Field Meetings, 1906. 123 
careous grit, but more generally the cement has been removed by 
the solvent action of rain and replaced by iron oxide, often making 
_ it intoa friable brown or white Sandrock. Unweathered boulders 
of Spilsby sandstone occur in various localities, and from these a 
large suite of fossils have been obtained. Altogether the bed 
forms an interesting study both physically and palzontologically. 
Between this Sandstone and the Carstone above, the Tealby 
beds occur. The lower clays and ironstone are crowded with 
oolitic grains of iron oxide, about the size of millet seeds. 
These oolitic grains are formed of alternate layers of oxide 
and silica, and are nearly spherical in shape, and have a smooth 
polished surface. It is from the Earthy beds of the Ironstone 
that the greatest number of fossils are found. In the Benniworth 
cutting many fine specimens of Trigonia were obtained, besides 
Pecten, Exogyra, Cucculloea, Lucina, Lima, Belemnites, &c. © 
The Ironstone beds pass gradually up into the Tealby clay, a 
tough pale blue, homogeneous clay, well seen in the brick pit near 
Donnington Station. The Tealby Limestone is not well seen in 
the locality visited. The highest bed of the series, the Carstone, 
are well seen at the west end of Withcall Tunnel where the Red 
chalk, which forms the basal bed of the upper chalk, rests uncon- 
formable on it. 
~ The Carstone is unfossiliferous save for a few derived speci- 
mens found in phosphatic nodules, and consists of coarse sands 
composed of quartz grains with numerous pebbles of Lydian 
stone, yellow and brown phosphates, and debris from the Tealby 
Clays and other older Neocomian beds. Further subsidence of - 
the Neocomian sea brought in the great Cretaceous ocean in which 
were deposited all our Chalk rocks, beginning in Lincolnshire 
With the Red Chalk, the three zones of which are so beautifully 
een in the Withcall section. 
The shells observed were the following: Helix aspersa, H. 
rufescens, H. nemoralis, and varieties libellula and voseolabiata, 
1. hovtensis, Succinea putris. Physa fontinalis, Limnea pevegva, 
Spheevinm corneum, Planorbis albus, Valvata piscinalis and Anodonta 
ae 
