I shall describe some of the more common plants and animals of the period, that we may be able, in some measure, to look back through the ages of the past, and see how these plants would appear when they cast their broad shadow over river and lake, and how these animals would have seemed to human eye in the twilight of the forest, in the sluggish flow of the river, and in the stagnant waters of the lagoon. The _Flora_, or vegetation of the Carboniferous era, differed widely from any that now exists. With the exception of the highest or exogenous class, it possessed representatives of all the existing classes of the botanic scale, but in very strange proportions. The number of species of carboniferous plants already found in Great Britain amounts to about three hundred, amongst which the ferns are especially abundant. Some of them seem to have been low-growing plants, like the bracken of our hillsides, but others must have shot up to the height of forest trees. We can recognise a few coniferous and cycadaceous plants, a good many stems resembling the "horse-tail" of our marshy grounds, and some of large size akin to the creeping club-moss of our heaths; but there are still many to which there exist no living analogues. When we examine the roof of a coal-pit, or split open plates of shale in a quarry of the coal-measures, we are struck with the similarity which the ferns in the stone bear to those among our woods and hills. One of the most common, and, at the same time, most elegant forms, is the _Sphenopteris_ or wedge-leaved fern, of which a large list of species is known. One of them (_S. crenata_) had a strong stem, from which there sprung straight tapering branches richly dight with leaflets. The leaflets--somewhat like minute oak-leaves--were ranged like those of our modern ferns, along two sides of the stalk, in alternate order, and tapered gently away to its outer extremity. The effect of the whole is singularly rich, and one can well believe that a garland of this ancient fern would have wreathed as gracefully around a victor's brow as the parsley of Nemea or the laurel-leaves of Delphi. Another plant of the same genus (_S. affinis_, Fig. 3) has leaflets like the petals of the meadow-daisy, arranged in clusters along its slim diverging stalks. From a collection and comparison of many specimens, the late lamented Hugh Miller was enabled to make a drawing of this fern as it must have appeared when it waved green along the old carboniferous hill-sides. I enjoyed the privilege of going over these specimens with him, and marked how, under a master-hand, piece by piece fell into its proper place, and yielded up its evidence. His restoration, which forms the frontispiece to his last work, is a very beautiful one, and it is as true as it is beautiful. [Illustration: Fig. 3. Sphenopteris affinis.] [Illustration: Fig. 4. Pecopteris.] [Illustration: Fig. 5. Cyclopteris.] [Illustration: Fig. 6. Neuropteris.]