In one of my last papers on the “Bottom-rocks” I appended a coloured map to a portion of the first dry-land of our mother-earth, a portion of the first division of the land from those waters “which covered the globe,” a fraction of one of those primeval cracks or ridges which then remotely shadowed out our present continents and oceans; and in the little green patches I gave all the traces known of the first beaches and sands which spread around those low and barren tracts in the great region of North America which I selected for an illustration. To this map I hope soon to add, as supplements, others of South America and of Europe. Africa must be left yet a long while ere one dare make the like attempt. To these maps, from time to time, I shall add colour after colour to show the successive deposition of those great rock-formations in which the animals and plants of the successive life-creations of our planet have been entombed; and I hope also to be able to give charts of the teeming oceans during each of those past wonderful ages severally characterised as the stages of progress and development of organic beings.