MINERALOGY OF PARIS. 239, 



ant of these, drawn up chiefly from his great work on the 

 Fossil Remains of Quadrupeds. 



Mineralogy of Paris. 



In order to enable the reader to understand the va- 

 rious details in regard to the fossil remains discovered 

 by Cuvicr, we shall premise a short description of the mi- 

 neralogy of Paris, as many of them were dug up in that 

 neighbourhood. Chalk, which is the fundamental rock 

 of the district, is covered with plastic clay, and what is 

 termed coarse marine limestone. The limestone abounds 

 in marine petrifactions, and is associated with a kind of 

 siliceous limestone, which contains the well-known mine- 

 ral in the arts, used as a millstone, and named tiuhrstone. 

 Over this limestone rests a remarkable formation of gyp- 

 sum. It alternates with beds of marl, containing menilite, 

 and beds of clay, with imbedded lenticular crystals of 

 jrypsum. The gypsum contains remains of extinct qua- 

 drupeds, birds, amphibious animals, fishes, and shells, ail 

 of which are said to be land or fresh water species ; hence 

 it is denominated afresh water formation. Above this gyp- 

 sum lie beds of marl and sandstone that contain marine 

 shells, thus affording another marine formation. These 

 rocks are covered with beds of millstone, limestone and 

 flint, both of which contain petrifactions of fresh water 

 shells ; hence this association is named the second fresh wa- 

 ter formation. The uppermost formation is of an alluvial 

 nature. It is composed of variously coloured sand, marl, 

 clay, or a mixture of these substances impregnated with 

 carbon, which gives the mixture a brown or black colour* 

 It contains rolled stones of different kinds, but is most 

 particularly characterized by containing the remains of 

 large organic bodies. It is in this formation that we find 

 great trunks of trees, bones of elephants, also of oxen, 

 rein-deer, ai\d other mammalia. From the intermixture 



