1852.] LYELL BELGIAN TERTIARY FORMATIONS. 281 



Such an instance of the superposition of loess to a certain class of 

 erratics, will not justify the conclusion that the origin of the loess 

 generally was of later date than the northern drift. I should rather 

 infer from the fact here mentioned, that the transportation by ice of 

 large blocks was still going on when a part of the Belgian loess was 

 deposited ; — in other words, the glacial epoch coincided, in part at 

 least, with the epoch of the formation of the loess. I conceive that 

 the more intense cold had passed away, or receded northwards, before 

 the principal mass of the loess was thrown down. 



§ 3. Antwerp Crag (B. 1. Table I. p. 279). Systeme Scaldesien, 

 Dumont, 1851. Systeme Campinien, Dumont, 1839. 



The excellent and well-known work of M. Nyst, published in 1843, 

 on the shells and corals of the tertiary formation of Belgium, has 

 made every geologist familiar with the fact, that a large number of 

 species of fossils are common to the Suifolk Crag and to strata in 

 the neighbourhood of Antwerp. M. Nyst has taken frequent occa- 

 sion to acknowledge that a considerable proportion of these Antwerp 

 fossils were communicated to him by M. Norbert de Wael, and I was 

 fortunate enough to obtain the friendly cooperation of that excellent 

 observer and indefatigable collector during my visit to Antwerp. He 

 placed most liberally at my disposal, and for my use when writing this 

 memoir, not only a part of his collection, which Mr. Searles Wood 

 has compared with fossils from the English Crag, but also his MS. 

 lists of organic remains, and his notes on the geology of the localities 

 most fertile in fossils, several of which we visited together. 



There are no natural sections to be seen in the flat country around 

 Antwerp, but excavations to the depth of a few feet in the town and 

 its suburbs are continually exposing to view beds of sand and shells. 

 One of these I found in progress on my arrival on the eastern side of 

 the city, in the Zoological Gardens. Here they were digging ponds 

 20 feet deep, from which yellow sand had been thrown out, contain- 

 ing Fmsus contrarius^ Valuta Lamberti^ Pecten maximus, Pecten 

 opercularis, Ostrea edulis, Cyprina tumida, Astarte borealis, and 

 many others, which I at once recognized as among the most common 

 shells of the Suffolk Crag. I also observed that they had met with 

 many large vertebrae of Whales in a perfect and unrolled state. I 

 obtained one of these, measuring 6y inches in its longitudinal, and as 

 much in its transverse diameter, and Prof. Owen has pronounced it 

 to be the lumbar vertebra of a Balcenoptera. These cetacean relics, 

 which are very common in the district, were associated with large 

 Sharks' teeth, of the genus Carcharodon. 



At Steuvenberg (a name which implies a hill of sand), east of 

 the fortifications and north of the Zoological Gardens, I found ex- 

 cavations for sand, in which many of the same shells were seen, with 

 others which will be alluded to in the sequel. 



On the northern glacis of the fortifications I saw that a very dif- 

 ferent sand had been recently thrown up from a depth of 20 feet, 

 consisting of a dark green and almost black glauconite. This is 

 called " crag noir," or glauconiferous crag. It contains many of the 



