DAKYNS : FLOTS. 
383 
tical or approximately vertical courses having a general parallel 
trend of N.N.W., or nearly magnetic north and south. These Dun 
courses, or streaks as they are also called, are the important 
features in the flot district. The miners always look out for lead 
where they find a dun course. These dun courses bear a precisely 
similar relation to the flots that the cross veins above described 
do. There is this difference, however, a cross vein is a com- 
paratively narrow crack in which ore is found at the flot planes. 
Dun courses are sometimes several fathoms wide. Where a dun 
course crosses a flot plane, the metal is found up and down between 
the dun and the white limestone. 
GLACIAL SECTIONS NEAR BRIDLINGTON. BY G. W, LAMPLUGH. 
In the neighbourhood of the seaport towns on the east coast of 
Yorkshire, the continuity of the cliff-section is now nearly always 
broken by artificial works, raised sometimes for one purpose, some- 
times for another, but always with results equally fatal to geologi- 
cal interests. The gaps thus made, have a constant tendency to 
widen as the towns spread along the cliff -tops after the fashion of 
watering-places ; so that the inconvenience arising to geologists 
from this cause will become more and more evident. Already 
there are cases in which the sections thus hidden have been 
sorely needed, as for instance, at Bridlington ; where the shelly 
deposit in the boulder-clay to which the name of "Bridlington 
Crag " was given, was covered shortly after its discovery by a 
strong sea wall. It was so completely screened from observation, 
that when, some time after, the Drift deposits of the coast were 
examined and divided, the actual position of this bed in the series 
had become a matter of theory, and, as the open cliff on either 
side of the town showed only 1 Purple ' boulder-clay, with noth- 
ing to indicate the presence of any lower division in the neigh- 
