1852.] LYELL BELGIAN TERTIARY FORMATIONS. 363 



2. AngreSf near Quievrain. 



At Angres, near the southern frontiers of Belgium, fourteen English 

 miles south-west of Mons, the White Chalk with flints is covered with 

 a solid glauconite, free from calcareous matter, and full of the casts 

 of shells. I visited this place in company with M. de Beaulieu, Pro- 

 fessor of the Ecole des Mines at Mons. We found a section in a 

 hollow way, within half a mile N.N.E. of the church of Angres, 

 where a thickness of 25 feet of thin-bedded and half-solidified glau- 

 conite is seen. The stone at some points becomes very hard, and tbe 

 green grains are larger and more widely scattered in the upper beds. 

 I obtained the casts of about fifteen shells, belonging to the genera 



Area. Venus ? 



CucuUaea (allied to C. decussata). Tellina. 



Panopaea (like P. intermedia ?). Pinna. 



Pectunculus. Ostrea. 



Crassatella. Turritella. 



Nucula. Lucina ? 



Pholadomya (resembling P. cuneata, Natica. 



Sow. M. C. pi. 630). Calyptrsea. 

 Astarte. 



Also a Bryozoon (Retepora ?) and an Echinoderm. 



The casts were many of them decidedly the same as those already 

 mentioned as occurring near Tournay. We afterwards saw a similar 

 glauconite with similar fossils at Baisieux, two miles north of Angres, 

 and about a mile south of Quievrain. 



The matrix of the shells at Angres is sometimes quite undistin- 

 guishable from that Middle Eocene glauconite, with large coarse 

 grains of green earth, which occurs at Boeschepe near Cassel, before 

 described, p. 325, and in which casts of a large Ovula and other shells 

 occur. It is one of many instances in Belgium of the identity in 

 mineral character of tertiary beds of very different ages, to which the 

 abundance of glauconite particularly contributes. 



3. Folx-les-Caves, Jauche, Jendrain, Orp-le-grand, ^c. 



I shall now pass to another part of Belgium (between Brussels and 

 Liege, seventy or eighty miles eastward of Tournay), where strata, 

 also called '* Lower Landenian," and probably of about the same age 

 as those of Tournay and Angres already described, are met with in 

 the cantons of Landen, Jodoigne, and Tirlemont. See Map, fig. 2, 

 PI. XVIL 



At Folx-les-Caves, the most southern point where I saw this for- 

 mation, it rests on the Maestricht Chalk, fig. 11, I, which is there 

 quarried to the depth of 20 feet for building- stone, and exhibits 

 Belemnites mucronatus and other characteristic fossils. 



The chalk is covered by a bed of rolled flint-pebbles, some of which 

 are 4 inches in their longest diameter. This bed (G. 2), forming the 

 base of the "Lower Landenian," is 1 foot thick, and supports a 

 stratum (G. 1) of soft glauconite, 6 feet thick, the upper part of 

 which is clayey, and contains some small dark concretions, which, like 

 the greensand matrix, are highly calcareous. The fossils in the 



