174 Cornet and Briart—New Tertiary Limestone. 



a tropical to an arctic temperature, evidenced by the fossil remains 

 of former geological periods discovered in such extreme northern 

 latitudes as Greenland and Melville Island (lat. 75° north), repre- 

 senting forms of vegetable and animal life suited to tropical or 

 sub-tropical regions. 



Lastly, he read an extract from the Eeport of the Astronomer 

 Eoyal (for 1861), "That the Transit Circle and Collinators still 

 present those appearances of agreement between themselves and of 

 change with respect to the stars, which seem explicable only on one 

 of two suppositions — that the ground itself shifts with respect to the 

 general earth, or that the axis of rotation changes its position." 



A prolonged and interesting discussion ensued, in which Professors 

 Ramsay and Tyndall, Mr. Grove, Mr. Spottiswoode, Mr. Mallett, 

 Mr. Hopkins, and the Secretary took part. 



in. — ^On the Discovebt, in Hainatjt, of a Limestone with a 

 Tektiakt Fauna, beneath the Sands keferked by Pkofessob 

 Dumont to the Landenien System. 



By MM. F. L. Cornet and A. Briart. 



THE Lower part of the Tertiary strata of Belgium has been 

 divided by M. Dumont into five systems, distinguished by their 

 nature, relative position, and fossils, to which he has given the 

 names Landenien, Ypresien, Paniselien, Bruxellien, and Lackenien. 



The lower stage of the Landenien system, a marine formation, is 

 placed by M. Dumont on the same horizon as the lower bed of the 

 Paris Basin, and it is below this (Landenien) stage, in the neigh- 

 bourhood of Mons, that MM. Cornet and Briart have found a Lime- 

 stone containing a rich Tertiary fauna. But it is most remarkable 

 that this fauna, instead of resembluig that of the Landenien system 

 or the corresponding French stages, appears to be eqiiivalent to that 

 of the Bruxellien, from which it is separated by all the strata of the 

 Landenien, Ypresien, and Paniselien systems. 



The discovery was made during the boring of a well, which 

 traversed 1 metre 70 of diluvian debris, and 5 metres of glauconitic 

 sand, belonging to the lower Landenien system, and then 14 metres 

 of the Limestone, which has yielded a great quantity of fossils, 

 many of which appear new. The authors have determined specifi- 

 cally 12 Gasteropods and 10 Lamellibranchs, namely — 



Gasteropods. Lamellibranchs. 



Turritella intermedia, Desh. 

 I'urritella imbricataria, Lm. 

 Yoluta spinosa, Lm. 

 Ancillaria buccinoides, Lm. 

 Mitra terebellum, Lm. 

 Cerithium unisuleatum, Lm, 

 Melanopsis buccinoides, Fer. 

 Buecinum stromboides, Lm. 

 Nerita coronis, Brong. 

 Natica perforata, Lm. 

 Natiea epiglottina, Lm. 

 Monodonta Cerberi, Lm. 



Cytherea miiltisulcata, Desh. 

 Cardita planicosta, Lm. 

 Crassatella compressa, Lm. 

 Corbula striata, Lm. 

 Corbis lamellosa, Lm. 

 Area biangula, Lm. 

 Area modioliformis, Desh, 

 Tellina rostralis, Lm. 

 Tellina donacialis, Lm. 

 Lucina mitisj Sow. 



