364

THE FOSSILIFEKOTTS DEPOSITS

specimens of Cephalaspis (still a comparatively rare ichthyo-lite elsewhere), most of which are now in the hands of LordXinnaird, it would be well that some ichthyologist had ac-cess to the collection, in order to determine whether in Scot­ land , as in England, we have more than one species of thissingular genus. Dr Fleming found in this Middle Old Redformation an apparent fern, with kidney-shaped leaflets; andit yielded several years ago, near Clockbriggs, in Forfarshire,a large specimen of Lepidodendron, which exhibits the inter-nal structure. I owe a fragment of this fossil to an intelli-gent geologist, Mr William Miller, banker, Dundee ; but soimperfect is its state of preservation, that, though it presentsto the microscope the large irregularly-polygonal cells of itsgenus, it bears none of the nicer specific marks which mightserve to distinguish it from the several greatly more modernspecies which occur in the Coal Measures.

Above this Middle formation lies the "Upper Old RedSandstone, with its peculiar group of organisms, chiefly fishes.And of it, too, much remains to be known. Save that ithas not yet produced a Coccosteus ,—a genus which seems re-stricted to the oldest ichthyic group of the system,—its fishesmore resemble those of the Lower than of the Middle OldRed. It has its three species of Pterichthys, its Diplopterus,and apparently its Dipterus; and its Celacanths, chiefly ofthe Holoptychian genus, represent not inadequately the Cela-canths of the genera Asterolepis and Glyptolepis, which occurchiefly, though not exclusively, in the Lower formation. Thetwo formations appear, however, to have no species in com-mon. In looking over the fine collection of Mr PatrickDuff, derived chiefly from the Scat'Craig, in the neighbour-hood of Elgin, I found only a single ill-p"eserved gill-cover,—seemingly that of a Dipterus ,—which I could not at oncedetermine to be specifically different from aught produced bythe inferior deposit. Rocks of this "Upper formation have