138 LIAS OF ENGLAND AND WALES : 
may be seen above the Marble ; but elsewhere in the area, dis- 
tinctive beds of White Lias are not always to be found, and it is 
possible there is some overlap of the White Lias.* Near Bath, 
the Landscape Marble occurs at the base of the White Lias ; but 
beds of similar texture occur at other horizons in that division. 
At Aust Cliff we find thin beds of the Lower Lias, mostly 
inaccessible, capping the Rhaetic Beds.f It is remarkable that 
here the uppermost band of the Rhaeiic Beds, is a stone that 
resembles the Gotham Marble in texture, and judging by the 
section at Garden Cliff, it is on the horizon of the Afonotis-brd 
of that locality. It rests on bluish-grey marls and marly lime- 
stones, 8 ft. 6 in. thick, that represent the White Lias, as do 
similar beds at Penarth and other places. The Esther ia-\zQ(k of 
Garden Cliff, is an irregular limestone that occurs near the base of 
the marly beds of White Lias; and it exhibits arborescent 
markings. 
The Lower Lias consists of even-bedded limestones and clays, 
with Lima gigantea, and at the base thin shaly marl with Ostrea 
liassica, Pleuromya, and Avicula cygnipes. These beds belong 
to the zone of Ammonites planorbis, and Dr. Wright thought the 
zone of A. angidatus was also represented at this locality. 
West of Londonderry, to the north of Keynsham, -we find 
about 25 feet of limestones and clays with Ammonites Bucklandi, 
overlying thinner beds of limestone and brown clay. Among the 
fossils found were A. angidatus, A. Johnstoni, A. scmicostatus 1 
Cardinia, Gryphcea arcuata, Lima gigantea (large and small), 
Pholadomya alabra, Plcuromya costata, Unicardium cardioides, 
Rhynchonclla, and Waldheimia perforate. The species were 
identified by Messrs. Sharman and Newton. 
In the cutting of the Midland Railway near Willsbridge, the 
Lias and Rhsetic Beds are faulted against the Pennant Grit. 
The section shows 25 beds of Lower Lias limestone, with inter- 
vening layers of marl, containing Lima gigantea, Nautilus, Am- 
monites Bucklandi, A. planorbis, &c.J A curious nodule termed 
a " Peg-top " by the workmen, was obtained by Major Bonus, 
R.E., from the Lower Lias in this railway-cutting, and is now in 
the Museum at Jermyn Street. 
Northwards, the Lower Lias forms a broad vale from Doynton 
by Pucklechurch to Hawkesbury and Wotton-under-Edge. This 
is essentially a clayey tract with few sections, probably because 
the Lias limestones are feebly developed, as is the case in the vale 
of Gloucester further north. 
The Lower Lias and the Rhastic Beds here rest in places 
directly on the Carboniferous Limestone, which comes to the 
surface at the " Grammar Rock," north-west of Lansdown, at 
the " Wick Rocks," and again to the west of Codrington Court. 
* H. B. Woodward, Quart. Journ. Geol. Soc., vol. xlvii. p. 549; Geol. Mag., 1892. 
p. 333. 
f See section by liristow and Etheridge, Vertical Sections, Sheet 46, No. 6. 
J See Moore, Quart. Journ. Geol. Soc., vol. xxiii. p. 498. 
