246 DESCRIPTION OF THE MUSEUM. 



Lastly. In the other cases, which are at the 

 bottom of the hall to the right, we find the fol- 

 lowing series of rocks, which are only placed 

 there temporarily, as we have before said, and 

 which are intended for the completion of the 

 geographical collection already begun in the 

 third room. These are : 



i st. The principal rocks of the tertiary forma- 

 tion, which constitute the soil of the environs of 

 Paris. It is well known that this formation has 

 been the subject of a complete monography, pub- 

 lished by MM. Cuvier and Brongniart. 



2d. Various rocks from the neighbourhood of 

 Nantes, Piennes and Paimpol, given by M. I)u~ 

 buisson of Nantes and M. Regley. Amongst the 

 latter we remark the ancient lavae discovered at 

 Treguierin 1821, by M. Regley. 



3d. A fine series of rocks from the environs of 

 Cherbourg, Caen and Havre, collected and given 

 by M. Constant Prevost. 



4th. A series of rocks from the neighbourhood 

 of Aixand Marseilles, collected by M. Fontanier, 

 travelling naturalist to the Museum. Amongst 

 them we see a large specimen of compact lime- 

 stone more recent, containing scoriae, which was 

 brought from the volcanic mountain of Beaulieu 

 by M. Menard de la Groye, 



5th. A considerable number of specimens of 



