1852.] LYELL BELGIAN TERTIARY FORMATIONS. 357 



each approximate much nearer to each other, if we were able to ex- 

 tend our knowledge of the fossils of the respective districts ; although 

 there would still remain some distinctions arising from variations of 

 species in space or in time ; the representation of each precise stage, 

 or division in time, of the fossils of the same Middle Eocene group 

 being always imperfect, and usually unequally so in the several 

 countries compared. The small number common to the "upper and 

 lower Brussels" beds, or to the upper and lower Cassel beds, i. e. to 

 the Upper and Middle Nummulitic, is no doubt in part the effect of 

 change of species in time, and corresponds to the distinction between 

 the Barton beds and the lower Bagshot (or lower Bracklesham) in 

 England, or that of the Sables moyens {gres de Beauchamp) and the 

 Glauconie grassier e in France. 



The number of Plants, Zoophytes, and Vertebrata common to the 

 different divisions, or to the two districts, is too small to require me 

 to dwell upon them. So far as they go, they coincide in their bear- 

 ing with the conclusions to which we are led by the fossil MoUusca. 



[2.] Middle Eocene strata near Mons. Mont JPanisel. 



It is well known that in the neighbourhood of Mons (about thirty- 

 five English miles S.S.W. of Brussels) the Maestricht chalk is seen 

 at Ciply, and above it are sands and clays (at Chasse Royale and other 

 places), referred to the Systems Landenien of Dumont. At a higher 

 level, strata containing Nummulites planulatus in abundance have been 

 found in wells sunk in the city of Mons, I found the same Nummu- 

 lite in Mont Panisel, in the suburbs, sparingly dispersed through 

 beds of clay and in greenish and yellowish ferruginous sands in which 

 were some cherty beds containing casts of fossils with silicified shells. 

 I examined Mont Panisel in company with M. A. Vroilliez and M. 

 Ch. De Beaulieu, and with their assistance obtained the following 

 fossils : — 



Nummulites planulatus. 



TelUna. 



Pinna margaritacea ; abundant. 



Nucula. 



Loripes divaricata, 



Crassatella. 



Cardium porulosum ? 



Astarte. 



Cassidaria nodosa. 



Cardita. 



Natica patula ? 



Fusus. 



Lucina gibbosa. 



Voluta. 



Solen. 





These seem to be inferior to the Brussels Beds, of which the fossils 

 are enumerated in the *' Lower Brussels " column of Table XIII. 



[3.] BenaiXj Crage, and Audenaerde. 



From the hills of Renaix, Mont Panisel above-mentioned may be 

 seen. Near Renaix, about two miles S.E. of the town (see Map, 

 PI. XVII.), the stony beds with Nummulites planidatus are exposed 

 to view in the bed of a small brook, where they are associated with 

 clays and sands. The locality alluded to occurs in the Commune of 

 St. Sauveur, on the farms of Tombelles and Arabic, where I was 



