( 102) 
which, up to a depth of 1.5 M., shows an irregular mixing with 
brown clay, there is on the highest part of the Buiner Veld (and the 
Hondsrug in those parts), under 0.5 to 0.8 M. of boulder-sand, a 
yellowish red boulder-elay bed of 1 M. thickness. It is situated at 
about 1 K.M. south of Buinen and measures about two hundred 
Meters in every direction. 
The clay found in pit XVII extends, as shewn by borings, only 
some 50 Meters in different directions. 
Another patch of boulder-clay is found south of the Zuider Esch 
of Eksloo on the southern Hooge Veld, in an oak-underwood, under 
about 0.5 M. of boulder-sand. This patch too is of small dimension. 
The same is the case with another on the Zuider Veld of Eksloo. 
Farther, in the neighbourhood of Valthe, a clay bed is found on 
the Kwabben Veld, under + 0.5 M. of boulder-sand, 1.5 M. thick, 
at least, of about 300 M. dimension in every direction and extending 
still somewhat farther south-east on the Nieuwe Esch; a smaller one 
exists south-east of the Kampen Veen. 
The four latter clay patches are situated, with the two first men- 
tioned, pretty well in one direction, from north-west to south-east, 
but they are separated by large intervals in which the boulder-sand 
rests immediately on preglacial stratified white Rhine-sand. The 
mutual distances of these clay patches are resp. 2, 3, 1, 2,1.5 K.M. 
With the only exception of the small clay patch on the Noorder 
Veld, all these, though situated very near to the eastern border of 
the Hondsrug, are on the highest parts of that ridge. 
The stratified white Rhine-sand is, amongst other localities, to be 
seen in a sand digging on the Kleine Esch of Eksloo (under + 0.4 M. 
of boulder-sand) in a sand digging at the northern border of that Esch 
(under 0.38 M. of boulder-sand) and on the Zuider Veld, near to the 
southern border of the Achter Esch; further at the Valther Schans 
(under 0.3 or 0.4 M. of boulder-sand), in a sand digging east of the 
Kampen Veen (under a bed of boulder-sand of the same thickness) 
and further, along the great Bourtangher Peat-moss, from Valthe to 
Weerdinghe. 
The western boulder-clay, on the contrary, forms a long and 
broad strip, which from Ees to Emmen seems not to be interrupted 
and is 1 to 1'/, K.M. wide. It has probably in its whole length a 
thickness of 2 or 3 M. and is covered by 0.7 to 1 M. of boulder-sand. 
The origin of the Hondsrug according to the hypothesis indicated 
in the former communication can thus only be applied to that 
western strip of boulder-clay. Other facts now observed have brought to 
my mind, besides the already mentioned factors, others which may have 
