PART II. CHAPTER XIV. 169 



Recent and Newer Pliocene Strata. 



Although I cannot enter in this work into farther details, it 

 may be stated that, if we compare tertiary formations on this 

 principle, the nomenclature above proposed will not be inappro- 

 priate ; for the fauna of the older, or Eocene tertiary formations 

 is still the first in the order of time in which there is an assem- 

 blage of testacea like that of the present ocean between the tro- 

 pics ; and in this period a small proportion of mollusca are un- 

 distinguishable from living species ; whereas at the opposite ex- 

 treme of the series, or in the Newer Pliocene deposits, ail con- 

 chologists agree that the marine shells are all, or nearly all, 

 identical with those now inhabiting the nearest seas. As to the 

 Miocene and Older Pliocene groups, the terms less and more will 

 always express correctly the different degrees of analogy which 

 their fossils bear to the assemblage of living species in similar 

 latitudes. 



But it should never be forgotten, that, as the extinct species 

 preponderate in all groups, with the exception of the Newer Pli- 

 ocene, it is from their characters that we derive the distinguish- 

 ing feature in the palaeontology of each period. The relative 

 approach which the shells may make to the living fauna affords 

 a useful and interesting term of comparison ; but it is one fea- 

 ture only, and by no means the most prominent one, in the or- 

 ganic remains of successive periods. 



CHAPTER XIV. 



RECENT AND TERTIARY FORMATIONS. 



How to distinguish Recent from Tertiary strata Recent and Newer Pliocene 

 strata near Naples near Stockholm and Christiania in South America, on 

 coasts of Chili and Peru Rocks of recent period, with human skeleton, in 

 Guadaloupe Shells of living species, with extinct mammalia, in loess of the 

 Rhine Recent and Newer Pliocene deposits in England Older Pliocene strata 

 in England Crag Red and Coralline crag their fossils in part distinct 

 their strata uncomfortable belong to the same period London clay Its 

 shells and fish imply a tropical climate Tertiary mammalia Fossil quadru- 

 mana. 



Recent and Newer Pliocene strata.- If we begin with the his- 

 tory of the more modern aqueous formations, and then pass on 

 to the more ancient, the first strata which present themselves are 

 those termed, in the last chapter, the Newer Pliocene. But in 



