Page:Quarterly Journal of the Geological Society of London, vol. 26.djvu/829

 The Brachiopoda, as usual in the Carboniferous limestone, are the most abundantly represented class, the genera Productus and Spirifer being especially rich. The author mentions as abundant species, Spirifer striatus, Mart., S. rotundatus, Mart., S. glaber, Mart., S. lineatus, Mart., Spirigera Roissyi, Leveille, S. planosulcata (expansa), Phil., Chonetes papilionacea, Phil., Productus giganteus, Mart., P. latissimus, Sow., P. longispinus, Sow., P. pustulosus, Phil., P. punctatus, Mart., P. fimbriatus, Sow., P. subloevis, Kon., and P. mesolobus, Phil. Other species noticed are Lingula mytiloides, Sow., Orbicula concentrica, Kon., O. nitida, Phil., Rhynchonella pleurodon, Phil., R. pugnus, Mart., and R. papyracea, A. Rom. A few true Terebratuloe occur rarely. The only Bryozoa detected are a few badly preserved Fenestelloe.

The remains of Echinodermata include an Echinide described by Kunth some years ago, fragments of Poteriocrinus, and Cyathocrinus macrocheirus, M'Coy. Lithostrotion junceum and Cyathophyllum Murchisoni are the most abundant corals. A Receptaculites, nearly allied to the Upper Devonian R. neptuni occurs. Pentremites are wanting.

The palaeontological character of these limestones, especially the abundance and diversity of their Brachiopod fauna, indicates that their place is in the lower horizon of the Carboniferous formation. Possibly certain black shales at the upper boundary of the Culm, which still require to be further investigated, may correspond to the middle horizon of the Mountain- Limestone. They contain vegetable remains and Goniatites mixolobus ; but Spirifer mosquensis, a characteristic form of the middle horizon, has not yet been found in them. As in all places where the productive coal-measures appear above the Mountain-Limestone, the Fusulina-beds are wanting. The limestones of Rothwaltersdorf, Altwasser, &c, containing Trilobites, Gasteropods, Cephalopods, and Bivalves, seem to represent a higher horizon than those of Neudorf-Silberberg, of which the fauna consists almost exclusively of Brachiopods; but the difference can only be of local importance, as Productus giganteus and P. latissimus are found in both.

As far as Lower Silesia is concerned, the notion that the Mountain-Limestone is the marine, and the Culm the lacustrine, phase of the Lower Carboniferous formation, is contradicted by the facts. The genuine Carboniferous Limestones and those of Neudorf-Silberberg are concordant deposits in the Grauwackes with vegetable remains. In accordance with the above-mentioned supposition the deposits must have been at first lacustrine, then decidedly marine, then again lacustrine ; and such alternations as these could only have been caused by changes of level which must have disturbed the conformity of the stratification. But the plant-bearing Grauwackes have a strongly conglomerate character, especially below — a condition which indicates violent motion of the waters ; whilst the localities in which truly marine forms are most abundant have the character of being deposited as a fine argillaceo-calcareous mud. The presence of Brachiopoda and of pelagic Cephalopoda excludes the notion of