360 



PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [May 19, 



clay and sand near London. No progress seems yet to have been 

 made here or elsewhere in obtaining fossils from the argile Ypresien, 

 whether in French Flanders or Belgium. In the latter country this 

 clay appears to be feebly developed, or usually wanting, as in the 

 Paris basin. 



At Bailleul, between Cassel and Lille (see Map, PI. XVII.), many 

 shells were met with in boring a well through this clay, but they were 

 not preserved. 



At Brussels, a mass of clay, lying over the Chalk and about 80 feet 

 thick, was found in boring wells. It is separated from the chalk, as 

 before stated (p. 350), by a band of flint-pebbles coated with green 

 earth. There are not sufficient data as yet for deciding whether part 

 of this clay should be referred to the London Clay proper. 



§ 9. Plastic Clay, Sand, and Lignite (F. 2. Table I. p. 279). Systeme 

 Landenien superieur, Dumont. Lower London Tertiaries, Prest- 

 wich. 



1 . Carvin, near Lille. 



Below the London Clay near Lille are sands and clays, about 

 80 feet thick, which resemble the beds near London usually called 

 " Plastic clay and sand." The only fossils as yet found in them are 

 marine, and occur in a clay, not more than 25 or 30 feet above 

 the chalk. M. Meugy took me to the junction of the chalk and ter- 

 tiary strata at Carvin, twelve miles south of Lille (see Map, PL XVII.). 

 Within 300 yards of the church of Carvin we saw an open well just 

 dug, where the White Chalk with flints appeared within 10 feet of 

 the surface. Upon it there was no parting band of pebbles, but, in 

 contact, schistose sandy clay, greenish but not glauconiferous, with a 

 few well-rolled black pebbles interspersed. This clay or loam was 

 10 feet thick. At a short distance, and no doubt incumbent on the 

 above, a tenacious clay occurs, several feet thick, which is worked 

 for pottery ; and above this again, in another pit, the sandy clay with 

 concretions in which shells abound. Among these the Cyprina Mor- 

 risii, Sowerby (* Min. Con.' vol. vii. p. 20, pi. 620), abounds, which 

 is characteristic of the Plastic Clay near London, and a Turritella, 

 Area, and Corbula, in casts too imperfect to admit of being specific- 

 ally determined. There are white sands with some solid beds of sand- 

 stone in them near Lille, between the clay with Cyprina Morrisii, 

 above-mentioned, and the London Clay, but I saw no good sections. 



2. Jauche, Huppaye, Oplinter, ^c. 



In Belgium, above the "Lower Landenian," which I shall pre- 

 sently describe, and below the Brussels beds with Nummulites pla- 

 nulatus, there occurs a formation of sand, siliceous paving-stone, and 

 lignite, to which the name of Landenien superieur has been given by 

 M. Dumont. As no fossil shells have been found in it, I cannot 

 identify it palseontologically with that part of the British Tertiaries 

 with which it may probably be contemporaneous. I saw its super- 



