I would fain have visited some of the neighboring outliers of the Oolite, but time did not permit. Mr. Duff's collection, however, enabled me to form a tolerably adequate estimate of their organic contents. Viewed in the group, these present nearly the same aspect as the organisms of the Upper Lias of Pabba. There is in the same abundance large Pinnae, and well-relieved Pectens, both ribbed and smooth; the same abundance, too, of Belemnites and Ammonites of resembling type. Both the Moray outliers and the Pabba deposit have their Terebratulae, Gervilliae, Plagiostoma, Cardiadae, their bright Ganoid scales, and their imperfectly-preserved lignites. They belong apparently to nearly the same period, and must have been formed in nearly similar circumstances,--the one on the western, the other on the eastern coast of a country then covered by the vegetation of the Oolite, and now known, with reference to an antiquity of but yesterday, as the ancient kingdom of Scotland. I saw among the Ammonites of these outliers at least one species, which, I believe, has not yet been found elsewhere, and which has been named, after Mr. Robertson of Inverugie, the gentleman who first discovered it, _Ammonites Robertsoni_. Like most of the genus to which it belongs, it is an exceedingly beautiful shell, with all its whorls free and gracefully ribbed, and bearing on its back, as its distinguishing specific peculiarity, a triple keel. I spent the evening of this day in visiting, with Mr. Duff, the Upper Old Red Sandstones of Scat-Craig. In Elginshire, as in Fife and elsewhere, the Upper Old Red consists of three grand divisions,--a superior bed of pale yellow sandstone, which furnishes the finest building-stone anywhere found in the north of Scotland,--an intermediate calcareous bed, known technically as the Cornstone,--and an inferior bed of sandstone, chiefly, in this locality, of a grayish-red color, and generally very incoherent in its structure. The three beds, as shown by the fossil contents of the yellow sandstones above, and of the grayish-red sandstones below, are members of the same formation,--a formation which, in Scotland at least, does not possess an organism in common with the Middle Old Red formation; that of the Cephalaspis, as developed in Forfarshire, Stirling, and Ayr, or the Lower Old Red formation; that of the Coccosteus, as developed in Caithness, Cromarty, Inverness, and Banff shires, and in so many different localities in Moray. The Sandstones at Scat-Craig belong to the grayish-red base of the Upper Old Red formation. They lie about five miles south of Elgin, not far distant from where the palaeozoic deposits of the coast-side lean against the great primary nucleus of the interior. We pass from the town, through deep rich fields, carefully cultivated and well inclosed: the country, as we advance on the moorlands, becomes more open; the homely cottage takes the place of the neat villa; the brown heath, of the grassy lea;