68 REVIEW—GEOLOGY OF EAST SOMERSET. 
marked divisions—an upper series, about 2,000 feet thick, containing 
sixteen coal-seams, and a lower series, 2,500 feet thick, with twenty-six 
coal-seams. These are separated by a thick mass of sandstone, 2,000 
feet thick, called the Pennant Grit, which contains only two or three thin 
seams. Altogether there are twenty seams which exceed two feet in 
thickness, producing an aggregate thickness of from seventy to one 
hundred feet of workable coal. The production is about one million tons 
per annum, at which rate of consumption the coal within a depth of 
4,000 feet would last for 4,219 years. 
The Permian Rocks are absent, and so are the Bunter Beds. The 
Keuper marls consequently rest directly upon the Coal-measures. They 
are about 300 feet thick, and the well-known bed, known as the dolomitic 
conglomerate, forms the base. The Penarth or Rhetic Beds are well 
exposed; they obtain a maximum (for England) thickness of 150 feet 
near Castle Carey. A valuable list of British Rhetic Fossils is also 
given. It includes three species of mammals, seven reptiles, thirty-one 
fishes, seven insects, four crustaceans, two annelids, seventy-five 
mollusks, four echinoderms, two corals, and three plants. 
The Lias is very fully described. It is not in this area of great 
thickness, (not exceeding 300 feet,) but palzontologically is very 
interesting. The Midford Sands, classed by Professor Phillips with the 
Oolites, and by Dr. Wright with the Lias, are considered by Mr. Woodward 
to be true passage beds, linking the two great formations together. 
The Oolitic Beds of East Somerset have long been famous for the 
excellent building-stone they furnish. The Inferior Oolite is quarried at 
Doulting, near Yeovil, and at Ham Hill. The chief quarries in the 
Great or Bath Oolite are at Corsham, Combe, Bath Hampton, Farley 
Downs,and Box. We mention these places, as it is usually possible to 
ascertain from the workmen on any new building where the stone comes 
from, but not so easy to obtain a reference to its exact geological 
position. 
The alluvial deposits are also described at length. Bath bricks we 
note derive their name from the discoverer of their manufacture, a Mr. 
Bath, of Bridgwater. They are made from the slime of the river 
Parret. A good accountis given of the minerals of the district, of its 
caverns, water supply, fissures, faults, cliffs, combes, and coast. Mr. 
Rutley describes the igneous rocks, which are illustrated by five beautiful 
plates (three in colours.) Lastly, there is an appendix prepared by 
Messrs. Woodward and Whitaker, including no fewer than 750 titles of 
papers which have been written on the Geology of Gloucestershire and 
Somersetshire. 
Altogether this work does Mr. Woodward great credit. By the 
judicious use of large and small type he has been able to classify his 
information in a way which shows great mastery of detail, combined 
with method and power of generalisation, qualities which are indis- 
pensable to the field geologist, and which are not less necessary to the 
writer who undertakes to make known to the public the results of 
original research of a nature so complicated as those which we have here 
