84 LIAS OF ENGLAND AND WALES : 
Rimpton. North of Came] Hill, the clays occupy the surface at 
Sparkford, North and South Barrow, Babcary. "Wheathill, and 
East Lydford, whence they extend around Hornblotton in the 
country north-east of the river Brue, to the foot of Pennard 
Hill. (See Figs. 43, p. 90, and 84, p. 263.) 
The clays are worke 1 here and there for brickmaking, &c., as 
at Butleigh, and near North Barrow, and they have been exposed 
in some of the railway-cuttings. 
The beds contain occasional bands of limestone, as at Stone, 
near Hornblotton. These stone-beds sometimes furnish a limited 
supply of water. Thus on South wood Common, near Evercreech, 
a well, sunk 10 feet in sandy shale and marl, found water; while at 
a short distance to the north-west by the high road, a well was 
sunk 60 feet deep, and yielded little or no water. 
One of the most interesting fossil-beds in the Lower Lias clays 
in this area, h the famous Ammonite-marble of 'Marston Magna 
north-east of Yeovil. Various accounts have been published of 
the discovery of masses of this stone, which consists almost 
entirely of small Ammonites whose white pearly layer is well 
preserved. They comprise A. oltusus and A. planicosta. Like 
a bed, previously noticed, at Lyme Regis, it belongs to the zone 
of Ammonites obtusus, sometimes locally termed the zone of A. 
planicosta. According to Maton the stone was discovered in 1778 
in the opening of a marl-pit ;* but a specimen of it, in the British 
Museum, was in the original collection of Sir Hans Sloane, who 
died in 1753. 
I am informed by Mr. Alfred Gilletf, that a large and 
apparently nodular mass of this stone was obtained at Marston, 
when a well was sunk about the year 1815; and this mass, 
weighing a ton or more, supplied many of the specimens known 
from this locality. On inquiry I ascertained that a well had been 
sunk near the church, to a depth of about 70 feet, and that the 
stone had been obtained there, though at what depth was not 
known. Sowerby observed that it was found " in moderate masses, 
occasionally big enough to form tolerable sized sideboards. "f 
Being polished in the neighbourhood of Yeovil, some confusion 
has arisen on the application of the term " Yeovil Marble ;" a term 
given by some to the Forest Marble of Long Burton, and by 
others to the Marston Marble.} 
A specimen of Ammonites Dudressieri (an old form of A. plani- 
costa), has been obtained by Mr. Giliett in a limestone-nodule 
from the Lower Lias clay of Northover, near Glastonbury. 
Evidence of the zone of Ammonites oxynotus was to be found 
in the banks of the Brue above Hornblotton Mill, where beds of 
stiff blue and bluish-grey clay are exposed here and there beneath 
the valley-gravel. In 1868 I collected a number of small 
* W. G. Maton, Observations on the Western Counties, vol. ii. p. 21. 
f Sowerby, Mineral Conchology, vol. i. p. 167, and Tab. 73, and 406. The 
A. Smithi, Sow., is regarded by Wright as a young form of A. obtttsus. 
J J. Townsend, Character of Moses, pp. 105, 275. 
