he help of a
geological map, the sketch which is given in the following pages.

Of the "Black Countries"--the actual coal districts I shall speak
hereafter. They are in England either shores or islands yet
undestroyed, which stand out of the great sea of New Red sandstone,
and often carry along their edges layers of far younger rocks, called
now Permian, from the ancient kingdom of Permia, in Russia, where
they cover a vast area. With them I will not confuse the reader just
now, but will only ask him to keep his eye on the rolling plain of
New Red sands and marls past, say, Birmingham and Warwick. After
those places, these sands and marls dip to the south-east, and other
rocks and soils appear above them, one after another, dipping
likewise towards the south-east--that is, toward London.

First appear thin layers of a very hard blue limestone, full of
shells, and parted by layers of blue mud. That rock runs in a broad
belt across England, from Whitby in Yorkshire, to Lyme in
Dorsetshire, and is known as Lias. Famous it is, as some readers may
know, for holding the bones of extinct monsters--Ichthyosaurs and
Plesiosaurs, such as the unlearned may behold in the lake at the
Crystal Palace. On this rock lie the rich cheese pastures, and the
best tracts of the famous "hunting shires" of England.

Lying on it, as we go south-eastward, appear alternate beds of sandy
limestone, with vast depths of clay between them. These "oolites,"
or freestones, furnish the famous Bath stone, the Oxford stone, and
the Barnack stone of Northamptonshire, of which some of the finest
cathedrals are built--a stone only surpassed, I believe, by the Caen
stone, which comes from beds of the same age in Normandy. These
freestones and clays abound in fossils, but of kinds, be it
remembered, which differ more and more from those of the lias
beneath, as the beds are higher in the series, and therefore nearer.
There, too, are found principally the bones of that extraordinary
flying lizard, the Pterodactyle, which had wings formed out of its
fore-legs, on somewhat the same plan as those of a bat, but with one
exception. In the bat, as any one may see, four fingers of the hand
are lengthened to carry the wing, while the first alone is left free,
as a thumb: but in the Pterodactyle, the outer or "little" finger
alone is lengthened, and the other four fingers left free--one of
those strange instances in nature o