362 Pampean Formation : part n. 



megatherium, megalonyx, mylodon, an extinct horse 

 and ox, likewise co-existed with numerous land, fresh- 

 water, and marine recent shells. 1 The enumeration of 

 these extinct North American animals naturally leads 

 me to refer to the former closer relation of the 

 mammiferous inhabitants of the two Americas, which 

 I have discussed in my Journal, and likewise to the 

 vast extent of country over which some of them ranged : 

 thus the same species of the Megatherium, Megalonyx, 

 E quits (as far as the state of their remains permits of 

 identification), extended from the Southern United 

 States of North America to BahiaBlanca, inlat. 39° S., 

 on the coast of Patagonia. The fact of these animals 

 having inhabited tropical and temperate regions does 

 not appear to me any great difficulty, seeing that at 

 the Cape of Good Hope several quadrupeds, such as the 

 elephant and hippopotamus, range from the equator to 

 lat. 35° south. The case of the Mastodon Andium is 

 one of more difficulty, for it is found from lat. 36° S., 

 over, as I have reason to believe, nearly the whole of 

 Brazil, and up the Cordillera, to regions which, according 

 to M. d'Orbigny, border on perpetual snow, and which 

 are almost destitute of vegetation : undoubtedly the 

 climate of the Cordillera must have been different when 

 the mastodon inhabited it.; but we should not forget 

 the case of the Siberian mammoth and rhinoceros, as 

 showing how severe a climate the larger pachyderm ata 

 can endure ; nor overlook the fact of the guanaco rang- 

 ing at the present day over the hot low deserts of Peru, 

 the lofty pinnacles of the Cordillera, and the damp 

 forest-clad land of Southern Tierra del Fuego ; the 



1 Many original observations, and a summary on this subject, are 

 given in Mr. LyelFs paper in the ' Geolog. Proc' vol. iv. p. 3, and in 

 his ' Travels in North America,' vol. i. p. 164, and vol. ii. p. 60. For 

 the European analogous cases, see Mr. LyelFs ' Principles of Geology' 

 (6th edit.) vol. i. p. 137. 



