The blue clay I found at one spot where the pathway had cut deep into the hill-side, richly charged with bivalves of the species I had seen so abundant in the resembling clay of the Bay of Laig; but the closing twilight prevented me from ascertaining whether it also contained the characteristic univalves of the deposit, and whether its shells,--for they seem identical with those of the altered shales of the _Ru-Stoir_,--might not be associated, like these, with reptilian remains. Night fell fast, and the streaks of mist that had mottled the hills at sunset began to spread gray over the heavens in a continuous curtain; but there was light enough left to show me that the trap became more columnar as we neared our journey's end. One especial jutting in the rock presented in the gloom the appearance of an ancient portico, with pediment and cornice, such as the traveller sees on the hill-sides of Petraea in front of some old tomb; but it may possibly appear less architectural by day. At length, passing from under the long line of rampart, just as the stars that had begun to twinkle over it were disappearing, one after one, in the thickening vapor, we reached the little bay of Kildonan, and found the boat waiting us on the beach. My friend the minister, as I entered the cabin, gathered up his notes from the table, and gave orders for the tea-kettle; and I spread out before him--a happy man--an array of fossils new to Scotch Geology. No one not an enthusiastic geologist or a zealous Roman Catholic can really know how vast an amount of interest may attach to a few old bones. Has the reader ever heard how fossil relics once saved the dwelling of a monk, in a time of great general calamity, when all his other relics proved of no avail whatever?