Page:Quarterly Journal of the Geological Society of London, vol. 27.djvu/96

 Devonian formations must be drawn below the yellow sandstones. The presence of fishes of Old-Bed-Sandstone type in the overlying slates he regarded as furnishing no argument to invalidate this conclusion. The sandstones of Parry Island and Melville Island are also regarded by the author as belonging to the " Ursa-stage," which, by these additions, presents us with a flora of seventy-seven species of plants. The author remarked upon the singularity of plants of the same species having lived in regions so widely separated as to give them a range of 26-1/2° of latitude, and indicated the relations of such a luxuriant and abundant vegetation in high northern latitudes to necessary changes in climate and in the distribution of land and water.

Discussion.

Sir Charles Lyell remarked that the Yellow Sandstones of Dura Den in Fife, and of the county of Cork in Ireland, contain Glyptolepis and Asterolepis, genera of fish exclusively Devonian, or belonging to the middle parts of the Old Red Sandstone — also the genus Coccosteus, which is abundantly represented in the Middle Old lied Sandstone, and sparingly, or only by one species, in the Carboniferous formation. The evidence derived from these fishes inclined him to the belief that the Yellow Sandstone, whether in Ireland or Fife, should be referred to the Upper Devonian, and not to the Lower Carboniferous, as Sir Richard Griffiths contended, and as Heer now thinks.

As to the argument founded on the plants, he considered it an important and truly wonderful announcement, that many well- known Carboniferous species are common to Bear Island (in lat. 74° 30' N.), in the Arctic regions, and to Ireland and other parts of Europe (26° of latitude further south). But fossil plants are supposed to have a wider range in space and time than fossil fish ; and we know that the cryptogamic flora of the ancient coal is remarkable for the wide horizontal spread of the same species, extending from North America to Europe, so that we need not be surprised if many species should extend vertically from the Devonian into the Carboniferous strata.

Mr. Carruthers remarked on the bearing of the paper on the Kiltorkan beds, and considered that Dr. Heer had completely established the correlation of the deposits. He differed, however, as to the numerical proportions of the species. He could not recognize Cyclostigma as a genus, but considered it founded on insufficient grounds, in which view Prof. Haughton now agreed. It was, in fact, founded on fragments of the bark of Lepidodendron Griffithsii, Brongniart, to which species the Lepidodendron indicated by Prof. Heer as L. Veltheimianum really belonged. Other detached portions of this same plant had been described by various authors under no less than seven different specific names, and referred to nearly an equal number of distinct genera ; and Prof. Heer had reckoned these as species in his comparison of the Bear-Island and