The sand described in the following notes was dredged from the mid-channel of the river at the following places:—Swale Nab, Dunsforth, Aldwark Bridge, below Linton Lock, and Beningbrough. Two samples were also obtained from the Nidd at points 100 and 200 yards respectively from its confluence with the Ouse. For comparative purposes sand from the banks and alluvial flat of the Swale above Ainderby Steeple is likewise included.