The Burdiehouse limestone is twenty-seven feet thick, of a yellowish or bluish-grey colour, very compact, splintery, and often fissile in structure, with a finely striped and laminated appearance, which probably indicates a slow and tranquil origin. It is Crowded with fossils, every fragment when taken up showing its seed-cone, fern-stem, fish-scale, or minute _cyprides_. All the plants seem to belong to terrestrial species, and have a broken and often a macerated look. Manifestly they never grew where we now find their remains; they must have come drifting down from swamp, or jungle, or hill-side. And so we come to know that during the later ages of the Lower Carboniferous period, there lay somewhere in the neighbourhood of Burdiehouse a land clothed with ferns and club-mosses, and through whose swampy hollows there spread a network of stigmariæ, while sigillariæ waved their fronds high overhead. From what has been said on a previous page we may infer that the climate of the old land was moist and equable like that of New Zealand, nourishing a prolific growth of ferns and other plants comparatively low in the botanical scale. The scenery of the vegetation displayed perhaps no great variety of outline, but exhibited rather an endless succession of the same graceful forms. But the limestone presents us with other remains than merely those of terrestrial plants. It displays in abundance the minute dissevered cases of _cypris_, the small crustaceous animal described above. Recent species of this genus inhabit stagnant ponds or the bottoms of gently-flowing rivers, and we hence infer that the ancient species must in like manner have possessed a similar habitat, and consequently that the rocks which preserve their remains must have been deposited in fresh (or, perhaps, brackish) water. Tried by this test the Burdiehouse limestone must be regarded as a lacustrine, or more probably a fluviatile formation, which gathered slowly on an undisturbed bottom swarming with crustaceans and plentifully covered with leaves, branches, rootlets, and other fragments of terrestrial plants brought down by streams from the adjoining land. Thus the inferences drawn from the numerous plants, and from the countless multitude of cypris-cases, come to be mutually corroborative. The former tell us of some neighbouring forest-covered country; the latter lead us, as it were, into its river-mouths, whence we can descry the waving woods on either side.