n, 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 fi