42 
CHAPTEE IV. 
LENHAM BEDS (DIESTIAN). 
Besides the calcareous rocks described in the last chapter we 
have other representatives of the Older Pliocene series, corre¬ 
sponding in lithological character with those found on the opposite 
side of the North Sea, especially around Antwerp and Diest. 
These Deposits of Diestian type consist of fine glauconitic 
greensands, which are often changed, by the oxidation of their 
glauconite, into rusty sands, or become compacted into masses of 
ironstone. The sands are poorly represented in this country, but 
are of great interest; for they point to different conditions from 
those indicated by the Coralline Crag, and yield a somewhat diffe¬ 
rent fauna from that contained in the latter deposit. Sands of 
this type are confined to the county of Kent. About nine miles 
east of Maidstone, at the foot of the North Downs, lies the 
village of Lenham. Behind the village the Down rises rapidly to 
a height of over 600 feet, and forms a long escarpment ranging 
in the one direction to Maidstone, in the other to Folkestone. 
It is on the edge of this escarpment that the sands and fossili- 
ferous ironstone now to be described are found. 
The first discovery of the outliers at Lenham seems to have 
been made in 1854 by Prof. T. E. Jones and William Harris, who 
spoke of them as belonging to the basement-bed ” [of the 
London Clay]. However, a series of the specimens was sent to 
Prof. Prestwich, whose “ first impression was rather in favour of 
such a conclusion. Still there were some fossils which did not 
belong to that period—there were Lnnulites, a large Terehratula, 
a species of Emarginula^ and some peculiar spines of Echini^ 
such as I had never met with in our Lower Tertiary strata.’’ 
Prof. Prestwich was able to visit the sections himself in the 
following year, and was so struck with the resemblance of some 
of the fossils to Crag species that he asked Searles Wood to 
examine them. 
Wood, though he inclined to the view that the deposit was of 
the age of the Coralline Crag, spoke with great caution, owing 
to the bad preservation of the specimens, and to the impossibility 
of satisfactorily determining any of them. He observed that “ In 
the present case, I am afraid the most that can be said is, that 
there is a stronger resemblance in these fossils to the shells of the 
Crag than to those of any other formation, and what may also 
perhaps assist in the assignment is the apparent absence of any 
