298 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [May 19, 



§ 6. Limhurg Tertiary series (D. Table I. p. 279). Systemes Rupe- 

 lien and Tongrien of Dumont. Upper Eocene (Lower Miocene of 

 some writers). 



The tertiary strata of Belgium, which follow next in the descend- 

 ing series, or which underlie the Bolderberg sands already described, 

 have been long known to palaeontologists as the "Kleyn Spawen 

 beds." At the village of Kleyn Spawen, in the ancient province of 

 Limburg, west of Maestricht (see Map), and in the neighbourhood, 

 they exhibit several marked subdivisions in regular oi:der of super- 

 position. 



We are indebted to M. Hebert for having in 1849 pointed out the 

 palseontological relation of the Limburg beds to the highest portion 

 of the Parisian series, or, in other words, for having proved them to 

 be the equivalents of strata which Cuvier and Brongniart originally 

 styled *' the second marine formation," comprising the Gres de Fon- 

 tainebleau and the green marls with Ostrea cyathula which overlie 

 the gypsum*. 



After studying the Limburg beds with the advantage of the assist- 

 ance of M. Bosquet, of Maestricht, I came to the conclusion that 

 they may be most conveniently divided into three groups, of which 

 the uppermost and the lowest are marine, and the middle fluvio- 

 marine. The uppermost member has not afforded as yet in the Kleyn 

 Spawen district, where it is of small thickness, more than thirty-two 

 species of fossils, chiefly Mollusca and Entomostraca (see Table IX.) ; 

 but at several places on the Scheldt near Antwerp, fifty miles E.N.E. 

 of Kleyn Spawen, especially at Rupelmonde, Boom, Basele, and 

 Schelle, it has yielded a large number of Mollusca. The names of 

 these localities are familiar to the readers of Nyst*s 'Coquilles tertiaires 

 de Belgique,' and as I visited them all in the course of the summer I 

 shall now describe them. (See Map, PI. XVIL fig. 1.) 



1. Rupelmonde Clay {Upper Limhurg beds). Systeme Rupelien of 

 M. Dumont (D. 1. Table I. p. 279). 



Ascending the Scheldt from Antwerp (see Map), for a distance of 

 about eight miles, to a point just above its junction with a small stream 

 called the Rupel, we see on the left or north bank a line of cliffs 

 half a mile long and about 100 feet high, adjoining the village of 

 Bupelmonde. These cliffs consist chiefly of clay used for brick- 

 making. At the top of the perpendicular precipice appears a bed 

 of sand, varying from 5 to 20 feet in thickness, and below it, a mass 

 of dark clay from 80 to 90 feet thick, under which I was informed 

 whitish sandy strata have been pierced in boring. 



The yellow sand at the top, usually about 16 feet thick, is strati- 

 fied, and in it I found a few fragments of shells, apparently belonging 

 to Corbula planulata, Nyst (0. gihba, Oliv.), and Cyprina tumida, 

 Nyst, to which M. de Wael, of Antwerp, who has better specimens 



* Hebert, Bulletin de la Soc. Geol. de France, 2 ser. vol. vi. p. 459, April 1849. 



