50 
LENHAM BED&. 
At Folkestone and Paddleswortb, where little or no trace of 
glauconite occurs, and where the whole deposit seems much more 
weathered than at Lenham, a few quartz pebbles may still be 
noticed, mixed with the flints towards the base of the sands. The 
way in which the beds lie somewhat irregularly on the Chalk, 
and do not follow the dip slo[)e towards the north, but are almost 
confined to the edge of the escarpment, is suggestive of a marked 
unconformity, though this cannot at present be proved from actual 
sections. 
On the further side of the Straits of Dover similar deposits 
cap the hills between Calais and Boulogne, generally at a height 
of from 400 to 500 feet. Inland they stretch eastward into 
Belgian Flanders, and form a continuous chain of outliers con¬ 
necting the fossiliferous beds of Lenham with those of Diest. 
In France no fossils have yet been found in these deposits, 
though on Cassel Hill, where they reach an elevation of 515 feet, 
they are of a very considerable thickness (about 45 feet) and have 
been carefully searched. 
A few miles across the French frontier, in Belgian Flanders, 
M. Piret has lately discovered a cast of Terehratala grandis, at a 
place called Wevelghem, between Courtrai and Menin.* The 
specimen was not found in place, but there seems no reason to 
believe that it had been transported far.. 
Though palaeontological evidence is not always forthcc'ming, 
the stratigraphical and lithological evidence of the former con¬ 
tinuity of the beds seems clear. The gaps between the outliers 
which connect Diest and Lenham are unimportant, the largest 
being that occupied by the Straits of Dover. There appears 
now to be no reasonable doubt that we are dealino* with a wide- 
spread sandy Diestian formation, which once covered great part 
of Holland, Belgium, northern France, and southern England, 
though denudation has since cut it into numerous outliers, often 
capping isolated hills, f 
Still tracing the beds eastward one finds that beyond Brussels 
the ferruginous sands begin to form larger masses, till finally they 
unite into a wide sheet stretching from Louvain to Antwerp, and 
northward into Holland. At the same time the deposits change 
in lithological character and become less weathered as they sink 
beneath the sea level. Except the above-mentioned Terehratula 
from Wevelghem the first occurrence of determinable Diestian 
fossils is at Everbergh, about 10 miles east of Brussels, and 
from this point there is no doubt as to the continuity of the 
deposits. 
In the summer of 1886 I had the great advantage of visiting 
the typical Diestian area in company with my friend Mr. Van den 
Broeck, who had recently mapped in detail great part of that 
* Note sur an nouveau Gisement de la Terehratula grandis. . . . par E. Van 
den Broeck. Mem. Soc. Beige Geol., vol. i. p. 49. (1887.) 
f A good map of the distribution of the Pliocene deposits in Belgium will be 
found in M. Van den Broeck’s paper. Op. cit. PI. II. 
