332 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [May 19, 



2. Middle Eocene Strata of Brussels. 

 [1.] Laeken beds. Dileghem, Jette, Laeken, ^'c. 



I shall now pass to the neighbourhood of Brussels, the most im- 

 portant of the districts after Cassel, where I had an opportunity of 

 studjdng the Middle Eocene strata. The capital of Belgium is distant 

 from Cassel about seventy-five English miles, in a straight line due 

 east. In exploring its environs I had the great advantage of being 

 accompanied by my friend Captain Le Hon, who had made a fine 

 collection of tertiary fossils, and whose accurate knowledge of palse- 

 ontology enabled him to render me the greatest assistance. We visited 

 together most of the localities which I shall have to mention. M. 

 Deby also of Brussels accompanied us in many of our excursions, and 

 gave us much information respecting the geological structure of the 

 country. 



The general level above the sea of the higher grounds or table-lands 

 round Brussels is about 300 feet, the valleys which intersect them 

 cutting to the depth of 200 feet and upwards, so as to descend to 

 within 60 and 70 feet of the sea-level. On the highest grounds, and 

 at many intervening elevations, loess is found (see Section, fig. 6). 



Fig. 6. — Section near Dileghem, two miles N.N.W. of Bi^ussels. 



A. Loess. y. Yellow and green sands. 



B 2. Diest sands. E ] . Laeken beds. 



X. Bed of rolled flint-pebbles. 



Thus, near Dileghem, two miles N.N.W. of Brussels (Map, fig. 3, 

 PI. XVIT.), it may be seen crowning the elevated platform (fig. 6, A). 

 Next in order iron-sandstone and green sands, exactly resembling 

 those of Diest (B. 2. fig. 6), about 10 feet thick, below which is a 

 bed of well-rolled flint-pebbles {x, fig. 6). Under this, yellow ferru- 

 ginous sands {y, fig. 6), with hydrate of iron and green sands, 30 feet 

 thick, and without shells, succeed. I had no means of determining 

 their age, whether they are contemporaneous with the beds of Mont 

 Noir near Cassel, before described as containing Middle Eocene fossils, 

 or whether they are part of the Limburg series, as I was assured by 

 several Belgian geologists. 



At a somewhat lower level, sands, containing unquestionable Eocene 

 fossils, are seen in the fields at the points marked A. and B. in Map, 

 fig. 3, PI. XVII., but their contact with the incumbent beds, y, fig. 6, 

 is not exposed. Scattered over these fields, which are often called 

 indifferently " Jette" and " Laeken'* by collectors of fossils, and also 

 in a sand-pit from which shelly matter had been extracted for agri- 

 cultural purposes, I found Cytherea suberycinoides, Pecten corneus, 



