MODE II. KONITE. 437 



tries, as in the Cote d'Or, near Dijon, instead of 

 slates, to cover the houses ; and these flat stones 

 have received the absurd name of lava. This 

 limestone is often an impure mixture of calcareous 

 sand and fragments of shells ; and sometimes con- 

 tains entire shells, which are generally of the kind 

 called Littoraly because they are found near the 

 shores of the sea*. The limestone of the neigh- 

 bourhood of Paris is full of great numbers of 

 these shells, called cerites, or screws, which are 

 sometimes so abundant, that the stone seems 

 entirely formed of them. There is found at 

 Weissenau, near Mentz, a bed of limestone, 

 which is entirely composed of little limnes^, of 

 the size of a grain of millet seed. 



" There are neither veins nor beds of metals 

 in this limestone, which only contains oxyd of 

 iron, either argillaceous or calcareous, in beds or 

 in heaps; it is also said that carbonate of zinc 

 has been found in it; but of this there is no 

 proof. Coal is never found in this kind of lime- 

 stone ; even silex is rare; and sulphurets of iron 

 are excluded. 



* It may be observed in the catacombs under the city of Paris, 

 that the shells form layers between the beds, like flint in chalk : so 

 that the depositions must have been at successive periods. P. 



f The Linnaean name is wanting. 



