When we descend from the land to _the sea_ we find equally extensive accumulations, spread over the bottom, or raised along the tide-level in the form of bars, shoals, and banks. The whole eastern coast of the United States[15] is bordered throughout by a line of sand-banks and islands, of various forms and outline, but very uniform in their mineral ingredients, being composed for the most part of a fine, white, and quartzose sand. On the coasts of the southern states, the Carolinas and Virginia, they form a chain of low islands, separated from the coast by a series of lagoons; while higher up, on the southern coasts of New England, they occur as submarine ridges, parallel to the coast, and separated from each other by wide channels. To the north, these arenaceous deposits are still more extensive, forming vast submarine plateaux, such as the St. George and Newfoundland banks. And at the bottom of all the bays and creeks of that much indented land, prodigious _siltings_ are going forward, not under the form of narrow ridges, but as broad connected strata or flats; consisting seaward of very fine sand, and more inward of a coarse gravel, and in not a few instances of _calcareous mud_, where the deposit takes place in the vicinity of coral reefs. The same processes are in operation around every island and by the shores of every continent where tidal action favors the deposition of the materials—the result as now ascertained, not so much of rivers, as of oceanic currents. The depth of these sands it is impossible to determine; but thousands of feet may not reach their soundings. And as to organic remains, they are most favorably situated and composed for attracting and sustaining every kind of marine creature: it is upon the banks that border the coast of North America that the most extensive fisheries are carried on, because these are the abodes of those myriads of invertebral animals—the molluscs, annelides, and zoophytes, types of the older formations—which serve for the food of fishes, the ctenoids and cycloids of maritime enterprise. And thus, co-extensive with the littoral territories of the ocean, we have all the elements and ingredients of a FORMATION, completing within the human epoch, that may almost rival the Old Red Sandstone itself.