244 



THE WONDERS OF GEOLOGY. 



Lect. II 



32. Shells of the tertiary strata. — The shells of 

 the tertiary epoch already determined by naturalists, 

 amount to nearly three thousand. We have seen that 

 some of the strata are almost entirely composed of these 

 remains in a broken and compressed state, and many seams 



Lign. 38.— Marine eocene shells of the Paris basin. 



Fig. 1. Cyprasa inflata. 2. Ancilla canalifera. 3. Fusus uniplicatus. 

 4. Cerithium lamellosum. 5. Pleurotoma dentata. 6. Lucina sulcata. 

 7. Ampullaria sigaretina. 8. Pectunculus angusti-costatus. 



in the argillaceous beds consist of shell-dust. In some 

 localities the shells are finely preserved ; and the calcaire 

 grossier at Grignon, a few leagues from Paris, has long 

 been celebrated for its beautiful fossils ; hundreds of 



