THE FAUNA AND FLORA OF FLORDON COMMON. I73 
the surface soil a few Neolithic flint implements have been 
found. 
The valley in which the marshy part of the common lies 
is about three-fourths of a mile wide from ridge to ridge, 
with an average depth of about 60 feet. It is probably due 
to glacial action, for it seems impossible that so short a stream 
could ever have cut away so much of the adjoining hills, 
and left so wide a stretch of alluvium. There are six springs 
on the common, one on the middle of the eastern portion 
which flows by a ditch to the stream ; one near the house ; 
three others close together in the western portion, only 
a few feet from the ditch, and virtually on the same level ; 
while the sixth and most powerful is below the parish pit, 
and flows westward to the stream. 
By digging nine sections in different parts of the Common 
it was possible to obtain a fairly accurate knowledge of the 
constitution of the subsoil. In a hillock on the higher 
ground of the eastern common there were three feet of made 
soil containing two Neolithic flint implements, but a section 
at the bottom of a hollow a few yards away showed gravel 
(as in the pit) immediately beneath the turf. On one of the 
small hillocks in the marsh but close to the high ground 
there were a few flints in the 15 inches of surface soil, and 
beneath that undoubted chalky boulder clay full of flints. 
In another hillock there was one foot of surface soil, then 
calcareous soil containing land and fresh-water shells, the 
water-level being 15 inches from the surface. One of the 
low-lying places in the marsh showed 22 inches of black 
surface soil, then calcareous matter with plant-remains and 
land and fresh-water shells, the water-level being 24 inches 
from the surface. One of the raised areas quite in the middle 
of the marsh gave a most instructive section. Beneath four 
inches of black soil (brown when dry) there was one foot of 
brown calcareous soil and two feet of white, the whole section 
showing rootlets, plant remains, abundant fragments of 
Limncea, Planorbis, Vertigo, and Valvata, and Chara fruits, 
probably of the two species still found on the common, as 
they show 10 and 13 spires. A cutting in a shallow de- 
