202 LIAS OF ENGLAND AND WALES: 
springs. Thus portions of the zone of Ammonites maryaritatus 
have been included in the Lower Lias, for when the boundary was 
surveyed, attention was not paid to palaeontological horizons. 
Even if fossils were taken as the guide, the boundary could only 
be traced hypothetically over the greater part of the area, for 
sections are few and far between, and fossils are not always to be 
had when wanted. Thus near Chard, my colleague Mr. Clement 
Reid and myself, when engaged in re-surveying portions of the 
area, hesitated to interfere with the boundary of Lower and 
Middle Lias from the absence of any reliable guides in fixing the 
junction. In the area mapped as Middle Lias from Bridport, by 
Pillesdon and Lewston Hills, to Ford Abbey and Chard., there is 
little evidence beyond micaceous sand and sandy shales, with 
occasional bands of calcareous sandstone. The brickyard at 
Chalkway, north of Winsham, opened in laminated micaceous clay 
and sand, afforded no fossils,* while a well at Avishay, near 
ChaiFcombe, sunk through sandy loam and blue clay with 
pyrites, to a depth of 45 feet, tells us again only the nature of the 
strata. 
Somersetshire. 
Further north, more evidence is obtainable, for the Marlstone 
becomes sufficiently well-developed to be quarried. In the 
neighbourhood of Ilminster, the home at one time of Charles 
Moore, there are many sections, and the strata and their fossils 
have been described in much detail by that geologist* The 
following is the general section of the beds beneath the Upper 
Lias at Ilminster : 
FT. IN. 
6. Pale earthy and sandy limestone with 
large Belemnites -05 
5. Greenish and ferruginous sandy marl 
with Belemnites paxillosus - 4 
4. Brown sandy and iron-shot lime- 
stone in thick beds, (the workable 
stone of the district) with many 
fossils . 8 to 12 
3. Sands with ironstone-nodules - 20 
2. Yellow micaceous brick-marls with sandstones; 
Ammonites margaritatus - - - - 30 
1. Blue and grey micaceous marls with intercalated 
nodular sandstones .... 100 
The details of the beds below the Marlstone are given on the authority of 
Moore. f These beds may be compared with the yellow sands and laminated 
beds of the sections at Thorncombe Beacon. 
In the railway-cutting at Donyatt, blue an i brown micaceous 
sandy beds, with a layer of hard sandy limestone, were shown 
resting on blue micaceous sandy clay, and dipping a little to the 
east of south. A cutting bj the old canal (south of the tunnel) 
* See Memoir of C. Moore, by the Kev. H. H. Winwood, Proc. Bath Nat. Hist, 
Club, vol. vii. p. 232. 
t See list in Proc. Somerset Arch, and Nat. Hist. Soc., vol. xiii. p. 120. 
Marlstone. 
Middle 
Lias. 
