198 L. Dudley Stamp— 
Lutetian.—There are good reasons for believing that the 
“ Paniselian ”’ is a local shallow-water representative of the lower 
part of the Lutetian. Its fossils on the whole seem to be inter- 
mediate between those of the Ypresian and the normal Lutetian. 
To the west, in the hills of Cassel and Mont des Recollets, 1t passes 
up gradually by loss of glauconite into the “ Bruxellian” sands. 
The latter have the fauna of the lowest zone of the Lutetian—the 
zone of Maretia Omaliusi. As one goes westwards there is still 
a gradual passage from the “ Paniselian”’ into the paler and more 
calcareous Bruxellian sands, but the latter become very thin, being 
only a foot or two in thickness at Mont Aigu, and are absent at Mont 
Kemmel.! It appears, then, that the “ Paniselian”’ is a facies of 
the lower part of the Lutetian, deposited in a shallow sea stretching 
eastwards as far as Brussels. Hast of Brussels one has again the 
‘* Bruxellian ’’ —siliceous or calcareous sands—of the age of the 
lowest zone of the Lutetian. Possibly the Lutetian sea transgressed 
from the north towards the Paris area, so that the “‘ Bruxellian ”’ 
deposits are slightly earlier in age than the zone of Maretia Omaliusi 
in the Paris Basin. In any case all the Bruxellian deposits are earlier 
than the zone of Nummulites levigatus, except in the extreme west 
at Cassel, where the zonal fossil occurs in the higher part of the 
“ Bruxellian’’ sands. 
Further work on the “ Paniselian’’ is very necessary, and the 
junction between the “ Paniselian”’ and the Ypresian is still 
uncertain. 
Ledian.—The Lutetian deposits must have been very considerably 
denuded before the deposition of the Ledian. Although the Lutetian 
zone of Nummulites levigatus is nowhere found in situ in Belgium, 
this Nummulite occurs in enormous numbers, associated with other 
Lutetian fossils, in a rolled condition in the basal conglomerate of 
the Ledian. The Ledian consists of fine whitish sands, characterized 
by the presence of Nummulites variolarius. 
Bartonian.—The Bartonian consists mainly of a grey glauconitic 
clay—the Argile d’Assche. Locally there are beds of sand at the 
base. These are the ““ Wemmelian’’ or Wemmel Sands, and they 
contain Nummulites Orbignyi Gal—wemmelensis De la Harpe. 
Where they are absent the basal bed of the “‘ Asschian ” is formed 
by a sand extremely rich in glauconite and known as the “ Bande 
noire”. The Assche Clay passes up into sands with Nummulites 
wemmelensis. 
They are succeeded by the Oligocene (Tongrian), of which the base 
does not always seem to be very clearly defined. 
5) 
1 Stamp, “ Note sur la Géologie du Mont Aigu et du Mont Kemmel”’: 
Ann. Soc. géot. Nord, vol. xliv, 1919, p. 115. 
