THE EOCENE SERIES 551 



sandy clays which yield Nummulites planulatus, Turritella edita, 

 Pectunculus decussatus and other fossils, and are from 100 to 150 

 feet thick. Of about the same age are the sands of Mount Panisel 

 near Mons and those of Oeltre in Flanders, which contain Pinna 

 margaritacea, Rostellaria fissurella, Turritella edita, and Cardita 

 planicosta. 



Bruxellian, better latinised as Brussellian ; this name is 

 : icti'd by Belgian geologists to the lower part of a mass of sand 

 and sandstone which corresponds to our Bracklesham Beds. 

 Fossils are abundant in these sands, but generally in a bad state 

 of preservation, except sharks' teeth such as Lamna elegans, Otodus 

 macrotus, Galocerdo minor, Enchodm Blecheri, and Myliobates 

 toliapicus. The fruits of the Nipa palm (Nipadites Burtini) are 

 also common. The higher sands are known as Laekinian and 

 are characterised by Nummulites Heberti, N. variolaria, and Ditrupa 

 strangulata. The total thickness is not more than 180 feet. 



The Wemmelian has a basement -bed of sandy gravel 

 containing Nummulites variolarius, overlain by sands and a band 

 of sandy glauconitic clay. In these beds Num. wemmelensis is a 

 characteristic species, with Turritella sulcifera, Voluta elevata, 

 Cardium porolosum, Tellina rostralis, and Pectunculus pulvinatus. 

 The thickness of these beds varies from about 50 feet near 

 Brussels to 170 at Malines, and over 200 in a boring at Anvers. 



2. The Paris Basin 



Montian. This is not so well developed in France as it is in 

 Belgium, because it has been deeply eroded in many places before 

 the deposition of the succeeding Thanet sands. It varies, con- 

 sequently, in thickness from 6 feet at Meudon to 162 at Mont Airne 

 near Vertus. 14 Typically it is a yellow granular limestone, partly 

 oolitic and partly composed of shell debris. It is probably some- 

 what older than the limestone of Mons, for it contains \Nautilus 

 danicus, but with this are large Cerithia, Turritella montensis, 

 Pseudoliva robusta, Fasciolaria prima, Lima Caroli, Corbis multi- 

 lamellosa, and other Montian species. At Meudon it is succeeded 

 by white marls which are partly of marine and partly of freshwater 

 origin. Limestones of the same age occur in the Pays de Bray at 

 Vigny, and at Laversine near Beauvais. 



Thanetian. Glauconitic sands which appear to be about the 

 age of our Thanet Beds are found all along the northern and 

 eastern borders of the Paris basin, and as a rule they rest directly 

 on the Chalk. Such are the sands of Watten and St. Omer near 

 Calais, which are characterised by Cyprina planata and are often 

 indurated by a siliceous cement into a stone known as tuffeau, 



