( 217 ) 



allowtible oxqv such a small distance, in (•onii)arison vvilli tiie great 

 extension of the bed, and with regard to tiie lioi-izontal strnetnrc of 

 the clay. Then we have to regard it as |)re[)ieistocene, an inter- 

 pretation entirely confirmed by the following palaeontological facts. 

 Much more improbable 1 hold it that the clay under Veido and 

 on the Meuse near that own, was deposited after the first Pleisto- 

 cene Glacial epoch, that of the "Rhine-dilnvinnr'. In that case we 

 should be obliged to suppose two jieriods of erosion. In the first 

 one the "Rhine-diluvium", with the underlying Clay of Tegelen in 

 the valley of the Meuse, should have been eroded, afterwards (during 

 an interglacial period) clay should again have been dei)osited in it, 

 which was attacked in a second period of erosion, on which than 

 in the Second or Great Pleistocene Glacial epoch a deposit of gravel 

 accumulated. 



For the chronology of the different beds of the Dutch Pleistocene 

 formations now it is of great importance to ascertain, by means of 

 enclosed fossils, the age of the Clay of Tegelen, which was deposited 

 in the time preceding the accumulation of the "Rhine-diluvium". 



I am much obliged to Mr. L. Stuns, at the time medical student, 

 now physician at Roermond, for having sho^vn me, already in 1<S97, 

 fossil remains of Mammals (especially l^nKjoiUlu'rhnn and Deer) and 

 of Molluscs, together with such of plants, which he had found in 

 the clay-pit of Messrs. Canoy, Herfkens and Smut.ders, a number of 

 which he has yielded to me for a closer examination. 1 haxe further 

 to acknowledge the benevolence of the last named gentlemen for 

 the opportunity of collecting some fine and characteristic fossil remains 

 of Mammals, especially of Cerrus, Rhinoceros, I'J</a/is, HiitpoitoUdiiiis and 

 Trogontherlain (now in Teyler Museum at Haarlem), by the aid of 

 which the fixing of the geological horizon has been arrived at. The 

 shells and plant remains (especially seeds ajid wood) and many Ixmes ai-e 

 found at about 5 M. below the upper surface of the clay bed, where this 

 is rather sandy, another, more abundant, ossiferous niveau is at nearly 

 3 M. below that upj)er surface, in stiff clay '). Opposite Belfeld bones 



1) To an average of 2.70 M. below the upper siufaco, t'loin below which a vei-y .stiir 

 clay begins, the clay in iliis pit has a yellow colour, caused by tlie action of the 

 almospheiilia on the f'eirugineous conipouncls in the clay, which action is lower down 

 shut oil' by that stiÜ" clay. The latter itself' is of' a bluish colour and at the bottom 

 of the pil il is nearly lilack. Excepted near the upper surface, the yellow clay is 

 on the whole sandy, only at a few places in the pit it is rather stiff. In those 

 places the blue colour continues up to a higher level and the limiting line is not 

 at all right and horizontal, on the (-oiitiary the yellow clay, there, is sinking 

 down, in that blue clay, which continues to a relatively higher level, Agaliform 

 wrinkling brown parallel lines, in those yellow insinkings, imitate then contortions, 



