[037]

PLATE 26'''. V. I. p. 265.

Footsteps of a small web-footed animal, probably crocodilean, drawn from a Cast of impressions on Sandstone, found near Hildburghausen. (Original.)

The Sandstones in which all these fossil footsteps have been discovered in Germany and Scotland, appear to be referrible to the same division of the sccondary strata, [038] which lies in the middle region of that large, and widely extended series of Sandstones, and Conglomerates, Lime-stones, and Marls, which English Geologists have usually designated by the common appellation of the New red Sandstone Group, including all the strata that are interposed between the Coal formation, and the Lias.

M. Brongniart, in his Terrain de l'Ecorce du Globe, 1829, has applied to this middle division the very appropriate name of Terrain Pścilien, from the Greek ), a term equivalent to the names Bunter Sandstein, and Grès bigarré, which it bears in Germany and France; and indicating the same strata which, in England, we call the new Red Sandstone. (See Plate l. Section No. 17.)

Mr. Conybeare, in his Report on Geology to the British Association at Oxford, 1832 (Page 379, and P. 405, Note), has proposed to extend the term Pścilitic to the entire Group of strata between the Coal formation and the Lias; including the five formations designated in our section (Pl. 1, No. 15, 16, 17, 18, 19), by the names of New Red Conglomerate, Magnesian Limestone, Variegated Sand stone, Shell Limestone, and Variegated Marl. Some common appellative for all these formations has been long a desideratum in Geology; but the word Pścilitic is in sound so like to Pisolite, that it may be better to adhere more literally to the Greek root , and apply the common name of Poikilitic group to the strata in question.*

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* The general reception of such a common name for all these strata, and the separation of the Grauwacké series into the Cambrian and Silurian systems, as proposed by Professor Sedgwick and Mr. Murchison, will afford three nearly equal and most convenient groups or systems, into which the strata composing the Transition and Secondary series may respectively be divided; the former comprehending the Cambrian, Silurian, and Carboniferous systems, and the latter comprehending the Poikilitic, Oolitic, and Cretaceous Groups.