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EXPEDITION   TO   THE
appearance, or at least much less so than the inferior beds; it contains specks and some veins of calcareous spar and gypsum; also crystals of quartz, &c.; it likewise offers sometimes specks of galena. It generally presents but few petrifactions, Corallites and Millepores, as well as several species of Terebratulites; Ammonites, &c. have been found in it."
"Above this compact limestone another stratum of calcareous rock is found which is known in the country under the name of rauchwacke, (smoky wacke;) it is a limestone probably intermixed with silex, of a dark-gray, sometimes blackish colour, with a somewhat scaly fracture, occasionally fine-grained, sometimes though seldom oolitic, hard, tough, and filled with pores or cavities; this last feature is characteristic; it may be observed even in those parts of the stratum which appear most compact; the cavities are angular, long, and narrow, (as in a cracked clay;) the interior of the cavities is lined with small crystals of calc-spar, these cavities are sometimes large, being several yards in length and breadth, &c."
He afterwards proceeds to describe the ashes or pulverulent substance found near it. This, from its great similarity to the residue of the combustion of wood, is designated in Germany by the name of asche, (ashes.) These characters, when taken into connection, appear to us to correspond so well with those observed on the Wasse-mon, on the Mississippi, and throughout the country between Rock river and Prairie du Chien, that we feel strongly induced to consider the limestone of this country as analogous to that observed by Mr. Freiesleben. This limestone is by some European continental geologists referred to the Lias of English geologists; but we would