We have given a few, and those the lower coals only, such as are found in the vicinity of Coalbrookdale; it would require more space than we can devote to it to enter upon a description of the measures occurring higher up in the series, in what is called the Coalbrookdale Coalfield. The ideal representation given of coal producing plants at the head of this article and in subsequent pages, and the one given p. 213, will convey a tolerable idea of the surface as it occurs to the minds of geologists during successive periods of the coal formation, and upon which we purpose offering some remarks, condensed and as brief as is consistent with a due explanation of the circumstances. We have already spoken of the oil which exudes from the rock described. It is the same which oozed from a similar rock at the “Tar Tunnel” at Coalport, at the rate, it is said, of 1,000 barrels per week. We extract from it naptha, rectified naptha, gas to illumine our houses, and those magnificent colours derived from the sun’s rays when the earth was young and green, mauve, magenta and a hundred medium tints. Coal itself rarely contains well preserved specimens of plants, but Sporangia (_Flemingites gracilis_) may be found in the Lancashire Ladies’, the Flint coal, and most if not all others, the tough little seed cases having resisted the effects of fermentation and crystallization, which destroyed the cellular tissues of plants, but which may sometimes be seen in a carbonised state. If the reader will be at the trouble to split open a piece of coal where he finds brown streaks at the edge, he may detect with the naked eye thousands of little discs clustered and heaped together so thick as to constitute one third at least of the coal; and if he applies a lens he will find some open, with bright amber coloured matter inside; and others closed and imbricated. We have found them in all the coals we have yet examined. Let any one doubtful of the vegetable origin of coal take a bass burnt white from the grate, tap it on the edge, and he will find between the laminated plates numerous impressions of plants. Lindley and Hutton, from experiments instituted by them, state that plants such as are represented on pages 305 and 313, were peculiarly adapted for preservation under water. [Picture: Alethopteris lonchitica] Many hundreds of species of plants have been made out, two thirds being ferns. Very beautiful and clear impressions of the accompanying one, Alethopteris lonchitica, or true fern, are obtained, the finest impressions being generally in the Ballstone. It was in fact the great age of ferns: as many as 250 having been described, according to form, structure, &c. Thus, we get:—Asterophyllites (star leaf fern), Cyclopteris (round fern) chiefly in the Ballstone, Caulopteris (star fern); Sphenopteris (wedge shape fern); also Newropteris, or nerved winged fern, which are given on the two following pages:—