It might have been deemed the skull of some long-lived contemporary of Enoch,--one of the accursed race, mayhap, "Who sinned and died before the avenging flood." But, alas! the laborer dug a little further, and struck his pickaxe against an old rybat that lay deeper still. There could be no mistaking the character of the champfered edge, that still bore the marks of the tool, nor that of the square perforation for the lock-bolt; and a rising theory, that would have referred the boulder-clay to a period in which the polar ice, set loose by the waters of the Noachian deluge, came floating southwards over the foundered land, straightway stumbled against it, and fell. Both rybat and skull had come from an ancient burying-ground, that occupies a projecting angle of the table-land above. I must now state, however, that my skepticism has thoroughly given way; and that, slowly yielding to the force of positive evidence, I have become as assured a believer in the _comminuted recent shells_ of the boulder-clay as in the belemnites of the Oolite and Lias, or the ganoid ichthyolites of the Old Red Sandstone. I had marked, when at Wick, on several occasions, a thick boulder-clay deposit occupying the southern side of the harbor, and forming an elevated platform, on which the higher parts of Pulteneytown are built; but I had noted little else regarding it than that it bears the average dark-gray color of the flagstones of the district, and that some of the granitic boulders which protrude from its top and sides are of vast size. On my last visit, however, rather more than two years ago, when sauntering along its base, after a very wet morning, awaiting the Orkney steamer, I was surprised to find, where a small slip had taken place during the rain, that it was mottled over with minute fragments of shells. These I examined, and found, so far as, in their extremely broken condition, I dared determine the point, that they belonged in such large proportion to one species,--the _Cyprina islandica_ of Dr. Fleming,--that I could detect among them only a single fragment of any other shell,--the pillar, apparently, of a large specimen of _Purpura lapillus_. Both shells belong to that class of old existences,--long descended, without the pride of ancient descent,--which link on the extinct to the recent scenes of being. _Cyprina islandica_ and _Purpura lapillus_ not only exist as living molluscs in the British seas, but they occur also as crag-shells, side by side with the dead races that have no place in the present fauna. At this time, however, I could but think of them simply in their character as recent molluscs; and as it seemed quite startling enough to find them in a deposit which I had once deemed representative of a period of death, and still continued to regard as obstinately unfossiliferous, I next set myself to determine whether it really _was_ the boulder-clay in which they occurred. Almost