Page:Quarterly Journal of the Geological Society of London, vol. 26.djvu/830

 marshy deposits. In this respect the slates of Rothwaltersdorf, which constitute a lenticular intercalary deposit in the upper Grauwackes of the Culm, are particularly interesting from their combination of typical Culm fossils, such as Posidonomya Becheri, Calamites transitionis, Cyclopterix polymorpha, G. dissecta and other plants, with fossils of the typical Carboniferous limestone. Vegetable remains may certainly be transported from dry land or fresh waters into marine deposits, but not such an abundance of decidedly marine forms into fresh- or brackish-water deposits. The presence of Posidonomya Becheri at Rothwaltersdorf, and at no other locality, may be accidental ; but as it is always found associated with remains of plants, it is allowable to suppose that it is a freshwater form carried into the sea with those plant-remains. The Culm, with its conglomerates and micaceous sandstones, is a coast formation ; and the coast on which it was deposited was strongly acted upon by the waves, whilst the finer mud was thrown down in the quieter parts. [Count M.]

3. Geology of the Odenwald (Environs of Heidelberg). By Prof. M. N. Benecke.

[Proc. Imp. Geol. Inst. Vienna, April 5, 1870.]

The Granites and Quartz-porphyries of this district are immediately overlain by Dyas deposits (which have but a small extent both vertically and horizontally), partly Old Bed Sandstone Conglomerates and partly Marls, Dolomite, and iron-ores, with remains of Schizodus obscurus, representing the " Zechstein." The greater portion of the district is occupied by Triassic deposits, of which the Bunter Sandstone is above 1000 feet in thickness, and has furnished the materials for the most conspicuous buildings of this region (such as the Castle of Heidelberg, the cathedrals of Spires and Worms, &c). The Muschelkalk presents an interesting form intermediate between those of Franconia, Thuringia, and Swabia. Jurassic deposits occur at the surface only in the basin of Langenbrucken, where the Lias and Inferior Dogger are recognized. Tertiary, diluvial, and alluvial deposits are of quite local occurrence, [Count M.]