NORMAN — UPPER GREENSAND OF ISLE OF WIGHT. 509 
has been found, but it is difficult to determine from its bad state of 
preservation. 
I have now enumerated ten separate periods in which animal life, 
for the most part of distinct species, existed, during the times of the 
several deposits of coal-beds and ironstones from the period of the 
mountain-limestone up to the Pennant rock, and I have no doubt that 
more continuous research will prove that we must not limit too 
strictly our line of demarcation. 
DESCRIPTION OF THE SECTION OF THE UPPER GREEN- 
SAND AT THE UNDERCLIFF, IN THE ISLE OF WIGHT. 
By Mr. Makk W. Norman. 
{Cyntinued from page 4f0.) 
The next division, 8th, consists of a bed of fawn-coloured sandstone 
of about ten feet in thickness, containing nodules of rag, with 
Pectines, TerebratulcB, Rhynchonelloi, ^-c, in the lower portion, which, 
owing to its softness and looseness of texture, the weather wears 
away, leaving the shells finely exposed. It is chiefly owing to such 
excavation of this bed, by the combined influence of the elements, 
that those great falls of the superincumbent masses have taken place at 
intervals along the line of the Undercliff, many such "founders" having 
happened within the memory of residents, and others being likely to 
occur constantly from this hard and solid mass of strata resting on an 
insecure foundation, the effects of which are still further increased by 
the presence of the Gault below. 
But a few years back a large mass near Blackgang thus assumed such 
a dangerous and threatening attitude, by the lower part of it being so 
much worn away, that the authorities blew it down with gunpowder. 
Many thousand tons of rock and debris were thus thrown down, com- 
pletely blocking up and destroying the original road j one huge mass 
still stands close to the road, as large and as high as a good-sized 
cottage.* 
* Gore Cliff, below ■which occurred the great landslip, in the month of February, 
1798, when, during a severe frost, an entire tract of land, on which was a fiirm, 
called Pitlands, became separated from the Clilf, and descended towards the sea, 
burying the farm-house and carrying with it in its progress rocks, trees, and 
