29 
Shuttington, widening between Baddesley Endsor and 
that place. The coal measures are affected by numerous 
faults, and by intrusive igneous rocks of greenstone,* 
which latter appear chiefly between Atherstone and Bed- 
worth. At Hartshill the latter have long been quarried 
for the roads. Near Nuneaton a large mass of greenstone 
may be seen, succeeded by highly inclined quartz rock 
(millstone grit) and true coal measures, having four bands 
of intrusive greenstone intercalated amongst them. The 
coal series are made up of alternating beds of shale, 
hardened clays, sandstone, ironstone, and coal, with a 
band of limestone in the upper part. Their total thick- 
ness is given as 38,000 feet, the best workable seams 
occurring about the middle. The coal generally is not 
of the very best quality; and as the coalfield is com- 
paratively small and much has been already worked out, 
it will probably be exhausted before very many years 
have elapsed. Like the other coalfields, the fossils consist 
for the most part of the fragmentary remains of plants 
which helped to form the coal itself, among which Lepido- 
dendon, Sigillaria, and the roots ealled Stigmaria, Cala- 
mites, and numerous fronds of ferns chiefly Pecopteris, 
Neuropteris, Odontopteris, and other genera, are the most 
characteristic. ‘They are generally broken and imperfect, 
for it is very rare to find the fronds of the numerous ferns 
in any case attached to the stem, and the other plants are 
usually in a similar state. They are chiefly present in 
the shales and ironstones. At many of the pits numerous 
small estuarine shells, such as Mytilus, Myalina, and 
Anthracosia occur, and more rarely a small Limuloid 
Crustacean, and bones, scales,*and teeth of fish, many 
* The plutonic rocks which prevail in this coal field differ considerably, according 
to Mr, Allport, from those which affect the carboniferous district of South Stafford- 
shire ; and I agree with him that they all probably belong to the carboniferous period 
which was generally one of great igneous activity. 
