(hiring the Formation of the Crust of the Earth. 177 



fauna which agrees especially with that of the Northern Ocean ; 

 the fauna of these same strata in Italy finds its congener in the 

 existing fauna of the Mediterranean ; in the West Indies we 

 find the fauna of the existing sea agreeing for the most part 

 with the tertiary fauna of the most recent of the islands. The 

 bone-caves of Europe and the north of Asia are especially rich 

 in remains of bears, hyaenas, oxen, deer, and elephants, — that is 

 to say, genera, species of which (although generally distinct 

 from the diluvian species) still live for the most part in the 

 same countries. In the caverns of South America we find the 

 remains of Platyrrhine Quadrumana and of Edentata predomi- 

 nating, and even, as regards the latter, remains belonging to 

 genera which still exist in that country, or which are very nearly 

 allied to existing genera; some species even are identical. In 

 the bone-caves of Australia, lastly, only bones of Marsupials 

 have been found; and we know that at the present day we 

 scarcely find any Mammalia on that continent which do not be- 

 long to the Marsupial division. One of the most remarkable 

 proofs of the gradual passage from one period to the other is 

 derived from the study of the ancient forests of Taxodium disti- 

 chum in Louisiana (which, however, have for the most part 

 existed in the present epoch). 



The appearance of Dicotyledonous vegetation at the close* of 

 the Cretaceous and commencement of the Tertiary period has 

 been repeatedly represented as an event of immense importance 

 for the development of the whole terrestrial fauna. Its import- 

 ance is, in fact, incalculable in comparison with the characters 

 to which we are compelled to have recourse in order to separate 

 the Tertiary from the present period, and which are of so sub- 

 ordinate a nature. Thus one is often tempted to throw back 

 the limits of the most recent period to this moment, and to 

 confound the tertiary and recent strata in a single common 

 period. In fact, in order to distinguish the Tertiary period 

 from the actual epoch, we are forced to have recourse to one or 

 other of the three following events, which probably indeed 

 followed each other very closely, but which we cannot show to 

 have been synchronic : — 



1. The last appearance of existing plants and animals; 



2. The last extinction of ancient species without the interven- 

 tion of man ; 



3. The appearance of man himself. 



The date of these three events can only be determined by the 

 investigation of the fossil remains which come to our knowledge. 



* Not only in the Upper Chalk of Germany have Crednerice, &c., been 

 found, but the Loicer Cretaceous beds of Aix-la-Chapelle have yielded 

 numerous leaves of Angiosperms. — Ed. Annals. 



Ann. cy Mag. X. Hist. Ser. ?>. Vol. iv. 12 



