484 
THE GEOLOGIST, 
free-stone proper, averaging four feet in thickness, and being about 
thirty-four feet from the top of the " Upper Greensand." It is 
succeeded by a thick bed of darkish-blue rag, and a bed of chert, the 
last in the series. 
The 7th division has a depth of about thirty-nine feet, and is com- 
posed of thick beds of fine sandstone, alternating with beds of blue 
rag ; it may be divided into fifteen strata. The first is a bed of 
yellowish sandstone, about three feet in thickness, full of a species of 
Siplionia, nodules with a sponge-like texture, remains of Pohjparia, very 
large '.mmonites, Nautili, and nodules of rag. Below this is another 
layer of rag, a foot thick, succeeded by a bed of fine sandstone of a 
softer nature than the one above, and extending to a depth of about 
three feet. 
In contact with the last is a bed of tough sandstone a foot thick, 
locally termed the "Black-band," and containing fossils. The writer 
has now in his possession the claws of an Astacus (?), which must have 
belonged to an individual more than a foot in length. He has, besides, 
from this band, a species of Echinus (?). 
To this sandstone several alternating bands of light sand with thin 
belts of the " Black-band" succeed, the whole amounting to about seven 
or eight feet in thickness. 
Below this, again, are stratified layers with nodules, termed " Whill- 
Kags," in shape like a compressed cone, many of which are two feet in 
diameter, and most of them containing organic remains as nuclei. 
They are very hard and tough, and difficult to break. They are, how- 
ever, much used by builders in the construction of sea-walls, and for 
the front-walls of dwelling-houses. On being cloven or split by the 
quarrymen, by means of very large wedges inserted in a hole made by a 
mallet and chisel, and afterwards driven in with a weighty sledge- 
hammer, they are often found to contain Ammonites of very large 
size, with the mouth entire; and a fine species of Astacus (?) is reported to 
have been thus obtained from one of them some years ago by Mr. Saxby. 
The writer has seen some magnificent specimens of Ammonites in the 
possession of Dr. Leeson, one of which, about sixteen inches in 
diameter, was obtained whilst sinking a well at Bonchurch. It is, 
perhaps, worthy of remark in this place that the fossils are generally 
found at the base of the " Whills." 
fTo he continued. J 
