates, which includes the Lemurs, the Apes, and Man. This 

 order has a great antiquity, and even at the base of the Eocene 

 we find it represented by several genera belonging to the lower 

 forms of the group. In considering these interesting fossils, it is 

 important to have in mind that the Lemurs, which are usually 

 regarded as Primates, although at the bottom of the scale, are 

 only found at the present day in Madagascar and the adjacent 

 regions of the globe. All the American Monkeys, moreover, 

 belong to one group, much above the Lemurs, while the Old 

 World Apes are higher still, and most nearly approach Man. 



In the lower Eocene of New Mexico, we find a few repre- 

 sentatives of the earliest known Primates, and among them are 

 the genera Lemuravus and Limnotherium, each the type of a 

 distinct family. These genera became very abundant in the 

 middle Eocene of the West, and with them are found many 

 others, all however, included in the two families, Lemttravidce 

 and Lim?iotheridce. Lemuravus appears to have been most 

 nearly allied to the Lemurs, and is the most generalized form 

 of the Primates yet discovered. It had forty-four teeth, form- 

 ing a continuous series above and below. The brain was 

 nearly smooth, and of moderate size. The skeleton most 

 resembles that of the Lemurs. A nearly allied genus, belong- 

 ing to the same family, is Ilyopsodus. Limnotherium (Tomiihe- 



