76 LIAS OF ENGLAND AND WALES : 
there by patches of gravel, or of cherty detritus from the Green- 
sand hills. At Broadway, north-west of Ilminster, a well (accord- 
ing to Mr. Reid) was sunk 90 feet in clay, and at Ashill the 
" Lower Lias marls " were proved to a depth of 80 feet. 
A cutting by the railway east of Horton near Ilminster, showed 
the following section : 
FT. IN. 
Gravel .... about 4 
f Stiff blue clay with nodular and septa rian 
Lower Lias -< limestones; Belemnites and Cardinia 12 to 15 
I Sandy limestones - - about 4 
The evidence for marking out zones in the Lias in this area is 
thus extremely meagre. As indicative of the zone of Ammonites 
capricornus, it may be mentioned that in the Bath Museum there 
is a specimen of A. Davcei from the neighbourhood of Ilminster. 
At Hambridge Mills, a boring made in 1873, was carried to a 
depth of a little over 300 feet, as follows : 
FT. IN. 
f Dark blue clay - - - - 121 1 
I Blue lias rock - - 11 
T T } Clay - - - - - 41 3 
Lower Lias --< ^ &nd twQ bandg of rock _ .49 
\ Clay 21 10 
[_ Clay and rock, alternating - - - 119 2 
309 
Vale of llchcster and the Polden Hills. 
Passing on to the Vale of Ilchester and the Polden Hills, we 
still find the main limestones to belong to the zone of Ammonites 
planorlris. (See Fig. 66, p. 206, and Fig. 84, p. 263.) The general 
divisions are as follows : 
FEET. 
f 4. Blue and brown clays - - about 200 
3. Clays with bands of limestone - 80 
2. Even-bedded grey argillaceous and 
compact blue limestones and 
Lower Lias -<^ shales, aad fissile or "slaty" 
marls - - - - 20 to 40 
1 . Rubbly white or pale grey earthy 
limestones and marls (locally) ; 
[_ resting on the White Lias - 6 to 10 
The lower beds (1) contain Ostrea liassica and Modiola minima, 
and are seen in some road-cuttings near Somerton, and near 
Walton windmill, Street. They form passage-beds between the 
White Lias and Lower Lias, rendering it in some places 
perplexing to fix a line of demarcation.* In the even-bedded 
limestones (2), which are largely quarried, Ostrea liassica is abun- 
dant (in the lower beds), and Pleuromya crowcombeia, small speci- 
mens of Lima gigantea, and Ammonites planorbis, may generally 
be found. Saurian remains also occur. Some of the more compact 
* See Geology of East Somerset, &c., pp. 103, &e. 
