Ch. XVI] 



EOCENE FORAHINIFERA. 



227 



described, was precipitated from the waters of others situated farther to 

 the south. 



In some parts of the calcaire grossier round Paris, certain beds occur 

 of a stone used in building, and called by the French geologists " Miliolite 

 limestone." It is almost . entirely made up of millions of microscopic 

 shells, of the size of minute grains of sand, which all belong to the class 

 Foraminifera. Figures of some of these are given in the annexed wood- 

 cut. As this miliolitic stone never occurs in the Faluns, or Miocene strata 



EOCENE FORAMINIFERA. 



Fig. 287. 



Calearina rariepina, Desh. 

 b. Natural size. a. c. Same magnified. 



SpiroUna stenosloma, Desh. 

 B. Natural size. A, C, D. Same magnified. 



Fig. 238. 



Triloculina inflata, Desh. 

 6. Natural size. a, c, d. Same magnified. 



Fig. 239. 



ClamtMna corrugata, Desh. 

 a. Natural size. 6, c. Same magnified. 



of Brittany and Tourame, it often furnishes the geologist with a useful 

 criterion for distinguishing the detached Eocene and Miocene forma- 

 tions, scattered over those and other adjoining provinces. The dis- 

 covery of the remains of Paleotherium and other mammalia in some 

 of the upper beds of the calcaire grossier shows that these land animals 

 began to exist before the deposition of the overlying gypseous series 

 had commenced. 



