THE ORGANIC REMAINS, which fall next to be described, are confined to three of the beds, as enumerated above. The first of these, in the order of superposition, is the micaceous flagstone of Carmylie and Arbroath, likewise extending along the south bank of the Tay, and distinguished by the vegetable culmiferous impressions with which it abounds. These, in some places, are so numerous, as to cover the entire surface of the rock. The idea of an ancient marsh is immediately called up in the mind, as one sees stone after stone split up, and all the interstices mottled and streaked over with the stems and leaves of the plants which were fed by its waters. While we write, every pond, and every lake in the neighborhood has crept quietly under its carpeting of ice, a congelation of the living with the dead. How beautiful and distinctly delineated the culms and leaves of the chara locked in its crystal embrace; the flower of the juncus yet lingers on the stalk; and there, how gracefully float the long broad continuous stems of the scirpus lacustris! The pike and perch, both typified in the olden rocks, may be seen motionless as a stone, or softly buoyant as the down, in the clear depths below. Not so brightly, but now as fixedly set, and as minutely preserved, are the fragments of the flora of the Devonian age: if blackened and jetty in their hoary antiquity, these films of mica give light and relief to the darker background of the picture; and shapes, too, were there sporting in the waters,—the seraphim and buckler-headed cephalaspis,—which painter never conceived, nor poet feigned.