EARLY LOCALIZATION OF TYPES. 153 



of Australia 1 and the types now living upon that conti- 

 nent. 



If there is any naturalist left who believes that the 

 Fauna of one continent may be derived from another por- 

 tion of the globe, the study of these facts, in all their bear- 

 ings, may undeceive him. 



It is well known how characteristic the Edentata are 

 of the present Fauna of the Brazils, for there is the home 

 of the Sloths (Bradypus), the Tatous (Dasypus), the Ant- 

 eaters (Myrmecophaga) ; there also have been found those 

 extraordinary extinct genera, the Megatherium, the Mylo- 

 don, the Megaloiix, the Glyptodon, and the many other 

 genera described by Dr. Lund and Professor Owen, all of 

 which belong to this same order of Edentata. Some of 

 these extinct genera of Edentata had also representatives 

 in North America during the same geological period, 2 thus 

 showing that, though limited within a similar area, the 

 range of this type has been different in different epochs. 



Australia, at present almost exclusively the home of 

 Marsupials, has yielded also a considerable number of 

 equally remarkable species and two extinct genera of that 

 type, all described by Owen in a report to the British 

 Association in 1844, and in Mitchell's Expeditions into the 

 Interior of Australia. 



How far similar facts are likely to occur in other classes 

 remains to be ascertained. Our knowledge of the geo- 

 graphical distribution of the fossil remains is yet too frag- 

 mentary to furnish any further data upon this point. It 

 is, however, worthy of remark, that, though the types of 



2 OWEN, (R.,) On the Geographical Srnithson. Contrib. 1855, 4to. fig. 

 Distribution of Extinct Mammalia, WYMAN, (J.,) Notice of Fossil Bones, 

 Ann. aucl Mag. Nat. Hist., 1846, vol. etc., Am. Journ. Sc. and A., 2d ser., 

 17, p. 197. 1850, vol. 10. OWEN, (R.,) On the 



3 LEII>VT, (Jos.,) A Memoir on the Megatherium, Trans. Roy. Soc., 1855, 

 Extinct yioth Tribe of North America, II, p. 359 ; 1856, II, p. 571. 



