208 LIAS OF ENGLAND AND WALES : 
flower-pots, and ornamental bricks are manufactured. A thick- 
ness of upwards of 40 feet of these beds is shown, but no fossils 
were to be had. They are probably on the same horizon as the 
beds yielding Am. margaritatus at Brent Knoll. 
Above these beds there is a development of micaceous sands 
with indurated masses of sandy limestone, and blue septarian 
limestone, overlaid by micaceous sandy clay. These beds are to be 
seen at Chalice Hill and in a deep-lane leading from it ; and they 
occur also on Wearyall Hill, which rises to a height of about 
190 feet. The well-bedded nature of the sands, is similar to 
that of the beds exposed in the road-cutting north of South 
Petherton. Springs are thrown out at the base of the Sands. 
The uppermost micaceous sandy clays yield Beleamites and 
Ammonites, and they are overlaid by the Rock-bed, blue iron-shot 
and oolitic limestone, from 1 to 2 feet thick.* 
The Rock-bed here and at Pennard, yields Ammonites spinatus, 
A. margaritatus, Belemnites, Lima, Pecten ceguivalvis, Rhyn- 
chonelhi acuta, R. tetrahedra, &c. Glastonbury Tor is based on 
a platform of Upper Lias, beneath which, and to the north of the 
hill, the Marlstone Rock-bed was formerly quarried in two or three 
places. The general section of the Middle Lias of Glastonbury 
is as follows (see .Fig. 84, p. 263) : 
FT. IN. FT. IN. 
f~ Rock-bed - - . -10 to 20 
,,.,,, Micaceous sandy clays - 10 
( Micaceous sands with indurated beds - 60 
Micaceous shales ... 140 
[_ Clay (to sea-level) - - - 20 
Brent Knoll, which is similarly constructed, exhibits beneath 
the Knoll (formed of Midford Sands), a platform of Upper Lias 
based on Middle Lias. (See Fig. 85, p. 263.) 
A well dug to a depth of 15 or 20 feet at the foot of the hill, near 
Brent Knoll railway-station, proved blue micaceous shale, which 
yielded Ammonites margaritatus, A. Loscombei, Belemnites, Avicula, 
and fragments of lignite, t The higher beds are not well exposed, 
but they form a comparatively steep scarp, surmounted by the 
Upper Lias. The Rock-bed is probably thin. 
Approaching the Mendip Hills we find evidence of irregular 
overlap of the divisions of the Lias and Lower Oolites, and some of 
the beds, where present, are too thin to be represented on the 
Geological Survey map. Between Batcombe and the Mendip 
Hills, near Doulting, we have no records of the Middle Lias, 
although the formation may be present in an attenuated form. 
In the vales of Nunney, Whatley, and Vallis near Frome, we 
find sometimes Rhaetic Beds, sometimes Lias, and also Inferior 
Oolite, resting directly on the Carboniferous Limestone, and pre- 
* The thickness of "ahout 15 feet" assigned to the Marlstone -rock by Dr. 
Wright, i far too great. Quart. Journ. Geol. Soc., vol. xvi. p. 34 ; see also Day, 
Froc. Cotteswold Cluh, TO!, iii. p. 121 ; and H. B. W., Proc. Geol. Assoo., TO!, xi. 
p. cciii. 
t H. B. W., Proc. Bath Nat. Hist. Club, vol. vi. p. 125. 
