The ravine excavated by the mill-dam showed me what I had never so well seen before,--the exact relation borne by the deep red stone of the Cromarty quarries to the ichthyolite beds of the system. It occupies the same place, and belongs to the same period, as those superior beds of the Lower Old Red Sandstone which are so largely developed in the cliffs of Dunnet Head in Caithness, and of Tarbet Ness in Ross-shire, and which were at one time regarded as forming, north of the Grampians, the analogue of the New Red Sandstone. I paced it across the strata this morning, in the line of the ravine, and found its thickness over the upper fish-beds, though I was far from reaching its superior layers, which are buried here in the sea, to be rather more than five hundred feet. The fossiliferous beds occur a few hundred yards below the dwelling-house of Rose Farm. They are not quite uncovered in the ravine; but we find their places indicated by heaps of gray argillaceous shale, mingled with their characteristic ichthyolitic nodules, in one of which I found a small specimen of Cheiracanthus. The projecting edge of some fossil-charged bed had been struck, mayhap, by an iceberg, and dashed into ruins, just as the subsiding land had brought the spot within reach of the attritive ice; and the broken heap thus detached had been shortly afterwards covered up, without mixture of any other deposit, by the red boulder-clay. On the previous day I had detected the fish-beds in another new locality,--one of the ravines of the lawn of Cromarty House,--where the gray shale, concealed by a covering of soil and sward for centuries, had been laid bare during the storm by a swollen runnel, and a small nodule, inclosing a characteristic plate of Pterichthys, washed out. And my next object in to-day's journey, after exploring this ravine of the boulder-clay, was to ascertain whether the beds did not also occur in a ravine of the parish of Avoch, some eight or nine miles away, which, when lying a-bed one night in Edinburgh, I remembered having crossed when a boy, at a point which lies considerably out of the ordinary route of the traveller. I had remarked on this occasion, as the resuscitated recollection intimated, that the precipices of the Avoch ravine bore, at the unfrequented point, the peculiar aspect which I learned many years after to associate with the ichthyolitic member of the system; and I was now quite as curious to test the truth of a sort of vignette landscape, transferred to the mind at an immature period of life, and preserved in it for full thirty years, as desirous to extend my knowledge of the fossiliferous beds of a system to the elucidation of which I had peculiarly devoted myself.