which I had a hundred times examined,
but which, though scarce a foot in thickness, had concealed from me the
ichthyolite bed for five twelvemonths together!

Wherever the altered shale of _Ru-Stoir_ has been thrown high on the
beach, and exposed to the influences of the weather, we find it fretted
over with minute organisms, mostly the scales, plates, bones, and teeth
of fishes. The organisms, as is frequently the case, seem
indestructible, while the hard matrix in which they are embedded has
weathered from around them. Some of the scales present the rhomboidal
outline, and closely resemble those of the _Lepidotus Minor_ of the
Weald; others approximate in shape to an isosceles triangle. The teeth
are of various forms: some of them, evidently palatal, are mere blunted
protuberances glittering with enamel,--some of them present the usual
slim, thorn-like type common in the teeth of the existing fish of our
coasts,--some again are squat and angular, and rest on rectilinear
bases, prolonged considerably on each side of the body of the tooth,
like the rim of a hat or the flat head of a scupper nail. Of the
occipital plates, some present a smooth enamelled surface, while some
are thickly tuberculated,--each tubercle bearing a minute depression in
its apex, like a crater on the summit of a rounded hill. We find
reptilian bones in abundance,--a thing new to Scotch geology,--and in a
state of keeping peculiarly fine. They not a little puzzled John
Stewart: he could not resist the evidence of his senses: they were
bones, he said, real bones,--there could be no doubt of that: _there_
were the joints of a backbone, with the hole the brain-marrow had
passed through; and _there_ were shank-bones and ribs, and fishes'
teeth; but how, he wondered, had they all got into the very heart of the
hard red stones? He had seen what was called wood, he said, dug out of
the side of the Scuir, without being quite certain whether it was wood
or no; but there could be no uncertainty here. I laid open numerous
vertebrae of various forms,--some with long spinous processes rising over
the body or _centrum_ of the bone,--which I found in every instance,
unlike that of the Ichthyosaurus, only moderately concave on the
articulating faces; in others the spinous process seemed altogether
wanting. Only two of the number bore any mark of the suture which
unites, in most reptiles, the annular process to the centrum; in the
others both centrum and process se