270 



The Study of Animal Life 



PART III 



Ungulates, it seems likely enough that the Cetaceans (whales and 

 dolphins) diverged. 



A third line, which we may call median, leads through the 

 Lemurs on to Monkeys. It must be noted, however, that these 

 lines, which seem distinct from one another if we confine our 

 attention to living mammals, are linked by extinct forms. Thus a 



Fig. 60.— Head of male Semnopithecus. (From Darwin.) 



remarkable fossil type, Phenacodtis, is regarded by Cope as pre- 

 senting affinities with Ungulates, Lemurs, and Carnivores. 



The monkeys which most closely resemble man in structure, 

 habits, and intelligence, are the so-called anthropoid apes, the 

 gorilla, the chimpanzee, the orang-utan, and the gibbon. A 

 second grade is represented by the more dog-like, narrow-nosed 

 Old World apes, such as the baboons and mandrills. Lower in 

 many ways are the broad-nosed New World or American monkeys, 

 e.g. the numerous species of Cebus, some of which are the familiar 



