21G ANNALS NEW YORK ACADEMY OF SCIENCES 



rope, in the Pliocene ol" India, in the .so-called riioceue (which may be 

 Miocene) of China. These may all be referred to a central Asiatic 

 source. The dispersal of this cycle must date back at least to the be- 

 ginning of the Oligocene, for it had reached as far as Eg}'pt at the date 

 of the Fayum fauna as shown by Schlosser's recent discoveries.*^ With 

 the New World monkeys, the evidence seems rather to point to inde- 

 pendent evolution in South America from early Tertiary Primates of an 

 Eocene cycle of dispersal. For no remains of Primates have been dis- 

 covered in any Oligocene or later formation in the United States, while 

 the later Tertiary formations of the Argentine have yielded remains of 

 a number of Primates apparently intermediate between Eocene lemurs 

 and South American monkeys. 



The oldest cycle of primate dispersal is that represented by the lemurs. 

 These are now most abundant in Madagascar; a few^ exist in west and 

 central Africa, peninsular India and the East Indies. Lemuroid pri- 

 mates, lacking certain specialized characters of modem lemurs but other- 

 wise closely related, and equivalent in stage of development, are found 

 abundantly in the Eocene of Europe and the United States. They are 

 very doubtfully represented in the early Tertiary fomiations of the 

 Argentine. We know too little of the Tertiary of other parts of the 

 world to make any inference as to the extent of their distribution at 

 that time, or the course of its subsequent changes. Tliey disappear in 

 Europe and North America at the end of the Eocene; in South America, 

 they may have evolved into New World monkeys, while in the Old World 

 they must have given rise to the higher primates. It is reasonably cer- 

 tain that the theater of their evolution was not Europe, and although 

 they are not known in the Oligocene Fayiim fauna of Eg}'pt, we may 

 doubtfully suppose that they had reached that continent at some time 

 dnring the Eocene. Madagascar most probably received its lemurs from 

 Africa, but it is reasonable to suppose that only a single type, allied to 

 the Eocene AdapidiE, reached the island, and in the favorable environ- 

 ment radiated out into a Dumber of diverse adaptations taking the place 

 of various mammal groups not present in the island fauna. 



Fi'oni the fnct that the luiro])can and North American lemurs are in 

 an equivalent stage of development, although not very closely related, 

 we may fairly infer that they were derived very early in the Tertiary 

 from an intermediate center of dispersal, presumably Asia north of the 

 Himalavas. 



"Max SfiiLO.s.sF.R : "Beitrilsre ziir Keimtuiss der OIi<roz:inen I^andsiiugethieren aus dem 

 Fayum Acgypten," Beit, zur Pal. ii. Oeol. Oest-Uiig.. D'd xxiv. s. .52. 1012. 



