180 GEOLOGY.. 



SUPERIOR SECONDARY EARTH. 

 GREEN FREESTONE. 



Characterized by small grains of green matter found dis- 

 seminated therein. 



CRETACEOUS EARTH. 



Thick and numerous strata, covering entire countries, and 

 having two varieties ; the one like chalk properly so called, 

 that is to say white, soft and tolerably friable; the other al- 

 together hard, and supplying fine stone for sculpture and even 

 true marble. Here are found Oysters, and Rudistes, very 

 irregular shells resembling horns diversely flexed, and with 

 uneven surface. 



THIRD EPOCH. 



Great swellings or erections; sinking of valleys; displace- 

 ment of seas and lakes; extinction of a great number of or- 

 ganized beings; appearance of new species, such as large 

 mammiferous quadrupeds (Cetacea and Pachydermata) ; at 

 the same time appear insects and fresh water fish; remark- 

 able progression in the vegetable kingdom ; the dicotyledonous 

 plants are more numerous than the acotyledonous and mono- 

 cotyledonous ; volcanic phenomena more strongly character- 

 ized than during the two first epochs ; trachytic and basaltic 

 eruptions, with productions more or less bullous and scorified. 



EARTHS OF THE THIRD EPOCH. 



INFERIOR TERTIARY EARTH. 

 MARINE FORMATION. 



i' : '. '; 



Coarse Cah, composed of calcareous layers of marine for- 

 mation, between which are inserted accidentally some beds 

 of fluviatile formation. One of these fresh water deposits is 

 oftqn found in the inferior portion ; it is that of plastic day ; 

 it is succeeded by strata of clay, marl, and sand, in the midst 

 of which are piles of lignite. Coarse calx is the building 

 stone of the Parisians. 



